1. Freshwater Ecosystems:
Littoral zone (bottom & shallow water with sun light penetrates.
Limnetic or open water Zone (mid zone) Profound or Deep Zone (Light not possible) There are two categories of fresh water ecosystems –
(A) Lentic (standing or stagnant water) e.g. Ponds, lakes.
(B) Lotic (Running water) e.g. Streams, springs, rivers.
Lentic waters are of two types (1) Lakes (2) Ponds
Concept of Habitat and Ecological Niche:
The habitat of an organism is the place where it lives or the place where are would go to find it.
The ecological niche, on the other hand, is more inclusive team that includes not only the physical space occupied by the organism, but also its functional role in the community and its position in environmental gradients of temperature, moisture, pH, soil and other conditions of existence. So niche can be designated as spatial or habitat niche, trophic niche and multidimensional niche, habitat is address of organism and niche is its profession.
Ecology and Human Welfares
Man depends on environment for food, water, air, space. His wastes are also decomposes by decomposers. Deforestation provides land for agriculture and rural rehabilitation.
The mass scale destruction of flora and fauna has become detrimental to ecological balance. The pioneer civilization altered their own biotic and physical environments and displayed man’s ability to trigger ecological changes leading to the downfall.
In Himalaya the landscape is being covered within an inch of its life to support a burgeoning human population.
In Latin America and Africa slash and burn agriculture is encroaching upon natural areas which have existed in ecological balance for thousands of years. Much of the environmental destruction is in the name of economic development.
Modern human civilization has to face many serious ecological problems such as land use, pollution, energy crisis, flooding, erosion, radioisotopes, rural and urban blights, population growth, group conflict and infections disease. The ecology may play a significant role in the modern human welfare but measures should be taken by humans for environmental and resource conservation without disturbing ecological process for sustainable development.