Summary Notes on Earth’s Life Support Systems and Biodiversity
Earth’s Life-Support Systems
Major Components of Earth's Environment: Earth's environment consists of four spheres: lithosphere, hydrosphere, atmosphere, biosphere.
Lithosphere: Includes crust and upper mantle, consisting of rocks and minerals.
Hydrosphere: Water in all forms (liquid, frozen, vapor) encompassing surface water, groundwater, and moisture in living organisms.
Atmosphere: Thin layer of gases (mainly nitrogen and oxygen) encasing Earth, crucial for weather and life.
Two main layers: Troposphere (most weather occurs) and Stratosphere (contains ozone).
Biosphere: All living organisms interacting with their environment, extends from ocean floors to mountain tops.
Energy Flow and Matter Cycling
Key Processes: Energy flow (from sun) and matter cycling (elements like carbon, nitrogen, etc.) are essential for ecosystem functioning.
Photosynthesis: Conversion of solar energy into chemical energy by plants ().
Ecological Efficiency: Typically 10% of energy is transferred to the next trophic level, implying 90% is lost.
Ecology Overview
Definition of Ecology: Study of interactions between living organisms and their environment, including populations, communities, and ecosystems.
Organismal Levels: Start from atoms, molecules, cells, tissues, organs, organ systems, individuals, populations, communities, ecosystems, to biosphere.
Biodiversity and Its Importance
Types of Biodiversity:
Genetic Diversity: Variability in genetic makeup within a species.
Species Diversity: Variety and abundance of different species.
Ecological Diversity: Variety of ecosystems in a given area.
Ecosystem Services: Biodiversity supports ecosystem services essential for human survival, such as pollination, nutrient cycling.
Ecosystem Components
Producers: Autotrophs like plants that convert sunlight into energy.
Consumers: Heterotrophs that consume other organisms (herbivores, carnivores, and omnivores).
Decomposers: Break down dead matter, returning nutrients to the ecosystem.
Succession in Ecosystems
Ecological Succession: Gradual process of species replacement in an ecosystem following disturbances. Types:
Primary Succession: Starts on bare rock without soil.
Secondary Succession: Occurs in environments where life has been removed but soil remains.
Human Impacts on Ecosystems
Monocultures: Simplification of ecosystems leads to loss of biodiversity.
Pollution and Resource Depletion: Human activities cause ecological imbalances and species extinction.
Climate Change: Alters habitats and species distributions, impacting ecological balance.