REU: Dynamics of Tropical Forest Seed Banks: Seed Predatorsas Determinants of Forest Regeneration Patterns and Plant- frugivore Coevolution

种子休眠机制广泛存在于热带地区， 定植于小规模扰动的植物（例如， 树倒），并推测进化，因为分散存款最 在不适当的生境中的种子（即，在完好的森林下面 檐篷）。 大多数殖民者确实在缝隙形成之前到达， 但是在间隙之前种子在土壤中的典型“停留时间” 信息不详。 种子在土壤中能存活多久 这取决于它们被“移除”的速率， 捕食者和超过固有的生存能力限制。 率 从土壤中移除对这种 “先锋”植物及其所在的群落：物种 从自然或人为恢复的斑块组成 干扰主要取决于种子的成分 银行在骚乱发生时。 此外，种子去除率 调节与不同成熟度相关的适合度增量 时间表和不同动物的传播。 本研究 将利用大量的发芽背景数据， 要求，种子休眠，鸟类产生的种子阴影， 哥斯达黎加的先锋植物来评估这些影响。 通过 几个受控的，重复的田间实验，P.I.将 测量种子进入土壤和从土壤中移出的速率 银行，然后检查种子人口的后果， 群落结构和成熟物候的演变， 植物与传播者的关系 这项工作将具有重要意义 对热带森林动态分析的影响。

Seed dormancy mechanisms are widespread among tropical plants that colonize small-scale disturbances (e.g., treefalls),and presumably evolved because disperses deposit most seeds in inappropriate habitats (i.e., beneath intact forest canopies). Most colonists indeed arrive before gap formation, but the typical "residence time" of seeds in the soil before gap information is unknown. How long seeds persist in the soil is dependent upon the rates at which they are "removed," both by predators and by exceeding inherent limits of viability. Rates of removal from the soil have profound consequences for such "pioneer" plants and the communities in which they occur: species composition in patches recovering from natural or anthropogenic disturbance is largely determined by the composition of the seed bank at the time of disturbance. In addition, seed removal rates mediate the fitness increments associated with different ripening schedules and with dispersal by different animals. This study will take advantage of extensive background data on germination requirements, seed dormancy, and bird-generated seed shadows in Costa Rican pioneer plants to evaluate these effects. Through several controlled, replicated field experiments, the P.I. will measure rates if seed input to and removal from the soil seed bank, and then examine the consequences of seed demography for community structure and the evolution of ripening phenologies and plant-disperser relationships. This work will have important implications for analyses of tropical forest dynamics.