easy learnings

  Deforestation: house severe is the problem? Deforestation rate is relatively less in temperate countries, but it is very alarming in tropical countries. The total forest area of the world in 1900 was established to be 7,000 million hectares which was reduced to 2890 million hectare in 1975 and fell down to just 2300 million hectares by 2000.we have already cut half of these forests and at the present read it is estimated that in the next 50 years we would lose more than 90% of are tropical forests. the forested area in India seems to have established since 1982 with about 0.04% declining annually between 1982 to 90. FAO (1983) estimated that about 1.44 million hectare of land was brought under afforestation during this period leading to stabilization. As per FAO estimates, the deforestation rate per unit population in India is the lowest among the major tropical countries, despite the fact that we have a huge population size and very low per capita forest area (0.075 hectare per ...

  What are ecosystems? Various kinds of life supporting systems like the forests, grasslands, oceans, lakes, rivers, mountains, deserts and estuaries show wide variations in their structural composition and functions. However, they all are like in the fact that they consist of living entities is interacting with their surroundings in exchanging matter and energy. How do these different units like a hot desert, a dense evergreen forest, the Antarctic sea or a shallow pond differ in the type of the flora and fauna, how do they derive the energy and nutrients to life together, how do they increments each other and regulate their stability are the questions that answered by ecology. The term ecology was coined by Ernest Haeckel in 1869. It is derived from the Greek words Oikos -home + logos -study. so ecology deals with the study of organisms in their natural home interacting with their surroundings. the surroundings of environment consists of other living organisms called biotic comp...

Big dams in forest areas: what are the major problems? Dams and their effects on forests and people. Big dams and river valley projects have multipurpose uses and have been referred to as " temples of modern India" . However, these dams are also responsible for the destruction of vast area of forests. India has more than 1550 large dams, the maximum being in the state of Maharashtra (more than 600) followed by Gujarat (more than 250) and Madhya Pradesh (130). The highest one is tehri dam , on river bhagirathi in Uttarakhand and the largest in terms of capacity in bhakra dam on river satluj in Himachal Pradesh. Big dams have been in sharp focus of various environmental groups all over the world which is is mainly because of several ecological problems including deforestation and socio economic problems related to tribal or native people associated with them. The silent valley hydro electric project was one of the first such projects situated in the tropical rainforest area of...

What is biodiversity? Biodiversity refers to the variety and variability among all groups of living organisms and the ecosystem complexes in which they occur. In the Convention of Biological Diversity (1992), biodiversity has been defined as the variability among living organisms from all sources including inter alia , terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are a part.  Levels of biodiversity In many range from the genetic level within a species to diversity found in different biomes based on which three categories of biodiversity recognised: 1. Genetic diversity When the genes within the same species show different versions due to new combinations, it is called genetic variability or diversity. It is the basic source of biodiversity. The genes found in organisms can form enormous number of combinations each of which gives rise to some variability. Genes are the basic unit of hereditary information transmitted from one generation...

 Ecological pyramids Graphic representation of tropics structure and function of ecosystem, starting with producers at the base and successive tropic levels forming The apex is known as logical pyramid.  Ecological pyramids are of three types: 1. Pyramid of numbers : it represent the number of individual organisms at each trophic level. We may have upright or inverted pyramid of numbers, depending upon the type of ecosystem and food chain. A grassland ecosystem and a pond ecosystem show at applied pyramid of numbers. The producers in the grasslands are grass and that in a pond are phytoplankton (algae etc.), Which are small in size and very large in number. So, the producers form a broad base. The herbivores in grasslands are insects while tertiary carnivores are hawks or other birds which are gradually less and less in number and hence the pyramid apex becomes gradually narrower forming and upright pyramid. Similar is the case with the herbivorous, carnivorous and to...