Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, 750 07 Uppsala, Sweden.
Ambio. 2011 Dec;40(8):867-77. doi: 10.1007/s13280-011-0206-9.
The aims of this study were to investigate spatial patterns and temporal changes in understorey vegetation at four forest catchments forming a depositional gradient. Inventories of the bottom and field layers were carried out in the 1990s and repeated after 5-14 years, depending on catchment. It was hypothesized that changes and patterns in ground vegetation would be related to changes and patterns in N and S deposition. The data were analyzed using Ellenberg indices and multivariate methods. All catchments showed temporal changes in species composition. Analyses of the bottom layer were confounded by a change of field staff, but after accounting for this observer effect, differences in species composition between the catchments remained. Within catchments, the changes in species composition were unrelated to N or S deposition. Relationships between environmental factors, expressed as Ellenberg indices, and compositional patterns differed between catchments although Ellenberg indices showed small temporal changes.
本研究的目的是调查四个形成沉积梯度的森林集水区林下植被的空间格局和时间变化。在 1990 年代进行了底层和野外层的清查，并根据集水区的不同，在 5-14 年后进行了重复清查。研究假设，地面植被的变化和格局与 N 和 S 沉积的变化和格局有关。使用 Ellenberg 指数和多变量方法对数据进行了分析。所有集水区的物种组成都发生了时间变化。底层分析受到野外工作人员变化的干扰，但在考虑到这种观测者效应后，集水区之间的物种组成差异仍然存在。在集水区内，物种组成的变化与 N 或 S 沉积无关。尽管 Ellenberg 指数显示出较小的时间变化，但环境因子（表示为 Ellenberg 指数）与组成模式之间的关系在集水区之间存在差异。
