Dissertation Research: Local Controls of Landscape Abundance Patterns of a Stream Salamander.

0105091博尔格这项研究调查了当地和规模的控制丰富的春季蝾螈，Gyrinophilus porphriticus（Plethodontidae），在整个美国东北部的源头流。 春季蝾螈丰度呈负相关（1）木材收获后沉积物在流中的积累，（2）捕食性溪鳟的存在，和（3）距离其他流是潜在的移民来源。 实验探索沉积水平和溪鳟对春季蝾螈生存的综合影响提出。 这些实验将解决这一假设，即收获后的沉积物输入减少溪鳟所占据的溪流中的幼春蝾螈的生存，减少了河床的岩石之间的避难所的可用性。物种丰富度是由当地和在生态系统尺度上的因素控制的。 地方控制包括种群内繁殖率和存活率。 景观尺度控制是种群间扩散率的函数。景观规模的控制已被证明是至关重要的物种在自然系统中受人类活动影响的持久性，但在流系统知之甚少。 这些实验将阐明栖息地的干扰如何影响物种的相互作用，在源头流，并允许评估的缓解影响的支流分散。 这项分析将扩大对溪流物种基本生态学的理解，并显着提高木材采伐后这些物种恢复策略的有效性。

0105091BolgerThis research investigates local and landscape-scale controls on the abundance of the spring salamander, Gyrinophilus porphyriticus (Plethodontidae), in headwater streams throughout the northeastern United States. Spring salamander abundance is negatively related to (1) post-timber harvest accumulation of sediment in streams, (2) the presence of predatory brook trout, and (3) distance to other streams which are potential immigrant sources. Experiments exploring the combined effects of sediment level and brook trout on spring salamander survival are proposed. These experiments will address the hypothesis that post-harvest sediment input reduces the survival of larval spring salamanders in streams occupied by brook trout by reducing the availability of refuges among the rocks of the streambed. Species abundance is controlled by factors acting both locally and at the landscape-scale. Local controls include within-population reproduction and survival rates. Landscape-scale controls are a function of dispersal rates among populations. Landscape-scale controls have been shown to be critical to species persistence in natural systems affected by human activities, but are poorly understood in stream systems. These experiments will elucidate how habitat disturbance affects species interactions in headwater streams and will permit the assessment of the mitigating influence of among-stream dispersal. This analysis will expand understanding of the basic ecology of stream species, and significantly improve the effectiveness of recovery strategies for these species following timber harvest.