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The influence of energy availability on population-, community-, and ecosystem-level processes in cave stream ecosystems.

机译：能源供应对洞穴溪流生态系统中人口，社区和生态系统级过程的影响。

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摘要

Detritus from surface environments supplies the energy that shapes community structure and fuels productivity in most cave ecosystems. However, only qualitative descriptions of cave energy dynamics are available, hindering development of quantitative models describing how energy availability influences cave ecosystem processes. In contrast, the importance of detritus for surface ecosystem processes has been appreciated for decades. This dissertation begins to close this knowledge gap by exploring how energy availability shapes cave stream ecosystem processes at multiple organizational levels (ecosystem-, community-, population-level) and time scales (evolutionary vs. ecological).;Chapter Two examined potential correlations between litter breakdown rates and detrital storage, but found no such relationships among four cave streams. However, surface-adapted species dominated macroinvertebrate biomass, suggesting that surface-adapted taxa can have a significant influence on cave ecosystem processes. In Chapter Three, a whole-reach litter amendment was conducted to explore the influence of enhanced detrital inputs on cave community structure and energy flow. While the litter amendment significantly increased total consumer biomass via assimilation of amended corn-litter, the response was dictated by evolutionary history. Biomass of surface-adapted taxa increased significantly following the amendment, while biomass of obligate cave species remained unchanged. As in Chapter Two, consumer biomass was dominated by surface-adapted taxa, reinforcing their role in cave ecosystem processes relative to cave-adapted taxa, the traditional focus of cave studies.;Chapters Four and Five utilized a 5+-year mark-recapture data set on the cave-adapted crayfish Orconectes australis to explore how energy availability has shaped its evolutionary history and population dynamics. Time-to-maturity, age-at-first-reproduction, and longevity of O. australis were substantially longer than those estimated for most crayfish species, indicating evolution of a K-selected life history. Chapter Five found that biomass and secondary production of O. australis were positively related to resource availability. Energetic models indicated resource deficits were not present, but that nearly all prey production is necessary to support each O. australis population. Thus, inter- and intra-specific competition for resources within caves is likely high. Collectively, Chapters Four and Five provide the first quantitative explanation of why K-selected life histories are an evolutionary advantage to obligate cave taxa like O. australis..
机译：在大多数洞穴生态系统中，地表环境中的碎屑会提供能量，从而改变群落结构并提高生产力。但是，只能对洞穴能量动力学进行定性描述，这阻碍了描述能源可利用性如何影响洞穴生态系统过程的定量模型的发展。相反，碎屑对地表生态系统过程的重要性已被人们认识了几十年。本论文通过探索能量的可获得性如何在多个组织层面（生态系统，社区，人口层面）和时间尺度（进化与生态）上塑造洞穴溪流生态系统过程，从而弥合了这一知识鸿沟。第二章研究了两者之间的潜在相关性。凋落物分解率和碎屑存储量，但在四个洞穴流之间没有发现这种关系。然而，表面适应性物种主导了大型无脊椎动物生物量，这表明表面适应性分类单元可能对洞穴生态系统过程产生重大影响。在第三章中，进行了全范围垃圾修正，以探讨增加的碎屑输入对洞穴群落结构和能量流的影响。废弃物改良剂通过同化后的玉米废弃物的同化显着增加了总消费者生物量，但这种反应是由进化史决定的。修正后，表面适应性分类单元的生物量显着增加，而专性洞穴物种的生物量保持不变。与第二章一样，消费者生物量以适应表面的分类单元为主导，相对于适应洞穴的传统分类学（洞穴研究的传统重点）而言，增强了它们在洞穴生态系统过程中的作用;第四和第五章利用了5年以上的标记回收期。适应洞穴的小龙虾的数据集，以探索能源的可利用性如何影响其进化历史和种群动态。澳洲螯虾的成熟时间，第一次繁殖的年龄和寿命大大长于大多数小龙虾物种的估计时间，这表明其选择了K型生命史。第五章发现澳大利亚南方稻的生物量和二次生产与资源的利用成正相关。能量模型表明不存在资源短缺，但几乎所有猎物的生产都是支持每个澳大利亚稻种群的必要条件。因此，洞穴内资源的种间和种内竞争可能很高。总的来说，第四章和第五章提供了第一个定量的解释，说明为什么选择K的生活史是专为像O. austtralis这样的洞穴类群提供进化优势的原因。

著录项

  • 作者

    Venarsky, Michael Patrick.;

  • 作者单位

    The University of Alabama.;

  • 授予单位 The University of Alabama.;
  • 学科 Ecology.;Zoology.
  • 学位 Ph.D.
  • 年度 2012
  • 页码 154 p.
  • 总页数 154
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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