Abstract

Potentilla anserina is a common invasive species of Patagonian wetlands. Although this species is commonly found in temporary habitats, where it establishes during the dry phase, the littoral zones of lakes are also susceptible, as water fluctuations make this habitat extremely variable in terms of water availability. Decay rates and nutrient release of P. anserina were compared with two native macrophyte species, Eleocharis pachycarpa and Schoenoplectus californicus, in two different freshwater environments: a temporary wetland, where P. anserina develops important stands, and the littoral zone of a lake not yet colonized by the invasive plant. Our results showed that both environments differed in nutrient concentrations, being higher in the temporary wetland. However, the invasive species decomposed faster in the littoral zone of the lake, due to the presence of the amphipod Hyallela patagonica in the litter bags. The invasive plant litter decomposed twice faster than the native species. The species with highest N content, E. pachycarpa, released more N in leachates. After 71 days of decomposition, P. anserina loss more C and gained more N than the native species, while the P content remained constant across the three species. Our results demonstrated that the introduction of an invasive species as P. anserina into new habitats would contribute with dissolved and particulate organic matter impacting nutrient cycling and invertebrate assemblages with consequences to the entire ecosystem.

中文翻译：

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北巴塔哥尼亚入侵和非入侵淡水环境中入侵委陵菜的凋落物分解

摘要

委陵菜委陵菜是巴塔哥尼亚湿地的常见入侵物种。尽管该物种通常在临时栖息地中发现，并在干旱阶段建立，但湖泊的沿海地区也很脆弱，因为水的波动使该栖息地在水的可利用性方面极为不同。衰减率和养分释放鹅绒委陵菜有两个本地种类植物，进行比较荸荠pachycarpa和Schoenoplectus加利福尼亚小的临时湿地，其中：在两个不同的淡水环境鹅绒委陵菜发展重要的林分，而尚未被入侵植物定殖的湖泊的沿海地带。我们的结果表明，两种环境的养分浓度不同，在临时湿地中更高。然而，由于在垃圾袋中存在两栖类Hyallela patagonica，入侵物种在湖泊的沿海地区分解得更快。入侵植物凋落物的分解速度比本地物种快两倍。N含量最高的树种（E. pachycarpa）在渗滤液中释放出更多的N。分解71天后，鹅an的损失的C量和获得的N都比原生物种多，而P含量在这三个物种中均保持不变。我们的结果表明，入侵物种的引入进入新的栖息地的P. anserina将有助于溶解和颗粒状的有机物，影响养分循环和无脊椎动物的集聚，对整个生态系统产生影响。