Spread and current potential distribution of an alien grass, Eragrostis lehmanniana Nees, in the southwestern USA: comparing historical data and ecological niche models
Spread and current potential distribution of an alien grass, Eragrostis lehmanniana Nees, in the southwestern USA: comparing historical data and ecological niche models
复制标题
美国西南部外来草画眉草的传播和当前潜在分布：比较历史数据和生态位模型
DOI：
10.1111/j.1366-9516.2006.00268.x
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发表时间：
2006
影响因子：
4.6
通讯作者：
J. Ward
中科院分区：
文献类型：
--
作者：
Heather Schussman;E. Geiger;T. Mau;J. Ward
外来物种在新栖息地的潜在分布往往难以预测，因为限制物种分布的因素可能是新地区独有的。lehmanniana Eragrostis lehmanniana是20世纪30年代有意从南非引进到美国亚利桑那州的多年生草；到20世纪80年代，它的范围扩大了一倍。根据其引种和原生范围相关的环境特征，研究人员认为，到20世纪90年代初，lehmanniana已经达到了其分布的极限。我们从亚利桑那州和新墨西哥州西部的各个土地管理机构收集了莱曼尼亚纳绦虫分布的数据，发现了新的记录，表明莱曼尼亚纳绦虫在继续传播。此外，我们采用了两种建模技术来确定当前的潜在分布，并重新研究了与分布相关的几个环境变量。与过去研究表明的相似的降水和温度状况是影响模式输出的最重要变量。两个模型绘制的lehmanniana的潜在分布面积为71843 km2，覆盖了亚利桑那州东南部和中部的大部分地区。基于平均气温、降水、草地物种组成和记录发生量，Logistic回归（LR）预测lehmanniana的潜在分布比GARP预测的更接近于该物种目前的分布。交叉验证评估和外部检验的结果显示，基于敏感性、特异性和kappa指数，LR模型的表现与GARP一样好，甚至更好。
The potential distribution of alien species in a novel habitat often is difficult to predict because factors limiting species distributions may be unique to the new locale. Eragrostis lehmanniana is a perennial grass purposely introduced from South Africa to Arizona, USA in the 1930s; by the 1980s, it had doubled its extent. Based on environmental characteristics associated with its introduced and native range, researchers believed that E. lehmanniana had reached the limits of its distribution by the early 1990s. We collected data on E. lehmanniana locations from various land management agencies throughout Arizona and western New Mexico and found new records that indicate that E. lehmanniana has continued to spread. Also, we employed two modelling techniques to determine the current potential distribution and to re‐investigate several environmental variables related to distribution. Precipitation and temperature regimes similar to those indicated by past research were the most important variables influencing model output. The potential distribution of E. lehmanniana mapped by both models was 71,843 km2 and covers a large portion of southeastern and central Arizona. Logistic regression (LR) predicted a potential distribution of E. lehmanniana more similar to this species current distribution than GARP based on average temperature, precipitation, and grassland species composition and recorded occurrences. Results of a cross‐validation assessment and extrinsic testing showed that the LR model performed as well or better than GARP based on sensitivity, specificity, and kappa indices.