Explain Biodiversity and Population Dynamics - Biology

A new population starts from few individuals, altering allele frequencies. Random sampling of alleles creates genetic differences from source.

A sharp $N$ reduction that decreases genetic variation. Surviving individuals carry only a subset of original alleles.

$r$ is the per-individual rate of increase (births minus deaths per capita). Birth and death rates determine net population change.

Density-independent. External forces affect populations regardless of their size.

Higher biodiversity generally increases stability and resilience. Diverse communities buffer against environmental fluctuations.

Growth slows as $N$ approaches $K$; an S-shaped curve. Environmental resistance slows growth near carrying capacity.

The variety of life across genes, species, and ecosystems in an area. Encompasses genetic, species, and ecosystem variety in a defined region.

Two species with identical niches cannot stably coexist. Complete niche overlap leads to competitive displacement.

Species use different resources; it reduces competition and supports diversity. Resource specialization allows coexistence and maintains diversity.

Multiple species can maintain function when one species declines. Functional redundancy maintains ecosystem services when species decline.

More diverse ecosystems tend to show more stable functioning over time. More species provide functional backup during disturbances.

Higher biodiversity generally increases stability and resilience. Diverse communities buffer against environmental fluctuations.

The maximum population size the environment can sustainably support. Environmental capacity determines long-term population stability.

A resource that restricts population growth when scarce. Essential resources like food or space become bottlenecks.

Number of individuals per unit area or volume. Measures crowding intensity in a given space.

The total number of individuals in a population. Fundamental measure for tracking population changes over time.

How evenly individuals are distributed among species. Measures whether species abundances are balanced or skewed.

The number of different species present. Counts distinct species without considering their relative abundances.

Variation usually decreases (biomass becomes more stable). Portfolio effects from multiple species reduce temporal variability.

Population limits act regardless of density (e.g., drought, storms). Environmental factors affect all individuals equally.

Lower biodiversity can increase disease transmission in some systems. Fewer hosts can concentrate disease transmission pathways.

A reinforcing cycle of small $N$, low diversity, and rising extinction risk. Multiple factors compound to accelerate population decline.

Lower reproduction, later maturity, higher parental care; stable near $K$. Emphasizes survival and competitive ability in stable environments.

Biodiversity loss typically simplifies food webs and reduces redundancy. Fewer species create simpler, less stable food networks.

$r$ is the per-individual rate of increase (births minus deaths per capita). Birth and death rates determine net population change.

Growth slows as $N$ approaches $K$; an S-shaped curve. Environmental resistance slows growth near carrying capacity.

Growth proportional to $N$; a J-shaped increase when resources are abundant. Unlimited resources allow maximum reproductive potential.

Plant reproduction rates often decrease. Pollinator loss directly reduces plant reproductive success.

Reduced adaptability due to lower genetic variation. Fewer alleles limit evolutionary responses to future challenges.