Can large carnivores change streams via a trophic cascade?
Can large carnivores change streams via a trophic cascade?
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DOI：
10.1002/eco.2048
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发表时间：
2019-01-01
期刊：
影响因子：
2.6
通讯作者：
Ripple, William J.
中科院分区：
文献类型：
--
作者：
Beschta, Robert L.;Ripple, William J.
在19世纪末和20世纪初，美国怀俄明州黄石国家公园的大型食肉动物遭到迫害，导致灰狼（Canis lupus）和美洲狮（Puma concolor）灭绝。此后不久，落基山麋鹿（Cervus elaphus）对河岸植物群落的食草性增加，在公园的北方有蹄类动物冬季分布区或“北方分布区”广泛分布。狼在1995-1996年被重新引入，再次完成了公园的大型食肉动物协会。在2004年和2017年，我们对盖耶杨柳（Salix geyeriana）进行了采样，这是一种常见的高大杨柳，沿着北方山脉中部的Blacktail Deer Creek的西叉和东叉。结果表明，高水平的麋鹿食草动物在20世纪90年代，在过去的几十年中，不仅继续保持柳树短，一般= 200厘米（x在酒吧= 310厘米）是普遍存在的，树冠覆盖流，基本上没有在1995年，增加到43%和沿着西叉和东叉，分别为93%。这些最近增加的高杨柳高度，更大的树冠覆盖，植被良好的河岸，以及最近开发的一个插入洪泛区都指向河岸/水生生态系统开始恢复。总体而言，结果是一致的一个小规模的营养级联，即重新引入狼，与其他大型食肉动物合作，似乎有足够的减少麋鹿食草动物在河岸地区开始恢复黑尾鹿溪的河岸植物群落和流通道。
Large carnivores were persecuted in Yellowstone National Park, WY, USA, during the late 1800s and early 1900s, leading to extirpation of grey wolves (Canis lupus) and cougars (Puma concolor). Soon thereafter increased herbivory of riparian plant communities by Rocky Mountain Elk (Cervus elaphus) became widespread in the park's northern ungulate winter range or "northern range." Wolves were reintroduced in 1995-1996, again completing the park's large carnivore guild. In 2004 and 2017, we sampled Geyer willow (Salix geyeriana), a commonly occurring tall willow, along the West and East Forks of Blacktail Deer Creek in the central portion of the northern range. Results indicated high levels of elk herbivory in the 1990s, as in previous decades, not only continued to keep willows short, generally = 200 cm (x over bar = 310 cm) were prevalent, and canopy cover over the stream, essentially absent in 1995, had increased to 43% and 93% along the West Fork and East Fork, respectively. These recent increases in tall willow heights, greater canopy cover, well-vegetated streambanks, and the recent development of an inset floodplain all pointed towards a riparian/aquatic ecosystem beginning to recover. Overall, results were consistent with a landscape-scale trophic cascade, whereby reintroduced wolves, operating in concert with other large carnivores, appear to have sufficiently reduced elk herbivory in riparian areas to initiate the recovery of Blacktail Deer Creek's riparian plant communities and stream channels.