Transcript Slide 1
Terrestrial Ecosystems— Management and Threats Chapter 10 Forests Types of Forests (coniferous, temperate, and tropical) Cover 30% of the earths surface tropical forests account for more than half old growth forests (not seriously disturbed for 100+ years)--36% second-growth forests (result from secondary succession)--60% tree plantation (managed forest, same species, same age)--4% 3 3 Ecological and Economic Services Remove carbon dioxide and produce oxygen temperature stabilization (climate change) Hold soil in place minimize flooding recharge groundwater provide with food/medicine home for animals and humans provide a source of income 4 4 Major Threats Loss of habitat is the single biggest cause of species extinction! Unsustainable logging (deforestation) use wood for biofuel, lumber, paper, exotic woods for furniture, flooring, etc. harvesting illegally selective cutting, clear cutting, strip cutting Forest Fires surface fires (burn undergrowth and leaf litter), beneficial to forests crown fires (hot burning, leaps from treetop to treetop), destructive to forests 5 5 Major Threats Diseases and Insects accidentally or deliberately introduced Eat leaves (defoliate), flowers, buds, bore holes in bark and woody stems—cause extensive damage Easily spread from tree to tree, hard to control Climate change trees need certain climate conditions to produce seeds, germinate, or produce fruit increase in drought conditions also increases 6 6 Deforestation and Tropical Rainforests Most vulnerable ecosystems loss concentrated in less developed countries half of these forests have been lost since 1950 estimated that these forests will be gone in the next 20- 40 years endemic species that are highly vulnerable to extinction habitats are fragmented by roads slash and burn practice used to make room for agriculture 7 7 Rangelands (Grasslands) help with soil formation, erosion control, chemical cycling, storing carbon dioxide, maintaining biodiversity Rangeland--unfenced grassland used to support grazing species moderate grazing healthy overgrazing: grass is damaged due to too much grazing and grass not allowed to recover causes ecosystem to be susceptible to invasive species, drought and erosion 9 9 Managing Forests Purchase sustainably harvested wood products Limit clear-cutting, advocate for selective cutting Limit government subsidies and tax breaks, favor replanting efforts Educating the public about forest fires and prevention (Smokey the Bear) using prescribed burns to remove slash, and other ground debris Reduce the demand for wood products and use them more efficiently (other source for paper) Limit woods used as fuelwood source 10 10 Managing Grasslands control number of grazing animals and time allowed to graze rotational grazing eliminating invaders with herbicides, mechanical removal or burning 11 11 National Parks and Reserves 1,100 national parks in 120 countries 58 national parks in the US Many parks threatened by invasive species, illegal activities, limited funding, or inadequate staff especially in less developed countries 13% of global land and sea set aside for reserves, but only 5% strictly protected. “95% reserved for human use” wilderness: areas of land strictly protected from human activities (logging, mining, motor vehicle use) 1964 Wilderness Protection Act 12 12 Yellowstone National Park 13 Park History Founded in 1872. America’s first National Park. 3,468 square miles in size. Is the most popular park in the US, with annual visitors topping 3 million per year, with the most visits in the summer. In 1988 a devastating wildfire swept through the park, burning upward of 36% of the vegetation. Result of lots of underbrush gathered in forested areas. 14 Location and Climate 15 Wildlife 16 Popular Attractions 17 Threats Invasive species Lots of human traffic increases the chance of invaders being introduced Water Pollution Lots of vehicle traffic increases oil runoff—also garbage can accumulated in natural areas Overuse of hiking trails, campsites and fishing areas 18 If I were to visit… Old Faithful Inn The largest log structure in the world! I would visit in the spring…less people and wildflowers blooming I would also make sure to hike Yellowstone canyon and Mammoth Hot Springs trails 19