Biodiversity

Biodiversity 3 Types Species Diversity (Based on 2 things) number of species(Species Richness) their relative proportions (Species Evenness) Genetic Diversity The range of genetic material present within a gene pool (population) Basically it is the diversity within each species Humans alter through domestication/agriculture Habitat Diversity The range of different habitats per unit area in a particular ecosystem or biome How complex the niche structure of a biome is (High in tropics, lower near poles)

Advantages of High Biodiversity Resilience and stability due to range of plants present Resistance to disease due to genetic diversity Nutrient cycling increased by deep rooted plants But… Could be due to fragmentation or degradation (high richness of pioneer species after human disturbance) Different plant species make managing grazing difficult There are exceptions to the rule. (Some stable communities rely on very few types of producers)

Diversity Indices Can only compare two similar ecosystems or 2 communities within the same ecosystem Lower Biodiversity could indicate pollution, eutrophication, or recent colonization Only tells part of the story Investigations must be repeated to understand the natural fluctuations of a system These are just examples don’t copy them

Hot Spots Biodiversity is not equally distributed! Hot spots have an unusually high number of endemic species (There are about 30) ~10 in tropical rainforest regions Nearer the tropics due to fewer limiting factors All threatened where 70% of area has already been lost Contains more than 1,500 endemic plant species Cover only about 2.3% of land surface Tend to have large human populations nearby