Predators mediate above‐ vs. belowground herbivory in a salt marsh crab
Predators mediate above‐ vs. belowground herbivory in a salt marsh crab
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捕食者介导盐沼蟹的地上与地下食草行为
DOI：
10.1002/ecs2.2107
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发表时间：
2018
期刊：
影响因子：
2.7
通讯作者：
S. Pennings
中科院分区：
文献类型：
--
作者：
H. Vu;S. Pennings
捕食者可以通过移除猎物个体和改变猎物行为来显著影响猎物。觅食行为和捕食风险之间的权衡可能会导致营养级联，对生态系统过程产生重要影响。对于可以在地上和地下进食的食草动物来说，捕食风险可能会影响进食的位置。我们测试了两种捕食性沼泽蟹是否会影响草食性蟹类的摄食行为。我们发现，捕食性螃蟹可以杀死或伤害Sesarma，Sesarma在更危险的捕食者的存在下对它的食物植物互花米草的伤害较小。Sesarma更喜欢吃地下根茎，比地上叶子长得更好;然而，如果它是唯一的饮食选择，挖掘洞穴进入根茎的成本会导致更高的死亡率。取食地点对互花米草总生物量无明显影响。对于Sesarma来说，选择觅食地点可以让螃蟹的行为灵活性来平衡捕食的风险，地下觅食的营养利益和地下觅食的生存成本。类似的权衡可能会增加其他食草动物的成功，这些食草动物可以在地上和地下进食。
Predators can significantly affect prey by removing prey individuals and by changing prey behavior. The tradeoff between foraging behavior and predation risk may result in a trophic cascade that can have important effects on ecosystem processes. For herbivores that can feed both above‐ and belowground, it is likely that predation risk affects the location of feeding. We tested whether two species of predatory marsh crabs affected feeding behavior of the herbivorous crab,Sesarma reticulatum. We found that predatory crabs could kill or injureSesarmaand thatSesarmadid less damage to its food plantSpartina alterniflorain the presence of the more dangerous predator.Sesarmaprefers to feed on and grows better on belowground rhizomes than aboveground leaves; however, the costs of digging burrows to access rhizomes lead to higher mortality if it is the only diet option. The location of feeding did not affect total biomass ofS. alterniflora. ForSesarma, a choice in feeding location allows the crabs the behavioral flexibility to balance the risks of predation, the nutritional benefit of feeding belowground, and the survival costs of belowground feeding. Similar tradeoffs are likely to increase the success of other herbivores that can feed both above‐ and belowground.