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

破碎化和种群数量的下降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的丢失，减少遗传变异，诱发近交衰退，降低人口适合度，并导致生殖失败。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的方法，可以覆盖小尺度区域，并可以集成到空间显式模拟景观变化建模。这些新的工具部署到调查受威胁的树种，加州谷橡树（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）他们将表征景观中不同同种密度的个体树木的生殖隔离。(2)他们将研究成年遗传结构和花粉库的时间异质性对花粉运动估计的影响。(3)他们将把估计的参数纳入地理模型，以模拟历史和未来人口下降的影响。该项目是一个很好的案例研究的基因流的进化动力学及其景观规模的保护/恢复后果。它将被应用到一个关键的加州树种经历栖息地丧失和退化的住宅和农业发展，需要为未来的管理和政策决策的信息的情况。 这项研究将从进化生物学、保护生物学、地理学和受威胁物种的公共政策等方面进行研究。

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.