RUI: The Contribution of Secondary Seed Dispersal to the Reproductive Success of "Wind-Dispersed" Pines

范德墙9708155 本研究的目的是确定一次风和二次风的相对贡献（动物散布贮藏）散布到四种种子质量不同的有翅种子的松树的繁殖成功：黑松（扭叶松; 7 mg/种子）、美国黄松（美国黄松; 55 mg）、杰弗里松（美国松; 146 mg）和糖松（蓝柏松; 288 mg）。 散布囤积动物为种子提供了几个重要的好处，包括传播，通常会将种子从源植物中带走，将种子埋在土壤中，并将种子藏在通常有利于幼苗建立的微生境中。 种子大小的变化预计会影响种子的空气动力学行为和种子对脊椎动物觅食者的吸引力（即，第一次和第二次扩散）。 随着种子大小的增加，风传播的相对有效性应该降低，动物介导的传播的相对有效性应该增加。 这项研究将为我们理解植物种子传播和繁殖成功，特别是关于次级传播的作用，这方面的研究很少。此外，这项研究还将提供信息，帮助林业人员更有效地管理这些具有经济价值的树木。 这些松树种子传播和幼苗建立的关键步骤知之甚少。 目前的假设，根据种子形态和球果物候，是这些松树风分散，动物几乎完全作为种子捕食者。 这项研究的结果将填补我们知识中的这一空白，并提供科学合理的数据，作为管理决策的基础。

Vander Wall 9708155 The objective of this research is to determine the relative contributions of primary (wind) and secondary (animal scatter hoarding) dispersal to the reproductive success of four species of pines with winged seeds that vary in seed mass: lodgepole pine (Pinus contorta; 7 mg/seed), ponderosa pine (Pinus ponderosa; 55 mg), Jeffrey pine (Pinus jeffreyi; 146 mg), and sugar pine (Pinus lambertiana; 288 mg). Scatter-hoarding animals provide several important benefits to the seeds, including dispersal that often carries the seed away from the source plant, burial of the seeds in soil, and caching the seed in microhabitats that often favor seedling establishment. The variation in seed size is expected to influence the aerodynamic behavior of the seed and the attractiveness of the seed to vertebrate foragers (i.e., both primary and secondary dispersal). As seed size increases, the relative effectiveness of wind dispersal should decrease and the relative effectiveness of animal-mediated dispersal should increase. This research will make fundamental contributions to our understanding of seed dispersal and reproductive success in plants, especially with regard to the role of secondary dispersal, which has received little study. Further, this study will also provide information that will help foresters more effectively manage these economically valuable trees. The critical steps of seed dispersal and seedling establishment are poorly understood for these pines. The current assumption, based on seed morphology and cone phenology, is that these pines are wind dispersed and that animals act almost exclusively as seed predators. The results of this research will fill this gap in our knowledge and provide scientifically sound data on which to base management decisions.