Lesson 4 Biodiversity
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dwarkanathcLesson 4 Biodiversity
Uploaded by
dwarkanathcWHAT IS BIODIVERSITY?
- the sum of total of life forms at all levels of organization in
biological system.
Number of plant species
Number of animal species
Aves = Birds
Biogeographic zones in India
What is semi-arid zone?
Features of :Biogeographic zones in India
Trans-Himalaya: arid, high-altitude plateaus and cold deserts
Himalaya: towering heights, steep-sided peaks, and deep river
valleys, glacial activity
Desert: aridity, extreme temperatures, and sparse vegetation
Semi-arid: ?
Western Ghats: exceptional biodiversity and unique ecosystems,
influencing rainfall patterns
Deccan Plateau: elevated position, rocky terrain, and diverse landscapes,
rich in mineral ores
Coasts: ?
North east: ?
Islands: ?
Levels (types) of biodiversity
L- 1.
Within species (intraspecific) diversity; usually measured in terms
of genetic differences between individuals or populations
Levels (types) of biodiversity
L-2.
Species (interspecific) diversity, measured as a combination of
number and evenness of abundance of species.
Levels (types) of biodiversity
L- 3.
Community or ecosystem diversity, measured as the number
of different species assemblages
Measures of biodiversity (Whittaker -1972 )
Alpha Diversity refers to the diversity within a particular area or
ecosystem, and is usually expressed by the number of species (i.e., species
richness) in that ecosystem.
Beta diversity : a comparison of diversity between ecosystems, usually
measured as the amount of species change between the ecosystems (the
change in species as one moves across habitats, communities, or
ecosystems.. )
Gamma diversity : a measure of the overall diversity within a large region.
Geographic-scale species diversity according to Hunter (2002
Values of biodiversity
Consumptive: for direct consumption; such as fire
wood, fodder, game meat, etc.
Productive: traded through market on as is basis or
value-added basis; examples are commercially
harvested plants, timber, fish, game meat sold
in a market, ivory, and medicinal plants
Non-consumptive: meant for the future potential uses of
biodiversity (tourism, scientific research)
and ecological balance.
Indirect use: ecological services
Provisioning: regular supply
Regulating: maintaining
Supporting: facilitating
Cultural: emotional
Nutrient cycling
the process by which essential
elements and compounds move
through an ecosystem, linking the
biotic and abiotic components
Water Purification in Nature
Threats to Biodiversity
Clearcutting forests to create agricultural lands, creating dams that change river flow
and intensifying shipping in marine environments are all examples of land- and sea-
use change that cause habitat destruction
Pollutants can cause direct harm to organisms, lead to habitat loss, alter ecological
processes, and even drive climate change
A major impact of climate change on biodiversity is the increase in the intensity and
frequency of fires, storms or periods of drought
Examples of invasive species include the brown tree snake in Guam, the zebra mussel,
and the Asian carp. For example, lake trout are native to the Great Lakes, but are
considered to be an invasive species in Yellowstone Lake in Wyoming because they
compete with native cutthroat trout for habitat
Exercise: Write short notes on each of the issues