Effects of landscape modification on biodiversity patterns and processes

景观改造对生物多样性模式和过程的影响

• 批准号: 341932-2008
• 负责人: Wagner, Helene
• 金额: $ 1.46万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2009
• 资助国家: 加拿大
• 起止时间: 2009-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=429952
• 关键词: Effects; landscape; modification; biodiversity; patterns

Landscape spatial and temporal heterogeneity shapes diversity patterns at the levels of local communities, populations, and metacommunities, i.e., regional sets of local communities linked by dispersal: (1) differences in site conditions and disturbance create a mosaic of local plant communities that vary in the dominant processes governing their species composition and diversity, (2) the spatial configuration of patches of similar habitat type as well as the nature of the intervening habitat types (matrix quality) affect dispersal and gene flow, with important effects on genetic diversity and population persistence, and (3) patch size and spatial isolation affect immigration and extinction rates, with consequences for the relationship between local and regional diversity. These effects have rarely been tested in landscape-scale experiments, as large experimental areas are generally not available, experimental manipulation would be very costly and would need to run for many years to show the hypothesized long-term effects. An applied landscape connectivity project was established in 1989 to connect and maintain calcareous dry grasslands by improving abandoned sites (e.g., removal of woody species) and re-connecting sites through rotational sheep grazing. My lab and I will repeat the extensive baseline vegetation surveys (after 20 years) and combine them with simulation modeling, molecular genetics, spatial analysis and scaling of species diversity, to address three main questions: (1) does a change in site management lead to differences in the spatial community structure indicating a change in plant functional group composition and inter-specific interactions?, (2) does a change in habitat configuration and dispersal vectors lead to a change in gene flow patterns of plants (both pollen and seed dispersal)?, and (3) does a change in habitat configuration and dispersal vectors lead to a change in colonization rates in plants, with predictable effects on the relationship between local and regional species diversity? Understanding how the different processes shaping plant species diversity patterns interact will help to predict the effects of human landscape modification and improve the effectiveness of landscape-scale conservation management.

景观的时空异质性在当地社区、种群和准生境水平上形成多样性格局，即，通过分散联系在一起的地方社区的区域集合：（1）不同的立地条件和干扰造成了当地植物群落的镶嵌，这些植物群落在支配其物种组成和多样性的主导过程中存在差异，（2）相似生境类型斑块的空间配置以及介于其间的生境类型的性质（3）斑块大小和空间隔离度影响迁入和绝灭速率，影响局部和区域多样性之间的关系。 这些影响很少在小规模实验中得到检验，因为一般没有大的实验区域，实验操作将非常昂贵，需要运行多年才能显示假设的长期影响。1989年建立了一个应用景观连接项目，通过改善废弃场地（例如，移除木本物种）和通过轮流放牧绵羊重新连接地点。我和我的实验室将重复广泛的基线植被调查（20年后），并将其与模拟建模，分子遗传学，空间分析和物种多样性的缩放相结合，以解决三个主要问题：（1）场地管理的变化是否会导致空间群落结构的差异，表明植物功能群组成和种间相互作用的变化？(2)生境配置和传播媒介的变化是否会导致植物基因流动模式（花粉和种子传播）的变化？以及（3）生境配置和传播媒介的变化是否会导致植物定殖率的变化，并对当地和区域物种多样性之间的关系产生可预测的影响？了解植物物种多样性格局形成的不同过程是如何相互作用的，将有助于预测人类景观改造的影响，提高生态系统规模保护管理的有效性。