Terrestrial gastropod diversity in an alpine region: disentangling effects of elevation, area, geometric constraints, habitat type and land-use intensity
Terrestrial gastropod diversity in an alpine region: disentangling effects of elevation, area, geometric constraints, habitat type and land-use intensity
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DOI：
10.1111/j.1600-0587.2013.00312.x
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发表时间：
2014-04-01
期刊：
影响因子：
5.9
通讯作者：
Schmera, Denes
中科院分区：
文献类型：
--
作者：
Baur, Bruno;Meier, Trudi;Schmera, Denes
海拔梯度已被证明有助于检查影响物种多样性模式的关键因素。本研究探讨了海拔、面积、几何限制、生境类型、环境因素和土地利用强度对穆斯塔尔谷陆地腹足动物多样性模式的影响，穆斯塔尔谷是一个受瑞士东部阿尔卑斯山不同类型农业用地利用影响的高山地区。采用标准化方法在海拔 1215 至 2770 米、覆盖 11 种不同栖息地类型的 180 个地点对腹足动物进行了采样。总共记录了代表 70 个物种的 11 102 个标本。观测到的物种丰富度、统计估计的真实丰富度（Chao）和地理插值观测到的丰富度被用作当地物种丰富度的衡量标准。三种替代模型（环境、几何约束和腹足动物丰度模型）的比较表明，环境模型解释了所有当地多样性指标的大部分变化。结合所有三个模型的预测因子的最佳模型表明，海拔、土壤 pH 值和栖息地类型影响当地物种丰富度的所有指标。在150米海拔带水平上进行的类似分析表明，海拔再次是物种丰富度的最佳预测因子，而海拔带的面积没有任何影响。然而，在带物种丰富度的两种测量方法之一中，最佳模型表明几何约束也可能对观察到的模式有所贡献。在这两个空间尺度上，所有物种丰富度的测量值都随着海拔的升高而降低。对物种特定生活史特征的分析表明，成年蜗牛的壳尺寸随着海拔的升高而减小。大多数拥有大壳的物种都局限于海拔较低的地区。结果表明，环境因素可能对形成观察到的模式最重要。
Elevational gradients have proven to be useful to examine key factors shaping species diversity patterns. This study examines the effects of elevation, area, geometric constraints, habitat type, environmental factors and land-use intensity on terrestrial gastropod diversity patterns in Val Mustair, an alpine region influenced by different types of agricultural land use in the eastern Alps, Switzerland. Gastropods were sampled using a standardized method in 180 sites spanning an elevational range from 1215 to 2770 m and covering 11 different habitat types. A total of 11 102 specimens representing 70 species were recorded. Observed species richness, statistically estimated true richness (Chao) and geographically interpolated observed richness were used as measures of local species richness. The comparison of three alternative models (environmental, geometric constraints and gastropod abundance models) revealed that the environmental model explained most of the variation in all measures of local diversity. The best model combining the predictors of all three models showed that elevation, soil pH and habitat type affected all measures of local species richness. Similar analyses conducted at the level of 150-m elevational bands showed that elevation was again the best predictor of species richness, while the area of the elevational band did not have any influence. However, in one out of the two measures of band species richness, the best model indicated that geometric constraints may also contribute to the observed pattern. At both spatial scales, all measures of species richness decreased with increasing elevation. An analysis of species-specific life-history traits showed that adult shell size of land snails decreased with increasing elevation. Most species with large shells were confined to lower elevations. The results indicate that environmental factors might be most important in shaping the observed patterns.