Different ammonia tolerances may facilitate spatial coexistence of Gammarus roeselii and the strong invader Dikerogammarus villosus
Different ammonia tolerances may facilitate spatial coexistence of Gammarus roeselii and the strong invader Dikerogammarus villosus
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DOI：
10.1007/s10530-013-0408-0
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发表时间：
2013-08-01
影响因子：
2.9
通讯作者：
Rothhaupt, Karl-Otto
中科院分区：
文献类型：
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作者：
Gergs, Rene;Schlag, Lena;Rothhaupt, Karl-Otto
入侵物种的引入可以取代本地物种是对水生系统生物多样性最严重的威胁之一。本文研究了同一生态系统（康斯坦斯湖）不同微生境下，本地片足类Gammarus roeselii和入侵片足类Dikerogammarus villosus共存的潜在影响因素。我们定量研究了环境氨浓度对两种片足类动物分布的影响。我们还在实验室实验中通过测量死亡率、交配前破坏、卵死亡率和微生境选择来评估两种物种的氨耐受性范围。在两种片足类动物中，长绒夜蛾的比例与水体氨浓度呈显著正相关，说明在高氨浓度下，入侵长绒夜蛾的分布受到限制。尽管两种昆虫的死亡率没有显著差异，但在交配前破坏、卵死亡率和微生境选择方面，黄绒螯虾对氨的耐受性更强。导致绒毛田鼠直接繁殖成功率显著降低的有效氨浓度在最高的田间浓度范围内，其中只发生了绒田鼠。绒毛瓢虫的繁殖范围可能比本地瓢虫小，部分原因是其对高氨浓度的耐受性较低，从而导致繁殖成功率降低。除其他生境参数外，两种片脚类动物对氨耐受性的差异可能使它们在康斯坦斯湖沿微生境梯度共存。
The introduction of invasive species that can replace native species is one of the most critical threats to the biodiversity of aquatic systems. Here we investigated the potential contribution of one factor to the coexistence of the indigenous amphipod Gammarus roeselii and the invasive amphipod Dikerogammarus villosus in the same ecosystem (Lake Constance) within different microhabitats. We quantitatively studied the influence of ambient ammonia concentrations on the distributions of the two amphipod species. We also assessed the ammonia tolerance ranges of both species in laboratory experiments by measuring mortality rate, precopula disruption, egg mortality, and microhabitat choice. The proportion of G. roeselii among the two amphipod species was significantly positively related to the ammonia concentration in the water, which indicated that the distribution of the invasive D. villosus was limited at high ammonia concentrations. Although the mortality rates of the two species did not significantly differ, G. roeselii was more tolerant to ammonia with regard to precopula disruption, egg mortality, and microhabitat choice. The effective ammonia concentrations that led to a significantly reduced direct reproductive success in D. villosus were within the range of the highest field concentrations measured, where only G. roeselii occurred. D. villosus may have a smaller range than the indigenous G. roeselii partially because of its lower tolerance to higher ammonia concentrations, which lead to reduced reproductive success. Beside other habitat parameters differences on ammonia tolerance between the two amphipods might allow their coexistence along a gradient of microhabitats in Lake Constance.