ECOSYSTEM (2.2 Nutrient Cycle In An Ecosystem) - note

CHAPTER 2

ECOSYSTEM

2.2 NUTRIENT CYCLE IN
ECOSYSTEM

• Definition:A nutrient cycle is a repeated
pathway of a particular nutrient or element
from the environment through one or more
organisms and back to the environment.

• Example: water cycle, carbon cycle and
oxygen cycle.

WATER CYCLE

• The water cycle is the journey water takes as it
moves from the land to the sky and back again. It
follows a cycle of evaporation, condensation and
precipitation.

ROLE OF ORGANISMS IN WATER
CYCLE

• The sun's energy causes water to evaporate from
oceans and lakes into the atmosphere.

• Plants and animals also release water vapour
into the atmosphere as they carry out respiration.

• When the atmosphere cools, water vapour
condenses; making clouds that might produce rain.

C ARBON CYCLE AND OXYGEN CYCLE

• The process by which oxygen released into
the atmosphere while the carbon dioxide
released as a product of respiration is taken
up for photosynthesis.

C ARBON CYCLE AND OXYGEN CYCLE (PG26)

Role of organism in carbon and oxygen
cycle

• Decomposers, such as microbes and fungi, play
an important role in the carbon cycle.

• They break down the remains of dead plants
and animals, release carbon dioxide through
respiration.

• During photosynthesis, plants give
off oxygen and absorbs carbon dioxide.

ST E PS TO SOLV E P ROB L E MS W H E N T H E R E I S AN
INTERFERENCE TO THE NUTRIENT CYCLE.

Human activities that Steps to solve
disrupt the nutrient interferences to the
cycle nutrient cycle
Unrestricted logging
Create planned agricultural
Burning of fossil fuels systems

Use public transport

Overconsumption of Store rain water for daily use
water resources Replant trees

Tighten laws