Biodiversity – the fine balance of an ecosystem Design a Conservation Programme What is an ecosystem? An ecosystem is an environment consisting of all the organisms (bacteria, plants, trees, insects, mammals, birds, fish, coral etc) and non-living components (air, water, sand, soil, rock, sunlight etc) in a particular area. • There are many different kinds and sizes of ecosystem, ranging from the ecosystem of a single rock pool or hedgerow, to the ecosystem of an entire forest, ocean, island or even a whole planet. • An ecosystem provides all the habitat, nutrients, food and water required for an organism’s survival. Tristan albatross pair courtship preening, in habitat. What is biodiversity? • Biodiversity is the degree of variation of different life forms within an ecosystem. • Measuring diversity is used as a way to measure the health of an ecosystem. Greater biodiversity = Greater health! • There are different types of biodiversity: – Species diversity – Genetic diversity Ctenella chagius in coral reef habitat – Ecosystem diversity All the different members of an ecosystem play an important role in maintaining it. If something happens to upset the balance, it can cause ripples across the whole ecosystem: • Loss of prey can lead to food shortages • Loss of predators can lead to overpopulation (meaning an increase in the number of pests and competition for food and habitat) • An over-abundance of predators can devastate the population of their prey • The introduction of new species can lead to competition for food, nutrients and habitat, and the spread of diseases • An abundance of species that are destructive to certain habitats can lead to habitat loss • Habitat loss can mean that more species succumb to bad weather, disease and predation, (which would in turn lead to loss of food supply for their predators) What are ecosystem services? Ecosystems are not just important to the organisms living in them, they are also important to us. Ecosystem services are the benefits (including economic benefits) that human beings get from natural ecosystems. The ecosystem must be finely balanced to ensure these services are provided. Ecosystem services include: Services an ecosystem provides: Services that provide culture: • Clean drinking water Medicines Food e.g. wheat, fruit, meat, fish and spices Materials e.g. cotton, silk, metal, wood, oil Energy e.g. wind power, hydropower and biomass fuels • Recreational benefits – different landscapes and water-based environments are used for walking, swimming and sports • Spiritual and cultural benefits i.e. a beautiful landscape can inspire happiness, art, poetry and a sense of cultural pride Services an ecosystem regulates: Services an ecosystem supports: Pollination – to ensure the survival of crops Carbon sequestration Control of disease and pests (e.g. natural predators keep pest numbers low.) Waste decomposition Seed dispersal – essential for the continued reproduction of important plants Maintaining cycles and the dispersal of nutrients e.g. carbon cycle, nitrogen cycle, water cycle and oxygen cycle People v Conservation Human threats to conservation The biggest threat to conservation is human activity e.g. • • • • • • • Deforestation Coastal development Pollution Road building Using natural resources Over-exploitation Introducing exotic species On the island of St Helena, the endemic black cabbage tree is threatened by competition from the introduced New Zealand flax. People v Conservation Conservation efforts Many volunteer organisations and government departments have tried to conserve and protect endangered species e.g. The RSPB has announced plans to remove non-native rats from the Pacific Island of Henderson. The introduced rats eat an estimated 25,000 Henderson petrel chicks every year. •Breeding programmes •Regulations and bans •Eradication of invasive species •Monitoring and tagging •Re-building habitat •Creating artificial reefs Striking a balance • Conservation is not always easy. Communities need to develop and grow. People need homes, food and employment. As the population grows – we need more land, more food and more industry. But, it does not always have to be a choice. Some conservation attempts have also generated revenue streams and new industry. • See the case studies provided in your student briefing packs to see the different ways conservation and economic growth can go hand in hand. Look at the case studies: - What is the conservation? (What species is it conserving and how does it work?) What is the economic benefit?