BIOS 230: Threats to Biodiversity - Vocabulary Flashcards

Flashcards on Threats to Biodiversity

Pleistocene Extinction

A period approximately 11,000 years ago when many mammal species went extinct in North America, potentially caused by human activity or climate change.

Biome

A geographic region characterized by similar geological and climatic conditions (e.g., tropical rainforest, desert, grassland, tundra, deciduous forest).

Spatial Heterogeneity Hypothesis

The idea that habitats with intricate physical structures offer more niches, leading to greater species richness than habitats with simpler structures.

Climate Stability Hypothesis

The concept suggesting that consistent environments promote species specialization and speciation due to predictable resources; historically stable tropical regions experienced more speciation due to lack of glaciation.

Species-energy Hypothesis

The theory that the amount of available energy (ecosystem productivity) limits the richness of a system, where greater productivity fosters greater diversity.

Alpha (α) diversity

The species diversity within a particular community.

Beta (β) diversity

The change (turnover) in species diversity from one location to another.

Gamma (γ) diversity

The total species diversity across all communities within a geographic area.

Mass Extinction

The loss of at least 75% of species within a relatively short geological period (around 2 million years).

Overharvesting

The unsustainable removal of species from their natural habitats, leading to population declines and extinctions.

Habitat Fragmentation

The division of a habitat into smaller, isolated patches, increasing edge habitat and reducing interior habitat, typically reducing biodiversity.

Invasive Species

Plants and animals introduced by humans outside their natural geographic ranges that can cause extinction of native species and alter ecosystems.

Ecosystem Services

The benefits that the environment provides to people, including clean water, food, timber, and pollination.