Transcript Enviro2Go: Biodiversity
BIODIVERSITY • “Biological Diversity” which means the variety of life on Earth. This diversity includes all the plants and animals which are interconnected within ecological systems. Biodiversity is one of the major factors of a healthy and stable ecosystem and it is vital for the world. • A population of sea urchins in a kelp forest ecosystem is being overfished. A team of students believe that a decrease in the number of sea urchins will affect the organisms in the kelp forest ecosystem. The kelp forest food web below shows the relationships among the organisms in the kelp forest ecosystem. How stable is this ecosystem? It’s not stable if it relies on one producer! What would make this ecosystem more stable? More biodiversity! Biodiversity “hot spots” are places in the world that have many different species living in one place. Shade in the biodiversity “hot spots” of the world below: * In what biome are most of the “hot spots” found? Tropical rainforests * What determines the type of biome that exists? CLIMATE! Biodiversity is threatened by certain factors: 1. Population growth: increased need for food and space. This leads to habitat loss. . Biodiversity is threatened by certain biotic factors: 2. Deforestation, the harvesting of trees for manufacturing. This leads to habitat loss Biodiversity is threatened by certain biotic factors: 3. Poaching- Illegal hunting done by humans that kills animals for their tusks, tortoise shells, feathers, and organs. Biodiversity is threatened by certain biotic factors: 4. Invasive Species- species of plants and animals occurring further than their normal distribution within an ecosystem. Their populations can grow out of control because they have NO natural predators in the ecosystems where they are introduced. Often they can outcompete organisms in the same niche. They can also introduce pathogens and diseases that sicken and kill other animals in the ecosystem. – Invasive Species Example 1: The CANE TOAD came from South America It was introduced to Australia to eat cane grubs. The cane toad did not eat grubs and became a very big problem! – Check out this video about cane toads! Invasive Species Example 2 • Example 2: Zebra Mussels came from Asia transported in ballast water. Their populations grew so out of control in some U.S. waters they clogged pipes of wastewater facilities creating a major mess. • Invasive Species Example 3: Snakeheads from Canada and China introduced into the Chesapeake Bay in 2002 compete with native species for food (niches overlap!) Biodiversity is threatened by certain factors. • Pollution- a harmful side-effect of various activities . – Eutrophication- when algae blooms deplete oxygen levels in water. – Bioaccumulation- when toxins become more concentrated in successive trophic levels. – Temperature- Increasing temperatures due to global warming can impact the species that live in a delicate range of temperatures like coral. This is known as coral bleaching. Temperature can also increase the. spread of disease. Click here to see how coral reefs are threatened! What are humans doing to preserve biodiversity? • Endangered Species A list of organisms whose populations are threatened. If animals become extinct biodiversity is threatened. The list promotes awareness, preservation, and legal consequences. The list has over 1000 species! (Nearly half of the species on the list are there because of invasive species!) Endangered Species • Often these animals like manatees, elephants, and humpback whales have few young only once a year or longer. • Poaching in countries with few controls • Habitat Loss caused by deforestation and increasing human populations. • So, man is making attempts to save as many species as possible through public awareness and special programs. • Captive Breeding Programs: Mating animals in parks, zoos and preserves to increase threatened populations in the wild.