11

CHAPTER 2CHAPTER 2

LIFE ON LAND LIFE ON LAND

22

Life on Land Life on Land Natural history: Study of how organisms in Natural history: Study of how organisms in

particular area are influenced by factors such as particular area are influenced by factors such as climate, soils, predators, competitors, and climate, soils, predators, competitors, and evolutionary history.evolutionary history.

Daniel Janzen’s study case of Guannacaste tree Daniel Janzen’s study case of Guannacaste tree ((Enterolobium cyclocarpumEnterolobium cyclocarpum) in CR (1981a.1981b)) in CR (1981a.1981b)– Each tree produce average of 5000 fruit.Each tree produce average of 5000 fruit.– Most seeds remain on the floor under the treesMost seeds remain on the floor under the trees– Large herbivorous animals feeding on fruits were hunted Large herbivorous animals feeding on fruits were hunted

10,000 years ago.10,000 years ago.– European introduce cattle which feed on those seeds, European introduce cattle which feed on those seeds,

which eventually helped to disperse those trees. which eventually helped to disperse those trees. – His study help to understand the role of natural history His study help to understand the role of natural history

on restoration of G tree and G National Park. on restoration of G tree and G National Park.

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Fig. 2.2Fig. 2.2

44

Terrestrial BiomesTerrestrial Biomes Biomes: divisions of the terrestrial environment with Biomes: divisions of the terrestrial environment with

distinguish predominant plants and associated climate.distinguish predominant plants and associated climate.( e.g. tropical forest, desert).( e.g. tropical forest, desert).

Soil: Complex mixture of living and nonliving material Soil: Complex mixture of living and nonliving material upon which most terrestrial life depends.upon which most terrestrial life depends.

Soil form a medium in which organisms grow, and their Soil form a medium in which organisms grow, and their activities in turn affect soil structure.activities in turn affect soil structure.

Soil vertical profile :Soil vertical profile :– O horizon: organic, decomposed organics as result of bacteria, O horizon: organic, decomposed organics as result of bacteria,

fungi, and soil animals. Merger gradually with A horizon.fungi, and soil animals. Merger gradually with A horizon.– A horizon: mixture of minerals material such clay, support high A horizon: mixture of minerals material such clay, support high

level of biological activities, rich in mineral nutrients.level of biological activities, rich in mineral nutrients.– B horizon: contains clay, humus and other materials B horizon: contains clay, humus and other materials

transported from A. Distinct color and banding patterns. transported from A. Distinct color and banding patterns. Occupied by the roots of plants, and gradually merge with C.Occupied by the roots of plants, and gradually merge with C.

– C horizon: deepest layer, weathered parent material, small C horizon: deepest layer, weathered parent material, small fragments of particles (sand, silt, clay). fragments of particles (sand, silt, clay).

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Fig. 2.3Fig. 2.3

66

Large-scale patterns of climatic Large-scale patterns of climatic variationvariation

Uneven heating of earth’s spherical Uneven heating of earth’s spherical surface by the sun and tilt of earth axis surface by the sun and tilt of earth axis will results predictable climate variationwill results predictable climate variation

The geographical distribution of terrestrial The geographical distribution of terrestrial biomes corresponds closely to variation in biomes corresponds closely to variation in climate, especially temperature and climate, especially temperature and precipitations.precipitations.

Pattern of atmospheric circulation and Pattern of atmospheric circulation and Coriolis effect. Coriolis effect.

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Fig. 2.4Fig. 2.4

88Fig. 2.5Fig. 2.5

99Fig. 2.6Fig. 2.6

1010

Climate DiagramsClimate Diagrams

Develop by Heinrich Walter (1985)Develop by Heinrich Walter (1985) Tool used to explore the relationship Tool used to explore the relationship

between distribution of terrestrial between distribution of terrestrial vegetation and climate. vegetation and climate.

Scale of temperature and Scale of temperature and precipitation where scaled so 10 °C precipitation where scaled so 10 °C = 20 mm of precipitation. = 20 mm of precipitation.

Climate diagram for various cities Climate diagram for various cities (see fig 2.8 page 20) (see fig 2.8 page 20)

1111

Fig. 2.7Fig. 2.7

1212

BiomesBiomes

Tropical Rain ForestTropical Rain Forest– The more alive biomesThe more alive biomes– Illuminated by dim greenish light shining through a ceiling of Illuminated by dim greenish light shining through a ceiling of

leaves.leaves.– Availability of rain and warm and wet around the year.Availability of rain and warm and wet around the year.– Falls within the equator in three regions :Falls within the equator in three regions :

Southeast Asia, West Africa , and south and Central America.Southeast Asia, West Africa , and south and Central America.– Soil is nutrient-poor, acidic, thin, and low in organic matter.Soil is nutrient-poor, acidic, thin, and low in organic matter.– Nutrients are tied up in living tissues than in soil.Nutrients are tied up in living tissues than in soil.– Beneficiary partnership such as “Mycorrhizae” in which fungi Beneficiary partnership such as “Mycorrhizae” in which fungi

associated with plant roots.associated with plant roots.– Rain forest could occur on volcano fertile soil, or along rivers.Rain forest could occur on volcano fertile soil, or along rivers.– Animal and plants diversities are immense.Animal and plants diversities are immense.– Human influences on tropical rain forest has been devastated.Human influences on tropical rain forest has been devastated.

1313Fig. 2.10Fig. 2.10

1414

Tropical Dry Forest– Life responds to the rhythms of annual solar cycle.– During dry season most trees are dormant, they flourish during

the rainy season. – Occupy a substantial portion of the earth’s surface ( 10° and

25° latitude) (Cancer and Capricorn)– Climate is more seasonal than tropical forest (see fig 2.13).– More seasonal variations in temperature. – Soil is less acidic, and more richer in organic.– Soil is more vulnerable to erosion, particularly when disturbed

by agriculture.– Plants are strongly influenced by physical factors.– Share many animal species with the rain forest and savanna– Animal may migrate during dry season.– Dry forest has been severely exploited more than tropical

forest, by agriculture and cattle grazing.

1515Fig. 2.13Fig. 2.13

1616

Fig. Fig. 2.142.14

1717

Tropical SavannaTropical Savanna– Tropical grassland dotted with scattered trees. Tropical grassland dotted with scattered trees. – Believed ancient humans lived in it and scattered to other Believed ancient humans lived in it and scattered to other

biomes.biomes.– Occur north and south of tropical dry forests within Occur north and south of tropical dry forests within 10° to 20° of

the equator.– Life cycles to rhythms of alternating dry and wet seasons, with

intense lightening and often fires. – Fires help to maintains grassland as nutrients will be recycled.– Soil layers with low permeability resulting in maintaining plants.– Soil low permeability prevent trees as trees occur only where

soils are well drained.– Biological activities take place near ground level.– Animals response to rainfall and food availability.– Human early use as hunting and gathering of food ground. – Human influence were seen as livestock ranching activities.– Drought and climate change have devastated most of it.

1818Fig. 2.16Fig. 2.16

1919

DesertDesert– Landscape sculptured by wind and water scarcity in general.Landscape sculptured by wind and water scarcity in general.– Drought and treacherous floods, heat and better cold often go Drought and treacherous floods, heat and better cold often go

hand in hand.hand in hand.– Life is not luxuriant, organisms adapted to water shortage and Life is not luxuriant, organisms adapted to water shortage and

extreme temperatures (low & High).extreme temperatures (low & High).– Occupy 20% of the land surface of the earth.Occupy 20% of the land surface of the earth.– Two bands of deserts ring the globe, one 30°N and 30°S Two bands of deserts ring the globe, one 30°N and 30°S

latitudes. These bands corresponds to where dry subtropical latitudes. These bands corresponds to where dry subtropical air descends. air descends.

– Environmental conditions varies from one desert to another Environmental conditions varies from one desert to another (rain, temp, evaporation, plants transpiration).(rain, temp, evaporation, plants transpiration).

– Soil is low in organic and classified as lithosols, which means Soil is low in organic and classified as lithosols, which means stone or minerals soil. Soil may cumulate salts, and forming stone or minerals soil. Soil may cumulate salts, and forming calcium carbonate –rich hardpan horizon (Caliche)calcium carbonate –rich hardpan horizon (Caliche)

– Desert animals can effect soil properties (burrows, leaves Desert animals can effect soil properties (burrows, leaves under shrubs).under shrubs).

– Plant cover is rare, and plants are adaptive to drought through Plant cover is rare, and plants are adaptive to drought through leaves or dormancy. leaves or dormancy.

– Desert cultures flourished, because of human activities deserts Desert cultures flourished, because of human activities deserts have expanded in expense of other biomes. have expanded in expense of other biomes.

2020Fig. 2.19Fig. 2.19

2121

Temperate woodland and shrublandTemperate woodland and shrubland– Location above the tropic of Cancer and Capricorn between Location above the tropic of Cancer and Capricorn between

about 30° and 40° latitude, most extensive in the about 30° and 40° latitude, most extensive in the Mediterranean sea and North America. Mediterranean sea and North America.

– Climate is cool and moist during fall, winter and spring. Climate is cool and moist during fall, winter and spring. Summer in most regions is hot and dry, causing frequent fire.Summer in most regions is hot and dry, causing frequent fire.

– Soil is low to moderate fertility and fragile.Soil is low to moderate fertility and fragile.– Organisms show adaptations to drought and adapted Organisms show adaptations to drought and adapted

mutualistic relationship with microbes to fix atmospheric mutualistic relationship with microbes to fix atmospheric nitrogen. Decomposition is slow during dry summer.nitrogen. Decomposition is slow during dry summer.

– Fire-resistance plants and resprout rapidly.Fire-resistance plants and resprout rapidly.– Animals (vertebrate and invertebrate) are highly diverse.Animals (vertebrate and invertebrate) are highly diverse.– Human impacted it by clearing trees and shrubs and used it for Human impacted it by clearing trees and shrubs and used it for

agriculture.agriculture.– Most of temperate and woodlands and shrubs are destroyed Most of temperate and woodlands and shrubs are destroyed

and converted to various human land activities. and converted to various human land activities.

2222Fig. 2.22Fig. 2.22

2323

Temperate GrasslandTemperate Grassland– Largest biomes in North America and Eurasia.Largest biomes in North America and Eurasia.– Receive between 300 and 1,000 mm of rain. However, may Receive between 300 and 1,000 mm of rain. However, may

experience occasional drought that extend to several years.experience occasional drought that extend to several years.– Grass height varies from 5 cm to 200 cm with great species Grass height varies from 5 cm to 200 cm with great species

varieties. Supported once huge herds of herbivores. varieties. Supported once huge herds of herbivores. – Maximum precipitations during summer, with growing height in Maximum precipitations during summer, with growing height in

summer. Cold winter and hot summer.summer. Cold winter and hot summer.– Soil is drive from wide varieties of parent materials. Contain Soil is drive from wide varieties of parent materials. Contain

large quantities of organic matter and fertile.large quantities of organic matter and fertile.– Dominated by herbaceous vegetation. Trees and shrubs are Dominated by herbaceous vegetation. Trees and shrubs are

often limited to margins of streams and rivers.often limited to margins of streams and rivers.– Animals of intermediate size generally had one of two lifestyles Animals of intermediate size generally had one of two lifestyles

(borrowing and fleet).(borrowing and fleet).– First human populated it were nomadic hunters. Next came First human populated it were nomadic hunters. Next came

nomadic herders. Then came farmers.nomadic herders. Then came farmers.– Produce the most fertile farms and fed much of the world.Produce the most fertile farms and fed much of the world.– Lost its fertility through human usage 35-40%.Lost its fertility through human usage 35-40%.

2424Fig. 2.25Fig. 2.25

2525

Temperate ForestTemperate Forest– Found between 30° and 55° latitude, with majority lies between Found between 30° and 55° latitude, with majority lies between

40° and 50°.40° and 50°.– Forests may be coniferous or deciduous, with temperatures are Forests may be coniferous or deciduous, with temperatures are

not extremes with precipitation averages of 650-3,000 mm.not extremes with precipitation averages of 650-3,000 mm.– Few deciduous trees are restricted to streamside.Few deciduous trees are restricted to streamside.– Soil are usually fertile, with the most fertile develop under Soil are usually fertile, with the most fertile develop under

deciduous forests. Soil is neutral to slightly acidic and rich of deciduous forests. Soil is neutral to slightly acidic and rich of organic and inorganic nutrients. organic and inorganic nutrients.

– Have lower diversity than tropical forest, it is vertically stratified.Have lower diversity than tropical forest, it is vertically stratified.– Animals uses all levels, with small to medium animals presents.Animals uses all levels, with small to medium animals presents.– Organic materials are stored on the floor, with microscopic and Organic materials are stored on the floor, with microscopic and

invertebrates used to recycle those nutrients. invertebrates used to recycle those nutrients. – Large cities where build on temperate forests, first forests were Large cities where build on temperate forests, first forests were

removed and agriculture were practiced. removed and agriculture were practiced. – Most deciduous trees were cut to support lumber and wood Most deciduous trees were cut to support lumber and wood

industries. industries.

2626Fig. 2.28Fig. 2.28

2727

Boreal Forest or TaigaBoreal Forest or Taiga– Covers over 11% of the earth’s land area, and confined to Covers over 11% of the earth’s land area, and confined to

Northern Hemisphere. Northern Hemisphere. – Extend between 50° and 65° N latitude.Extend between 50° and 65° N latitude.– Winter is long (>6 months), with moderate precipitation Winter is long (>6 months), with moderate precipitation

ranging from 200 to 600 mm.ranging from 200 to 600 mm.– Low rate of evaporation and brief drought if any.Low rate of evaporation and brief drought if any.– Soil of low fertility, thin and acidic, with low decomposition Soil of low fertility, thin and acidic, with low decomposition

rate. Nutrients are tide up in a thick layer of plant litter. In rate. Nutrients are tide up in a thick layer of plant litter. In extreme boreal forest the subsoil is permanently frozen. extreme boreal forest the subsoil is permanently frozen.

– Plant roots are shallow with mycorrhizal fungi.Plant roots are shallow with mycorrhizal fungi.– Dominantly green, and home of many animals including Dominantly green, and home of many animals including

migratory birds and big animals like bears.migratory birds and big animals like bears.– Early caveman live in boreal forest.Early caveman live in boreal forest.– Human invasion is relatively light, however forest becomes Human invasion is relatively light, however forest becomes

intense lately as lumber being cut.intense lately as lumber being cut.

2828Fig. 2.31Fig. 2.31

2929

TundraTundra– Covering the land north of the Arctic circle. Covering the land north of the Arctic circle. – Climate is typically cold and dry, less temperature than boreal Climate is typically cold and dry, less temperature than boreal

forests. Winter is less severe and summer are shorter.forests. Winter is less severe and summer are shorter.– Precipitation varies from less than 200 to a little over 600 mm, Precipitation varies from less than 200 to a little over 600 mm,

as exceed evaporation.as exceed evaporation.– Soil loaded with accumulated organic matter.Soil loaded with accumulated organic matter.– Freezing and thawing of surface soil and action of water and Freezing and thawing of surface soil and action of water and

gravity produce “Solifluction” where soil moves slowly down gravity produce “Solifluction” where soil moves slowly down slopes and bringing stones to the surface forming a net of slopes and bringing stones to the surface forming a net of polygonal pattern (see fig. 2.35).polygonal pattern (see fig. 2.35).

– Dominated by perennial herbaceous plants (grass, sedges, Dominated by perennial herbaceous plants (grass, sedges, mosses and lichens).mosses and lichens).

– Support substantial numbers of large native mammals.Support substantial numbers of large native mammals.– Human is limited, however recently increasedHuman is limited, however recently increased

3030Fig. 2.34Fig. 2.34

3131

MountainsMountains– May consist of several biomes due to altitude variations.May consist of several biomes due to altitude variations.– Mountains built by geological process such as volcanoes or Mountains built by geological process such as volcanoes or

earth’s crust movement . North to South in America, and East earth’s crust movement . North to South in America, and East to West in Asia and Europe, and isolated in Africa and to West in Asia and Europe, and isolated in Africa and Australia.Australia.

– Climate is different according to latitude Climate is different according to latitude – Soil changes with elevation, soil is well drained, effected by Soil changes with elevation, soil is well drained, effected by

wind and erosion. wind and erosion. – Vegetation is influenced by altitude.Vegetation is influenced by altitude.– Human influenced mountains by exploitations and grazing. Human influenced mountains by exploitations and grazing.

3232Fig. 2.35Fig. 2.35

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Fig. 2.37Fig. 2.37

3434

Fig. 2.38Fig. 2.38