Laboratory for Integrative Studies in Amphibian Biology, Department of Integrative Biology, Museum of Vertebrate Zoology, Group in Endocrinology, University of California, Berkeley, CA 94720-3140, USA.
J Exp Biol. 2010 Mar 15;213(6):921-33. doi: 10.1242/jeb.040865.
Greater than 70% of the world's amphibian species are in decline. We propose that there is probably not a single cause for global amphibian declines and present a three-tiered hierarchical approach that addresses interactions among and between ultimate and proximate factors that contribute to amphibian declines. There are two immediate (proximate) causes of amphibian declines: death and decreased recruitment (reproductive failure). Although much attention has focused on death, few studies have addressed factors that contribute to declines as a result of failed recruitment. Further, a great deal of attention has focused on the role of pathogens in inducing diseases that cause death, but we suggest that pathogen success is profoundly affected by four other ultimate factors: atmospheric change, environmental pollutants, habitat modification and invasive species. Environmental pollutants arise as likely important factors in amphibian declines because they have realized potential to affect recruitment. Further, many studies have documented immunosuppressive effects of pesticides, suggesting a role for environmental contaminants in increased pathogen virulence and disease rates. Increased attention to recruitment and ultimate factors that interact with pathogens is important in addressing this global crisis.
超过 70%的世界两栖物种正在减少。我们认为，全球两栖动物减少可能不是单一原因造成的，并提出了一个三层的分层方法，以解决导致两栖动物减少的终极和近因因素之间的相互作用。两栖动物减少有两个直接（近因）原因：死亡和繁殖失败（减少补充）。虽然人们非常关注死亡，但很少有研究涉及导致繁殖失败的减少的因素。此外，人们非常关注病原体在引发导致死亡的疾病方面的作用，但我们认为，病原体的成功受到四个其他终极因素的深刻影响：大气变化、环境污染物、栖息地改变和入侵物种。环境污染物是导致两栖动物减少的一个可能重要因素，因为它们有可能影响繁殖。此外，许多研究记录了杀虫剂的免疫抑制作用，这表明环境污染物在增加病原体毒力和疾病发生率方面发挥了作用。更多地关注繁殖和与病原体相互作用的终极因素，对于解决这一全球性危机非常重要。
