Dissertation Research: Dispersal Distance, Deposition Site,and Survivorship of Cassowary-Dispersed Seeds

在大多数热带森林中，动物性疾病是主要的扩散综合症。很少有研究直接解决热带植物从动物寄生中获得的选择优势，或者食果动物介导的种子传播对热带树木的人口统计学影响。关于热带动物迁徙后缺乏经验数据的原因是很难找到种子，这些种子是由食果性散布者存放的。通过储藏室传播种子是研究的理想系统，因为储藏室是专门的食果性动物，实际上是许多大种子树木和藤本植物的唯一传播者，通常在新几内亚广阔的未受干扰的森林中找到。最重要的是，它们的粪便中含有分散的种子，在研究地点数量众多，非常明显。种子将被标记上标签或小型无线电发射器，然后由毒气罐将其驱散。在视觉搜索中发现的标记种子和通过无线电跟踪发现的发射器种子将揭示传播距离，包括那些携带长距离传播的种子。将为发现的每个液滴测量内部液滴参数(例如，参数(例如，曝光度))。将对粪便进行长达三年的发芽、幼苗生长和存活监测。分析了内滴参数和立地参数对幼苗萌发、生长和成活的影响。有关传播距离、落点内参数和地点参数的数据将汇集在概率矩阵中，以检验已发表的关于脊椎动物介导的种子传播后果的假设。在研究的后半部分，将对扩散的影响进行实验检验。被圈养的毒窖排空的种子将被用来制造“伪粪便”，以检验基于对自然散布的种子的观察得出的假说。

Zoochory is the predominant dispersal syndrome in most tropical forests. Few studies directly address what selective advantages tropical plants gain from zoochory or what the demographic effects of frugivore-mediated seed dispersal are to tropical trees. The paucity of empirical data on tropical zoochory after removal stems from the extreme difficulty of finding seeds where they have been deposited by frugivorous dispersers. Seed dispersal by cassowaries is an ideal system for study because cassowaries are specialist frugivores, virtually the sole disperser for many large-seeded trees and lianas, and are commonly found in the vast undisturbed forests of New Guinea. Most importantly, their droppings which contain dispersed seeds are numerous and conspicuous at the study site. Seeds will be marked with tags or small radio-transmitters before cassowaries disperse them. Tagged seeds found in visual searches and transmitter-seeds found by radio tracking will reveal dispersal distances, including those seeds carried long distances. Within- dropping parameters (e.g. parameters (e.g. insolation) will be measured for every dropping found. Droppings will be monitored up to three years for germination, seedling growth, and survivorship. The effects of within-dropping parameters and site parameters on germination, growth and survivorship of seedlings will be analyzed. Data on dispersal distances, within-dropping parameters and site parameters will be pooled in probability matrices to test published hypotheses regarding the consequences of vertebrate mediated seed dispersal. In the second half of the study the effects of dispersal will be experimentally examined. Seeds voided by a captive cassowary to make "pseudo-droppings" to test hypotheses based on observations of naturally-dispersed seeds will be used.