Pärtel Meelis, Laanisto Lauri, Zobel Martin
Institute of Botany and Ecology, University of Tartu, 40 Lai Street, Tartu 51005 Estonia.
Ecology. 2007 May;88(5):1091-7. doi: 10.1890/06-0997.
The relationship between net primary productivity and biological diversity has been a central topic in ecology for several decades. The unimodal ("hump-back") relationship has been the most widely accepted for plants with the decrease in diversity at high productivity usually attributed to competitive exclusion. However, the relatively small species pool size under high productivity conditions may account for this pattern as well. Small species pool sizes for highly productive habitats are characteristic of temperate regions, where productive habitats for speciation and species migration have historically been rare. In contrast, productive habitats in the tropics have been relatively common during evolutionary history, resulting in large species pools. We hypothesize that evolutionary history contributes to the observed productivity-diversity relationship of plants, and that the productivity-diversity relationship differs between temperate and tropical regions. We investigated the productivity-diversity relationship patterns from 163 case studies throughout the world. Latitude described approximately 80% of the variation in the shape of the relationships. The unimodal relationship was found to dominate in the temperate zone, whereas the positive relationship was significantly more common in the tropics. We detected no influence due to methods of productivity measurement, but unimodal or positive productivity-diversity relationships were more likely within larger ranges of productivity. The length of the productivity gradient did not affect the latitudinal influence. In summary, the shape of the productivity-diversity relationship differs between temperate and tropical regions and the different evolutionary history of the local species pools is a probable cause for the difference.
几十年来，净初级生产力与生物多样性之间的关系一直是生态学的核心议题。单峰（“驼峰状”）关系在植物中最为广泛接受，高生产力下多样性的降低通常归因于竞争排斥。然而，高生产力条件下相对较小的物种库规模也可能解释这种模式。高生产力栖息地的小物种库规模是温带地区的特征，在温带地区，历史上物种形成和物种迁移的高生产力栖息地一直很罕见。相比之下，热带地区的高生产力栖息地在进化历史中相对常见，从而形成了较大的物种库。我们假设进化历史促成了观察到的植物生产力 - 多样性关系，并且温带和热带地区的生产力 - 多样性关系有所不同。我们调查了来自全球163个案例研究的生产力 - 多样性关系模式。纬度描述了关系形状中约80%的变化。发现单峰关系在温带地区占主导，而正相关关系在热带地区明显更常见。我们未检测到生产力测量方法的影响，但在较大的生产力范围内，单峰或正的生产力 - 多样性关系更有可能出现。生产力梯度的长度不影响纬度的影响。总之，温带和热带地区生产力 - 多样性关系的形状不同，当地物种库不同的进化历史可能是造成这种差异的原因。
