Flow of matters

Plants -----> cows -----> lion

Plants -----> cows -----> lion

Energy loss Energy loss Energy loss

1. Number / biomass of organisms at lower trophic level > higher

trophic levels , because energy is lost ( by respiration and

excretion ) at each trophic level.

Plants

CowsLions

The number and biomass of organisms at the lower trophic level is more than that at higher trophic levels

Energy loss occurs at each trophic level due to respiration, so less and less amount of energy is available to organisms at higher trophic levels

處於食物鍊基層的生物的數目或生物質量一般較處於食物鍊高層生物的為多

因為在每一食物層次中 , 能量會因生物進行呼吸作用而散失 , 只有小部分可以傳給並養活處於食物鍊高層的生物

?

?

Grass ----> grasshopper ----> frogs ----> snakes

Pyramid of number

Trees ----> caterpillar ----> small birds ----> hawk

Pyramid of number ( ! )

Trees ----> small birds ----> parasites of birds

Pyramid of number ( ! )

Trees ----> small birds ----> parasites of birds

Pyramid of biomass

Water

Atmosphere

Living organisms

Fossil fuel

(underground)

Carbon Cycle ( CO2 , C in organic compounds )

Water

Atmosphere

Fossil fuel

(underground)

Carbon Cycle ( CO2 , C in organic compounds )

producers consumers

Water

Atmosphere

Fossil fuel

(underground)

Carbon Cycle ( CO2 , C in organic compounds )

producers consumers

Photosynthesis

Decomposition -decomposers

respiration

Decomposition prevented

combustion

Carbon cycle

Atmosphere

Organisms

Soil

Nitrogen Cycle ( N2, NO3+, N in Proteins )

Atmosphere

Producers

Soil

Nitrogen Cycle ( N2, NO3+, N in Proteins )

Consumers

Atmosphere

Producers

Soil

Nitrogen Cycle ( N2, NO3+, N in Proteins )

Consumers

Death / excretory products

NH4+

Nitrification nitrifying bacteria

NO3-

absorbed

Nitrogen fixation

Nitrogen fixing bacteria in legumes

Denitrification Denitrifying bacteria

Lightning / fertilizers

Decomposition decomposers

Root

Root nodule

Nitrogen cycle

Denitrification

Denitrifying bacteriaNitrogen fixation

Nitrogen fixing bacteria in legumes

Nitrification

Nitrifying bacteria

Predation ( prey and predator )

Competition - competitors

個體數目

時間 ( 年 )

Commensalism

Mutualism

Mutualism

Crustose lichen in

cross section

Fungal part

Algal part

?

Lichen grows on rock

(i) (1) CO2 from respiration of plants and decomposers, O2 from

photosynthesis of green plants

(2) by recycling, transpiration of plant --> condensation

-->soil ----> absorbed by plants

(3) decomposition of dead bodies of plants by decomposers

(ii) animals / consumers

(iii) for - adding nutrients to soil after decomposition of organic

matters

- holding water in soil

(ii) A, it involves more trophic levels , more energy will be lost in A as energy is lost at each trophic level

(ii) bee, help in pollination

(iii) (1) lizard and snake

(2) body is covered with dry horny scales

algae small fish large fish

Toxin : 0.05 ppm 5 ppm 200 ppm

Large fish -> higher concentration of toxin, why ?

1. Eat much toxin-containing food

2. Accumulate toxin for a long period of time

If toxins / compounds are resistant ( cannot be excreted or metabolized by organism tend to accumulate along the food chain

Therefore, top consumer suffer most

Water pollution - Organic wastes

Organic wastes Inorganic compounds decomposition

decomposers

. oxygen

. Turbidity

. Foul smell

Algal bloom

e.g. red tide

fertilizers

(i)

(iv)

(ii)

(iii)

(v)

Cutting down trees

= Deforestation

Landslide

Flooding

Monoculture

legumes

Crop 1 - deep-rooted plant

Crop 2 - shallow-rooted plant

Crop rotation

(i)

(iv)