Amphibian population dynamics in disturbed landscapes

世界各地的两栖动物种群正面临着种群数量下降和灭绝的问题，比鸟类或哺乳动物更严重。由于其复杂的生命周期(水生和陆地生命阶段)，池塘繁殖的两栖动物构成了一个有趣的挑战。池塘繁殖的两栖动物在一年中的不同阶段和不同时间使用不同的栖息地类型。与其他脊椎动物相比，特定景观中栖息地类型之间的迁移量是有限的(1公里)，这使得两栖动物成为研究栖息地扰动对迁移量和人口参数影响的理想候选者。然而，量化与人类干扰有关的种群动态所需的几个参数(例如，生存、招募)仍有待估计。这在北部地区尤其如此，在许多物种的北部范围限制，伐木活动向北移动，道路正在修建以获取采矿或森林资源。目前的提案侧重于模拟人类干扰景观中的两栖动物种群动态，并结合了基本组成部分和应用组成部分。在这项研究计划中，我将通过重复和操纵野外实验和捕获标记重新捕获研究，量化道路和森林做法对几种池塘繁殖的两栖动物物种的人口统计参数的影响。在接下来的五年里，我的研究目标将包括：1)量化道路和汽车交通对两栖动物池塘定居的影响；2)量化道路对个体繁殖概率、生存和健康的影响及其对种群持久性的影响；3)量化栖息地复杂性(粗木质碎片和树冠开阔)对两栖动物人工池塘定居的影响；4)估计生命早期经历的环境条件对后期生命阶段生存的遗留影响。除了生活史策略和遗留影响之外，我的工作的新的和重要的方面包括道路和木质垃圾对北部地区两栖动物种群过程的作用。

Amphibian populations worldwide are facing population declines and extinctions, more so than either birds or mammals. With their complex life cycles (aquatic and terrestrial life stages), pond-breeding amphibians pose an interesting challenge. Pond-breeding amphibians use different habitat types during different life stages and at different times of the year. Movements between habitat types in a given landscape are limited relative to other vertebrates (< 1 km), which makes amphibians ideal candidates to investigate the effects of habitat disturbances on movements and demographic parameters. Yet, several parameters (e.g., survival, recruitment) necessary to quantify population dynamics in relation to human disturbances remain to be estimated. This is especially true in boreal regions, at the northern range limit of many species, with logging activities moving North and roads being built to access mining or forest resources. The current proposal focuses on modeling Amphibian Population Dynamics in Human-disturbed Landscapes, and combines fundamental and applied components. In this research program, I will quantify the effects of roads and forest practices on the demographic parameters of several pond-breeding amphibian species, through replicated and manipulative field experiments and capture-mark recapture studies. Over the next five years, my research objectives will consist in: 1) quantifying the effect of roads and car traffic on amphibian pond colonization; 2) quantifying the effect of roads on breeding probability, survival, and fitness of individuals, and their repercussions on population persistence; 3) quantifying the effect of habitat complexity (coarse woody debris and canopy openness) on the colonization of artificial ponds by amphibians; and 4) estimating carry-over effects of environmental conditions experienced during early life stages on the survival at later life stages. Beyond life history strategies and carry-over effects, the novel and significant aspects of my work include the role of roads and woody debris on amphibian population processes in boreal regions.