Invading herbivory:: The golden apple snail alters ecosystem functioning in Asian wetlands
Invading herbivory:: The golden apple snail alters ecosystem functioning in Asian wetlands
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DOI：
10.1890/03-3146
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发表时间：
2004-06-01
期刊：
影响因子：
4.8
通讯作者：
Hansson, LA
中科院分区：
文献类型：
--
作者：
Carlsson, NOL;Brönmark, C;Hansson, LA
研究了外来蜗牛福寿螺对热带湿地生态系统生物多样性和生态系统功能的影响。这种大型蜗牛（壳高可达80毫米）在近几十年来入侵了东南亚的大部分地区。对泰国自然湿地的一项调查表明，高密度的蜗牛与几乎完全没有水生植物、高营养浓度和高浮游植物生物量有关，也就是说，生态系统状态和功能都发生了完全转变。一项野外实验表明，蜗牛的放牧会导致水生植物的损失，向浮游藻类的优势转变，从而向浑浊的水转变。通过蜗牛放牧水生植物释放的生物固定营养素的估计显示，磷的释放足以解释记录的浮游植物生物量的增加。因此，我们的研究表明，草食动物可能会引发从清水和水生植物占主导地位的混浊状态，以浮游藻类为主的转变。这种转变和这种外来物种的持续侵略性入侵对湿地生态系统的完整性和功能以及它们在东南亚提供的服务都是有害的。
We investigated the effects of an exotic snail, the golden apple snail (Pomacea canaliculata) on biodiversity and ecosystem functioning in tropical wetland ecosystems. This large snail (up to 80-mm shell height) has invaded large parts of Southeast Asia during recent decades. A survey of natural wetlands in Thailand showed that high densities of the snail were associated with almost complete absence of aquatic plants, high nutrient concentrations, and high phytoplankton biomass, that is, a complete shift in both ecosystem state and function. A field experiment demonstrated that grazing by the snail can cause the loss of aquatic plants, a change toward dominance of planktonic algae, and thereby a shift toward turbid water. Estimates of biologically fixed nutrients released through snails grazing on aquatic plants revealed that phosphorus releases were sufficient to explain the recorded increase in phytoplankton biomass. Hence, our study demonstrates how an herbivore may trigger a shift from clear water and macrophyte dominance to a turbid state dominated by planktonic algae. This shift and the continuing aggressive invasion of this exotic species are detrimental to the integrity and functioning of wetland ecosystems, and to the services these provide in Southeast Asia.