Herbivore-mediated linkages between aboveground and belowground communities
Herbivore-mediated linkages between aboveground and belowground communities
复制标题
DOI：
10.1890/02-0274
复制
发表时间：
2003-09-01
期刊：
影响因子：
4.8
通讯作者：
Wardle, DA
中科院分区：
文献类型：
--
作者：
Bardgett, RD;Wardle, DA
了解陆地生态系统如何发挥作用需要采用地上与地下相结合的方法，因为食草动物、生产者和分解子系统之间的反馈非常重要。在本文中，我们确定了食草动物通过改变进入土壤的资源的数量和质量来间接影响分解生物和土壤过程的几种机制。我们表明，对于叶和根食草动物来说，这些机制在本质上大致相似，无论它们是由于个体植物对食草动物攻击的生理反应而在短期内发挥作用，还是由于食草动物对植物群落结构的长期改变以及随后进入土壤的凋落物质量的变化而发挥作用。我们认为，多种可能的机制导致了草食动物对土壤生物群和生态系统功能的特殊影响；草食性可能产生积极、消极或中性的影响，具体取决于这些不同机制的平衡。然而，我们预测，食草对土壤生物群和土壤过程的积极影响在高土壤肥力和高消耗率的生态系统中最常见，而负面影响在低消耗率的非生产性生态系统中最常见。多物种食草动物群落的重要性也得到了强调，我们提出，如果食草动物物种或功能群体之间的资源利用互补性导致植物体的总消耗量增加，从而导致净食草量增加，那么增加食草动物多样性对地下特性和过程的积极和消极影响在理论上都是可能的。强调了研究重点，包括需要比较研究食草动物对不同生产力的生态系统地上和地下过程的影响，以及注意实验测试反食草动物防御化合物对根际复杂多营养相互作用的影响，以及多种食草动物物种群落对这些植物-土壤相互作用的重要性。
Understanding how terrestrial ecosystems function requires a combined aboveground-belowground approach, because of the importance of feedbacks that occur between herbivores, producers, and the decomposer subsystem. In this paper, we identify several mechanisms by which herbivores can indirectly affect decomposer organisms and soil processes through altering the quantity and quality of resources entering the soil. We show that these mechanisms are broadly similar in nature for both foliar and root herbivory, regardless of whether they operate in the short term as a result of physiological responses of individual plants to herbivore attack or long-term following alteration of plant community structure, by herbivores and subsequent changes in the quality of litter inputs to soil. We propose that a variety of possible mechanisms is responsible for the idiosyncratic nature of herbivore effects on soil biota and ecosystem function; positive, negative, or neutral effects of herbivory are possible depending upon the balance of these different mechanisms. However, we predict that positive effects of herbivory on soil biota and soil processes are most common in ecosystems of high soil fertility and high consumption rates, whereas negative effects are most common in unproductive ecosystems with low consumption rates. The significance of multiple-species herbivore communities is also emphasized, and we propose that if resource use complementarity among herbivore species or functional groups leads to greater total consumption of phytomass, and thus greater net herbivory, then both positive and negative consequences of increasing herbivore diversity for belowground properties and processes are theoretically possible. Research priorities are highlighted and include a need for comparative studies of herbivore impacts on above- and belowground processes across ecosystems of varying productivity, as well as a heed for experimental testing of the influence of antiherbivore defense compounds on complex multitrophic interactions in the rhizosphere and the significance of multiple herbivore species communities on these plant-soil interactions.