Biodiversity

Jigsaw activity – share your info Biodiversity Genetic diversity, Species diversity Habitat diversity.

Biodiversity comes from the phrase biological diversity. It is now used to mean the variety of life on Earth. ‘Bio’ makes it clear that we mean the biological parts of the ecosystem and ‘diversity’ means variety. Biodiversity can be used to evaluate both the complexity of an area and how healthy that area is. Biodiversity is measured in three ways: species diversity, habitat diversity and genetic diversity.

Species Diversity The variety of species per unit area. This includes both the number of species present and their relative abundance.

Species diversity is the variety or number of different species in a unit of area e.g. a km 2. It includes the number of species present and their abundance (how many of each one there are). The higher the species diversity of a community, the greater the complexity. Areas of high species diversity are also more likely to be undisturbed by people e.g. primary rainforest. *Species richness means only the number of species.

Genetic Diversity The range of genetic material present in a gene pool or population of a species.

Genetic diversity means the range of genetic material present in a gene pool or in a population of a species. Gene pool refers to all the different genes found in all the individuals of the species in that area. A large gene pool leads to a high genetic diversity and a small gene pool leads to a low genetic diversity. Gene pool can refer to the diversity of genes in all species within an area.

Habitat Diversity The range of different habitats or number of ecological niches per unit area in an ecosystem, community or biome.

Habitat diversity means the range of different habitats in an ecosystem. Habitat diversity is often connected to the variety of ecological niches. So, for example: A woodland has many different niches, such as a rivers, trees and soil, and so it has a high habitat diversity. A desert has few habitats, maybe sand and occasional vegetation, and so has a low habitat diversity.

Check understanding 1.Are species with a high or a low genetic diversity more prone to extinction and why? Think about what would happen if the environment changes. 2.How could we increase the genetic diversity of an area? 3.How could we increase habitat diversity? 4.How could we increase species diversity? 5.As an environmentalist, which of the three methods of increasing biodiversity will be the most successful and why? 6.How could we measure biodiversity in any given area?

Measuring diversity? Which ones… Quadrat Lincoln Simpson’s - how does it work? PAIRS

Communities with individuals evenly distributed between different species are said to have high evenness and have high diversity. This is because many species can co-exist in the many available niches within a complex ecosystem. Communities with one dominant species have a low diversity which shows a poorer ecosystem not able to support as many types of organism. Measures of diversity in communities with few species can be unreliable as relative abundance between species can misrepresent true patterns.

4.1.1 Define the terms biodiversity, genetic diversity, species diversity and habitat diversity.

So, why conserve species?

Preservation of habitats as people live there e.g. indigenous people in rainforest areas Plants to remove carbon dioxide and add oxygen to air Insects for pollination of crops and other plants Mammals and birds for seed dispersal Pleasure / aesthetic value from seeing species and habitats Need diversity so we can increase scientific knowledge Food such as rice and wheat all come from wild plants Genes preserved in case pests wipe out our food species now Some organisms control other species – biological control rather than chemical control e.g. ladybirds eat greenfly Ethical reasons – humans as dominant species should be protecting other areas, biorights – species have their own rights regardless of how they help us Natural products e.g. timber, oil palm, guano (seabird droppings – fertilizer), cotton, rubber etc Holidays in national parks and areas of beauty improve the quality of people’s lives Products such as medicine – the first antibiotics such as penicillin came from fungi, the rosy periwinkle in Madagascar’s forest gave us a drug for leukaemia and a rare yew tree has a chemical that may help to fight cancer Plants to regulate climate by keeping water in local area and providing shade Indicator species needed to show if ecosystem is being affected on greater level e.g. lichens show air quality Tourism may bring in revenue for local economy e.g. GBR Large number of species leads to stable ecosystems Bacteria, fungi worms for decomposition of waste May be valuable genes for genetic engineering - once gone, gone for ever

1a) Identify, giving reasons, two actions which will promote species diversity.(2) 1b) Explain why species diversity is considered to be an advantage to an ecosystem.(3)

IB questions: 1. Distinguish between the term biodiversity and abundance. 2. How can species diversity in an area be measured? 3. Discuss the characteristics of an ecosystem that would allow it to support high biodiversity and explain what the threats are to this ecosystem.

Are humans still evolving?