Plant species traits and capacity for resource reduction predict yield and abundance under competition in nitrogen-limited grassland
Plant species traits and capacity for resource reduction predict yield and abundance under competition in nitrogen-limited grassland
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DOI：
10.1111/j.1365-2435.2006.01116.x
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发表时间：
2006-06-01
影响因子：
5.2
通讯作者：
Tilman, D.
中科院分区：
文献类型：
--
作者：
Fargione, J.;Tilman, D.
1. 本研究的目的是检验资源竞争理论预测的植物性状是否与氮限制草地的竞争响应和丰度相关。在建立的重复单一栽培样地收集了非豆科多年生草原植物的物种性状和土壤养分数据。13种长期（5年）单一栽培的土壤硝酸盐浓度（R*）与其相对产量（竞争响应度量）和竞争丰度相关。与相对产量最相关的性状是根长密度（RLD），与竞争丰度最相关的性状是生物量：氮比。最能预测硝态氮R*的性状是生物量：氮比和细根分配，其中生物量：氮和细根分配较高的物种R*较低。因此，容易测量的物种性状可能是R*.4的有用替代度量。在单一栽培中，硝酸盐R*水平较低、RLD和生物量N较高的物种的优势与资源竞争理论的预测在质量上是一致的，即在获取、保留和利用主要限制性资源方面效率最高的物种将是最佳竞争者。需要更多的机制来解释这些物种如何共存。
1. The objective of this study is to test whether plant traits that are predicted by resource-competition theory to lead to competitive dominance are correlated with competitive response and abundance in a nitrogen-limited grassland. We collected species trait and soil nutrient data on non-leguminous perennial prairie plant species in replicated monoculture plots established for this purpose.2. The soil nitrate concentration of 13 species grown in long-term (5-year) monocultures (a measure of R*) was correlated with their relative yield (a measure of competitive response) and with their abundance in competition. The trait best correlated with a species' relative yield was root length density (RLD), and the trait best correlated with abundance in competition was biomass : N ratio.3. The traits that best predicted nitrate R* were the biomass : N ratio and allocation to fine roots, where species with higher biomass : N and allocation to fine roots had lower R*. Easily measured species traits may therefore be useful proxy measures for R*.4. The dominance of species with lower nitrate R* levels and higher RLD and biomass : N in monoculture is qualitatively consistent with the prediction of resource-competition theory that the species most efficient at acquiring, retaining and using the major limiting resource will be the best competitors. Additional mechanisms are needed to explain how these species coexist.