Initial colonization, community assembly and ecosystem function: fungal colonist traits and litter biochemistry mediate decay rate
Initial colonization, community assembly and ecosystem function: fungal colonist traits and litter biochemistry mediate decay rate
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DOI：
10.1111/mec.13361
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发表时间：
2015-10-01
影响因子：
4.9
通讯作者：
Zak, Donald R.
中科院分区：
文献类型：
--
作者：
Cline, Lauren C.;Zak, Donald R.
优先效应是塑造生物群落和生态系统过程的重要生态力量，早期殖民者的建立通过竞争排斥和栖息地改变改变了后来到达的生物的殖民成功。然而，我们不了解哪些生物和非生物条件导致强烈的优先效应和持久的历史偶然性。使用腐食性真菌在模型叶分解系统中，我们研究了初始殖民的组成和功能后果是否依赖于初始殖民者性状，资源可用性或其组合。为了测试这些想法，我们factorially操纵落叶生物化学和初始真菌定植者身份，量化随后的社区组成，使用中性遗传标记，和社区功能特征，包括酶的潜力和叶腐烂率。在前3个月，初始殖民者的呼吸速率和生理能力，降解植物碎屑的真菌群落组成和叶片腐烂的显着决定因素，表明快速增长和木质素降解潜力的早期殖民者的贡献改变轨迹的社区大会。此外，最初的殖民橡树叶产生越来越多的真菌群落组成和酶的潜力不同的轨迹，表明较强的初始殖民者的影响，能源贫乏的基板。总之，这些观察结果提供的证据表明，初始殖民化的影响，以及随后的后果凋落物腐烂，是依赖于基板的生物化学和生理特性在一个区域物种池。由于微生物腐烂的植物碎屑是重要的全球碳存储，我们的研究结果表明，了解的机制，初始条件改变优先级的影响，在社区集会可能是关键，以了解生态系统层面的驱动程序的过程。
Priority effects are an important ecological force shaping biotic communities and ecosystem processes, in which the establishment of early colonists alters the colonization success of later-arriving organisms via competitive exclusion and habitat modification. However, we do not understand which biotic and abiotic conditions lead to strong priority effects and lasting historical contingencies. Using saprotrophic fungi in a model leaf decomposition system, we investigated whether compositional and functional consequences of initial colonization were dependent on initial colonizer traits, resource availability or a combination thereof. To test these ideas, we factorially manipulated leaf litter biochemistry and initial fungal colonist identity, quantifying subsequent community composition, using neutral genetic markers, and community functional characteristics, including enzyme potential and leaf decay rates. During the first 3months, initial colonist respiration rate and physiological capacity to degrade plant detritus were significant determinants of fungal community composition and leaf decay, indicating that rapid growth and lignolytic potential of early colonists contributed to altered trajectories of community assembly. Further, initial colonization on oak leaves generated increasingly divergent trajectories of fungal community composition and enzyme potential, indicating stronger initial colonizer effects on energy-poor substrates. Together, these observations provide evidence that initial colonization effects, and subsequent consequences on litter decay, are dependent upon substrate biochemistry and physiological traits within a regional species pool. Because microbial decay of plant detritus is important to global C storage, our results demonstrate that understanding the mechanisms by which initial conditions alter priority effects during community assembly may be key to understanding the drivers of ecosystem-level processes.