C.4 Conservation of biodiversity Understanding: -An indicator species is an organism used to assess a specific environmental condition -Relative numbers of indicator specie can be used to calculate the value of a biotic index -In situ conservation may require active management of nature reserves or national parks -Ex situ conservation is the preservation of species outside their natural habitats -Biogeographic factors affect species diversity -Richness and evenness are components of biodiversity Applications: -Case study of the captive breeding and reintroduction of an endangered animal species -Analysis of the impact of biogeographic factors on diversity limited to island size and edge effects Skills: -Analysis of the biodiversity of two local communities using Simpson’s reciprocal index of diversity Nature of science: -Scientists collaborate with other agencies: the preservation of species involves international cooperation through intergovernmental and non- governmental organisations

In situ conservation Involves endangered species remaining in the habitat to which they are adapted. Allows species to interact with other wild species, conserving more aspects of the organism’s niche Do not have to reintroduce species back into the habitat again

Nature reserves

Nature Reserves Must manage nature reserves after they are established: -Controlled grazing -Removal of shrubs or trees -Removing alien/invasive species -Reintroduce species that have become locally extinct -Re-wetting of wetlands -Limiting predators -Controlling poaching -Feeding animals -Controlling access

Ex situ conservation Involves removing organisms from their natural habitat Plant species grown in botanic gardens Captive breeding of animals, followed by release into their natural habitats. Some zoos involved. Back up for In situ conservation measures, or if organisms cannot remain safely in their natural habitat

Case study Research one example of captive breeding and reintroduction of an endangered animal species -Why did it become endangered? -Why could it not be conserved In situ? -What were the steps in the conservation program? -How were they released? -Was it successful? How do you know? -Did the government of that country help? -Was the conservation done by an NGO? Make sure you include evidence and data.

Nature Reserve features Can influence biodiversity Large nature reserves more effective than smaller ones at maintaining biodiversity Larger area = higher population of a certain species that can be supported Corridors/tunnels between reserves allows them to be larger Maximize size of central area, minimize total length of perimeter

Indicator species Organisms that occurs only when specific environmental conditions are present Assess a specific environmental conditions by their presence or absence E.G lichens are pollutant intolerant – if they are present it indicates clean air

Biotic Index Compares the relative frequency of indicator species Stream health measured by macroinvertebrate biotic index

Macroinvertebrate Biotic Index Number of individuals of each indicator species in a sample is determined

Biodiversity Two components: richness and evenness

Species… Richness Evenness Number of individuals within a species Number of species present in the habitat

Species richness Number of species in a habitat More species present = richer habitat Does not take into account the number of individuals present for each species. Must estimate the evenness

Species evenness Abundance of individuals in a species Even numbers of animals in each species is more diverse than having one species that outnumbers all the others Measure by calculating percentage cover in a quadrat.

Sample ASample B

Species observedField A % coverField B % cover Cocksfoot grass5738 Timothy grass3216 Meadow buttercup 314 White clover322 Creeping thistle15 Dandelion45 Total100 What is the species richness of field A and B? Which field has more evenness? Which field therefore is considered more diverse?

Simpson’s Index of Diversity Measure of the diversity of the habitat. Uses both species richness and evenness. It ranges from 0-1 and it represents the probability that two individuals randomly selected from a sample will belong to different species. A higher value indicates higher diversity. n = number of individuals of a particular species N = total number of all individuals of all species D = 1-Σ(n/N) 2

Speciesnn/N(n/N) 2 Cocksfoot grass Timothy grass16 Meadow buttercup 14 White clover22 Creeping thistle 5 Dandelion5 Sum ( Σ) Σ --

Speciesnn/N(n/N) 2 Cocksfoot grass Timothy grass Meadow buttercup White clover Creeping thistle Dandelion Sum ( Σ) Σ

Speciesnn/N(n/N) 2 Cocksfoot grass Timothy grass Meadow buttercup 3 White clover3 Creeping thistle 1 Dandelion4 Sum ( Σ) Σ --

Speciesnn/N(n/N) 2 Cocksfoot grass Timothy grass Meadow buttercup White clover Creeping thistle Dandelion Sum ( Σ) Σ

Why is a habitat with a higher diversity more stable than one with a lower diversity? Higher diversity Many different species and many organisms Small change to the environment may affect one species (small proportion of total species) Affect on whole habitat is small Habitat is able to withstand the change

Why is a habitat with a higher diversity more stable than one with a lower diversity? Lower diversity Habitat dominated by a few species Small change that affects one of these species could destroy the whole habitat