Disturbance legacies of historic tie-drives persistently alter geomorphology and large wood characteristics in headwater streams, southeast Wyoming
Disturbance legacies of historic tie-drives persistently alter geomorphology and large wood characteristics in headwater streams, southeast Wyoming
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历史性联系驱动的干扰遗产持续改变怀俄明州东南部源头溪流的地貌和大型木材特征
DOI：
10.1016/j.geomorph.2014.10.029
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发表时间：
2015
期刊：
影响因子：
3.9
通讯作者：
K. Dwire
中科院分区：
文献类型：
--
作者：
C. Ruffing;M. Daniels;K. Dwire
在森林地区，入流木材被认为是河流形态的一个组成部分。然而，很少有研究评估了历史上的木材清除活动的遗留影响和相关的影响，通道形态，当代木材装载和招聘。本研究调查的作用，历史性的领带驾驶，一个广泛的渠道干扰遗产，在塑造当今的流通道条件在南怀俄明州。地貌和河岸调查被用来评估三套配对的领带驱动和非驱动的研究达到的干扰程度和恢复程度。领带驱动流窄，浅，并具有较低的横截面粗糙度和较高的宽深比相比，非驱动流。研究达到一阶领带驱动流的特点主要是平面床的形态和极低丰度的木材相比，配对，非驱动达到。木材负载在二阶领带驱动的达到类似于非驱动的达到，但整体木材分布变化，更容易积累在堵塞。现有的木材负载在领带驱动河段表现出较窄的范围内的地貌功能，整体不太稳定，虽然相对状态的衰减是相似的所有河段。断面积，流功率，并达到坡度被确定为主要机制，推动木材保留在研究达到。这项研究的结果表明，当代通道形态和木材负荷继续反映干扰的历史，但尚未受到其他当代干扰的影响，预计会影响木材负荷，如树皮甲虫侵扰。
Instream wood is recognized as an integral component of stream morphology in forested areas. However, few studies have evaluated the legacy effects of historic wood removal activities and associated impacts on channel morphology, contemporary wood loading, and recruitment. This study investigates the role of historic tie-driving, a widespread channel disturbance legacy, in shaping present-day stream channel conditions in southern Wyoming. Geomorphic and riparian surveys were used to assess the extent of disturbance and degree of recovery within three sets of paired tie-driven and non-driven study reaches. Tie-driven streams were narrower, shallower, and had low cross-sectional roughness and higher width-to-depth ratios when compared to non-driven streams. Study reaches in first-order tie-driven streams were characterized by predominantly plane-bed morphologies and an extremely low abundance of wood compared to paired, non-driven reaches. Wood loads in second-order tie-driven reaches were similar to non-driven reaches, but overall wood distribution varied and was more likely to accumulate in jams. Existing wood loads in tie-driven reaches exhibited a narrower range of geomorphic functions and were less stable overall, although the relative state of decay was similar across all reaches. Basal area, stream power, and reach slope were identified as key mechanisms driving wood retention in the study reaches. The results of this study suggest that contemporary channel morphology and wood loads continue to reflect disturbance histories but have not yet been affected by other contemporary disturbances expected to influence wood loads such as bark beetle infestations.