Chapter 15: Biodiversity, Conservation and
Environmental Issues
Introduction to Biodiversity
• Biodiversity refers to the variety of life,
including a vast array of species of
microorganisms (viruses, algae, fungi), plants,
and animals, found on Earth in terrestrial or
aquatic habitats, and the ecological complexes
they form part of.
• The biodiversity observed today is the result
of over 3.5 billion years of evolutionary
history, predominantly influenced by natural
processes and, more recently, by human
activities.
• Understanding biodiversity involves studying
its levels, patterns, expanse, importance, causes
of loss, and methods of conservation.
15.1 Levels of Biodiversity Diversity can be
observed at three major hierarchical and
interrelated levels:
• Genetic Diversity:
, ◦ Involves variations in genes and
chromosomes within a species.
◦ These variations enable species to adapt to
local environmental conditions [15.47].
◦ Examples: India has about 1000 varieties of
mangoes and 50,000 varieties of rice or
wheat [15.47]. The medicinal plant Rauwolfia
serpentina shows genetic variation in the
potency and concentration of its active
chemical, reserpine, across different Himalayan
ranges [15.47, 379].
◦ Genetic diversity is essential for a
healthy breeding population of a species.
• Species Diversity:
◦ Refers to the number and variety of plant
and animal species present in a
region (interspecific diversity).
◦ Some areas are richer in species than
others (species richness), and it also considers
, the number of individuals of different species
(species evenness) [15.48, 379].
◦ Example: Amphibian species diversity is
greater in the Western Ghats than in the Eastern
Ghats of India [15.48, 379].
◦ India is recognized as one of the 15 nations
globally rich in species diversity.
◦ Productivity-Stability Hypothesis (David
Tillman): Field experiments showed that species
richness helps the stability of an ecological
community, leading to less variation in biomass
production over time.
• Ecological (Ecosystem) Diversity:
◦ Relates to the different types of
ecosystems or habitats within a given
geographical area [15.46, 378].
◦ This diversity is based on differences in
habitat.
◦ Example: India exhibits high ecosystem
diversity, including deserts, rainforests,
deciduous forests, estuaries, wetlands, and
Environmental Issues
Introduction to Biodiversity
• Biodiversity refers to the variety of life,
including a vast array of species of
microorganisms (viruses, algae, fungi), plants,
and animals, found on Earth in terrestrial or
aquatic habitats, and the ecological complexes
they form part of.
• The biodiversity observed today is the result
of over 3.5 billion years of evolutionary
history, predominantly influenced by natural
processes and, more recently, by human
activities.
• Understanding biodiversity involves studying
its levels, patterns, expanse, importance, causes
of loss, and methods of conservation.
15.1 Levels of Biodiversity Diversity can be
observed at three major hierarchical and
interrelated levels:
• Genetic Diversity:
, ◦ Involves variations in genes and
chromosomes within a species.
◦ These variations enable species to adapt to
local environmental conditions [15.47].
◦ Examples: India has about 1000 varieties of
mangoes and 50,000 varieties of rice or
wheat [15.47]. The medicinal plant Rauwolfia
serpentina shows genetic variation in the
potency and concentration of its active
chemical, reserpine, across different Himalayan
ranges [15.47, 379].
◦ Genetic diversity is essential for a
healthy breeding population of a species.
• Species Diversity:
◦ Refers to the number and variety of plant
and animal species present in a
region (interspecific diversity).
◦ Some areas are richer in species than
others (species richness), and it also considers
, the number of individuals of different species
(species evenness) [15.48, 379].
◦ Example: Amphibian species diversity is
greater in the Western Ghats than in the Eastern
Ghats of India [15.48, 379].
◦ India is recognized as one of the 15 nations
globally rich in species diversity.
◦ Productivity-Stability Hypothesis (David
Tillman): Field experiments showed that species
richness helps the stability of an ecological
community, leading to less variation in biomass
production over time.
• Ecological (Ecosystem) Diversity:
◦ Relates to the different types of
ecosystems or habitats within a given
geographical area [15.46, 378].
◦ This diversity is based on differences in
habitat.
◦ Example: India exhibits high ecosystem
diversity, including deserts, rainforests,
deciduous forests, estuaries, wetlands, and
