Cyanobacreria

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Impact of Climate Change on Biodiversity

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  Climate change is due to the green house effect, the process by which absorption and emission of infrared radiation by gases in the atmosphere warm the earth’s lower atmosphere and surface. Atmospheric gases such as water vapour, CO 2 , O 3 and CH 4   act like the glass roof of a greenhouse trapping heat which results in the warming of the planet. That is why it is seen to be analogous to that which occurs within green houses. Man’s actions such as the burning of fossil fuels, farming activities and land use changes have all resulted in an increase in these natural gasses. The earth’s surfaces and lower atmosphere are thus warming rapidly. The phenomenon of ‘Global Warming’ was discovered by Joseph Fourier in 1824 and was first investigated quantitatively by Svante Arrhenius in 1896. The physical aspects of global warming, i.e. how and why it occurs and the climate models that are used to predict future changes in the global climate will be dealt with in detail in the nex...
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Sustainable Use of Land

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  Land is one of the most important natural resources on Earth. It refers to the Earth’s terrestrial surface consisting of forests, deserts, human settlement areas and agricultural lands. Land is essential for the provision of food, water and energy for many living systems and is critical to human activity. Land is used spatially (water reservoirs) and temporally (shifting cultivation, dumping grounds) for many purposes. Agriculture and Forestry The two dominant land use activities are agriculture and forestry. Agro-ecosystems cover more than a quarter of the global land area. Agricultural land use depends on the types of crops and agronomics systems which can vary from intensively managed monocultures, to more organic systems involving annual and perennial crops. Over most of the history, including much of the 20 th century, agricultural output has increased primarily bringing more land into production through conversion of forests and natural grasslands. Extractive purposes ...
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Terpenoids

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Terpenoids are a class of organic compounds, which are widespread in nature. The mixtures of substances that contain the fragrant compounds of plants are called “essential oils,’’ and the majority of terpenoids occur in the essential oils of many plants and flowers, and some in gums and resins. A few terpenoids have been isolated from animal sources also. They contain the “essence” or the odour of the plant. Practically, you are familiar with distinctly pleasant odours (aromas) produced by many plants. The fragrances of pine and cedar trees, flowers (e.g. rose, jasmine, etc.) peppermint, turpentine, cinnamon, cloves, and camphor (moth balls) are just a few of the examples one can name. All these aromas, of course, are the result of the volatile compounds produced by the plants. Many of them are valuable, because of their use as flavourings, perfumes, spices, incense, medicines, and insect repellents. Classification of terpenoids Number of isoprene units Number of carbo...
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