SC1121

2011/ie

SC1121

ECOSYSTEMS AND THE ENVIRONMENT

NCEA LEVEL 1

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Copyright © 2011 Board of Trustees of Te Aho o Te Kura Pounamu, Private Bag 39992, Wellington Mail Centre, Lower Hutt 5045, New Zealand. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means without the written permission of Te Aho o Te Kura Pounamu. 2 SC1121 © TE AHO O TE KURA POUNAMU

BIOLOGY AND THE LIVING WORLD

NCEA LEVEL 1

Expected time to complete work

This work will take you about 10 hours to complete.

You will work towards the following standard:

Achievement Standard AS90951 (version 1) Science 1.12

Investigate the biological impact of an event on a New Zealand ecosystem.

Level 1, Internal

4 credits

In this topic you will focus on the following learning outcomes:

identifying the characteristics of an ecosystem

explaining how environmental conditions affect ecosystems

You will also work towards this standard in the following topics:

SC1122 Ecosystems under threat.

CONTENTS

© TE AHO O TE KURA POUNAMU SC1121 3

CONTENTS

1 Goat island: a marine ecosystem 5

2 Overfishing 15

3 The rocky shore 20

4 Seals and people 25

5 Introduced species 35

6 Dinosaur forests 40

7 Forests and biodiversity 48

8 Trees, water and nutrients 52

9 Ecology – who cares? 58

10 Teacher-marked assignment 63

Answer guide 64

4 SC1121 © TE AHO O TE KURA POUNAMU

HOW TO DO THE WORK When you see: When you see:

Complete the activity.

Check your answers in the Answer guide at the back of this booklet.

Online activity. This activity uses the Topic webpage or the Internet.

An alternative activity for students who cannot complete an online activity.

Hands-on activity. Complete these practical activities to strengthen your learning.

Your teacher will assess this work.

You will need:

a pen or pencil

a small notebook to use as a

glossary.

a computer with Internet access

and access to the topic web page

Resource overview

This workbook provides an introduction to ecology, the study of ecosystems.

Complete all the activities. A computer with an Internet connection will be very useful for some of

the activities but it is possible to study this topic using the booklet and alternative activities.

Mark your own answers, using the Answer guide. Try to think critically about the science involved.

This booklet contains lots of background information about different ecosystems. You do not have to

learn all this information – you should try to understand the way that ecosystems work. Make sure

that you look carefully at the Learning Intentions in each lesson and check the Key Points at the end.

Keep a glossary There are a lot of special words you need to be able to use correctly. Use a small notebook to write

down the key words, with their meanings to make a glossary. Build up your glossary every lesson as

you work through this book. The words you need are generally in bold.

1A

GOAT ISLAND: A MARINE ECOSYSTEM


1 GOAT ISLAND: A MARINE ECOSYSTEM

LEARNING INTENTIONS In this lesson you will learn to:

identify the energy flow in an ecosystem using a food chain and a food pyramid

identify some environmental conditions which affect a marine ecosystem

INTRODUCTION The Cape Rodney-Okakari Point Marine Reserve is also known as Goat Island

Marine Reserve. It is New Zealand’s first marine reserve and was established

in 1975.

An ecosystem is all the living and non-living things in an area which interact

with one another. In this lesson you will start your study of ecosystems by

taking a virtual field trip to the marine reserve. Marine ecosystems include all

the ecosystems in the sea. That includes tropical lagoons and coral reefs

through to freezing, wind-swept rocks and ice floats near the poles. There are

a lot of different marine ecosystems!

SNORKELLING NEAR GOAT ISLAND

Use the Topic webpage watch the short video which shows LEARNZ field trip teacher Andrew going snorkeling off Goat Island. You may like to use the pictures on page 12 to identify some of the animals he saw. You can also use the NZMSC Seashore Guide, linked to the topic webpage.

If you cannot watch the videos, read the shaded writing below instead.

The marine reserve has a rocky shore. The video shows Andrew snorkeling on a blustery day. The wind and waves have caused currents in the water which have stirred up fine particles in the water, making the water slightly cloudy. On his dive Andrew saw some large blue cod and several other types of fish. There was also a variety of plant-life, including sea weeds and kelp. He also saw plenty of marine invertebrates (animals without backbones) – quite a variety of shell fish. Some of the animals Andrew saw are on page 12.

MARINE ECOSYSTEMS There are many different places where animals and plants live in the oceans. Goat Island marine

reserve is has a rocky shore line, and this affects that plants and animals which live there. Many

animals can live amongst the rocks that would not survive on a sandy beach or in the open ocean.

WHO LIKES ROCKY SHOR ES?

Suggest why these small fish and shell fish like to live in amongst the rocks, away from open water.

Check your answers.

1B

1A


FOOD AND SHELTER The fish and shellfish on the marine reserve can find the food and shelter they need. Other

environmental conditions on the rocky shore makes it a great place for blue cod, crayfish, blue

maomao and many other marine animals: the water is the right temperature and contains enough

dissolved oxygen for them to breathe underwater.

LIGHT Light intensity, the amount of light energy reaching a

surface, is another important environment factor.

The Sun powers almost all life in the oceans. Energy from

sunlight is captured by plants which convert the light

energy into chemical energy. This capture process is called

photosynthesis.

Only green plants are able to carry out photosynthesis.

Not all ‘green’ plants are actually green, but they all

contain green coloured chlorophyll, because this is

required for photosynthesis. Seaweeds can be brown,

orange or red – but they still contain green chlorophyll.

You can see seaweeds at places like Goat Island, but most

of the plants in the ocean are only visible under a

microscope. Billions of tiny plants called phytoplankton

capture energy from the Sun as they float in ocean

currents.

Almost everything that lives in the ocean depends on

energy that was originally captured by green plants. So

phytoplankton is extremely important to marine

ecosystems.

Plants in the marine reserve.

Phytoplankton under a microscope.

Phytoplankton in close up.

As you go beneath the surface of the ocean it gradually

gets darker because sunlight is absorbed by the water.

Light cannot be used as a source of energy below 100 m.

Ecosystems that do not use sunlight as a source of energy

are very rare. One example is the area around deep ocean

volcanic vents. There is very little sunlight in these places

so living organisms get energy from the chemicals coming

from inside the Earth. An undersea volcanic vent called a ‘white smoker’

http://upload.wikimedia.org/wikipedia/commons/a/aa/Champagne_vent_white_smokers.jpg



FOOD CHAINS AND WEBS

FOOD CHAINS Here is an example of a food chain on the coast near Goat Island:

1 plankton 2 mussel 3 shag

1. The plankton is capturing light energy and converting it into chemical, food energy. So it is

called the producer.

2. It is eaten (consumed) by the mussel, so the mussel is a consumer. The first consumer in a

food chain is the primary consumer.

3. The shag consumes the mussel. It is getting the plant’s energy from the mussel, so it is a

secondary consumer.

There are many food chains in the waters around Goat Island. Here is another example:

plankton krill blue

maomao snapper dolphin

Animals that catch other animals for food are called predators. Dolphins do not have predators in

this food chain. The predator at the top of the food chain is called an apex predator, so in this food

chain the dolphin is the apex predator.

TERM TIME: An organism is a general name for any living thing. It could be a plant, an animal or

micro-organism such a bacterium.

A species is a specific type of organism. Organisms of the same species are capable of

breeding together to produce fertile offspring – offspring that can also produce

offspring.

A food web shows the feeding connections in an ecosystem. It shows what

eats what, and the transfer of energy from green plants to other organisms.

A food chain tracks one path of energy in a food web.

http://upload.wikimedia.org/wikipedia/commons/7/7d/Green_Lipped_Mussel_(314300764).jpg

http://upload.wikimedia.org/wikipedia/commons/e/e9/Phalacrocorax_varius_-Queen_Charlotte_Sound,_Marlborough,_New_Zealand-8.jpg

http://upload.wikimedia.org/wikipedia/commons/1/1f/Krill_swarm.jpg


ENERGY AND ENERGY FLOW

The energy flow through an ecosystem is often pictured with boxes of decreasing size: At each

feeding level 90% of the energy taken in is lost as heat. This leaves only 10% of energy available for

the next feeding level.

The arrows show which way energy flows. (The size of the boxes in this picture is not to scale.)

Sometimes diagrams like this have arrows with different sizes to show how the amount of energy

decreases from one feeding level to the next.

NAMING TYPES OF ORGANISMS

There are lots of words to describe how an organism fits into an ecosystem. Add labels to the

diagram above using these words: producer, primary consumer, secondary consumer, predator,

prey.

Check your answers.

1C

Carnivores Herbivores

Plants

Herbivores

(plant-eating

animals) Carnivores (meat eaters)

Plants

Plants use sunlight to make food. The

rest of the ecosystem depends on

them for their energy

Sunlight



ENERGY FLOW ALONG A FOOD CHAIN

What you need:

a pair of scissors

the squared page from this booklet. What you do:

1. The grid below is divided up into 100 squares. The grid represents all of the energy that the

plants have.

2. Only 10% of this energy is passed onto the herbivores. So, cut off 10 of the squares. This is

how much energy the herbivores can get.

3. Only 10% of the herbivore energy is available for carnivores, for example, blue maomao. So,

of the 10 squares that you are left with, only one is available in the next stage in the food

chain.

4. This one small square which represents the amount of energy available to the snapper that

feeds on blue maomao. Can you see how very quickly the amount of energy available in the

food chain decreases? This is due to 90% being given off as heat at each feeding level.

5. Sometimes food chains may be four or five steps long. They are never longer than this.

Explain why a sixth level for a food chain would be unable to survive

Check your answers.

1D

E


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DECOMPOSERS As the food chain shows, most sea creatures have something

wanting to eat it for dinner; they also die for other reasons.

Apex predators don’t live forever, so what happens when they

die?

Animals that feed on the remains of other creatures (plants and

animals) are called scavengers. Many sea creatures get all or

part of their food by scavenging. Bacteria and worms break up

the remains left by scavengers until nothing is left of the

creature – they are decomposers. Scavengers and

decomposers are important in all ecosystems.

Gulls scavenging amongst rotting kelp.

TROPHIC LEVELS

Feeding levels in an ecosystem are called trophic levels. Study the table and fill in an example from a

marine ecosystem.

Trophic level Example from a garden ecosystem

Example from a marine ecosystem

1. Producers Green plants produce food by photosynthesis. They are the source of energy for the other trophic levels

Green plants e.g. cabbage

2. They are also called primary consumers

Herbivores Animals that feed on plants. E.g. caterpillar eats the cabbage.

3. Animals that prey on herbivores are called secondary consumers.

Carnivores that feed on herbivores. E.g. starling eats the caterpillar.

4. Animals that prey on other carnivores are called tertiary consumers.

Carnivores that feed on carnivores. E.g. cat eats the starling.

5. Apex predators are carnivores that are at the top of the food chain and have no predators.

Carnivores that feed on tertiary consumers e.g. a dog eats a cat.

Decomposers consume dead organisms.

Worms, bacteria, and fungi feed on dead plants, animals or their droppings.

Check your answers.

1E


SPECIES YOU MAY SEE WHILE SNORKELLING AT GOAT ISLAND

Red moki find crabs, kina and worms on the sea floor. Their stripes help to camouflage them amongst the kelp strands.

Blue cod/rawaru like this kind of rocky coastline where it feeds on a wide range of food, but mostly smaller fish and crabs.

Blue maomao patrol in groups or schools close to shore or over deep reefs. They feed on tiny plankton and krill.

Parore are mostly vegetarian, they are particularly common where there is a lot of kelp (a type of brown seaweed)

Goatfish/ahuruhuru have sensitive 'feelers' under their lower jaw to help find worms, crabs, shrimp and other food in the sandy sea bed.

Crayfish/koura can hide between rocks during the day. At night they feed on a variety of bottom life: crabs, seaweeds, small fish and sea urchins.

Snapper/tamure will eat almost anything in the way of animal food, crayfish, crabs, shrimps, kina, and small fishes.

Leatherjackets/kōkiri have tough skin and a retractable dorsal spine. They like to browse sponges from rocks, but will eat almost anything.

The red crabs feed on seaweed and scavenge on almost anything.

Kina feed on seaweed, especially kelp. Sponges are very simple animals which feed on phytoplankton, filtering their food from sea water.



FOOD CHAINS AND PYRAMIDS

1. Draw two different food chains which include at least three of the organisms mentioned on the

previous page.

2. Fill in the spaces with the correct word(s):

a. Energy in ecosystems comes from the __________________________

b. Carnivores get their energy by feeding on __________________________

c. Energy is lost from an ecosystem as ______________________________

d. Decomposers get their energy from both ________________ and _______________

3. Draw arrows on the Tuna Sandwich diagram, showing how energy flows from the Sun to a human eating a tuna sandwich.

4. Explain why a huge amount of phytoplankton is needed to produce just 100 g of tuna.

1F

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5. Trophic levels are often drawn as a pyramid, as in this example. Discuss why the pyramid is a helpful shape for describing:

What each organism eats

The total mass of each sort of organism

Check your answers.

KEY POINTS

An ecosystem is all the living and non-living things in an area which interact with one another.

Ecosystems are affected by environmental factors such as temperature, and light intensity.

All living things require energy. Green plants get their energy from sunlight, they are called

producers.

All other organisms get energy by consuming either plants or other animals.

Energy flows along a food chain from producers to primary consumers (herbivores), secondary

consumers (carnivores) and sometimes on to an apex predator. Trophic levels are the feeding

levels.

Remember to put the items in bold into your glossary

OVERFISHING


2 OVERFISHING


identify differences in ecological characteristics between two marine locations

link differences in ecological characteristics to the effects of fishing

INTRODUCTION Many New Zealanders have grown up close to the sea. Harvesting kaimoana is something we expect

to be able to do. But if you talk to much older people, they can probably tell you of a time when

there was much more life in the oceans around New Zealand.

Overfishing occurs when people take fish faster than they grow and are replaced. The number of fish

drops. Sometimes so many fish are taken that very few reach maturity. With few fish reproducing

the number of fish drops very quickly. In this lesson you will learn about the effect of fishing in a

rocky shore ecosystem.

MARINE ECOSYSTEMS

Use the Topic webpage link to explore the interactive Marine Ecosystem. Use the information from the movie clips and pop-ups to answer the questions below.

If you do not have Internet access, study the diagram on the next page instead.

1. Based on the information in the marine ecosystem, complete these food chains.

arrow squid

mussels human

2. If commercial fishing takes many of the larger fish, a. Would the number of dolphins increase or decrease? Explain your answer.

b. Would the number of small fish increase or decrease? Explain your answer.

Check your answers.

2A


UNDERSTANDING A FOOD WEB

1. Use the Goat Island food web, on the next page, to draw three different food chains which end with a predator such as a snapper.

s snapper

snapper

snapper

Check your answers.

2B

A

Cockles and muscles are bivalve

mollusks. They are very common in

estuaries.

Seaweed is a primary producer and an

important source of energy for other

sea creatures. Seaweed beds provide

shelter

Arrow squid feed on crustaceans,

small fish and sometimes other squid.

They are an important food for

penguins, diving birds and large fish.

Phytoplankton are important primary

producers. They are tiny single-celled

organisms that get their energy from

the Sun. They are eaten by

zooplankton.

Bryozoan colonies look like plants but they are really groups of animals which have tentacles. They provide shelter for baby fish.

Dolphins are an apex predator, they

feed on fish.

Red cod reach about 50cm in length.

They eat crabs, shrimps and small fish.

Almost all the energy used in marine

ecosystems comes from the Sun. Stalk-eyed mud crabs live in the low-

tide zone. They feed on the nutritious

mud they live in. Crabs are a popular

food for many fish, stingrays and sea

birds.

Many sea birds feed on little cockles

or little clams.

OVERFISHING


FOOD WEBS In the last activity you

probably began to

realise that food chains

are not all that simple.

Most sea creatures have

more than one type of

food. Most are eaten by

more than one

predator.

A food web is a diagram

that shows the feeding

relationships in an

ecosystem.

There are lots of food

chains in a food web.

The food web on the

right shows some of the

feeding relationships

around Goat Island.

INSIDE AND OUTSIDE THE MARINE RESERVE

Use the Topic webpage watch two short videos. Snorkeling at Matheson Bay and Inspired by Marine Reserves.

If you cannot watch the videos, read the notes below.

The video shows that at Matheson Bay, outside the marine reserve, there are far less plants and less fish. There are some areas with virtually no plants, no kelp and lots of small kina. In the ‘kina-barren’ areas the kina were not hiding between rocks but they were unafraid, out in the open. Both coastlines are typical rocky shorelines, but fishing is allowed in Matheson Bay. At Goat Island there were heaps of snapper and lots of diversity of reef fish. At Matheson Bay there were some reef fish but they were smaller. There were a few snapper but they swam away from the snorkelers.

2C

DIVERSITY Biological diversity (biodiversity) is the degree of variation of life forms in an

ecosystem.

One measure of biodiversity is the species diversity – the number of different

species that live in an ecosystem.


1. List the main differences that were observed between Goat Island and Matheson Bay?

2. Explain why, outside the marine reserve:

a. The fish are more afraid of people

The fish are more afraid of people because…

b. There are less large fish

There are less large fish because…

c. There are more kina.

There are more kina because…

d. There are fewer plants, especially in the kina-barren areas.

There are fewer plants, especially in the kina-barren areas, because…

OVERFISHING


3. How has human fishing affected the species diversity of the marine ecosystem? Explain your answer in as much detail as you can giving possible reasons for the change in diversity.

Check your answers.

KEY POINTS

There are many feeding relationships in an ecosystem. These are summarised in a food web.

Fishing removes larger fish from the ecosystem. This decreases the average size and the

total number of fish. It also reduces species diversity.


3 THE ROCKY SHORE


identify the adaptations of an organism and explain how they make it suited to its habitat

identify important environmental factors which affect the survival of organism in a location.

INTRODUCTION In this last lesson on the Goat Island field trip, you will be learning about the adaptations of various

creatures which enable them to survive in a challenging environment.

SURVIVING ON THE ROCKY SHORE

Use the Topic webpage to watch the video clips showing a field trip to a rocky shore. You may like to use the NZMSC Seashore Guide, linked to the topic webpage, to identify some of the organisms.

If you cannot watch the videos, read the shaded writing below instead.

Scientific work on the rocky shore shows students taking part in an NCEA level 2 Biology field work. The students are using two useful techniques that you will learn about if you study the Biology Practical module (SC1271). They have run a line (called a transect) across the shoreline from the high tide to the low tide mark, looking for changes along the line. To study the numbers of organisms in different areas they are using square frames called quadrats. The students are counting the organisms inside the frame. The frame keeps the investigation fair, so the same area is counted in different places and the differences between the high and low tide marks are clear.

At low tide there are a variety of creatures to study.

Low tide on the Echinoderm Reef shows field trip leaders looking around the low tide mark. Most of the organisms they have found are hiding under stones. If these animals didn’t hide, once the tide came in the carnivorous fish such as snapper would eat them up. They have seen brittle star, cushion star, hermit crabs, flat worms, sea slugs, limpets and chitons. They had also seen some juvenile fish which appear to have been chased up into the rock pools by ‘white-fronted terns. At the low tide mark the habitat is mostly under water, but creatures will die off if there is a really low tide because they can dry up and get over-heated.

3A

THE ROCKY SHORE


The Upper tidal zone Andrew explains how you can sometimes see more if you sit and wait, watching the rock pools. The rocks here get a hammering from the wind, the waves, the sunlight, the changes in temperature and moisture, so it is a very harsh environment in which to survive. Organisms which survive have to hand on tight, trap moisture, for example within their shell, and hide between cracks in the rocks where there is more moisture. Barnacles shut up tight and oyster borers cluster together.

For some organisms, crevices are important niche habitats. Image: LEARNZ.

Life in the rock pools shows some of the creatures to be found in the rock pools in the Goat Island marine reserve. In this trip they have spotted shrimp, triple-fins, kina, cats eyes and lots of different varieties of sea weed. The rock pools have quite a volume of water so they don’t get so overheated. The danger to the animals here is from predators such as octopus, crabs – there is always something eating something else. A white-faced heron could be seen walking around, taking feeding from the pools.

The videos show three habitats on the rocky shore. A few of the animals can live in all of them but

mostly they are adapted to live in one or two of them. This is because each habitat has slightly

different environmental conditions which affect the survival of the organism.

TERM TIME: A habitat is the natural environment where an organism lives.

An adaptation is a characteristic of an organism which has evolved to help it survive in

its habitat.


ENVIRONMENTAL FACTORS ON THE ROCKY SHORE

Which environmental factors apply in each of these locations? Put a tick in the box if the description

matches the location.

Low tide

zone Higher tidal

zone Rock pools

Under water all the time

Under water most of the time

Sometimes underwater but often exposed to air.

Can get very hot or very cold

Strong sunlight with no shade every day.

Exposed to strong winds

Exposed to strong surf waves

Unable to swim away from predators

Exposed to large predatory fish

Check your answers.

ADAPTATIONS ON THE ROCKY SHORE Each animal has adaptations which help it to survive in its habitat.

EXAMPLE: BARNACLES Barnacles are filter feeders. They feed under water by reaching out with a ‘leg’ and to draw water, containing plankton, inside its shell. Habitat: Barnacles have adapted to survive on rocks in intertidal zones where there are strong winds and waves. Adaptations: To cope with the waves they hold on very tight by growing their shells right into the rock. They protect themselves against the sun, wind and predators with their tough shells. The shells have trap doors which shut when the barnacle is exposed to air. The door traps water inside keeping them to wet until the tide comes back in. The hard shell also protects the soft body against predators.

Barnacles grow in groups. That means that if a few of the barnacles get eaten, there will still be a few which survive.

3B

THE ROCKY SHORE


EXPLAINING ADAPTATIONS

For each of the following organisms, describe the environmental conditions of its habitat and explain

how the animal is adapted to survive.

Habitat:

Adaptations:

Th is creature i s ab le t o we dge i t se l f in t o t ight crack s and cre v i ce s t o he l p st op i t d ry ing out . I t a ls o has s ome e xce l lent ca mou f lage. Can y ou

see i t?

Habitat:

Adaptations:

How migh t the s m ooth sha pe of th is cush i on star he lp i t t o sur v ive?

Habitat:

Adaptations:

Chit on s are ab le to c lam p them sel ve s aga in st roc ks

3C


Habitat:

Adaptations:

See h ow the se sna i ls have gathered in to a t ight pack to ho ld m ore wat er b etween the she l l s . The ir wh i te co l our a ls o re f lec ts heat .

KEY POINTS

A habitat is the natural environment where an organism lives.

Each habitat has environmental conditions which are suited to some organisms, but not

others.

An adaptation is a characteristic of an organism which has evolved to help it deal with the

environmental conditions so that it can survive in its habitat.

SEALS AND PEOPLE


4 SEALS AND PEOPLE


compare populations using graphs

outline adaptations of seals

relate the populations of seals to environmental factors

INTRODUCTION These next two lessons use information and videos from the 2011

LEARNZ field trip to the West Coast of the South Island. The focus

was on the kororā, little blue penguin, and on the kekeno, fur seals,

at Cape Foulwind.

KEKENO – FUR SEALS

Use the Topic webpage to watch the videos about the Fur Seals at Cape Foulwind.

If you cannot watch the videos, read about these seals here. The text is adapted from the notes to the LEARNZ field trip.

APPEARANCE Kekeno are fin-footed carnivorous marine mammals. They are different from true seals because they have external ears and hind flippers which rotate forward.

4A

TERM TIME: A habitat is the natural environment where an organism lives.

An adaptation is a characteristic of an organism which has evolved to help it survive in

its habitat.


This pointy-nosed seal has long pale whiskers and a body covered with two layers of fur. Their coat is dark grey-brown on the back and lighter below. When wet, kekeno look almost black. In some animals the longer upper hairs have white tips which give the animal a silvery appearance. Adult females: maximum length 1.5m, weight 30-50kg. Adult males: maximum length 2.5m, weight 90-150kg.

True seals do not have external ears and cannot turn their hind flippers forward. The kekeno pictured here is an eared seal. You can see its external ears.

HABITAT Although they breathe air, seals are most at home in the water and may stay at sea for weeks at a time. Fur seals may swim by themselves or gather in small groups. When the breeding season arrives, these social animals gather on shore in very large numbers. They prefer steep boulder beaches with plenty of crevices and tidal pools. Their layer of fat and thick fur coats enable them to endure long periods in water, but can cause overheating on land. Crevices provide shade and tidal pools a place to cool off. Kekeno are very good swimmers and weaned pups will turn up almost anywhere around New Zealand. A pup tagged on the west coast of the South Island has even been recorded in Australia. On land they sometimes become disoriented and have been found in unusual places such as back-yards, drains and streets. DIET AND FEEDING Kekeno feed mainly on squid and small mid-water fish but also take larger species such as conger eels, barracuda, jack mackerel and hoki, mostly off the continental shelf in depths greater than 22m. Most of the species which seals eat come nearer the surface in the middle of the night and sink back to deeper depths during the day. In summer seals feed over the continental shelf, or near the slope. They will dive continuously from sundown to sunrise. In autumn and winter, they dive much deeper with many dives being deeper than 100m. Kekeno are prey to sharks such as great whites and tiger sharks.

Kekeno dive deeper and longer than any other fur seal – seals have been tagged diving deeper than 238m and for as long as 11 minutes. Most dives are usually for only 1-2 minutes.

SEALS AND PEOPLE


The physical appearance of the seals helps them to hide. They blend in with the rocks around them.

KEKENO FOOD WEB

Based on the information from the videos, from this booklet and/or from other sources, sketch part of a food web which includes kekeno.

Check your answers.

KEKENO – PHYSICAL ADAPTATIONS

Here are seven physical adaptations of kekeno. For each adaptation choose the reason it helps kekeno survive in its habitat. Write the correct letter in each box.

1. Long whiskers A. for warmth

2. A streamlined body B. for efficient swimming

3. Strong flippers C. to help find fish in dark or murky water

4. Two layers of fur D. so flippers can be held out to release

heat so they do not overheat

5. Claws on their hind flippers E. to blend in with rocks so predators can’t

see them.

6. No fur on flippers F. to propel them through the water

7. Their brown colour is similar to the rocks they sit on.

G. for grooming

Check your answers.

4C

4B


BEHAVIOURAL ADAPTATIONS Kekeno seal pups spend much of their time playing to learn

life skills. Mother seals and pups find each other by using a

familiar call. A study in Alaska found that mothers and

offspring were still able to recognize each other's calls after

being apart for four years.

Another behavioural adaptation is that seals breed in large

colonies.

STUDYING SEAL POPULATIONS HUNTED TO THE BRINK OF EXTINCTION New Zealand has a population of just over over 60,000 kekeno. Before the arrival of humans there

may have been about 2 million.

Excavation of old rubbish heaps shows that seals were an important food for people on these islands

from about 1300 A.D. By the late 1700s Europeans arrived and began to hunt at the few remaining

seal colonies. Sealskins and oil were the first major exports to Europe. By 1830 there were very few

remaining seals.

Not scared of predators

The Bounty Islands are a bare and wind-swept group

of 22 slippery granite rocks 700km east of Invercargill.

Up on the rocks, away from sharks, the seals were

safe from predators. In 1800 there were about 52 000

seals. They had no fear of the men who arrived with

clubs. By 1831 only 5 remained. Seal hunting was

banned in 1894 and since then numbers have

recovered. In 1980 there were about 16000 seals on

the Bounty Islands, in 1992 about 20 000, and in 1994

about 21 500.

TERM TIME: Physical adaptations are adaptations which can be observed physically.

Behavioural adaptations are adaptations which affect the way an organism behaves.

A population is the number of organisms of a particular species which live in a given

area.

The range is the area or zone in which the species is normally found.

SEALS AND PEOPLE


ARE SEALS STILL MAKI NG A COME BACK?

Humans are one of the biggest

threats to penguins and seals. The

Department of Conservation

(DOC) is monitoring penguin and

seal populations to see how they

can be better protected.

Department of Conservation staff measure a seal pup as part of a fur seal population study. Studies like this help DOC to find ways to better protect seals.

Seals are tagged by DOC so that they can be monitored.

This is a kekeno seal pup. Can you see its tags? Seals are tagged so they can be monitored to help protect them.

SEAL POPULATION PROBLEMS

During the twentieth century seal populations have begun to recover. People have been counting the numbers of seals at a number of locations. The graphs below show estimated number of pups born at the three West Coast rookeries - Wekakura Point, Cape Foulwind, and Taumaka Island from 1991 to 2011. Note the vertical axis scale is different for each colony.

Wekakura Point, mean estimated pup numbers (+/- 1SD)

0

200

400

600

800

1000

1200

1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014

Year

Pup n

o's

4D


1. For each graph, draw a smooth curve that goes near most of the points

2. All the graphs show similar patterns. Describe the patterns the graphs have in common.

3. From 2004-2008 one of the seal colonies shows a different pattern to the others. Identify the

colony and describe the difference.

Cape Foulw ind, mean estimated pup numbers (+/- 1SD)

0

100

200

300

400

500

1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014

Year

Pup n

o's

Taumaka Island, mean estimated pup numbers (+/- 1SD)

0

300

600

900

1200

1500

1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014

Year

Pup n

o's

SEALS AND PEOPLE


4.

? Seals can get entangled in fishing nets and their food supply can run low in areas that have been over-fished. This map shows

the location of the main kekeno breeding colonies in the middle of the west coast of the South Island the trawl fishery area for winter spawning hoki.

Some people say commercial fishing is causing the seal populations to fall.

a. Is there any evidence to support this statement? Use the graphs, your earlier answers

and the map above.

b. Do we have any evidence to look at alternative explanations for the change in seal pup

numbers?

Check your answers.


THREATS TO KEKENO

The Department of Conservation lists four reasons that fur seal populations have declined in the 20th

century. Explain the meaning of each of these and how it affects seals.

1. Habitat loss

2. Entanglement with fishing gear and marine debris

3. Overfishing.

Check your answers.

SEAL TOURISM

The lookout at Cape Foulwind seal colony.

4E

SEALS AND PEOPLE


Next time you are in a tourist area of New Zealand look at the post cards on display. You will

probably see plenty of seal pictures. Seals are part of New Zealand’s natural image. Many tourists

come to New Zealand to see a beautiful natural environment, and seals are a highlight.

Looking up from the seal colony at Cape Foulwind. How many tourists can you see?

WHO CARES?

What views do you think these people might have about seal populations? The first one has been done for you.

Who? Their views on seal populations Reasons

Owner of a backpackers near a seal colony

Seals should be protected but people should be able to get a good view of them.

The seals attract lots of visitors, so it is good for business.

Commercial trawler crew

DOC worker

You

Check your answers.

Your teacher will be interested to read your views.

4F


KEY POINTS

There were hundreds of thousands of kekeno, (New Zealand fur seal) before people arrived

in New Zealand.

These seals are well adapted as carnivorous ocean creatures which breed on land.

People hunted kekeno for, food, oil and skins until they became almost extinct in the mid

19th century.

In the 20th century the number of seals has increased, but in recent years there have been

some declines due to loss of habitat and commercial fishing.

INTRODUCED SPECIES


5 INTRODUCED SPECIES


describe the adaptations of kororā

identify the impact of and introduced predators on penguin populations

investigate causal links between environmental conditions and population densities.

INTRODUCTION Kororā are also known as little blue penguins or fairy penguins. In this topic we will use the name kororā. These penguins are endangered – they could become extinct. In this lesson you will learn about kororā and why they have become endangered.

STUDYING KORORĀ

Use the Topic webpage to watch the videos about kororā.

If you cannot watch the videos, read about these penguins below The text is adapted from the notes to the LEARNZ field trip.

The kororā is the smallest penguin in the world, standing just over 25cm tall and weighing a little over one kilogram. These penguins are adapted to survive in rocky coastal areas. Physical adaptations

strong short legs, with webbed feet

claws for grip and they can use their short bills and tails for balance when walking or hopping

streamlined shape for swimming

strong flippers to propel them through water

tightly packed feathers to keep them warm

blue backs and white bellies to camouflage them when in water

solid bones (unlike other birds who have hollow bones) this makes them heavier so they can dive deeper

Kororā have distinctive blue and white plumage. This helps them to be camouflaged – when viewed from above they blend in with the blue of the ocean, when viewed from

below they blend in with the sky.

5A

http://upload.wikimedia.org/wikipedia/commons/7/71/Eudyptula_minor_-Perth_Zoo,_Australia_-swimming-8a_(1).jpg


Kororā live underground in burrows, natural holes, or under human structures and buildings. This natural hole has become home to a penguin on the West Coast of the South Island

Kororā can be difficult to find as they live in burrows and only come ashore under the cover of darkness.

Volunteers studying kororā can find tracks during the day while the birds are hiding in their burrows.

HABITAT Kororā only come ashore under the cover of darkness and live underground in burrows, natural holes, or under human structures and buildings. They remain around their colony all year, although they may make long foraging trips of more than 70km during the non-breeding period. Kororā are very faithful to their home site. Chicks will often return to within a few metres of where they were raised and once settled in an area never move away.

BREEDING Breeding seasons in New Zealand vary but most lay one clutch of eggs between September and November. In good food years, kororā in Otago will egg-lay from May to February, with many pairs raising two clutches of chicks. Usually two eggs are laid and are incubated for 36 days. Both parents share the incubation and feeding duties. The chicks are guarded by one parent for the first 2-3 weeks, after which both parents must go to sea to keep up the supply of fish. Chick growth is rapid, with adult weight (1000g) being achieved in 4-5 weeks. Chicks usually fledge at eight weeks and are independent from then on. Kororā usually breed for the first time at 2-3 years of age and breeding pairs usually stay together.

DIET AND FEEDING Kororā feed on a variety of surface schooling fish, squid and crustaceans. Although dive depths of 60m have been recorded, 10-20m is more common. The average dive time is 24 seconds. These penguins usually feed within 25km of the coast and may make daily round-trips of up to 75km. Long winter feeding trips of up to 750km (one way) have been recorded. Kororā can reach speeds of up to 6km/hr underwater.

INTRODUCED SPECIES


ENVIRONMENTAL CONDITIONS

1. Describe the habitat of kororā and environmental conditions to which they are adapted.

2. Describe how they are well adapted for feeding.

3. Describe how they are well-adapted for rearing young.

Check your answers.

PREDATORS Predation by introduced mustelids (stoats, ferrets and weasels) has devastated many mainland

colonies. In publicly accessible areas, dogs have also been major predators – particularly of penguins

returning from the sea. At Chatham and Stewart Islands, a large sea bird –the southern brown skua –

also attacks penguins returning from the sea.

5B


MUSTELIDS

Before people discovered the islands of Aotearoa

there were no mammals, just birds, insects and fish.

People arrived with dogs and rats. At the end of the

19th century some Europeans introduced rabbits to

provide themselves with meat, but without the

natural predators they would meet in Europe, the

rabbit populations grew huge. Mustelids (ferrets,

stoats, and weasels) are viscous European

mammals which prey on birds and rabbits. With a

plague of rabbits in New Zealand the decision was

made to ship over mustelids to control the rabbits.

The plan went badly wrong. The birds had no

natural defences against these aggressive

mammals, so the mustelids were able to feed very

well without bothering to chase rabbits.

Stoats have contributed to the extinction of the

huia, bush wrens, native thrushes and many more

birds and they still threaten many species

.

POPULATION The population and range of kororā has been declining in areas not

protected from predators. Where predator control is in place,

populations have been stable or increasing. The blue penguin trust,

the Department of Conservation and other agencies are working to

increase the numbers of penguins.

Penguins sometimes cross roads on the way to their burrows. This sign notifies drivers to watch out for penguins.

SAVING THE PENGUINS

1. All of these things kill penguins. Which of the following could have killed a West coast penguin a

thousand years ago? Explain your answers.

Dogs

Mustelids

Skua

Cars

5C

http://upload.wikimedia.org/wikipedia/commons/d/d0/Brehms_Het_Leven_der_Dieren_Zoogdieren_Orde_4_Hermelijn_(Putorius_erminea).jpg

INTRODUCED SPECIES


2. Discuss why kororā can be run over very easily if drivers are not especially careful.

3. Discuss why kororā are easy prey to dogs and mustelids.

4. “Where predator control is in place, populations have been stable or increasing” (page 38).

Suggest how predators be can controlled?

5. You go walking with your friend and her dog. You see some road signs telling drivers to be aware

of penguins. You friend asks you whether she should let her dog have a run off the lead. What

would you tell her?

Check your answers.

KEY POINTS

There were many kororā in New Zealand until the late nineteenth century.

Kororā are well adapted as carnivorous ocean creatures which breed on land.

Introduced mustelids (stoats, weasels and ferrets) ate eggs and chicks, causing numbers to

reduce.

Numbers are recovering on islands which are kept free from introduced predators.

On the mainland the birds also suffer road kill and loss of habitat, so their numbers are less

stable.


6 DINOSAUR FORESTS


identify features of a forest ecosystem

explain how plants are in competition for light in a forest ecosystem.

INTRODUCTION In the next two lessons you will study ecosystems

on land. The organisms and conditions are different

but the same big ideas apply.

Food chains and feeding relationships are

important to the ecology. Energy enters as sunlight.

It is captured by plants and flows through different

feeding levels, leaving as heat at each level.

WHY IS THIS LESSON C ALLED “DINOSAUR FORE STS”?

About 85 million years ago, during the age

of the dinosaurs, the land which was to

become New Zealand separated from the

rest of the supercontinent Gondwanaland.

Cut off from the rest of the world, life on

these islands evolved differently. As in the

rest of the world the dinosaurs became

extinct, but other plants and animals

evolved to suit the conditions.

Until a thousand years ago, when humans

first arrived in boats, land-based animals

and plants were isolated, except for

accidental new arrivals (plants and animals

which floated or got blown from other

places).

Many of our native species – for example

the kauri, kahikatea, tōtara, rimu, tuatara,

kiwi, kauri snail and wētā –evolved when

dinosaurs roamed on this land.

http://upload.wikimedia.org/wikipedia/commons/1/1b/Afternoon_sunlight_-_geograph.org.uk_-_137283.jpg

DINOSAUR FORESTS


RANGATIRA ISLAND

Use the Topic webpage to watch the short videos which show a LEARNZ field trip in the forest on Rangatira Island.

If you cannot watch the videos, read the text which follows.

The Chatham Islands are an isolated group of ten small islands in the Pacific Ocean 800km east of mainland New Zealand. Rangatira Island is the third largest of the islands and is a Nature Reserve managed by the Department of Conservation. Rangatira Island has remained free of introduced predators, such as mustelids, that have affected animals on the mainland. This fact allows scientists to study how native species, particularly birds, lived in ancient New Zealand. Welcome to Rangatira Island Melanie from the University of Canterbury is your host. No one lives on Rangatira, but Melanie and her colleagues are staying there to study the forest birds. They are particularly interested in the black robins, the Chatham Island warblers and the Chatham Island tomtits because these are all endangered species. The island has a rocky shore and is mostly covered in forest. The scientists arrive, bringing all their food for almost three months, in semi-rigid inflatable boat. Living on Rangatira Island shows where the scientists live and work together. In the Rangatira Forest shows how cold and dark the forest is, even on a sunny day in summer. Trapped in the Forest shows a harrier which has got trapped in the forest because its wings are too long and straight for taking off. It is adapted to strong flying, above the canopy, but not inside the forest.

The forest canopy makes much of the forest quite dark. The forest floor is quite bare due to the presence of thousands of seabird burrows. Can you see the cage the researchers use to catch birds?

On the Summit of Rangatira Island shows the full scope of the island from a height of about 200 m.

TERM TIME: Vertebrates are animals which have back bones (vertebrae).

Invertebrates are animals that don’t have backbones. In the forest the most important

invertebrates are insects, spiders and snails.

6A


Most of the island is covered by native forest that forms part of a community containing many species endemic to the

Chatham Islands. The forests are dominated by a few Chatham Island tree species: akeake, kawakawa, mahoe, matipo,

ngaio, ribbonwood.

COMPETING FOR LIGHT Green plants are primary producers. They make their own chemical energy from sunlight. Without

light plants quickly run out of energy.

Millions of years ago the first organisms to perfect photosynthesis were single-celled slime. By the

slow process of evolution plants have developed new adaptations, so that they can harness solar

energy successfully in different places.

In a forest ecosystem plants are in competition for light. Tawa and Kamahi, for example, grow into

big trees which form a canopy. Rimu will grow even bigger, so it can get the most light. By lifting

their leaves up high, trees capture light before it reaches shorter plants.

Trees may be the tallest plants but there are many others that grow

successfully in the forest. Some plants are well adapted for shade and

grow well in lower light conditions. They may have leaves that are very

effective at using the shaded light beneath the canopy and they can

have leaves that would dry out in exposed places in strong sunlight.

Each plant has adaptations which suit it to a certain position in the

forest.

The hen and chick fern is

adapted to grow well in shade. Notice its large thin leaves.

DINOSAUR FORESTS


COMPETING IN THE FOREST

Study the sketch, showing the plants in a New Zealand native forest, and then answer the questions.

1. Which layer of the forest receives the most light?

2. Why is there an advantage for plants to grow tall? Link your answer to a plant’s need for energy.

3. What is the challenge for smaller trees in the understory layer? Link your answer to a plant’s

need for energy.

4. Explain why there is very little grass growing in the forest?

5. Seeds that fall close to mature trees in the forest rarely survive. Explain why.

6B


6. The emergent trees, and the canopy trees, receive the most light. Their leaves are usually thick, with a waxy coating which stops them drying out. Explain why these type of leaves help the tree to survive. Link the environmental conditions in the canopy with the properties of the leaves.

7. The plants on the forest floor, in the understory and litter layers, often have large, thin leaves.

This is an adaption to gather as much light as possible, in the shade of the larger trees. Explain why these types of leaves help the tree to survive. Link the environmental conditions in the understory layer with the properties of the leaves.

8. Competition can happen between different species (inter-specific competition). Use the diagram

to identify two different species of tree that are in direct competition for light.

9. Competition can happen between organisms of the same type (intra-specific competition). From

the sketch name a tree that is competing with another of the same type, for access to light.

Check your answers.

Competition occurs when different organisms are competing for a limited

resource – in the forest example, the trees are competing for access to

light. Competition for resources happens in all ecosystems. Organisms

may be competing for water, food, light, space or some other need.

DINOSAUR FORESTS


LIVING IN THE FOREST

BIRDS ON RANGATIRA

Use the Topic webpage to watch the short videos from the LEARNZ field trip. Forest Birds, Seabirds in the Forest, Birds on Film, Working with Black Robins and Predator Free?

If you cannot watch the videos, read the text below very carefully.

Fifteen species of songbirds can be seen foraging throughout the forest during the day. Also eight species of seabird return to the forest at night where they breed in burrows dug in the ground. Black robins on Rangatira are banded and it is easy for researchers to get attached to the birds and their chicks. The Chatham Island snipe is difficult to see these beautiful little brown foraging birds blend into the leaves on the ground. You tend to only see them if they are moving. You will always hear parakeets on the islands. It sounds like they are constantly laughing at you. There are lots of tui which love to feed on the flax flowers. There are harriers and many sea birds. It is not unusual for seabirds to nest in forests but on Rangatira island there are hundreds of thousands of nesting pairs. They do not feed on the island; they just use it for nesting. They spend most of their time at sea. They just come into land to lay an egg, incubate it and rear the chick. They never come to the island to rest. To monitor the nesting birds the researchers on the island set up video cameras a few metres from the nests. The adults sit on the eggs to keep them warm, taking short breaks to feed.

Black robin

Female tomtit

Chatham Island snape

Rangatira island is called ‘predator-free’ because it is free of introduced predators such as stoats and weasels. Harriers and skua are the natural predators of the forest birds. Harriers fly above the canopy, seizing birds which emerge above the trees. Harriers have a huge wing span and if they happen to crash into the forest they get trapped because they do not have room to take off. Skua feed on storm petrels and little blue penguins. The other predators are huge spiders which will take even large weta.

A skua, a predatory sea bird

6C


SURVIVAL ON RANGATIR A

1. Rangatira supports sea birds and forest birds. What does the island provide for these birds? Tick

the boxes that apply.

Food Shelter

Forest birds

Sea birds

2. Explain why the island is able to support tens of thousands of sea birds, but a much smaller

amount of forest birds.

3. The sea birds are not in competition for food on the island. What might they compete for? (Hint,

there are thousands of nesting pairs on the island)

4. Bio security on the island is very important. Why are visitors not allowed?

Check your answers.

6D

DINOSAUR FORESTS


BIRDS AND LEVELS

Forest birds are adapted to live a certain levels. Do you know these three well-known birds? See if you can choose match the level and the diet of each bird. Choose a, b or c to describe the level and the diet of each bird.

North Island brown kiwi Lives in the:

a. Canopy Layer, b. Understory Layer, c. Litter and Ground Layers

Diet

a. Eats insects disturbed by other animals, including people b. Eats nectar from tree flowers c. Eats insects from the ground

Fantail Lives in the:


Diet


Tui Lives in the:


Diet


Check your answers.

KEY POINTS

Organisms compete with each other for the resources they need to stay alive.

The competition is intense for the resources which are most limited. For example in a forest

plants compete for light. Forest birds compete for food and seabirds compete for nesting

sites.

6E

http://upload.wikimedia.org/wikipedia/commons/8/82/TeTuatahianui.jpg

http://upload.wikimedia.org/wikipedia/commons/4/47/FantailMaunga.jpg


7 FORESTS AND BIODIVERSITY


explain the importance of native forests.

explain how deforestation of areas of New Zealand has affected its biodiversity

INTRODUCTION In pre-human times, 80% of New Zealand was covered

in forest. Māori settlers cleared forest, and by the

time the first Europeans arrived, up to 40 percent of

the original forest cover had gone.

Early European settlers used lots of timber for housing

and fuel. They also felled large areas of kauri forest to

export the high quality timber. Many of the trees they

logged where over a thousand years old! In some

places forests were burnt off to provide land for

farming. Only 25 percent of New Zealand is now

covered in native forest.

Native forest showing plant diversity. Forested areas

support a huge variety of wildlife, from fungi and lichens,

to plants, insects and animals. Deforestation results in

loss of habitat, extinction of wildlife and loss of

biodiversity

BIODIVERSITY IN THE WAITAKERE RANGES You have seen how biodiversity measures the variation of life forms in an ecosystem (page 17).

The Waitakere ranges are hills to the west of Auckland on the North Island of New Zealand. The Tasman Sea lies to the West, the Manukau Harbour is to the south and, just to the north is Auckland’s Waitemata Harbour. The natural forest ecosystem was determined by the hard basalt rock of the hills and the prevailing winds from the Tasman which makes the area a temperate rainforest – mild and wet. The ranges include a wide variety of habitats. In addition to the rainforest the ranges include freshwater wetlands, lake and streams, coastal wetlands dunes and estuaries plus urban areas.

A Google Earth view of the Waitakere ranges

FORESTS AND BIODIVERSITY


HABITATS OF THE WAITAKERES

Use the Topic webpage to find out about the animals and plants that live in different habitats in the Waitakere ranges.

If you cannot access, read about the information below which has been adapted from Waitakere City Biodiversity Report 2007

Although only 20% of the forested area is unmodified by logging or farming, the Waitakere Ranges are botanically rich containing 20% of all New Zealand’s flowering plant species and 60% of all native fern species. Although the following statistics are drawn from a number of sources and subject to change, the Ranges are home to: 542 species of native plant (111 species of these being native ferns) Many species of nationally threatened and regionally threatened plant 50 species of native bird 3 species of kauri snail (large land snail) 11 species of native freshwater fish 5 species of native reptiles 1 native frog 1 native mammal (long-tailed bat) There are now 240 introduced plant species identified as actual or potential threats to native vegetation, and there are 19 introduced bird species, 9 introduced mammals and 2 amphibians, all competing with our native species. Habitat types in the district can be broadly grouped into: Forests and shrub lands Freshwater wetlands, lakes and streams Coastal wetlands, dunes, and estuarine tidal flats and channels Urban area The transition zones of one habitat type into another and the corridors that link fragmented habitats are equally important. There are many categories of forest types within Waitakere, from the complex mature and regenerating forests of the Ranges to the lowland forest remnants and scrub. The forested areas of the Waitakere Ranges support species such as pied tit, shining cuckoo, long-tailed bat, Hochstetter’s frog and kauri snail as well as the more common tui, kereru and fantail. There are some particular species that capture the public interest, whether or not they may be indicators of overall ecological health. Such species are kereru, tui, giant and banded kökopu, kauri and any rare species. KAURI SNAIL The geographic range of kauri snails coincides with the historic geographic range of kauri forests. Kauri snails were traditionally found in the large clumps of dense vegetation that grew as epiphytes on the kauri, their eggs being laid at the foot of these large trees. The habitats associated with old kauri forests have been destroyed. Colonies of the kauri snail still survive in several areas of the Waitakere Ranges, in thick, damp patches of scrub and fern. These snails are highly mobile and are carnivorous, feeding mainly on worms. The heavy shell of the large kauri snails gives them protection from predation by birds and rats, but not from pigs.

7A


EFFECTS OF DEFORESTATION Maori cleared forest, burning undergrowth and felling trees. The land was farmed for crops for only

one or two seasons, then bracken fern was grown – the roots were used for food.

From the nineteenth century until the 1920s Europeans cleared the ranges for timber and farmland

until only about 20% of the original forest remained.

Many animal species depended on the forest. Many bird species disappeared from the area

including kiwi, weka, kokako, bellbird, stitchbird, North Island robin, whitehead, kaka, kākāriki, teal,

scaup, dabchick and the short-tailed bat.

EXTINCT SPECIES OF NEW ZEALAND At least 67 species of animals have been extinguished since humans first arrived in New Zealand. Birds like the moa were hunted for food. In lesson 5 you learned how penguins nearly became extinct too. The beautiful huia bird was hunted to extinction because its feathers became very trendy in Europe. The main threats to endangered species today are loss of habitat and introduced species.

ENDANGERED SPECIES

Find out about one endangered species which lives in the Waitakere rainforest. Use the links on the Topic webpage, and then answer the questions which follow.

If you cannot access the Internet, then answer the questions which follow.

Kiwi are well adapted for living at ground level in native forests. They especially like places with wetland vegetation and where trees run down to river edges. They eat worms, spiders, fruits and seeds. They sometimes eat crayfish and even frogs. They are nocturnal creatures – they hide away and sleep in burrows during the day. Their eggs are huge – 20% of the female’s body weight. They take up to 80 days to hatch. Kiwis are very territorial and have been known to kill other kiwis that come onto their ‘patch’. One kiwi pair may have a territory equivalent to about 60 football pitches. Discuss how your species might have been affected if:

1. a small area of forest was cleared by burning all the undergrowth,

7B

TERM TIME: Deforestation is when a forest is cleared and not replaced, such as when land is cleared

for a dairy farm.

Logging is the process of cutting and removing trees. New trees may or may not be re-

planted

FORESTS AND BIODIVERSITY


2. a large area of forest was cleared to become a potato farm

3. a small area of forest was developed as a commercial tree plantation.

Check your answers.

KEY POINTS

Native forests contain a wide variety of organism – they have a high level of biodiversity.

People have caused many organisms, particularly birds, to become extinct.

Endangered species are no longer hunted but they are at risk because of predation and

competition with introduced species and through loss of habitat.


8 TREES, WATER AND NUTRIENTS


explain the importance of nutrient cycling and the role of decomposers.

describe how trees affect soil and water run-off

In this lesson you will study some of the effects of logging on ecosystems.

NUTRIENTS AND ENERGY All living organisms require energy and nutrients.

Because food chains all begin with plants, the nutrition of plants is important for an ecosystem. If

plants don’t get the nutrients they need then all the other organisms in the food chain will go hungry

and possibly starve.

In lesson 1 you saw how food chains show the flow of energy from the Sun to producers and

consumers. Eventually the energy becomes heat. Heat is steadily lost from planet Earth, balancing

the energy arriving from the Sun. This keeps the average temperature of the Earth steady.

Nutrients are slightly different. Carbon, nitrogen, hydrogen, oxygen.., all the atoms living things need

to carry out life processes, are never lost from Earth. They absorb them in one chemical form (by

feeding) and excrete them in another form. Decomposers have feed on dead cells and break them

down.

Decomposers: are mainly

bacteria and fungi that break

down dead plants and animals.

They get their energy from the

plants and animals they feed on.

Decomposers are important

because they release nutrients

that producers and consumers can

use. For example mushrooms

often grow on dead wood from

trees

Producers: e.g. trees, grass

Producers capture energy, usually

from the Sun, and store it as

sugars for their own food and to

provide food for consumers.

Consumers: get their energy and nutrients by

eating producers. Consumers can be divided

into herbivores (plant eaters e.g. rabbits,

caterpillars), carnivores (meat eaters, e.g. dogs,

spiders) and omnivores (animals that eat plants

and animals e.g. humans, rats)

nutrients

energy

energy

energy

nutrients

nutrients

nutrients

NUTRIENTS Nutrients are the chemicals needed for growth, the ingredients for life

processes. Animals get their nutrients in their food. Plants get their nutrients

from their environment, usually from air and soil.

TREES, WATER AND NUTRIENTS


NUTRIENT CYCLING CARBON CYCLING Carbon dioxide is everywhere in the atmosphere and it is also dissolved in the oceans. Carbon cycles

into plants, it is essential for photosynthesis, and back into the atmosphere when chemical energy is

used by organisms.

The picture shows a cabbage tree and a kereru performing a very simple carbon cycle. Because

carbon compounds can be stored as oils and in shells and bones, they may take millions of years to

recycle. (For more about carbon cycling you could consider studying for Achievement Standard

90953, Demonstrate and Understanding of Carbon Cycling.)

NITROGEN CYCLING Nitrogen is an essential nutrient for living organisms. Although the atmosphere is mostly nitrogen

gas plants cannot absorb and use it. They can only absorb nitrogen when it is dissolved in water as

either nitrate or ammonium.

In many ecosystems the usable nitrogen is limited, so this has a very strong influence the on the

living things in the ecosystem.

Only small amounts of nitrogen move between the atmosphere and the ground, but the nitrogen in

living things is constantly re-used by plants after they have been broken down by decomposers.

Without decomposers the useable nitrogen would quickly get locked into the bodies of living

organisms and plants would be starved of nitrogen.

Carbon dioxide from the air is absorbed by the

leaves of the cabbage tree.

With energy from sunlight, the leaves make

carbohydrates which are stored in the small

white berries.

As energy is released from the carbohydrates

the kereru breaths out carbon dioxide.

Carbon dioxide

Carbohydrate

Carbon dioxide

Carbohydrate The kereru feeds on the berries and uses them

for nutrition.

carbon dioxide.

PH

OTO

: P

HIL

IP P

OO

LE


This picture shows a very simple nitrogen cycle. The bacteria in the picture are Clostridium perfringens. These rod-shaped

bacteria are common in soil.

NITROGEN STARVATION

1. What would happen to the flax bush in the picture if there was no useable nitrogen in the soil?

Explain your answer.

2. Gardeners add compost made from rotted animal and plant material to their gardens. What

does this have to do with nitrogen?

8A

The starling gets

nitrogen in its diet as it

feeds on the flax

flowers.

Nitrogen is absorbed through

the roots of the flax.

The plant uses

nitrogen to grow. When the starling

dies its body will

decompose and

release useable

nitrogen into the

soil.

Dead leaves and bird

droppings add

nitrogen to the soil.

Bacteria and

fungi act as

decomposers.



3. In a commercial forest the trees are cut down, and the wood is taken away. How might this affect the nitrogen levels in the soil?

4. The loggers who came to the region shown in the picture

have only taken the main logs; they have left the small branches and tree tops behind. Why do did they do this?

Check your answers.

MORE PROBLEMS WITH DEFORE STATION For many settlers to New Zealand their first job was to fell trees. The wood from the native trees was

very useful and the land that was cleared could be used for farming. In some places the farms failed

and cutting down the forest proved to be a big mistake.

You have learned how, in a forest ecosystem, nutrients are cycled, so the soil never runs short of

nutrients such as nitrogen. When trees are removed some of the nitrogen goes with them, but there

can be other issues. Without tree roots to hold the soil together the nutrients wash out of the soil

more quickly. In heavy rains the soil may be lost completely.

STABILISING SOIL

Use Google Earth to study the changes in a forest after it was commercially logged. Full instructions are on the Topic Webpage.

If you cannot use Google Earth, complete the activity using the pictures in this booklet.

2004 2007 2009

1. What happned in this area just before the photograph was taken in 2004?

8B


2. What did people do between 2004 and 2007?

3. How can you be sure that the trees did not grow naturally?

4. Study these close up pictures of a slope where there is evidence of water run-off.

2004 2007 2009

a. In 2004 you can see that after a rain storm there are two areas where the soil has

slipped. Draw a line around the area where soil has slipped away. b. Now look at the 2007 picture. Draw a line around the area where there has been soil

loss. How does this area compare with area in the 2004 picture?

c. Now look at the 2009 picture. Suggest a reason that there are no trees growing in the

large central area.

d. Describe and explain the impact of logging on the soil in this area.

5. Around the world, regions where large amounts of trees have been logged are more prone to

flooding. Explain why removing trees increasing the chance of flooding.

Check your answers.



KEY POINTS

Food chains depend on plants as producers. Plant nutrition is essential for all the organisms

in the food chain.

In natural ecosystems nutrient elements are recycled by decomposers.

Useable nitrogen in soils is often limits the plant growth in an area.

Trees provide protection for soil; tree roots in particular are important for preventing slips

and run off.


9 ECOLOGY – WHO CARES?

LEARNING INTENTIONS You will learn to:

explain the importance of ecology

describe important features in an ecosystem

identify living and non-living components, energy flow and nutrient flow in an ecosystem.

ECOSYSTEMS

An ecosystem is made up of all the living

and non-living things which interact with

each other in an area.

Ecosystems are often described by their

physical environment, for example, a

sandy beach, rocky shore, lowland forest,

or slow flowing stream.

Part of a rocky shore ecosystem

Ecosystems are often described by the

plants or other organisms that are present,

for example the mangrove ecosystem

opposite. Mangroves are not the only type

of organism present, but they are the one

that is most dominant. Many other species

will live in and amongst the mangrove

plants.

Mangrove ecosystem

WHAT IS ECOLOGY?

Ecology is the study of ecosystems. You

study how living things in a place affect

each other and how they are affected by

the non-living things around them.

You learn how and why different

organisms live in different places and why

the numbers of animals, plants and other

organisms vary from place to place.

The success of all of New Zealand’s primary industries

(farming, forestry, fishing and horticulture) is reliant on a good understanding of ecology. This includes all the interactions between natural and manmade systems.

ECOLOGY – WHO CARES?


WHY STUDY ECOLOGY?

Studying ecology allows us to gain a better understanding of how to manage the environment

around us. This could help us use the land better and damage it less.

An understanding of ecology helps us to make predictions about how changes affect us and our

environment. It also helps us to make decisions about the best ways to try and fix mistakes that

were made in the past.

HUMAN INTERACTIONS Many ecosystems have been damaged or destroyed by people. We hope that by studying ecology

we will be able to restore and repair some ecosystems.

Here are some examples of things that happen because of what people do.

An oil tanker hits a reef and causes an oil spill.

Understanding the ecology of the ocean will

help us find the best way to clean up the mess

and how to prevent further damage.

Some people start a community garden.

Understanding how plants grow and what they

need will help us to grow more food.


A farmer plants trees along a stream.

Understanding more about stream ecology will

help protect our waterways to ensure we have

healthy water.

One of the basic understandings of ecology is that all things are interconnected. A change in one

small part can affect the whole system.

Did you know? Different cultures and worldviews use different words and concepts to describe the interactions between parts of an ecosystem. For example some traditions and cultures see water or a river as a living thing. In this workbook we have used the term physical characteristics to describe those parts of ecosystems that science has labelled non-living.

McLean Falls in the South Island

HOW MUCH ARE ECOSYSTEMS WORTH? In 1987 an international group of scientists and economists published a scientific paper about the

value of nature. They were concerned that political decisions were based entirely on money, so the

value of ecosystems was being overlooked.

They considered the many different benefits that the natural ecosystems around the world provide.

They then worked out that these ‘ecological services’ are worth about $50 trillion – that’s more than

value of all the businesses in the world. (Global GNP is around $24 trillion).

http://upload.wikimedia.org/wikipedia/commons/d/d6/McLean_Falls.jpg

ECOLOGY – WHO CARES?


Ecosystem service

1 Gas regulation Ecosystems keep the air clean and with the right amount of oxygen and carbon dioxide, so that we can breathe and plants can grow. They remove poisons.

2 Climate regulation Ecosystems help to keep the temperature comfortable for life on Earth; they affect the weather and the climate.

3 Disturbance regulation

Ecosystems help to reduce landslips, floods and sandstorms.

4 Water regulation Ecosystems help to keep clean water flowing steadily along rivers.

5 Water supply Ecosystems store clean water. 6 Erosion control and sediment retention

Ecosystems prevent soil loss.

7 Soil formation Ecosystems help to form good soil – they break up rock and add organic matter to soil.

8 Nutrient cycling Ecosystems cycle nutrients to keep soil fertile.

9 Waste treatment Ecosystems clean water and remove poisons.

10 Pollination Ecosystems provide birds and insects which are essential to pollinate crops so that they form fruits.

11 Biological control The predators in ecosystems ensure that plant-eaters do not destroy too many plants.

12 Refugia

Ecosystems provide habitats for many birds, fish and animals, many of which are valuable (e.g. as food)

13 Food production Ecosystems provide naturally produced foods - fish, game, crops, nuts and fruits.

14 Raw materials Ecosystems provide fuel, building materials and animal feeds.

15 Genetic resources Ecosystems are sources of unique biological materials, useful for medicines, for genetic resistance, for garden plants and pets.

16 Recreation Providing opportunities for recreational activities.

People love to be out in the natural world - Eco-tourism, sport fishing, and other outdoor recreational activities are valuable.

17 Cultural People value ecosystems for artistic, spiritual and intellectual reasons.

Based on The Value of the World’s Ecosystem Services and Natural Capital, Costanza et al, Nature 1987. http://www.ecy.wa.gov/PROGRAMS/wr/hq/pdf/naturepaper.pdf

http://www.ecy.wa.gov/PROGRAMS/wr/hq/pdf/naturepaper.pdf

http://upload.wikimedia.org/wikipedia/commons/0/0e/Nasa_earth.jpg

http://upload.wikimedia.org/wikipedia/commons/1/1a/Tui_07.jpg

http://upload.wikimedia.org/wikipedia/commons/f/fe/Catching_salmon_in_the_ocean_off_Raspberry_Island.JPG

http://upload.wikimedia.org/wikipedia/commons/2/23/Real_Journeys_Milford_Sound_Ship.jpg


WHAT DO YOU VALUE MOST?

Look at the 17 ecological services provided by nature.

1. Which of these services is most important to you? Explain your choice.

2. Are there any services that you don’t think are important? Explain your answer.

Your teacher will be interested to read your ideas.

KEY POINTS

An ecosystem consists of: o All the organisms that are in a particular location o The physical characteristics of that location

Earth’s ecosystems are vital to life. Ecosystems take care of air, water, weather, soil and much

more.

Remember to check that you have included the words in bold into your glossary

9A

TEACHER-MARKED ASSIGNMENT


10 TEACHER-MARKED ASSIGNMENT


review your progress over this topic. INT RODUC TION

In this lesson you will take a quick look back at all the lessons you have completed in this topic. Think about what you have learned. When you are ready, try the teacher-marked assignment SC1121A. If you did not receive this with your booklet, contact your teacher. When you have finished, complete the self-assessment section at the end of this booklet. Send the booklet and the teacher-marked assignment to your teacher. Make sure that you have written your name and ID number on the back cover of your booklet and the teacher-marked assignment. You can also use a label if you have one at hand. By post: Put the booklet and teacher-marked assignment in the plastic envelope provided. Make sure that the address card shows the Te Aho o Te Kura Pounamu (The Correspondence School) address. Seal the envelope with tape before you post it. By email: Scan the pages including the cover sheet and email to your teacher. The standard format for Te Kura teacher email addresses is: [email protected] If you aren’t sure who your teacher is, call 0800 65 99 88.

Before you finish this topic you should have agreed your next steps with your teacher. If you do not have your next set of study materials, contact your teacher immediately. If you are not sure what to do next, ask your teacher for advice.


11 ANSWER GUIDE

WHO LIKES ROCKY SHOR ES?

They find food and shelter. The rocks protect them from bigger fish that want to eat them.

NAMING TYPES OF ORGA NISMS

Plants producer

Herbivores Primary Consumer, prey

Carnivores Secondary Consumer, predator

ENERGY FLOW ALONG A FOOD CHAIN

5. They would not get enough energy to survive because most of the energy is lost at each level.

Each time you go up a level you need ten times more plants to support the top level.

TROPHIC LEVELS

Trophic level Example from a marine ecosystem

6. Phytoplankton, seaweed

7. Krill, mussels,

8. Shag, blue maomao,

9. Snapper, shag

10. Dolphin, shark

Decomposers Crabs, worms, bacteria

FOOD CHAINS AND PYRAMIDS

6. There are many possible answers. Here are two examples.

Kelp Red crabs Crayfish Snapper

Phytoplankton Sponge Leatherjacket Snapper

7. a. Energy in ecosystems comes from the __Sun__________________ b. Carnivores get their energy by feeding on __ animals__________ c. Energy is lost from an ecosystem as __heat_____________________ d. Decomposers get their energy from both _animals________ and ___plants____

1F

1E

1D

1C

1B

Answer guide


8.

9. Because energy is lost as heat, not much energy gets passed on along a food chain. A tuna needs to consume 1000 g of fish to grow by 100 g. The midsize fish need to eat lots more little fish and the little fish have to eat lots more zoo plankton. Finally, with each layer increasing by ten each time, 10 000kg of phytoplankton is needed for just 100 g of tuna.

10. It shows what each organism eats because each feeding level in

the food chain is one layer of the pyramid. Animals feed on the layer below. The shape shows how the amount of living things gets smaller going up the food chain (because of energy loss). It shows how a large amount of plants (primary producer) is needed to support one top carnivore.

MARINE ECOSYSTEMS

3. There are many possible correct answers. Here are some examples:

Seaweed Small fish arrow squid Penguin

Phytoplankton mussels snapper human

4. a. Decrease, because they would have less food. b. Increase, because there are less large fish eating them. (If you thought of this next part,

you are working at Excellence level. In the longer term they may eat too much of the plant life, so they could suddenly all die for lack of food.

UNDERSTANDING A FOOD WEB

2.

plankton filter feeders snapper

seaweeds browsers snapper

algal film grazers snapper

INSIDE AND OUTSIDE THE MARINE RESERVE

1. At Matheson Bay there are less fish, and fewer plants than Goat Island. Amongst the fish there is

less diversity and there are much fewer big fish. There are kina-barren area, where there are few

plants and lots of small kina, in Matheson Bay, but not at Goat Island. The larger fish are more

scared of people in Matheson Bay.

2.

a. …outside of the marine reserve the fish have learned that people are their predators, so

they hide. Inside the reserve people are not a threat to them.

2C

2B

A

2A


b. … people take the largest to eat.

c. … the predators of kina such as snapper and crayfish have been removed.

d. … because the kina have eaten the plants.

3. There are less species outside the marine reserve where fishing is allowed. This indicates that

human fishing is has decreased species diversity. Fishing has caused some species to disappear

completely – either because they were overfished or because fishing disrupted the ecology in

another way. They may have disappeared because they had more predators, because their food

ran out, or because their shelter was removed.

ENVIRONMENTAL FACTORS ON THE ROCKY SHORE

Low tide

zone Higher tidal

zone Rock pools

Under water all the time

Under water most of the time

Sometimes underwater but often exposed to air.

Can get very hot or very cold

Strong sunlight with no shade every day.

Exposed to strong winds

Exposed to strong surf waves

Unable to swim away from predators

Exposed to large predatory fish

EXPLAINING ADAPTATIONS

Each organism has many adaptations; here are some of the more obvious ones which can be seen in

the pictures. You may have thought of others.

Crab

Habitat: Rock pool

Adaptations: wedges itself into tight cracks – this helps to stop it drying out and also protects from

predators. Its colour helps it to be blend in so it can’t be seen. Hard shell protects from predators.

Cushion star

Habitat: Rock pools

Adaptations: Its colour helps it to blend in with the rocks to it isn’t spotted by predators. It is smooth

with a body that can grip strongly to the rock so that it isn’t washed away.

Chiton

Habitat: All rocky shore zones.

Adaptations: Its colour helps it to blend in with the rocks to it isn’t spotted by predators. It is smooth

with a body that can grip strongly to the rock so that it isn’t washed away. Hard shell protects from

predators.

Snails

Habitat: higher tidal zone

Adaptations: white colour reflects heat, they group together when the tide goes out so that they

hold moisture better. Hard shell protects from predators.

3C

3B

Answer guide


KEKENO FOOD WEB

There are many possible webs; here is an example of one. The black lines show information from the

video and in the text.

KEKENO – PHYSICAL ADAPTATIONS

8. Long whiskers C

9. A streamlined body B

10. Strong flippers F

11. Two layers of fur A

12. Claws on their hind flippers G

13. No fur on flippers D

14. Their brown colour is similar to the rocks they sit on.

E

SEAL POPULATION PROBLEMS

5. The graphs of seal pup numbers all show:

an increase from roughly 1991-93;

a decrease, with a minimum around the year 2000;

3. Taumaka Island shows an increase in pup numbers, the other two show a decrease.

4. a. Wekakura Point and Cape Foulwind are both

close to areas which are trawled for hoki. Taumaka Island is the only colony which shows a general increase in pup numbers over the last decade. It is also the only colony a long way from the areas which are trawled. If we assume that the number of pups is a good indicator of seal populations, there is evidence to support the statement.

Wekakura Point, mean estimated pup numbers (+/- 1SD)

0

200

400

600

800

1000

1200

1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014

Year

Pup n

o's

Cape Foulw ind, mean estimated pup numbers (+/- 1SD)

0

100

200

300

400

500

1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014

Year

Pup n

o's

4D

4C

kekeno

squid

small mid-

water fish

conger eels

hoki

barracuda

great white

shark

tiger shark

mussels

kelp

plankton

4B


b. No, we don’t have enough evidence to know if there is an alternative explanation. The changes in pup numbers could be due to pollution, local dogs, tourists…. But we don’t have any data about these things.

THREATS TO KEKENO

4. Habitat loss – this means that the kekeno have less places that they can live. The places which are good for their breeding colonies might have been turned into farms or housing

5. Entanglement with fishing gear and marine debris 6. Overfishing.

ENVIRONMENTAL CONDITIONS

1. Habitat: both the sea and land along coasts. They feed at sea and breed on land in burrows and

any suitable holes.

2. There are a lot of adaptations you could have thought of. Here are some examples. They are

good swimmers with streamlined bodies and waterproof feathers. The can dive deep and catch

fish in their strong beaks.

3. There are a lot of adaptations you could have thought of. Here are some examples. They lay

their eggs in burrows, hidden away from predators. They move to and from the burrows under

cover of darkness.

SAVING THE PENGUINS

1.

Dogs – were not in NZ until people arrived

Mustelids– were only introduced in NZ just over 100 years ago.

Skua - - this is a native predator of penguins

Cars– were only introduced in NZ just over 100 years ago.

2. Kororā have not natural fear of cars, so they don’t know what to do if a car is heading towards

them.

3. Kororā have not developed any defence from dogs and mustelids. They can’t run very fast and

their burrows are easily accessible by mustelids.

4. Predator control could involve trapping and poisoning mustelids and having very strict dog

control law and enforcement.

5. You might tell her that the road sign suggests that there might be kororā around. The dog might

like to chase a penguin or disrupt a burrow. Because kororā have no natural defence from dogs

the dog could end up hurting the penguin.

Taumaka Island, mean estimated pup numbers (+/- 1SD)

0

300

600

900

1200

1500

1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014

Year

Pup n

o's

5C

5B

4D

Answer guide


COMPETING IN THE FOREST

1. The canopy.

2. The tallest plants get the most sunlight so are able to get most energy from the Sun.

3. Smaller trees won’t get as much energy from sunlight because they are shaded by the taller

trees.

4. There is not enough light for grass to grow (because grass is short, even the small trees are

taller).

5. Close to mature trees there is little light at ground level, so the seedlings don’t get enough

energy to survive.

6. The environmental conditions are full sunlight, unprotected from the wind. These conditions will

dry things out quickly. The thick leaves with waxy coatings dry out more slowly than thin leaves

without a coating.

7. The environmental conditions are indirect sunlight, protected from the wind. In this situation

leaves are not at risk of drying out but they don’t get much sunlight. By growing large and thin

they get as much sunlight as possible.

8. Any two species at the same layer are in direct competition e.g. tawa and kamahi.

9. The two tawa trees are in competition.

SURVIVAL ON RANGATIR A

1.

Food Shelter

Forest birds

Sea birds

2. The seabirds only need the island for nesting, so they don’t use up lots of the resources. They

don’t get food from the island. The forest birds get their food on the island, so they are limited

by the food provided by the forest.

3. The seabirds are in competition for the best nesting sites.

4. If visitors came they might bring invasive species such as insects, plants or mammals such as rats

and mice. These invaders could destroy the ecosystem and make some of the birds become

extinct.

BIRDS AND LEVELS

North Island brown kiwi

Lives in the:b. Litter and Ground Layers; Diet: c. Eats insects from the ground

Fantail

Lives in the: c. Understory Layer; Diet: a. Eats insects disturbed by other animals, including people Tui

Lives in the: a. Canopy Layer; Diet: b. Eats nectar from tree flowers

6E

6D

6B


HABITATS OF THE WAITAKERES

Your answers will depend on which species you have chosen. The example here relates to the kiwi.

1. Burning the undergrowth might kill kiwi that are in burrows, it will certainly kill any chicks and

eggs. If only small areas are burned the kiwi populations would not be reduced by much.

2. Clearing a large area would kill all the kiwi in the area. Kiwi would not have a suitable habitat on

a potato farm because they would not have shelter and their burrows would be destroyed.

3. Kiwi may be able to survive in a commercial tree plantation, provided that they had other forest

to live in during logging and replanting.

NITROGEN STARVATION

1. It would stop growing and probably die because it would not be getting the nutrients it needs to

grow and stay alive.

2. Rotted animal and plant material is rich in nutrients, including useable nitrogen.

3. Nitrogen levels would go down (because the nitrogen in the wood is not being returned to the

soil).

4. The twigs thin branches aren’t worth much money, but they will help to keep the soil fertile

because they will rot down and provide nutrients for next lot of trees.

STABILISING SOIL

1. It was logged.

2. The replanted trees.

3. The trees are in rows that wouldn’t happen naturally.

4.

a.

2004 2007

b. The area is bigger.

c. The soil got washed away, so they couldn’t grow.

d. Logging has c

5. Tree roots hold soil together and help land absorb water. Without trees the water runs off more

quickly causing floods.

8B

8A

7A

ACKNOWLEDGEMENTS


ACKNOWLEDGEMENTS




SELF-ASSESSMENT

Fill in the rubric by ticking the boxes you think apply for your work. This is an opportunity for you to

reflect on your achievement in this topic and think about what you need to do next. It will also help

your teacher. Write a comment if you want to give your teacher more feedback about your work or

to ask any questions.

Fill in your name and ID Number.

Student Name: Student ID:

Not yet

attempted Didn’t

understand Understood

some Understood

most Very confident in my understanding

I can identify the characteristics of an ecosystem.

I can explain how environmental conditions affect ecosystems.

.

Please place your comments in the relevant boxes below.

Student Comment I can identify the characteristics of an ecosystem.

I can explain how environmental conditions affect ecosystems.

Any further student comments

SELF-ASSESSMENT


Phone, fax or email your teacher if you want to talk about any of this work. Freephone 0800 65 99 88

TEACHER USE ONLY

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Teacher Comment

+

COVER SHEET – SC1121

STUDENTS – PLACE STUDENT ADDRESS LABEL BELOW OR WRITE IN YOUR DETAILS.

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(if changed)

AUTHENTICATION STATEMENT I certify that the assessment work is the original work of the student named above.

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