Coastal urbanization and the integrity of estuarine waterbird communities: Threshold responses and the importance of scale
Coastal urbanization and the integrity of estuarine waterbird communities: Threshold responses and the importance of scale
复制标题
DOI：
10.1016/j.biocon.2008.07.023
复制
发表时间：
2008-11-01
影响因子：
5.9
通讯作者：
Marra, Peter P.
中科院分区：
文献类型：
--
作者：
DeLuca, William V.;Studds, Colin E.;Marra, Peter P.
由于人口集中在海岸线附近，河口生态系统正在发生越来越多的变化，但缺乏关于这种变化的有力指标。我们开发了一个水鸟群落完整性指数(IWCI)，并在美国切萨皮克湾的28个流域和相关的子河口测试了其对人类活动的敏感性。IWCI被用作了解人类土地利用如何影响河口生态系统完整性的工具。根据Akaike的信息标准(AIC)，包括河口流域已开发土地百分比的单变量模型比包括农业和森林覆盖率的模型拟合IWCI数据的可能性分别高出13(2002)和26(2003)倍。因此，我们研究了郊区、城市和总体发展如何在三个空间尺度上影响IWCI得分：(1)分水岭；(2)反距离加权(IDW)分水岭(海岸线附近的土地覆盖按比例大于较远的土地覆盖)；(3)本地(海岸线500米以内的土地覆盖)。郊区、城市和总体发展都是IWCI得分的显著预测因子。在IDW和地方尺度上的关系比在整个流域尺度上的关系更强。非参数变点分析显示，当分水岭内的IDW土地覆盖只有3.7%(2002年)和3.5%(2003年)是城市时，IWCI评分达到阈值的概率为80%。我们的结果表明，在我们研究的景观应激源中，河口海岸线附近的发展是河口水鸟群落完整性的主要应激源；即使海岸城市化水平极低，河口生态系统的完整性也可能受到损害。(C)2008爱思唯尔有限公司。保留所有权利。
Estuarine ecosystems are becoming increasingly altered by the concentration of human populations near the coastline, however a robust indicator of this change is lacking. We developed an index of waterbird community integrity (IWCI) and tested its sensitivity to anthropogenic activities within 28 watersheds and associated subestuaries of Chesapeake Bay, USA. The IWCI was used as a tool to gain insight into how human land use affects estuarine ecosystem integrity. Based on Akaike's information criteria (AIC), a single variable model including percent developed land in estuarine watersheds was thirteen (2002) and twenty-six (2003) times more likely than models including percent agriculture and forest cover to fit the IWCI data. Consequently, we examined how suburban, urban, and total development shaped IWCI scores at three spatial scales: (1) watershed; (2) inverse-distance-weighted (IDW) watershed (land cover near the coastline weighted proportionally greater than that farther away); (3) local (land cover within 500 m of the coastline). Suburban, urban, and total development were all significant predictors of IWCI scores. Relationships were stronger at the IDW and local scales than at the whole watershed scale. Nonparametric changepoint analysis revealed a >80% probability of a threshold in IWCI scores when as little as 3.7% (2002) and 3.5% (2003) of the IDW land cover within the watershed was urban. Our results indicate that, of the landscape stressors we examined, development near estuarine coastlines is the primary stressor to estuarine waterbird community integrity; and that estuarine ecosystem integrity may be impaired by even extremely low levels of coastal urbanization. (c) 2008 Elsevier Ltd. All rights reserved.