Soil‐related performance variation and distributions of tree species in a Bornean rain forest
Soil‐related performance variation and distributions of tree species in a Bornean rain forest
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DOI：
10.1111/j.1365-2745.2005.01030.x
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发表时间：
2005-10
影响因子：
5.5
通讯作者：
S. Russo;S. Davies;D. A. King;Sylvester Tan
中科院分区：
文献类型：
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作者：
S. Russo;S. Davies;D. A. King;Sylvester Tan
1热带树木的空间分布往往与环境变化相关，这表明生态位分化引起的生态排序对维持物种多样性可能是重要的。[2]在婆罗洲龙脑香混交林的52公顷森林动态图中，确定了四种土壤类型（按肥力和湿度的增加排序：桑迪壤土、壤土、细壤土和粘土）。样地中73%的树种分布在这些土壤类型之一上显著聚集。我们测试的假设，这些土壤偏置物种分布的基础性能（生长和死亡率）的变化。3对直径≥ 1 cm的树木估计了5年以上的年生长率和死亡率，并比较了土壤类型、生活史和物种聚集模式。4总的来说，在最贫瘠的土壤（桑迪壤土）上，生长和死亡率最低。每种土壤类型的生长率与土壤肥力的先锋，而死亡率与土壤肥力的先锋和后期演替物种。[5]几乎没有证据表明土壤专家具有本土土壤性能优势。每个物种聚集组的生长和死亡率的土壤特定等级在很大程度上反映了其在整个地块中的速率等级，并且在土壤类型之间没有实质性变化。在每种土壤上，聚集在桑迪壤土或粘土上的物种排名最后或倒数第二，聚集在壤土上的物种排名最高。6土壤物种的生态分选性较强。随着直径的增加，物种从土壤中丢失，他们不聚集更频繁地比预期的随机死亡率的基础上。生态分类的基本机制可能涉及低死亡率作为物种在最贫瘠的土壤上实现高丰度的要求，而对于较肥沃的土壤，具有高生长率似乎对实现高丰度相对更重要。7因此，物种对土壤类型之间资源变化的人口学反应，特别是与最贫瘠的土壤有关的，影响了这片森林中的树种分布格局，从而影响了热带森林群落的结构。
1 Spatial distributions of tropical trees often correlate with environmental variation, suggesting that ecological sorting caused by niche differentiation may be important for maintaining species diversity. 2 Four soil types have been identified in a 52‐ha forest dynamics plot in Bornean mixed dipterocarp forest (ranked by increasing fertility and moisture: sandy loam, loam, fine loam, and clay). The distributions of 73% of tree species in the plot are significantly aggregated on one of these soil types. We tested the hypothesis that variation in performance (growth and mortality) underlies these edaphically biased species distributions. 3 Annual growth and mortality rates over 5 years were estimated for trees ≥ 1 cm in diameter and compared among soil types, life histories and species‐aggregation patterns. 4 Overall, growth and mortality rates were lowest on the poorest soil (sandy loam). Growth rates on each soil type correlated with soil fertility for pioneers, while mortality rates correlated with soil fertility for both pioneers and late‐successional species. 5 There was little evidence that soil specialists had a home‐soil performance advantage. Soil‐specific ranks of growth and mortality rates of each species‐aggregation group largely mirrored the ranks of their rates across the plot and did not shift substantially among soil types. On every soil, species aggregated on sandy loam or clay ranked last or next‐to‐last, and species aggregated on loam ranked the highest. 6 Ecological sorting of species among soils was strong. With increasing diameter, species were lost from the soils on which they were not aggregated more frequently than would be expected based on random mortality. The underlying mechanisms of ecological sorting may involve low mortality rates as a requirement for species to achieve high abundance on the poorest soil, whereas for the richer soils, having high growth rates appears relatively more important for achieving high abundance. 7 Thus, species’ demographic responses to resource variation among soil types, especially related to the poorest soil, affects tree species distribution patterns in this forest and thereby influences the structure of tropical forest communities.