The persistence of beaver-induced geomorphic heterogeneity and organic carbon stock in river corridors: Beaver-induced heterogeneity
The persistence of beaver-induced geomorphic heterogeneity and organic carbon stock in river corridors: Beaver-induced heterogeneity
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海狸引起的地貌异质性和河流廊道中有机碳储量的持续性：海狸引起的异质性
DOI：
10.1002/esp.4486
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发表时间：
2018
影响因子：
3.3
通讯作者：
Wohl, Ellen
中科院分区：
文献类型：
--
作者：
Laurel, DeAnna;Wohl, Ellen
海狸被广泛认为是生态系统工程师，因为它们能够通过建造水坝、挖掘小运河和改变河岸植被来塑造河流走廊。通过这些活动，海狸创造了海狸草甸，这是河流走廊的一部分，其特征是地貌异质性高、下游通量衰减和生物多样性。我们检查了美国科罗拉多州落基山国家公园东侧的七个海狸草甸，其中海狸活动程度不同。我们将这些站点分为四类：活跃、部分活跃、最近废弃（< 20 年）和长期废弃（> 30 年）。我们描述了河流廊道内的地貌单元，并计算了与海狸活动类别相关的表面地貌异质性指标。我们还使用地下地貌异质性（土壤湿度、土壤深度、粘土含量百分比、有机碳浓度）的测量来比较河狸草甸类别之间的异质性。最后，我们计算每个草地上部 1.5 米内的有机碳储量，并将这些值与海狸活动类别进行比较。我们发现，地表地貌异质性和平均土壤湿度仅在活跃的草甸和长期废弃的草甸之间存在显着差异，这表明在海狸废弃草甸后，地表地貌异质性和平均土壤湿度会随着时间的推移而呈非线性下降。与河狸草甸类别相关的土壤深度和有机碳储量并没有一致的差异，这表明在河狸放弃草甸后，培育深层洪泛区土壤的更大规模地质控制可以继续维持大量有机碳储量。这些结果还表明，在河狸大部分放弃河流走廊后，生态系统工程的影响可以持续近三十年。 © 2018 约翰威利父子公司。
Beavers are widely recognized as ecosystem engineers for their ability to shape river corridors by building dams, digging small canals, and altering riparian vegetation. Through these activities, beavers create beaver meadows, which are segments of river corridor characterized by high geomorphic heterogeneity, attenuation of downstream fluxes, and biodiversity. We examine seven beaver meadows on the eastern side of the Rocky Mountain National Park, Colorado, USA with differing levels of beaver activity. We divide these sites into the four categories of active, partially active, recently abandoned (< 20 years), and long abandoned (> 30 years). We characterize geomorphic units within the river corridor and calculate metrics of surface geomorphic heterogeneity relative to category of beaver activity. We also use measures of subsurface geomorphic heterogeneity (soil moisture, soil depth, percent clay content, organic carbon concentration) to compare heterogeneity across beaver meadow categories. Finally, we calculate organic carbon stock within the upper 1.5 m of each meadow and compare these values to category of beaver activity. We find that surface geomorphic heterogeneity and mean soil moisture differ significantly only between active and long abandoned meadows, suggesting a non‐linear decrease with time following beaver abandonment of a meadow. Soil depth and organic carbon stock do not differ consistently in relation to category of beaver meadow, suggesting that larger‐scale geologic controls that foster deep floodplain soils can continue to maintain substantial organic carbon stocks after beavers abandon a meadow. These results also indicate that the effects of beaver ecosystem engineering can persist for nearly three decades after the animals largely abandon a river corridor. © 2018 John Wiley & Sons, Ltd.