French Kristine, Westoby Mark
School of Biological Sciences, Research Unit for Biodiversity and Bioresources, Macquarie University, 2109, North Ryde, Australia.
Oecologia. 1992 Sep;91(3):447-454. doi: 10.1007/BF00317636.
The hypothesis that more plant species with vertebrate-dispersed fruits occur on fertile soils because there is a greater probability of fruit removal from the parent plant was tested at 16 sites around Sydney, Australia. Removal rates from artificial fruit spikes were two and a half times greater on fertile than infertile soil sites, although this was not quite statistically significant. High variability in removal rate between sites was evident irrespective of fertility. Most removal occurred during the day indicating that birds were important consumers, rather than nocturnal mammals. Bird abundance and diversity did not differ between soil types. More frugivorous species were found in plant communities growing on fertile soil. Two models could explain the patterns observed. Firstly, plants with vertebrate-dispersed fruits could be favoured on fertile soils because of a high abundance of frugivorous birds accomplishing seed dispersal. Alternatively, plants with vertebrate-dispersed fruits could be favoured on fertile soil sites for some other reason and frugivorous birds could be attracted to these areas of abundant food. The correlation between soil fertility and the percentage of vertebrate-dispersed fruits was stronger than the correlation between soil fertility and removal rates and suggests that the second model is more likely to be true. Frugivorous birds are unlikely to be responsible for the high percentage of species with vertebrate-dispersed fruits in fertile soil environments.
在澳大利亚悉尼周边的16个地点，对“肥沃土壤上有更多果实由脊椎动物传播的植物物种，是因为果实从母株上被移除的可能性更大”这一假说进行了测试。人工果穗在肥沃土壤上的移除率比在贫瘠土壤上高出两倍半，尽管这在统计学上并不十分显著。无论土壤肥力如何，各地点之间的移除率都存在明显的高变异性。大多数移除发生在白天，这表明鸟类是重要的消费者，而非夜间活动的哺乳动物。不同土壤类型之间的鸟类丰度和多样性并无差异。在肥沃土壤上生长的植物群落中发现了更多的食果物种。有两种模型可以解释所观察到的模式。首先，果实由脊椎动物传播的植物在肥沃土壤上可能更受青睐，因为有大量食果鸟类完成种子传播。或者，果实由脊椎动物传播的植物在肥沃土壤地点可能因其他原因而更受青睐，食果鸟类可能会被这些食物丰富的区域所吸引。土壤肥力与果实由脊椎动物传播的植物所占百分比之间的相关性，强于土壤肥力与移除率之间的相关性，并表明第二种模型更有可能是正确的。食果鸟类不太可能是肥沃土壤环境中果实由脊椎动物传播的植物物种比例高的原因。
