29-06-2013, 02:12 PM
ECOSYSTM AND BIODIVERSITY
ECOSYSTM.pptx (Size: 2.84 MB / Downloads: 33)
INTRODUCTION
The interaction and exchanging of materials between the biotic community and abiotic environment ecosystem
Tansley 1935 eco- environment, system-co ordinate units
Natural unit of living organism co-existing with their environment through material cycling and energy transfer to form a stable self-supporting system
FUNCTIONS
Energy flow-unidirectional-producer to consumer-irreversible
Preparation organic compounds-light energy-primary production
Energy–consumers-secondary production
Food web and food chain-ecological stability
Ecological pyramid-trophic levels-based on their linkages
Cycling of nutrients-biotic and abiotic phases- biogeochemical cycle
ENERGY FLOW
Transfer of energy-one trophic level to another-flow unidirectional-energy irreversible
Energy flow-two basic principles of thermodynamics
Thermodynamics- energy and its conservation
First law- energy can either be created nor destroyed. One form of energy can be converted into another form
Second law- when one form of energy converted into another there is degradation of energy
TROPICAL SEASONAL FOREST
Plains of Africa, south-east Asia, Australia and some parts of India
Rainfall is seasonal but high-1000mm to 1500mm
Warm climate
Dry and wet seasons alternately
Coarse grass and scattered trees
MARINE & ESTUARY
High concentration of salt-3.5%
Abundance of minerals such as Na, Ca, Cl, S, Mg etc.
Salinity is more in deeper regions of the oceans
Less near the north and south poles & also on river mouths
Fresh water and marine water boundaries overlap in certain regions-estuary
Physical condition is not uniform, Nutrients are rich, Abundance of fish, good breeding sites for fishes