Functional community structure of African monodominant Gilbertiodendron dewevrei forest influenced by local environmental filtering
Functional community structure of African monodominant Gilbertiodendron dewevrei forest influenced by local environmental filtering
复制标题
局部环境过滤对非洲单一优势白云石林功能群落结构的影响
作者：
E. Kearsley;H. Verbeeck;K. Hufkens;F. Van de Perre;S. Doetterl;G. Baert;H. Beeckman;P. Boeckx;D. Huygens
摘要在中非热带森林中，常见以黄背木为主的单优势斑块，与物种多样性较高的森林并存。虽然这些森林通常被发现稀疏分布沿着，他们的出现被认为是不是（明确）驱动的土壤条件，而是由性状组合G。dewevrei，这有助于实现单优势。然而，这些单优势和混交林之间的功能群落结构尚未进行比较。此外，对单优势森林群落中的非优势种知之甚少。这两个主题在这项研究中得到解决。我们调查了刚果盆地中部地区10个一公顷的单优势和混合森林的功能群落结构。13叶和木材性状进行了测量，覆盖95%（断面积加权）的所有物种存在的地块，包括叶营养成分，叶同位素组成，比叶面积，木材密度，和导管解剖。基于特质的G. dewevrei显示了与水的利用和运输有关的一系列特征，这可能有利于其靠近森林河流的位置。此外，在单优势林中发现了N和P限制的迹象，可能与G. dewevrei。与混交林相比，在群落水平上，单一优势林和不同的非优势类群的叶片N和P含量降低。总之，这项工作表明，环境过滤确实占主导地位的单显性G。dewevrei森林，导致在这种森林类型的功能多样性较低，优势种表现出有益的性状，其共同的河流的位置，并与减少土壤中的N和P的可用性，在这种环境中发现，共同调节树群落组装。
Abstract Monodominant patches of forest dominated by Gilbertiodendron dewevrei are commonly found in central African tropical forests, alongside forests with high species diversity. Although these forests are generally found sparsely distributed along rivers, their occurrence is not thought to be (clearly) driven by edaphic conditions but rather by trait combinations of G. dewevrei that aid in achieving monodominance. Functional community structure between these monodominant and mixed forests has, however, not yet been compared. Additionally, little is known about nondominant species in the monodominant forest community. These two topics are addressed in this study. We investigate the functional community structure of 10 one‐hectare plots of monodominant and mixed forests in a central region of the Congo basin, in DR Congo. Thirteen leaf and wood traits are measured, covering 95% (basal area weighted) of all species present in the plots, including leaf nutrient contents, leaf isotopic compositions, specific leaf area, wood density, and vessel anatomy. The trait‐based assessment of G. dewevrei shows an ensemble of traits related to water use and transport that could be favorable for its location near forest rivers. Moreover, indications have been found for N and P limitations in the monodominant forest, possibly related to ectomycorrhizal associations formed with G. dewevrei. Reduced leaf N and P contents are found at the community level for the monodominant forest and for different nondominant groups, as compared to those in the mixed forest. In summary, this work shows that environmental filtering does prevail in the monodominant G. dewevrei forest, leading to lower functional diversity in this forest type, with the dominant species showing beneficial traits related to its common riverine locations and with reduced soil N and P availability found in this environment, both coregulating the tree community assembly.