Climatic resources mediate the shape and strength of grassland productivity-richness relationships from local to regional scales
Climatic resources mediate the shape and strength of grassland productivity-richness relationships from local to regional scales
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DOI：
10.1016/j.agee.2022.107888
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发表时间：
2022-02-08
影响因子：
6.6
通讯作者：
Wang, Shiping
中科院分区：
文献类型：
--
作者：
Du, Jianqing;Wang, Yanfen;Wang, Shiping
植物生产力与物种丰富度（P-SR）的关系一直是生态学研究的中心课题。气候资源（CR、温度和降水）对P-SR关系的影响日益受到重视，这表现在：（1）植物生产力和物种丰富度对CR的响应不同;（2）植物-植物相互作用沿着CR梯度变化。然而，人们对这些效应如何介导从局部地点到区域尺度的P-SR关系的形状和强度知之甚少。在这里，我们提出了一个跨尺度的框架，解开气候控制的P-SR关系在草原上使用的HerbDivNet数据集，其中包括28个天然草地在19个国家和6大洲的广泛的降水和温度梯度。我们的研究结果表明，在当地的网站规模，一个驼峰回P-SR关系是常见的网站在贫穷和丰富的CR条件下，而在中等CR条件下的P-SR关系的形状和强度强烈的网站之间的变化。而在区域尺度上，P-SR关系只有在CR较差的情况下才出现驼峰型。我们认为，生产力和物种丰富度增加CR的异步响应是一个非生物驱动程序的不一致的P-SR关系沿着气候梯度，除了不断变化的植物-植物的相互作用所建议的应力梯度假说。这些研究结果有助于调和长期以来的争论P-SR的关系，并强调CR条件在发展或比较草地生态系统理论和管理在小尺度上的重要性。
The plant productivity and species richness (P-SR) relationship has been a central topic in ecology for decades. It is increasingly recognized that climate resources (CR, temperature and precipitation) might affect the P-SR relationship as (1) the response of plant productivity and species richness to CR are different; (2) plant-plant interactions change along the CR gradient. However, little is known about how these effects mediate the shape and strength of the P-SR relationship from local-site to regional scales. Here, we proposed a cross-scale framework to disentangle the climatic control over the P-SR relationship in grasslands using the HerbDivNet dataset, which covers 28 natural grasslands in 19 countries and 6 continents with wide precipitation and tem-perature gradients. Our results showed that, at the local-site scale, a humped-back P-SR relationship is common at sites under poor and rich CR conditions, whereas both the shape and strength of the P-SR relationship strongly vary among sites under moderate CR condition. However, at the regional scale, the humped-back P-SR rela-tionship is only observed under poor CR condition. We suggested that the asynchronous responses of productivity and species richness to increasing CR is an abiotic driver of the inconsistent P-SR relationships along the climatic gradient in addition to the changing plant-plant interactions suggested by the stress-gradient hypothesis. These findings help to reconcile the long-standing debate over the P-SR relationship and highlight the importance of CR conditions in developing or comparing grassland ecosystem theories and management at small scales.