Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA.
Ecol Lett. 2011 Jan;14(1):36-41. doi: 10.1111/j.1461-0248.2010.01547.x. Epub 2010 Nov 14.
One robust result from many small-scale experiments has been that plant community productivity often increases with increasing plant diversity. Most frequently, resource-based or competitive interactions are thought to drive this positive diversity-productivity relationship. Here, we ask whether suppression of plant productivity by soil fungal pathogens might also drive a positive diversity-productivity relationship. We created plant assemblages that varied in diversity and crossed this with a ± soil fungicide treatment. In control (non-fungicide treated) assemblages there was a strong positive relationship between plant diversity and above-ground plant biomass. However, in fungicide-treated assemblages this relationship disappeared. This occurred because fungicide increased plant production by an average of 141% at the lower ends of diversity but boosted production by an average of only 33% at the higher ends of diversity, essentially flattening the diversity-productivity curve. These results suggest that soil pathogens might be a heretofore unappreciated driver of diversity-productivity relationships.
从许多小规模实验中得出的一个可靠结果是，植物群落的生产力通常随着植物多样性的增加而增加。最常见的是，基于资源或竞争的相互作用被认为是推动这种正多样性-生产力关系的原因。在这里，我们想知道土壤真菌病原体对植物生产力的抑制是否也会推动正的多样性-生产力关系。我们创建了多样性不同的植物组合，并将其与土壤杀菌剂处理进行交叉。在对照（未用杀菌剂处理）组合中，植物多样性与地上植物生物量之间存在很强的正相关关系。然而，在杀菌剂处理的组合中，这种关系消失了。这是因为杀菌剂在较低多样性端平均增加了 141%的植物产量，但在较高多样性端仅平均增加了 33%的产量，基本上使多样性-生产力曲线变平。这些结果表明，土壤病原体可能是一个以前未被重视的多样性-生产力关系的驱动因素。
