Chapter 7: The Biosphere and Ecosystems

Section 1: The components of the Biosphere

Section 2: The structure of the Biosphere

Section 3: The Formation and evolution of the Biosphere

Section 4: Ecosystems Section 5: Human Beings and Ecosystems

The Components of the Biosphere

Material Components ： Organism belongs to organic materials, while rock, atmosphere and water, as the part of the environment, are inorganic minerals.

Element Components ： The main components are hydrogen , oxygen and carbon, which separately accounts for 49.8 percent, 24.9 percent and 24.9 percent of the total number of the organism. While the sum of them accounts for 99.6 percent of the total. Besides the above, there are some microelements, such as Nitrogen, Calcium, Kalium, Silicon, Magnesium, Phosphorus, Sulfur, Aluminium and so on.

System Components ： There are terrestrial ecosystems and marine ecosystems

Biology Components: There are prokaryotic microorganism ， protozoa, metaphyte, metazoa 。

Material Components

The biosphere

Organic bodis

Inorganic Environments

Producer

Consumer

Decomposer

AtmosphereWaterRock and soilSunlightOther inorganic compounds

Element Components of the Organism

As indicated by research, the element components of the organism are mainly hydrogen , oxygen and carbon, which separately accounts for 49.8 percent, 24.9 percent and 24.9 percent of the total number of the organism. While the sum of them accounts for 99.6 percent of the total. Besides the above, there are some microelements, such as Nitrogen, Calcium, Kalium, Silicon, Magnesium, Phosphorus, Sulfur, Aluminium and so on.

System Components of the Biosphere

Th

e b

iosp

here

Terrestrialecosystem

Marineecosystem

Forest ecosystem

Prairie ecosystemDesert ecosystemLake ecosystem

Marsh ecosystemRiver ecosystem

Tundra ecosystem Urban ecosystem

Agricultural ecosystem︰……

Tropic rainforest ecosystemSubtropic evergreen forest

ecosystemTemperate deciduous ecosystem Northern needlepoint ecosystem

Wheat ecosystemPaddy ecosystemCorn ecosystem

Northern pine forestEcosystem

Northern spruce forestEcosystem

Northern fir forestecosystem

Deep-sea ecosystemShallow-sea ecosystemEstuarine ecosystem

The Biology Components of the Biosphere

As indicated by the early research, biology includes animal, plant and microorganism. But proved by the later research, there are also some animals existing which structures and functions are between those of animals and plants. Therefore, it is suggested by scientists that biology be divided into four categories: Prokaryotic microorganism, protozoa, Metaphyte and metazoa .

Biology

Prokaryotic

microorganism

Protozoa

Metaphyte

Metazoa

The Structure of the Biosphere

The structure of the biosphere

The structure of vertical quasi-

normal distribution

Horizontal continuous and asymmetrical structure

Multilevel nested structure

The Structure of the Biosphere

Structure of vertical quasi-normal distribution Biology distributes concentrating in some areas along the vertic

al direction but gradually decreases upwards or downwards. Horizontal, continuous and asymmetrical structure Biology distributes continuously everywhere on the earth surfac

e. The structure of biosphere is uneven and biology distributes asymmetrically on the earth surface.

Multilevel nested structure Multilevel systems intersect and overlap mutually in space. At t

he same time, they interrelate and interact.

Structure of Vertical Quasi-normal Distribution of the Biosphere

In the sea, the amount and category of biology decrease gradually with the increase of depth. But on the land, the amount and category of biology decrease with the increase of the elevation. In a word, we can use a simple chart to illustrate the vertical structure of biological distribution. On the whole, it has the characteristic of quasi-normal distribution. From this point of view, the vertical structure of the biosphere is also entitled as the structure of vertical quasi-normal distribution.

As far as the structure of the biosphere is concerned, there is the characteristic of vertical quasi-normal distribution. Structure of vertical quasi-normal distribution means that biology distributes concentrating in some certain area along the vertical direction and tends to decrease gradually upwards or downwards. Specifically, biology distributes near the rising sea level but its amount and category decrease orderly upwards or downwards from the sea level with the increase of depth or elevation.

（ JiangWang ， 2000 ）

Biomass

or biological category

Dep

th o

f seaw

ate

rEle

vatio

n

Increasing

The Structural Characters of the Biosphere

亲 岩 性 亲 水 性 亲 气 性 Ç ×¹ âÐ Ô Î Â¿ ØÐ Ô

½ á¹ ¹Ì ØÐ ÔStructural characters

Temperaturecontrolled

Lightneeded

Gas needed

Waterneeded

Rockneeded

Different Distribution of District and Flora of Biology

Different distribution of district and flora of biology

Latitude Zone

Aridity/humidity zone

Vertical zone

Local

Floral

Different Distribution of District and Flora of Biology

◆ Latitude zone Global biology distributes along the altitude and changes regularly. ◆ Aridity/humidity zone Because of different amount of moisture resulting from different distance from the sea, the distribution of animals and plants alters orderly from the coast to the inland. ◆ Vertical zone Biological distribution alters regularly with increasing altitude. ◆ Local The rule of different distribution happens in local district. ◆ Floral During far-flung history of succession, different animals and plants formed a biological flora because they distribute in the same area.

The Relation of Horizontal Distribution of Terrestrial Vegetation to the Latitude and Arid Index

Altitude zone means that global biology distributes along the altitude and changes regularly. The rule of different distribution of district results from the grads change of solar radiation along the altitude and accordingly results in the zonal distribution of climate and biology. Precipitation permits, from the equator to poles, there are tropical rainforests, subtropical evergreen forest, temperate deciduous forest, boreal needlepoint forest, cold tundra and arctic desert.

Desert

Tundra

Taiga

Forest

Woodland

Chaparral

Rain forestMonsoon

forest

SavannaDesert

Arctic

Subarctic

Temperate

Tropical

Decreasing precipitation

Incr

easi

ng lati

tude

Desert

The Relationships Between Vertical Zone and Latitude zone of Vegetation

With the change of altitude, the distribution of biology alters regularly. This phenomenon is called vertical zone. Topography is the premise of vertical zone. The direct cause for vertical zone is that climate varies with increasing altitude. With the topography drives up, climate and biology vary accordingly in vertical direction. Vertical zone is not only restricted by zonal factors but by non-zonal factors. From this point of view, it is joint result of the both. There is some kind of comparability in structure and property between vertical zone and latitude zone. But as far as causes of formation are concerned, there is great difference between the both.

Latitude

Ele

vatio

n

Tropicforest Taiga Cold

tundra

Taiga

Temperateforest

Taiga

TundraHighlandtundra

Snowline

Treeline

Snowbelt

Tree

line

Snowline

Polarice

The International Flora and Its ZoneDuring the far-flung history of succession, different animals and plants formed a biological flora because they distribute in the same area. The flora is the reflection of the kindred relationships, geographic isolation and growing process between animals and plants. In the same flora, the more the numbers of the special species are and the senior its grade is, the older animals and plants are and the longer the history of geographic isolation is.

（塔赫他间， 1978 ）1978

1 Northern area2 Ancient tropic area

3 New tropic area4 Cape area

5 Australian area6 Antarctic area

The Formation and Succession of the Biosphere

The origin of life

The phase from inorganic mineral to simple organic

material;

The phase from simple organic material to complex one;

The phase from macromolecule organic material to

metabolic

protein. The succession of the biosphere

Biological categories increase gradually;

The structure of the biosphere becomes more and more

complex;

The spatial distribution of biology expands gradually and

extends from ocean to land.

Ecosystems

◆ Components of ecosystems ：

A typical ecosystem has two basic components. The first is abiotic material such as water, carbon dioxide, oxygen, nitrogen, acid, alkali and elements or compounds that exits outside the body of the organism anytime. The other is organism composed of producer, consumer and decomposer.

◆ Structure of ecosystems Trophic levels ： This is the physical part of ecosystems. Trophic levels are

the levels and positions at which species feed and all steps removed from plants in a food chain are included.

Food chains ： In ecosystems, plants are eaten by animals and herbivores are eaten by carnivores, therefore, the sequence of levels in the trophic levels is referred as a food chain.

Food webs ： A food chain often has different branches. The food chains overlap and intersect to form feeding mosaic are called a food web.

The Components of Ecosystems （ Mackenzie,1998 ）

A typical ecosystem has two basic components, one is abiotic substance, the other is organism.

Producer

Consumer

DecomposerLoss

of heat

The composition of inorganic matters

Trophic Level, Food Chain and Food Wet

The trophic structure is the most primary structure of ecosystems. The structure relates all kinds of organisms with food.

Fox

3

2-3

Food chain Food net

1st-level

2nd-level

3rd-level

Trophiclevel

Grass

Rabbit

Rabbit

Hawk

Fox

Skunk

Deer

Mouse

Leaf

Grass Seed

The Functions of Ecosystems

Productivity Energy flow of ecosystems The energy through ecosystems flows toward one direction. According

to Lindeman’s law of trophic efficiency, biomass decreases with each successive trophic level and the efficiency of energy transferring from one trophic level to the next is about 10%.

Material cycle of ecosystems There are many kinds of organic materials. These materials can be deco

mposed and released into the environment so as to be utilized repeatedly. By this way, materials of ecosystems can move in cycles.

Information transfer of ecosystems The stability of ecosystems–ecological balance The energy flow and material cycle of the ecosystems stable or balance

able can maintain its own state for a long time.

Biological Amplification

As far as pollution ecology is concerned, the research of food chains is very significant because chemical pollutants are passed along a simple food chain to the top carnivores, where the accumulation becomes concentrated. This phenomenon is biological amplification. Chemicals become increasingly concentrated at each higher trophic level, as a result, they do serious harms to the development or health of biology at higher trophic level. Take the DDT as an example, if the concentration in the air is 0.000003 ppm and when it is absorbed by planktons in the sea, the concentration in the body of plankton then reaches 0.04 ppm which is 130 thousand times of that in the air. If plankton is devoured by small fish, the concentration adds up to 0.5 ppm and if small fish is devoured by the big one, the concentration reaches 2 ppm and then if fishes are eaten by the waterfowl, the concentration reaches 25 ppm. Finally if waterfowl is eaten by human beings, the concentration adds up to 30 ppm which is a hundred million times of that in the air. The higher the trophic level is, the more the concentration in the body of the organism is.

Accumulated130 thousand times

Plankton Small fish

Big fish Waterfowl Human body

The Relationships Between Energy Flow and Material cycle of the Ecosystem

In order to maintain the natural operation of the ecosystem, energy has to be imported continuously. Energy comes to ecosystems in the form of sunlight which is used by plants. This energy is stored in the system in the form of organic materials in animals and plants. It flows through the system along food chains and webs from one trophic level to the next. It is finally released into the environment from the system by means of decomposition. At the same time, addition energy is lost through respiration at all trophic levels. Therefore, energy is no longer utilized by producer to repeat this kind of recycle. This phenomenon that the energy flows through ecosystems toward one direction is referred as energy flow.

Energy flow

Material cycle

Decomposer

Primary productivity

Respiration

Respiration

Respiration

CarnivoreHerbivore

The sun Import or

nutrimentExport ofnutriment

Storage oforganic

materials

Storage of soil

Ecological Pyramid

In every ecosystem, biomass decreases with each successive trophic level and the efficiency of energy transferring from one trophic level to the next is about 10%.This is Lindeman’s law of trophic efficiency. According to this theory, every ecosystem has a pyramid of numbers and energy, reflecting the relationship between energy flow and loss of the organisms in the food chain. The smallest organisms are the most numerous and consume the greatest energy, while large life forms, such as secondary consumers, are lowest in population and represent the least energy. This phenomenon is called ecological pyramid.

Vegetation

Herbivore

Carnivore

The firstlevel

The secondlevel

The thirdlevel

The Energy of Ecosystems （ small biological cycles ）（ jiangwang ， 2000 ）

The material of ecosystem circulates by the following means:(1)environment-producer-environment;(2) environment-consumer-environment;(3) environment-decomposer-environment;(4) environment-producer-consumer-environment;(5) environment-producer-decomposer- environment;(6) environment-consumer-decomposer-environment;(7) environment-producer-consumer-decomposer-environment.

environment

producer

consumer

decomposer

Feedback can be classified into two types,that is to say, the positive and the negative. The both behave reversely. The negative feedback is essential to the self-regulation of ecosystems. The feedback mechanism is very complex, which shows not only between biology components and environment but between structure and function. In an ecosystem, when the number of preys increases, the number of captors increases a lot accordingly because there is much food for them. When the number of captors increased, the number of preys decreases and because there are not enough food for captors, the number of them decreases spontaneously.

The Negative Feedback and Its Regulation of Ecosystems

Vegetation increases

Vegetationdecreases

The food forrabbit increases

Number of foxincreases

Little food for rabbit

Much foodfor rabbit

Food forfox increases

Number of rabbits

decreases

Number of rabbits increases

Number of foxdecreases

Few rabbits for

fox

A lot ofrabbits for

fox

Rabbits die ofhunger

Fox die ofhunger

Human Beings and the Biosphere

The human being is the part of the

biosphere;

The food human beings needed is

gained from the biosphere;

Plants supply oxygen to human beings

for their survivals;

The biosphere and biology resources.

The Relationships Between Human Beings and the Other Animals

Besides human beings, there are many other mammals such as horses, cattle, tigers, rabbits, sheep, monkeys, dogs and pigs. They are viviparous and homoiothermous. They feed their children by themselves and most of them have furs. Among all the mammals, only human beings, monkeys, orangutans and apes belongs to primates. In fact, human beings are evolved from apes. From this point of view, the human being is a special kind of animal and there is close relationship between human beings and animals. But there is essential difference between them because human beings can make tools and their cerebra develop so well that they have thoughts. But whatever to say, human beings are evolved from animals and are parts of the biosphere. Animals

Pisces, Aves…Mammalias

Primatescarnivore …

Mollusca, Arthropoda … Craniota

Sub-craniota… …

Gibbon… Humanbeings

The role of Human Beings in the Food Chain

The lives of human beings depend on the biosphere. The physical body of human itself can not make organic material directly. The maintenance of physical body is indispensable of the organic material supplied or made by biology. As far as the food chain is concerned, human beings are senior consumers. In order to maintain the lives of human beings, there must be enough plants and animals to supply enough food. 

Land area

moisture

Agricultural land

The human being

fertilizer

Solar energy

CO2