Shrinking Habitats Have Adverse Effects on World Ecosystems
For Immediate Release
对全球栖息地分裂的广泛研究 - 栖息地划分为较小，更孤立的斑块 - 对于许多世界生态系统和生活中的植物和动物的主要麻烦点。
The study shows that 70 percent of existing forest lands are within a half-mile of the forest edge, where encroaching urban, suburban or agricultural influences can cause any number of harmful effects – like the losses of plants and animals.
The study also tracks seven major experiments on five continents that examine habitat fragmentation and finds that fragmented habitats reduce the diversity of plants and animals by 13 to 75 percent, with the largest negative effects found in the smallest and most isolated fragments of habitat.
The study, led by a researcher from North Carolina State University and involving about two dozen researchers across the globe, is reported today in a paper published inScience Advances.
研究人员组建了一张全球森林覆盖的地图，发现了一些人类发展不受影响的森林土地。
“It’s no secret that the world’s forests are shrinking, so this study asked about the effects of this habitat loss and fragmentation on the remaining forests,” said Dr. Nick Haddad, William Neal Reynolds Distinguished Professor of Biological Sciences at NC State and the corresponding author of the paper.
“结果令人惊讶。世界上剩余森林的近20％是足球场的距离 - 或约100米 - 远离森林边缘。百分之七十的林地位于森林边缘的半英里。这意味着几乎没有森林可以真正被认为是荒野。“
The study also examined seven existing major experiments on fragmented habitats currently being conducted across the globe; some of these experiments are more than 30 years old.
Covering many different types of ecosystems, from forests to savannas to grasslands, the experiments combined to show a disheartening trend: Fragmentation causes losses of plants and animals, changes how ecosystems function, reduces the amounts of nutrients retained and the amount of carbon sequestered, and has other deleterious effects.
“The initial negative effects were unsurprising,” Haddad said. “But I was blown away by the fact that these negative effects became even more negative with time. Some results showed a 50 percent or higher decline in plant and animals species over an average of just 20 years, for example. And the trajectory is still spiraling downward.”
Haddad points to some possible ways of mitigating the negative effects of fragmentation: conserving and maintaining larger areas of habitat; utilizing landscape corridors, or connected fragments that have shown to be effective in achieving higher biodiversity and better ecosystem function; increasing agricultural efficiency; and focusing on urban design efficiencies.
“The key results are shocking and sad,” Haddad said. “Ultimately, habitat fragmentation has harmful effects that will also hurt people. This study is a wake-up call to how much we’re affecting ecosystems – including areas we think we’re conserving.”
The study was supported by the National Science Foundation.
- kulikowski
Note to editors: An abstract of the paper follows.
“Habitat Fragmentation and its Lasting Impact of Earth’s Ecosystems”
Authors: Nick M. Haddad, North Carolina State University, et al
Published: March 20, 2015, inScience Advances
Abstract: We conducted an analysis of global forest cover to reveal that 70% of remaining forest is within 1 km of the forest’s edge, subject to the degrading effects of fragmentation. A synthesis of fragmentation experiments spanning multiple biomes and scales over five continents and 35 years demonstrates that habitat fragmentation reduces biodiversity by 13-75% and impairs key ecosystem functions by decreasing biomass and altering nutrient cycles. Effects are greatest in the smallest and most isolated fragments, and they magnify with the passage of time. These findings indicate an urgent need for conservation and restoration measures to improve landscape connectivity, which will reduce extinction rates and help maintain ecosystem services.
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