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Tuesday, 18 March 2008 |
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BEIJING (Xinhua): Important eco-resources, such as peatlands, have been on decline, experts warned. Peatlands, the most space-effective carbon stocks, have deteriorated, despite the government's efforts to increase wetlands in the Dongting Lake and Poyang Lake areas. Covering only 3 percent of the world's land area, or 4 million sq km, peatlands hold 550 billion tons of carbon, which is equivalent to 75 percent of all atmospheric carbon, said Faizal Parish, director of the Global Environment Center and head of Wetlands International-Asia Pacific. The degradation of wetlands led to increasing greenhouse gas emissions. Species that are vulnerable to climate change could thus face extinction. "People previously were not aware of the connection between biodiversity and our daily life," said John MacKinnon, an official with the EU-China Biodiversity Program. A study by the Intergovernmental Panel of Climate Change (IPCC) showed that 20 percent to 30 percent of species would be at high risk of extinction if the temperature increased by 1.5 to 2.5 degrees Celsius. |
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Last Updated ( Monday, 30 June 2008 )
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Tuesday, 18 March 2008 |
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There may be complex dynamics from a changing climate as a result of different responses from interacting species. Species that closely interact or compete may have different responses to climate change, influencing the outcome of their interactions.
Examples of ecosystem changes include: - Warmer spring weather led to disruption of synchrony between the winter moth hatching and the oak bud burst in Europe. This led to a change in the peak of insect availability, conflicting with the food demands on the great tit nestlings.
- Studies of large mammals show that juvenile survival is influenced by climatic extremes. Warm weather has incluenced the fecundity of red deer adn Soay sheep in Norway and the UK. These changes may create impacts on future population dynamics when the juveniles reach reproductive maturity.
- Winter warming in Britain has led to breeding season changes among amphibians. These changes have led changes in temporal niche overlaps, leading to consequences for trophic interactions.
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Last Updated ( Monday, 30 June 2008 )
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Tuesday, 18 March 2008 |
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Humans are altering the composition of biological communities through a variety of activities that increase rates of species invasions and species extinctions, at all scales, from local to global. These changes in components of the Earth’s biodiversity cause concern for ethical and aesthetic reasons, but they also have a strong potential to alter ecosystem properties and the goods and services they provide to humanity. Ecological experiments, observations, and theoretical developments show that ecosystem properties depend greatly on biodiversity in terms of the functional characteristics of organisms present in the ecosystem and the distribution and abundance of those organisms over space and time. Species effects act in concert with the effects of climate, resource availability, and disturbance regimes in influencing ecosystem properties. Human activities can modify all of the above factors; here we focus on modification of these biotic controls. The scientific community has come to a broad consensus on many aspects of the relationship between biodiversity and ecosystem functioning, including many points relevant to management of ecosystems. Further progress will require integration of knowledge about biotic and abiotic controls on ecosystem properties, how ecological communities are structured, and the forces driving species extinctions and invasions. To strengthen links to policy and management, we also need to integrate our ecological knowledge with understanding of the social and economic constraints of potential management practices. Understanding this complexity, while taking strong steps to minimize current losses of species, is necessary for responsible management of Earth’s ecosystems and the diverse biota they contain.  |
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Last Updated ( Monday, 30 June 2008 )
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Tuesday, 18 March 2008 |
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A healthy biodiversity provides a number of natural services for everyone: - Ecosystem services, such as
- Protection of water resources
- Soils formation and protection
- Nutrient storage and recycling
- Pollution breakdown and absorption
- Contribution to climate stability
- Maintenance of ecosystems
- Recovery from unpredictable events
- Biological resources, such as
- Food
- Medicinal resources and pharmaceutical drugs
- Wood products
- Ornamental plants
- Breeding stocks, population reservoirs
- Future resources
- Diversity in genes, species and ecosystems
- Social benefits, such as
- Research, education and monitoring
- Recreation and tourism
- Cultural values
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Last Updated ( Monday, 30 June 2008 )
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Sunday, 16 March 2008 |
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The most straightforward definition is "variation of life at all levels of biological organization". A second definition holds that biodiversity is a measure of the relative diversity among organisms present in different ecosystems. "Diversity" in this definition includes diversity within a species and among species, and comparative diversity among ecosystems. A third definition that is often used by ecologists is the "totality of genes, species, and ecosystems of a region". An advantage of this definition is that it seems to describe most circumstances and present a unified view of the traditional three levels at which biodiversity has been identified: |
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Last Updated ( Monday, 30 June 2008 )
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