Patterns of Species Loss in Forest Understory Plant Communities

森林林下植物群落物种丧失模式

• 批准号: 9974041
• 负责人: Donald Waller
• 金额: $ 15万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2002-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9974041&HistoricalAwards=false
• 关键词: Patterns; Species; Loss; Forest; Understory

9974041WallerPlant communities in many areas are losing species at unprecedented rates. While the mechanisms responsible for these losses vary and are often difficult to identify, there appear to be general trends governing which species are most vulnerable to being lost. Rare and localized species are usually at greater risk of local extirpation, and patterns of species loss often result in most habitat patches containing common and widespread species. Habitat fragmentation, shifts in historic disturbance regimes, the invasion of exotic species, and herbivory by elevated populations of white-tailed deer all appear to be proximate mechanisms driving these losses in various habitats. This study will investigate patterns of community composition and species loss in understory plant communities in forests of northern Wisconsin and Michigan's upper peninsula as a vehicle to understand the nature, extent, and mechanisms of these losses. Data will be collected from 120+ sites distributed across six community/soil types in this region to address several ecological questions. To test the predictability of species loss, nested species compositions will be analyzed. To assess historic losses, contemporary species presence data will be compared to historical data collected by John T. Curtis and colleagues for these forests. Patterns of historical decline will be compared to current patterns of nestedness among habitat patches to assess how well current patterns of nestedness reflect historical processes. Hierarchical spatial sampling will allow us to construct species-area curves for comparisons across community and soil types. These results will improve our understanding of natural community dynamics, historical shifts in these communities, and current mechanisms of species loss.

9974041许多地区的沃勒植物群落正在以前所未有的速度丧失物种。虽然造成这些损失的机制各不相同，而且往往很难确定，但似乎有一个总的趋势，决定了哪些物种最容易丧失。稀有和本地物种通常面临更大的局部灭绝风险，物种丧失的模式往往导致大多数栖息地斑块包含常见和广泛的物种。栖息地碎片化、历史干扰机制的转变、外来物种的入侵以及白尾鹿数量增加的食草性似乎都是导致不同生境中白尾鹿数量减少的直接机制。这项研究将调查威斯康星州北部和密歇根州上半岛森林中林下植物群落的群落组成和物种损失的格局，以此来了解这些损失的性质、程度和机制。数据将从分布在该地区六种群落/土壤类型的120多个地点收集，以解决几个生态问题。为了测试物种损失的可预测性，将分析嵌套物种的组成。为了评估历史损失，当代物种存在的数据将与约翰·T·柯蒂斯和他的同事收集的这些森林的历史数据进行比较。历史衰落的模式将与栖息地之间当前的筑巢模式进行比较，以评估当前的筑巢模式在多大程度上反映了历史进程。分级空间抽样将允许我们构建物种-面积曲线，用于跨群落和土壤类型的比较。这些结果将提高我们对自然群落动态、这些群落的历史变迁以及当前物种丧失机制的理解。