Tree species of wet tropical forests differ in their tissue biochemistry and effects on soil carbon dynamics

Given the hypothesized effects on soil organic matter (SOM) of polyphenols in plant tissues, differences among tree species in their biochemical composition could influence the turnover and accrual of SOM in various ways. The extent to which the biochemical composition of leaf and fine-root tissues differ among tropical tree species, and the effects on soil dynamics, are largely undocumented, however. We used cupric oxide analyses of plant tissues and soil in long-term, replicated, mono-dominant 15-yr-old plantations at La Selva Biological Station, Costa Rica, to test for differences among six tree species. We related these results to companion studies in this experimental site to evaluate relationships between interspecific differences in tissue biochemistry and SOM dynamics. Newly senesced leaves and fine roots of the six species differed in their concentrations of three lignin-derived families of phenols, the cinnamyls, syringyls and vanillyls (P <0.0001 for all tests). Cinnamyl a...

鉴于植物组织中多酚对土壤有机质（soil organic matter, SOM）的假定效应，不同树木物种的生化组成差异可通过多种途径影响土壤有机质的周转与积累。然而，热带树木物种间叶片与细根组织的生化组成差异程度，及其对土壤动态的影响，在很大程度上尚未被探明。我们采用氧化铜分析法，对哥斯达黎加拉塞尔瓦生物站长期、重复布设的15年生单优人工林内的植物组织与土壤样品开展检测，以检验6个树木物种间的差异。我们将上述结果与该实验站点的配套研究相结合，以评估组织生化特性的种间差异与土壤有机质动态之间的关联。6个物种的新近衰老叶片与细根，在三类木质素衍生酚类家族——肉桂基酚类、丁香基酚类与香草基酚类——的浓度上存在显著差异（所有检验的P值均<0.0001）。肉桂基a...