ENVIRONMENTAL SYSTEMS AND SOCIETIES

ENVIRONMENTAL SYSTEMS AND SOCIETIES. BIODIVERSITY AND EVOLUTION.

Biodiversity & Ecosystem Stability. Biodiversity ensures ecosystems remain functional and stable. Operates at the habitat, species, and genetic levels. Spreads ecological risks → enhances recovery, resilience, and adaptation after disturbances..

Levels of Biodiversity. 1. Habitat diversity Variety of ecosystems: forests, wetlands, grasslands, coral reefs. More habitats → more niches → more species supported. Maintains ecosystem function even if one habitat is degraded. Definition: range of different habitats/ecosystems in an area..

Levels of Biodiversity. Species diversity Variety of species + their relative abundances. Greater diversity buffers against disease/predation. Supports nutrient cycling, pollination, energy transfer. Definition: richness (number of species) + evenness (distribution)..

Levels of Biodiversity. Genetic diversity Variation of genes within populations. High diversity → better adaptation to change. Reduces the risk of population collapse. Ensures long‑term survival and evolutionary potential. Definition: total genetic characteristics within a species..

Biodiversity & Resilience. Role of resilience Ability to recover after disturbance and maintain function. Biodiversity acts as insurance against variability and human impact. Definition: the capacity to resist, absorb, or recover while maintaining processes..

Biodiversity & Resilience. Risk‑spreading mechanism Habitat diversity: other habitats persist if one is lost. Species diversity: functional overlap ensures continuity. Genetic diversity: Tolerant individuals survive stress. Redundancy protects ecosystem services (oxygen, soil fertility, food)..

Adaptation & recovery. Adaptation & recovery Genetic diversity → traits for stress tolerance. Species diversity → functional overlap. Habitat diversity → migration/refuge opportunities..

Examples Of Resilience. Coral reefs: recover faster from bleaching; herbivorous fish prevent algae dominance. Tropical rainforests: species richness spreads ecological roles; genetic diversity aids adaptation. Agricultural systems: monocultures vulnerable; polycultures spread risk and preserve soil health..

Human implications. Ecosystem services Provisioning: food, medicine, raw materials. Regulating: climate, flood control, disease resistance. Supporting: nutrient cycling, soil formation, pollination. Cultural: recreation, spirituality, aesthetics..

Human implications. Conservation importance Protecting biodiversity ensures adaptation to climate change. Maintains ecosystem services. Supports recovery from human and natural disturbances..

Key Takeaways. Biodiversity exists at three levels: habitat, species, genetic. Each level spreads ecological risk → enhances resilience. High biodiversity = better adaptation, recovery, and stability. Conservation must protect all three levels to sustain ecosystems and human well‑being..