Guzy Jacquelyn C, McCoy Earl D, Deyle Anna C, Gonzalez Shannon M, Halstead Neal, Mushinsky Henry R
Integrative Biology Department, University of South Florida, 4202 E. Fowler Ave., Tampa, FL, USA.
Department of Biology, Davidson College, Davidson, NC 28035-7118, USA.
J Appl Ecol. 2012 Aug;49(4):941-952. doi: 10.1111/j.1365-2664.2012.02172.x. Epub 2012 Jul 17.
Wetlands are ecologically and economically important ecosystems but are threatened globally by many forms of human disturbance. Understanding the responses of wetland species to human disturbance is essential for effective wetland management and conservation. We undertook a study to determine (i) whether anurans can be used effectively to assess the ecological integrity of wetlands affected by groundwater withdrawal and, if so, (ii) what effect increasing urbanization might have on the utility of anurans as wetland indicators. We monitored the intensity of anuran calls at 42 wetlands in south-western Florida throughout 2001-2002 and 2005-2009. We first validated the use of anurans to assess wetland integrity using a small group of wetlands by comparing anuran calling and subsequent tadpole development with an established index employing vegetation composition and structure. We then verified that the results could be expanded to a variety of sites throughout the region. Finally, we focused on urbanized wetlands to determine whether urbanization could interfere with the use of anurans to assess wetland integrity. We used PRESENCE to estimate occupancy and detection probabilities and to examine the relationship between occupancy and five covariates expected to influence individual species occurrence. We used FRAGSTATS to calculate the mean proximity index for urbanized wetlands, which assesses the size and distribution of land use types within a specified area. Our results showed that the group of species including oak toad , southern cricket frog , pinewoods treefrog , barking treefrog , and little grass frog is a reliable indicator of wetland integrity. However, this same group of species, which is sensitive to wetland health, is selectively excluded from urbanized wetlands. . Although anurans are effective indicators of wetland health and complement vegetation surveys, the usefulness of this group for monitoring the ecological integrity of wetlands can be substantially reduced, or eliminated, as a consequence of urbanization. We urge for careful consideration of confounding factors in any studies examining the utility of indicator species.
湿地是具有重要生态和经济意义的生态系统，但在全球范围内受到多种形式人类干扰的威胁。了解湿地物种对人类干扰的反应对于有效的湿地管理和保护至关重要。我们开展了一项研究，以确定：（i）无尾两栖类动物是否可有效用于评估因地下水抽取而受影响的湿地的生态完整性，如果可以，那么（ii）城市化程度的提高可能会对无尾两栖类动物作为湿地指标的效用产生何种影响。在2001 - 2002年以及2005 - 2009年期间，我们对佛罗里达州西南部的42个湿地中无尾两栖类动物的鸣叫强度进行了监测。我们首先通过将无尾两栖类动物的鸣叫情况以及随后蝌蚪的发育情况与一个利用植被组成和结构的既定指数进行比较，在一小部分湿地中验证了使用无尾两栖类动物来评估湿地完整性的方法。然后，我们证实这些结果可以推广到该地区的各种地点。最后，我们重点关注城市化湿地，以确定城市化是否会干扰利用无尾两栖类动物来评估湿地完整性。我们使用PRESENCE软件来估计占有率和检测概率，并研究占有率与预期会影响单个物种出现的五个协变量之间的关系。我们使用FRAGSTATS软件来计算城市化湿地的平均邻近度指数，该指数评估指定区域内土地利用类型的大小和分布。我们的结果表明，包括橡木蟾蜍、南部蟋蟀蛙、松林雨蛙、吠叫雨蛙和小草蛙在内的这组物种是湿地完整性的可靠指标。然而，这同一组对湿地健康敏感的物种被选择性地排除在城市化湿地之外。尽管无尾两栖类动物是湿地健康的有效指标并可补充植被调查，但由于城市化的影响，这组物种用于监测湿地生态完整性的效用可能会大幅降低或消除。我们敦促在任何研究指示物种效用的研究中都要仔细考虑混杂因素。
