Dissertation Research: Does the Presence and Spatial Arrangement of Co-flowering Species Affect Threshold Critical Population Densities in Plants?

在小的或稀疏的种群中，植物可能没有足够的传粉者来产生足够的种子来代替死亡的个体。因此，低于某个阈值大小或密度的种群可能注定要灭绝。如果一个共存的植物物种共享传粉媒介，它的存在可以通过增加当地的花密度来增加稀疏种群中植物的访花率和种子产量。这可能会降低种群持续存在的阈值密度。提出的实验将确定在何种条件下植物物种可以降低或提高其他植物物种的阈值种群密度，使用不同密度的植物实验阵列，有或没有共存的植物，并测量传粉者的访问，花的花粉接收，以及产生的果实和种子的数量。实验数据，结合自然种群中个体的生长和生存数据，将用于种群模型，以确定每种密度的种群和物种处理是否持续存在。随着景观变得更加破碎和退化，植物种群可能会变得更小、更稀疏。这个项目将告诉生态学家和自然资源保护主义者，在其他物种存在的情况下，小种群或稀疏种群是否更有可能持续存在。此外，该项目将为土地管理者提供信息，帮助他们在恢复的地区重新建立本地植物种群。

Plants in small or sparse populations may receive insufficient pollinator visits to produce enough seeds to replace dying individuals. Thus, populations below some threshold size or density may be doomed to extinction. If a co-occurring plant species shares pollinators, its presence may increase both visitation and seed production of plants in sparse populations by increasing local flower density. This may lower the threshold density above which populations persist. Experiments proposed will determine conditions under which plant species can lower or raise threshold population densities of other plant species, using experimental arrays of plants at different densities, with and without co-occurring plants, and measuring pollinator visitation, pollen receipt by flowers, and the numbers of fruits and seeds produced. Experimental data, combined with data on growth and survival of individuals in natural populations, will be used in population models to determine whether populations of each density and species treatment persist.Plant populations will likely become smaller and sparser as the landscape becomes more fragmented and degraded. This project will inform ecologists and conservationists about whether small or sparse populations are more likely to persist in the presence of other species. Also, this project will inform land managers working to re-establish populations of native plants in restored areas.