Requirements
Question1234
notes.docxSustaining Biodiversity - Ecosystem and Species Approaches
Many human activities have decreased biodiversity worldwide. Humans have decreased biodiversity through environmental stress, habitat destruction and degradation, and accidental or deliberate introduction of harmful non-native species into ecosystems.
Ecological restoration has a critical role in protecting and understanding the Earth's environments. Unfortunately, even if personnel and financial resources are available, many sites are too damaged to be effectively restored. In such cases, alternatives to restoration must be pursued, including: rehabilitation, remediation, replacement, or the creation of artificial ecosystems. Some individuals worry that large-scale ecological restoration could mislead the public into believing that any amount of environmental damage can be undone. Ultimately, a massive and expensive restoration program could be offset by weakened regulations and increased environmental damage in other areas.
Furthermore, alternatives to ecological restoration may be able to repair more sites at less cost.
Based on what you have read and researched, do you believe that the loss of biodiversity is a concern for humans? Should the government not only preserve but restore ecosystems that we have degraded the biodiversity even though this will be quite costly?
Forests
Sustaining Biodiversity - Ecosystem and Species Approaches
The federal government manages public lands in the United States. These lands include the National Forest System, Natural Resource Lands, National Wildlife Refuges, National Park System, and the National Wilderness Preservation System. The uses of these lands vary from restricted to moderate use by the public.
The forests are classified as old growth, which includes both virgin and second growth forests, which are hundreds of years old. Second growth forests result from ecological succession and tree plantations often planted with a single species. When the trees are mature in plantations, they are clear-cut and replanted. These trees are rapid growing species used for fuel wood, timber, or pulpwood. Most of the old growth forests have been cut and replanted.
The United States National Forests provide important economic and ecological services. Much controversy exists over which of these benefits should receive the highest priority. The timber industry wants to cut more timber in the national forests with the taxpayers paying for the roads and other items to make the timber available to the loggers. Environmentalists feel the timber interests have been favored at the expense of biodiversity protection and recreation.
Tropical deforestation has cleared about half of the world's mature tropical forests. At current rates of cutting, the remaining tropical forests will be depleted in 25-83 years. These forests provide important ecological and economic services. Their degradation and disappearance threatens biodiversity. The root causes of tropical deforestation include population growth, poverty, and favorable government policies. Once roads are built, the forest can be used for logging, farming, cattle grazing, construction dams and reservoirs, mined, and drilled for oil. The website Journey into Amazonia provides information about the habitats and species of the Amazon Rain Forest. Rainforest Action Network is an excellent portal to such information as:
1. Why are rainforests important?
2. What is happening in the rainforests?
3. Why are rainforests being destroyed?
4. How are rainforests protected?
Most of the world's national parks exist in name only and have little protection. An increasing number of visitors, introduction of non-native species, and harmful effects of activities in adjacent areas threaten parks in the United States. Wilderness areas have scenic and recreational value. Most biologists however, feel they are most valuable as undisturbed islands of biodiversity and natural laboratories to help understand how nature works. To better understand how the Earth's natural resources are being degraded at an accelerated rate (as a result of population growth and resource use) view the following animation. Ocean and freshwater systems provide us with a variety of economic and ecological services. Overfishing, pollution, habitat destruction, and degradation threaten marine and freshwater species. A majority of the commercially valuable marine fish species are overfished. Non-native species have displaced native species and they have disrupted ecosystems.
Most ocean area lies outside of the legal jurisdiction of any country. This opens up the seas to overexploitation. International agreements to protect the open seas are difficult to develop, monitor, and enforce. Any attempt to protect unique marine habitats is threatened by activities in nearby coastal areas.
Environmentalists believe that efforts to protect the world's rapidly disappearing biodiversity should be focused on the most biodiverse countries and on the hot spots that are important, but highly endangered, centers for biodiversity.
