Ecosystem-productivity

Functional unit of nature, where living organism interact among themselves and also with the surrounding physical environment

Components of ecosystem:

1.Biotic components

2. Abiotic components

Stratification
•Vertical distribution of different species occupying different levels is called stratification. Like in a forest many layers of plants are presntsuch as herbs shrubs treesand creepers.

Aspects of ecosystem:
ØPRODUCTIVITY
ØDECOMPOSITION
ØENERGY FLOW
ØNUTRIENT CYCLING

ØPRODUCTIVITY
vPrimary productivity- the amount of biomass or organic matter produced per unit area a time period by plants during photosynthesis.
vIt is expressed in terms of wt (g-2) or energy (Kcal m-2).
vThe rate of biomass production is called productivity g-2 yr-1 or K Cal m-2 yr-1.

Secondary productivity
•It is defined as the rate of formation of new organic matter by consumers.
Factors affecting primary productivity:
•Solar radiation
•Temperature
•Soil moisture
•Availability of nutrients
•Photosynthetic capacity of plants
TROPICAL REGIONS
Pp is very high because of very high soil moisture

TEMPERATE REGIONS
•pp is very low because of cold climate and short snow free growing period
NPP of whole biosphere =170 billion tons (dry weight of organic matter )
•70% area of is covered by water but the NPP of oceans = 55 billion tons

Why NPP is very low in oceans than tropical regions?

Ans.
•Photosynthesis decreases with increasing water depth.
•In deep oceans nutrients often become limiting for productivity.
•Nitrogen is the most limiting factor in marine eco system.