Biodiversity

Biodiversity is the variety of life in an area, including diversity of habitats, species, and genes.

Food webs become simpler with fewer connections, so disturbances spread more easily and the ecosystem is less stable.

Habitat diversity, species diversity, and genetic diversity.

It increases resilience by providing more connections and alternative species that can maintain ecosystem functions after disturbance.

Habitat diversity, species diversity, and genetic diversity.

With fewer species and less redundancy, the loss of one key species can cause cascading effects and system failure.

Resilience is the ability of an ecosystem to recover from disturbance and keep functioning.

Redundancy means nature has backup species that can do similar jobs.

A tipping point is a threshold where change becomes difficult or impossible to reverse, leading to a new stable state.

More species create more interactions and alternative pathways, so if one species declines, others can maintain ecosystem functions.

Lower biodiversity reduces resilience and increases the chance of ecosystem collapse under stress.

More habitat types create more niches, supporting more species and increasing overall biodiversity.

Resilience is the ability of an ecosystem to recover after disturbance and continue functioning.

Genetic variation increases the chance that some individuals have traits that tolerate new conditions, helping populations adapt and persist.

Redundancy means multiple species can perform a similar role; if one is lost, others can compensate and keep the system functioning.

It helps identify threatened species and priority habitats, so protection efforts target what matters most.

Camera traps and evidence of field signs such as tracks or scat can confirm presence.

It shows which species/habitats are most at risk so efforts can focus where they will be most effective.

It increases sample size and geographic coverage because many people can report observations over large areas.

They take photos or video of animals without disturbance, providing direct evidence that the species occurs in the area.

Citizen science is when non-scientists help collect data (for example recording sightings), increasing coverage across large areas and time periods.

The Christmas Bird Count is an example where volunteers record bird sightings to track population change.

Examples include governments, NGOs, and local/indigenous communities (also citizens and researchers).

Governments can create protected areas and enforce laws that limit habitat loss and illegal exploitation.

eDNA sampling detects DNA left by organisms in water or soil, indicating that a species is present even if it is not seen.

Citizen scientists, government agencies (for example park staff), and NGOs (for example WWF) also indigenous/local knowledge holders and trained parabiologists.

It makes large-scale monitoring possible by increasing the number of observations across space and time.

NGOs fund projects, run monitoring and education programmes, and support species recovery actions such as breeding programmes.

Indigenous/local knowledge is long-term understanding of local ecosystems; combined with science it improves detection of change and strengthens decisions.

It works only when a species has distinctive, recognisable calls that can be recorded and identified reliably.

Local knowledge can detect patterns and changes early, while scientific methods test and quantify them, giving stronger evidence for decisions.

Because biodiversity, migration, and threats like pollution operate across borders, requiring shared goals and coordinated action.

Species, migration, and pollution cross borders, so countries must share data and coordinate protection through agreements.

Species diversity measures both species richness (how many species) and evenness (how evenly individuals are distributed).

It combines richness (number of species) and evenness (how balanced the individuals are).

N = 30 individuals in total.

It converts biodiversity into a single value that increases when both richness and evenness increase.

It identifies which habitats or populations are most threatened by comparing diversity and tracking changes over time.

N is the total number of individuals of all species combined in the sample.

If diversity increases or stabilises after an intervention, it suggests management is helping; if it declines, strategies may need change.

Species richness is the number of different species present in an area.

It reduces bias by using the same metric (for example D) so different habitats can be compared fairly.

n is the number of individuals of a single species in the sample.

Species evenness is how evenly individuals are shared among the different species in a community.

If one species dominates most individuals, evenness is low, so overall diversity is still low despite multiple species being present.

D decreases because evenness is low and the sum of n(n-1) becomes large for the dominant species.

Changes in disturbance or human impacts (for example pollution, land use change, invasive species) can alter richness and evenness over time.

It allows objective comparison between habitats and monitoring of change over time to evaluate threats or conservation success.

A higher D means higher biodiversity, typically due to higher richness and/or more even distribution of individuals.