Biodiversity and Habitat Fragmentation Quiz

Environment and Ecosystem

• The word "Environment" originated from the French word "Environner" (encircle or surround).
• Environment (Protection) Act, 1986 defines Environment as the sum of water, air, and land, as well as the inter-relationships between them and with humans, other living organisms, and materials.
• Environment is the social, cultural, and physical conditions that surround, affect, and influence the survival, growth, and development of people, animals, or plants.
• Environmental science is the study of the environment, its biotic and abiotic components, and their relationships.
• Environmental science integrates physics, biology, and geography to study the environment and solve environmental problems.
• Environmental engineering applies engineering principles to protecting and enhancing environmental quality, and public health and welfare.
• Environmental studies educates people on preserving environmental quality.

Scope and Importance of Environmental Science

• To be aware and sensitive to environmental problems
• To motivate active participation in environmental protection
• To develop skills to identify and solve environmental problems
• To understand the importance of conserving natural resources
• To evaluate environmental programs in terms of social, economic, ecological, and aesthetic factors
• To promote local, national, and international cooperation in preventing and solving environmental issues
• To provide a clear picture of current resource potential and environmental situations
• To understand the interdependent connection between nature and people

Earth Life Support Systems

• The earth system comprises four main components—the geosphere, atmosphere, hydrosphere, and biosphere.
• These components are interconnected and essential for life
• The atmosphere is the layer of air surrounding Earth
• The hydrosphere includes all water bodies on Earth (oceans, rivers, lakes, ponds)
• The lithosphere includes all the soil and rocks on Earth’s surface
• The biosphere contains all living organisms and their interactions with the environment

Atmosphere

• The atmosphere is a blanket of air around Earth.
• Oxygen is essential for living beings
• Carbon dioxide is vital for plants
• Dust particles influence precipitation.
• Water vapor influences plants and living organisms
• Ozone layer protects life from harmful UV rays of the sun

Hydrosphere

• The hydrosphere is the discontinuous layer of water on Earth.
• Water is crucial for human life
• Supports many other organisms
• Regulates temperature
• Essential for atmospheric existence

Lithosphere

• The lithosphere includes all the solid rock layers of Earth.
• It includes the crust and uppermost mantle and it is important for supporting life
• Significance the tectonic plate activity.

Biosphere

• The biosphere is the zone where the lithosphere, hydrosphere, and atmosphere interact.
• Enables life on Earth

Ecosystem

• Ecosystem is a natural unit comprising biotic (living) and abiotic (nonliving) components that interact.
• Biotic components include producers, consumers and decomposers
• Abiotic components include climatic factors (rain, light, wind, temperature), edaphic factors (soil, minerals, pH) and topographic factors (topography).
• Ecosystems have characteristics of structure (living and non-living components), process (energy flow and cycling of matter) and change (dynamic progression of ecosystem).

Ecosystem Characteristics

• Ecosystem structure includes biotic components (producers, consumers, decomposers) and abiotic components (climate, soil, topography).
• Ecosystem processes include energy flow and the cycling of nutrients (matter).
• Ecosystems are dynamic (not static). Succession, the gradual change in ecological communities over time, is an important process impacting ecosystems.

Types of Ecosystems

• Terrestrial ecosystems: occur on land, including forests, grasslands, deserts, and tundra
• Aquatic ecosystems: occur in water bodies, including freshwater ecosystems (rivers, lakes, ponds, wetlands) and marine ecosystems (oceans, estuaries).

Flora and Fauna of Grassland Ecosystems

• Grasslands are dominated by grasses with few shrubs and scattered trees.
• Various animals graze in grasslands
• Large populations of rodents, reptiles, and insects are present in grasslands
• Grasslands are important for dairy and leather industries.

Importance of Grasslands

• Grazing land for livestock
• Fodder for animals
• Source of fuelwood
• Support diversity of insects and other creatures

Desert Ecosystems

• Occur in regions with low rainfall and high evaporation rates
• Plants and animals have adapted to the dry conditions.
• Desert ecosystems include xerophytic plants (plants adapted to arid environments) like cacti.
• Animals include reptiles and birds

Aquatic Ecosystems

• Aquatic ecosystems refer to water-based ecosystems.
• Classified into freshwater (lakes, rivers, ponds) and saltwater (oceans, seas) ecosystems.
• Aquatic life relies on water for survival
• Plants (producers), animals (consumers), fungi, and bacteria (decomposers) are part of aquatic ecosystems.

Ecological Succession

• Ecological succession refers to gradual changes in species composition and processes in a community over time.
• Classified into primary succession (occurs on newly exposed land) and secondary succession (occurs in disturbed areas).

Biodiversity

• Biodiversity relates to species richness, diversity at different levels (genetic, species, ecosystem)
• Genetic diversity refers to variations of genes within a species
• Species diversity is the count of species present in an ecosystem
• Ecosystem diversity is the variety within different habitats, communities, and ecological processes

Biodiversity Hotspots

• Biodiversity hotspots are areas rich in species and experiencing high levels of threat
• Defined by criteria like high endemism (species found nowhere else), and high levels of habitat loss
• Critical for maintaining global biodiversity

Threats to Biodiversity

• Habitat destruction due to deforestation, urbanization, agriculture, etc.
• Poaching/overhunting for profit
• Human-wildlife conflicts due to encroachment and habitat loss
• Pollution (air, water, land)
• Species introduction that cause competition, diseases, or predator-prey scenarios
• Global climate change
• Exploitation of resources

Biodiversity conservation

• In-situ conservation (on-site conservation) protects species in their natural habitat using methods like biosphere reserves, national parks.
• Ex-situ conservation (off-site conservation) involves protecting species outside their natural habitats (zoos, botanical gardens, seed banks, etc.)

Energy Flow in an Ecosystem

• Organisms obtain energy by consuming one another
• The flow of energy is unidirectional and goes through producers, consumers and decomposers.
• Top consumers receive less energy because energy is lost at trophic levels (the amount of energy decreases successively from producers to top consumers).

Environmental Problems

• Issues caused by human activities
• They affect the quality of air, water, land, health of humans and other living things
• Includes Pollution (air, water, land, noise), deforestation, biodiversity loss, food insecurity, climate change.
• Factors such as population growth, poverty, affluence based on wasteful and unsustainable resource use, and exclusion of harmful environmental costs from the market prices of goods and services, are major causes.

Natural Resources and Natural Services

• Materials and energy in nature necessary for human survival
• Natural services are processes that maintain life and support human economies.
• Examples: Clean water/air purification, soil renewal, etc.
• Overuse of natural capital can result in unsustainability.
• An ecological footprint tracks the impact of resource consumption.