Light and nitrogen competition limit Lolium perenne in experimental grasslands of increasing plant diversity.
Light and nitrogen competition limit Lolium perenne in experimental grasslands of increasing plant diversity.
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DOI：
10.1111/j.1438-8677.2010.00338.x
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发表时间：
2011
期刊：
影响因子：
3.9
通讯作者：
C. Roscher;W. Kutsch;E. Schulze
中科院分区：
文献类型：
--
作者：
C. Roscher;W. Kutsch;E. Schulze
据报道，在实验草地上，物种丰富度对地上群落生产力的积极影响与单个物种的可变响应相关。到目前为止，它在很大程度上是未知的，是否更充分地利用资源在社区一级与特定物种的资源限制，并可能解释其性能下降，植物多样性的增加。以多年生黑麦草Lolium perenne L.作为一个模型，我们在82个不同植物多样性的实验草地（耶拿实验）上监测了建立后2 - 6年的种群，并测量了与光和养分获取和利用相关的生态生理叶片性状。种群和植株个体大小。多年生植物随物种丰富度的增加而减少。随着物种丰富度和豆科比例的增加，透射光减少，比叶面积（SLA）增加。尽管这种形态适应较低的光可用性，减少叶片δ（13）C的签名，增加物种丰富度和低变化的叶片气体交换和叶绿素浓度表明，低容量的L。多年生植物，用于调节树冠遮荫。叶片氮浓度和叶片δ（15）N特征表明，豆科植物群落的氮供应更好，随着物种丰富度的增加，不同形态氮的吸收发生了变化。叶片硝酸盐和碳水化合物浓度作为植物营养状况的指标，支持随着物种丰富度和豆类比例的增加而增加的光限制，以及随着非豆类比例的增加而增加的群落中的氮限制，与L.在植物多样性不断增加的群落中多年生植物。
Positive species richness effects on aboveground community productivity in experimental grasslands have been reported to correlate with variable responses of individual species. So far, it is largely unknown whether more complete use of resources at the community level correlates with resource limitation of particular species and may explain their decreasing performance with increasing plant diversity. Using the subordinate grass species Lolium perenne L. as a model, we monitored populations in 82 experimental grasslands of different plant diversity (Jena Experiment) from year 2 to 6 after establishment, and measured ecophysiological leaf traits related to light and nutrient acquisition and use. Population and plant individual sizes of L. perenne decreased with increasing species richness. A decrease in transmitted light with increasing species richness and legume proportion correlated with increasing specific leaf area (SLA). Despite this morphological adaptation to lower light availability, decreasing foliar δ(13) C signatures with increasing species richness and low variation in leaf gas exchange and chlorophyll concentrations suggested a low capacity of L. perenne for adjustment to canopy shade. Leaf nitrogen concentrations and foliar δ(15) N signatures indicated a better N supply in communities with legumes and a shift in the uptake of different N forms with increasing species richness. Leaf blade nitrate and carbohydrate concentrations as indicators of plants nutritional status supported that light limitation with increasing species richness and legume proportions, combined with a N limitation in communities with increasing proportions of non-legumes, correlated with the decreasing performance of L. perenne in communities of increasing plant diversity.