Collaborative Research: Landscape Patterns of Pollen Movement in Declining Populations of California Valley Oak, Quercus Lobata

合作研究：加州谷橡树、栎树种群数量下降中花粉运动的景观模式

• 批准号: 0242422
• 负责人: Victoria Sork
• 金额: $ 29.74万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-14 至 2005-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0242422&HistoricalAwards=false
• 关键词: Collaborative; Research; Landscape; Patterns; Pollen

Sork0089445Fragmentation and population declines jeopardize the survival of many species. Excessive reproductive isolation can cause a loss of valuable alleles, decrease genetic variation, induce inbreeding depression, reduce demographic fitness, and lead to reproductive failure. When tree populations are reduced to scattered and clustered individuals, pollen movement is critical to connectivity. This project develops a novel approach that can cover landscape-scale areas and can be integrated into spatially explicit simulation modeling of landscape changes. These new tools are deployed to investigate a threatened tree species, California Valley oak (Quercus lobata). Using allozyme and microsatellite genotypes, the investigators examine three objectives: (1) They will characterize reproductive isolation of individual trees in landscapes with variable conspecific density. (2) They will examine the impact of adult genetic structure and temporal heterogeneity of pollen pools on estimates of pollen movement. (3) They will incorporate estimated parameters into geographic models to simulate the impact of historical and future population decline.This project represents an excellent case study of the evolutionary dynamics of gene flow and its landscape scale conservation/restoration consequences. It will be applied to a critical California tree species experiencing habitat loss and degradation from residential and agricultural development, a situation in need of information for future management and policy decisions. This research will dovetail issues from evolutionary biology, conservation biology, geography, and public policy of the threatened species.

碎片化和人口减少危及许多物种的生存。过度的生殖隔离会导致有价值的等位基因丢失，减少遗传变异，诱发近交抑制，降低人口适应度，导致生殖失败。当树木种群减少到分散和聚集的个体时，花粉运动对连通性至关重要。该项目开发了一种新颖的方法，可以覆盖景观尺度区域，并可以集成到景观变化的空间显式模拟建模中。这些新工具被用来调查一种受威胁的树种，加利福尼亚山谷橡树（栎）。利用等位酶和微卫星基因型，研究人员研究了三个目标：(1)他们将表征不同密度景观中单个树木的生殖隔离。(2)研究花粉池的成虫遗传结构和时间异质性对花粉运动估计的影响。(3)将估算参数纳入地理模型，模拟历史和未来人口下降的影响。该项目代表了基因流动的进化动力学及其景观尺度保护/恢复后果的极好案例研究。它将应用于加州一种因居住和农业发展而遭受栖息地丧失和退化的重要树种，这种情况需要为未来的管理和政策决策提供信息。这项研究将结合进化生物学、保护生物学、地理学和濒危物种公共政策等方面的问题。