An experimental test of the effects of productivity and environmental stress on a rocky intertidal food web

生产力和环境压力对岩石潮间带食物网影响的实验测试

• 批准号: 13640622
• 负责人: NODA Takashi
• 金额: $ 2.24万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640622/
• 关键词: Foodweb; productivity; environmental stress; intertidal rocky store; top-down control; bottom-up control; field experiment; indirect effects; 野外操作実験

Food web dynamics can be controlled by both external factors of primary productivity and environmental stress of ecosystem. However, little is know about how these two factors affect the food web dynamics in natural communities. Here I report a field factorial experiment manipulating the nutrient levels (as an external factor controlling primary productivity), and desiccation stress (as a factor of envilonmental stress), and the presence /absence of macrograzer (limpets ; their grazing is a key process in the food web) in a rocky intertidal algae-grazer food web. The results revealed that desiccation stress and nutrient availability independently influenced the food web dynamics, and their effects occurred without modifying the limpet top-down effect. Desiccation stress directly reduced only foliose algae, and consequently increased competitive inferior filamentous algae and reduced mesograzers (amphipods) through a reduction in food and refuges from desiccation stress. High nutrient availability caused the increase of both filamentous and foliose algae, and consequently caused increase of mesograzers (amphipods). These results suggest that the both nutrient availability and desiccation stress affected the food web dynamics not via top-down process but via bottom-up process, and supported not environmental stress hypothesis but exploitative ecosystem hypothesis.

食品网络动态可以通过主要生产力的外部因素和生态系统的环境压力来控制。但是，几乎不知道这两个因素如何影响自然社区的食物网络动态。在这里，我报告了一个野外阶乘实验，该实验操纵营养水平（作为控制主要生产力的外部因素）和干燥应力（作为环境应力的一个因素），以及宏观的存在 /不存在（limpers; limpets;它们的擦伤是食物网络中的关键过程）在岩石间杂质的杂质杂质的Algae-Grazae-Grazer-Grazer-Grazer-Grazer-Grazer-Grazer-Grazer-Grazer-Grazer-Grazer-Grazer-Grazer Web。结果表明，干燥应力和养分的可用性独立地影响了食品网络动力学，并且它们的效果发生在没有修改lim骨自上而下效果的情况下。干燥应力直接减少了叶状藻类，因此增加了竞争性的下丝藻类和减少中摩龙（Amphipods），这是通过减少食物和避孕因素中的避孕胁迫而减少的。高养分的可用性导致丝状和叶状藻类的增加，因此导致中摩雷斯（Amphipods）的增加。这些结果表明，养分的可用性和干燥应力都不会通过自上而下的过程而是通过自下而上的过程影响食物网络动力学，而是通过自下而上的过程，而不是支持环境压力假设，而是剥削性生态系统假设。