Evidence of biogeomorphic patterning in a low‐relief karst landscape
Evidence of biogeomorphic patterning in a low‐relief karst landscape
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低浮雕喀斯特景观中生物地貌格局的证据
DOI：
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发表时间：
2014
期刊：
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通讯作者：
L. Kobziar
中科院分区：
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作者：
A. Watts;D. Watts;M. Cohen;J. Heffernan;D. McLaughlin;Jonathan B. Martin;D. Kaplan;T. Osborne;L. Kobziar
图案化景观往往是生物控制地貌过程的证据，是对不同空间尺度上的耦合生态系统过程的反应。局部尺度上的自我强化过程扩大了斑块，而在一定距离上运作的自我抑制过程则限制了扩张。在佛罗里达西南部的大柏树国家保护区（BICY），孤立的森林湿地洼地（柏树圆顶）似乎均匀地分布在短水周期沼泽和松树高地的马赛克中。为了检验这一假设，明显的图案是定期的，我们的特点是频率分布和空间格局的植被群落，地表和基岩海拔，土壤性质（厚度和磷含量）。最近邻距离表明强烈显着的湿地空间过度分散，基岩高程表现出周期性的空间自相关性，这两个观测结果是一致的定期图案。基岩海拔和土壤磷明显双峰，这表明湿地斑块的发展强烈的正反馈。土壤表面高程表现出较弱的双峰性，表明表面形态的平滑，一些组合的沉积物运输，矿物再沉淀和有机质的生产。基岩高程的显着负自相关的规模类似于湿地间距表明存在远端负反馈补丁扩展。这些研究结果支持的推论，定期图案，并与水文周期，植被生产力和基岩溶解之间的存在当地的正反馈是一致的。这些过程最终受到远端负反馈的约束，可能是由景观尺度对水量的限制所引起的，从而使这一机制成为可能。版权所有© 2014约翰威利父子有限公司.
Patterned landscapes are often evidence of biotic control on geomorphic processes, emerging in response to coupled ecosystem processes acting at different spatial scales. Self‐reinforcing processes at local scales expand patches, while self‐inhibiting processes, operating at a distance, impose limits to expansion. In Big Cypress National Preserve (BICY) in southwest Florida, isolated forested wetland depressions (cypress domes) appear to be evenly distributed within a mosaic of short‐hydroperiod marshes and pine uplands. To test the hypothesis that the apparent patterning is regular, we characterized frequency distributions and spatial patterns of vegetation communities, surface and bedrock elevation, and soil properties (thickness and phosphorus content). Nearest neighbor distances indicate strongly significant wetland spatial overdispersion, and bedrock elevations exhibited periodic spatial autocorrelation; both observations are consistent with regular patterning. Bedrock elevations and soil P were clearly bimodal, suggesting strong positive feedbacks on wetland patch development. Soil‐surface elevations exhibited weaker bimodality, indicating smoothing of surface morphology by some combination of sediment transport, mineral reprecipitation, and organic matter production. Significant negative autocorrelation of bedrock elevations at scales similar to wetland spacing suggest the presence of distal negative feedbacks on patch expansion. These findings support the inference of regular patterning, and are consistent with the presence of local positive feedbacks among hydroperiod, vegetation productivity and bedrock dissolution. These processes are ultimately constrained by distal negative feedbacks, potentially induced by landscape scale limitations on the water volume required to enable this biogeomorphic mechanism. Copyright © 2014 John Wiley & Sons, Ltd.