Science 9 Notes 1.8 Biodiversity and Invasive Species PDF

Unit 1 Ecology Science 9 Mr. Yeo 2023-2024 Biology STATEMENT OF INQUIRY FOR UNIT 1 ▸ Human interactions with natural systems can have global consequences. KEY CONCEPT: Systems RELATED CONCEPTS: Interactions, Consequences GLOBAL CONTEXT: Globalization and Sustainability Biodiversity- the variety of l...

Unit 1 Ecology Science 9 Mr. Yeo 2023-2024 Biology STATEMENT OF INQUIRY FOR UNIT 1 ▸ Human interactions with natural systems can have global consequences. KEY CONCEPT: Systems RELATED CONCEPTS: Interactions, Consequences GLOBAL CONTEXT: Globalization and Sustainability Biodiversity- the variety of life across all levels of biological organization. Ecological diversity- refers to the number of different ecosystems in a region Species diversity- refers to the number of different species within an ecosystem Genetic diversity- refers to the different genes present within a species that can be passed down to future generations Populations with little genetic diversity are more likely to be vulnerable to environmental change, as they lack the variation needed to help adapt to new conditions. Biodiversity is unevenly distributed. Some groups of organisms include more species than others: Insects are the most diverse group of organisms, with >1 million species. Some biomes are more diverse than others Tropical rainforests have the highest biodiversity of all the biomes. Many species have not yet been discovered So far we only know about ~1.8 million species of plants, animals, microorganisms Estimates for total number of species on Earth: 3—100 million Our species knowledge is incomplete because most of unknown species are small, such as bacteria, fungi, etc. Benefits of Biodiversity Biodiversity provide potential new or unused food sources, drugs and medicines – Wild relatives of crops we already use also provide genetic diversity to protect against disease – About half of today’s medicines are derived from substances in wild plants Benefits of Biodiversity Biodiversity provide “free” ecosystem services – Food, fuel, fiber, and shelter – Air and water purification – Waste decomposition – Climate stabilization (reduction in droughts, floods, etc.) – Pollination of plants – Controlling pests and diseases – Cultural and aesthetic benefits Benefits of Biodiversity Biodiversity helps maintain functioning ecosystems Increases the resilience of an ecosystem—its ability to withstand disturbance, recover from stress, or adapt to change. – If a keystone species like a top predator is lost, consequences will cascade down the entire food chain. The removal of wolves from Yellowstone National Park affected all the trophic levels and even changed the environment in the park – If an ecosystem engineer is lost, the entire structure of an ecosystem can change. The removal of elephants from some of Africa’s savannas has caused scrubby vegetation to overgrow, turning them into scrub forests The recovery of the beaver population, which was almost hunted to extinction, restored many natural habitats that helped increase the populations of many other species Benefits of Biodiversity Biodiversity boost economies through tourism and recreation Visitors to natural areas spend money at local businesses, hire locals as guides, and support parks that employ residents Human beings share an instinctive love for nature and feel an emotional bond with other living things. – Others believe that a lack of outdoor experiences and direct contact with wild organisms contributes to the emotional stress, angst, and anxiety felt by many young people. Biodiversity Loss and Extinction Humans have a tendency to change ecosystems Many populations are declining, losing biodiversity The sixth mass extinction event is currently happening due to human impacts Biodiversity Loss and Extinction Extinction occurs when the last member of a species dies and the entire species ceases to exist. Extirpation is the loss of a species from one area, but not the entire world. – The black rhino has been extirpated from most of its historic range but is not yet extinct. Major Causes of Biodiversity Loss Loss of Habitat due to deforestation, dams, farming, urbanization, etc. Pollution – Includes air pollution, water pollution, soil pollution, noise pollution, light pollution, plastic pollution, etc. Overconsumption of Resources – Deforestation, overfishing, poaching, mining, etc. Invasive Species Climate Change Native, Exotic, and Invasive Species Native Species: species that has existed for thousands or millions of years in an area – Native species can be considered pests if they are harmful to humans Exotic Species: species that originated from somewhere else, not native to an area – Exotic species may be beneficial, neutral, or harmful – Often brought to new habitats by humans, purposefully or accidentally Native, Exotic, and Invasive Species Invasive Species: exotic species that are harmful to humans, native species, and/or ecosystems – out-compete native species for resources – have few or no natural predators to keep their populations in check – can be resistant to diseases in their new communities