森林大火对蝙蝠生存影响甚少

A survey of bat activity in burned and unburned areas after a major wildfire in the southern Sierra Nevada mountains found no evidence of detrimental¹（有害的） effects on bats one year after the fire. The findings suggest that bats are resilient to high-severity fire, and some species may even benefit from the effects of fire on the landscape. The study, led by bat ecologist Winifred Frick of the University of California, Santa Cruz, was published in the journal PLOS ONE on March 6. The findings are important because current understanding of how wildlife responds to fire is based almost entirely² on studies of a limited number of species, most of them birds, Frick said. Bats make up a large component³ of mammalian diversity in forest ecosystems⁴, where they play an important role as insect predators⁶.

 

"This is the first study to directly address species-level response by bats to stand-replacing fire, and our results show that moderate to high-severity fire has neutral or positive impacts on a suite⁷ of bat species," Frick said.

 

Studies that show how animals respond to fire help inform the ongoing⁸ public policy debate over the role of fire in ecosystem⁵ management and whether fires should be suppressed or allowed to burn on public lands, according to coauthor Joseph Fontaine, a fire ecologist at Murdoch University in Perth, Australia.

 

"A great deal of tension exists between public land managers, environmental groups, and other stakeholders--including homeowners, ranching⁹ interests, and the timber industry--over allowing stand-replacing crown fires on public forests," Fontaine said. "This study fills a critical gap on how fire affects an important group of animals."

 

The researchers conducted the study in an area of Sequoia¹⁰ and Inyo National Forests where the 2002 McNally Fire burned more than 150,000 acres. The fire burned with mixed severity, leaving a mosaic¹¹ of low- to high-severity damage, as well as patches of unburned forest. The study compared bat foraging¹²（觅食） activity in areas of unburned, moderately burned, and severely¹³ burned forest.

 

The researchers conducted surveys in 2003, using high-frequency microphones to record the ultrasonic¹⁴ echolocation pulses that bats use to hunt insects. Of the 16 bat species known to live in the area, some have distinctive¹⁵ sonic signatures, while others can be sorted into groups with similar echolocation sounds and foraging behaviors. In this study, the researchers identified six "phonic groups," including three individual species and three groups of species.

 

The results showed that the responses of the six phonic groups to moderate and high-severity fire were either neutral or positive. The heterogeneity¹⁶ such fires create in the landscape may be an important feature, resulting in a habitat structure that benefits a range of species, Frick said.

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