Pan Xu, Berg Matty P, Butenschoen Olaf, Murray Phil J, Bartish Igor V, Cornelissen Johannes H C, Dong Ming, Prinzing Andreas
Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, People's Republic of China Centre National de la Recherche Scientifique Campus de Beaulieu, Université de Rennes 1, Bâtiment 14 A, 35042 Rennes, France State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, People's Republic of China.
Animal Ecology, Department of Ecological Science, VU University Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands.
Proc Biol Sci. 2015 May 7;282(1806):20150103. doi: 10.1098/rspb.2015.0103.
Phylogenetic distances of coexisting species differ greatly within plant communities, but their consequences for decomposers and decomposition remain unknown. We hypothesized that large phylogenetic distance of leaf litter mixtures increases differences of their litter traits, which may, in turn, result in increased resource complementarity or decreased resource concentration for decomposers and hence increased or decreased chemical transformation and reduction of litter. We conducted a litter mixture experiment including 12 common temperate tree species (evolutionarily separated by up to 106 Myr), and sampled after seven months, at which average mass loss was more than 50%. We found no effect of increased phylogenetic distance on litter mass loss or on abundance and diversity of invertebrate decomposers. However, phylogenetic distance decreased microbial biomass and increased carbon/nitrogen (C/N) ratios of litter mixtures. Consistently, four litter traits showed (marginally) significant phylogenetic signal and in three of these traits increasing trait difference decreased microbial biomass and increased C/N. We suggest that phylogenetic proximity of litter favours microbial decomposers and chemical transformation of litter owing to a resource concentration effect. This leads to a new hypothesis: closely related plant species occurring in the same niche should promote and profit from increased nutrient availability.
在植物群落中，共存物种的系统发育距离差异很大，但其对分解者和分解作用的影响尚不清楚。我们推测，凋落物混合物的系统发育距离大，会增加其凋落物性状的差异，进而可能导致分解者的资源互补性增加或资源浓度降低，从而增加或减少凋落物的化学转化和分解。我们进行了一项凋落物混合实验，包括12种常见的温带树种（在进化上相隔长达1.06亿年），并在七个月后取样，此时平均质量损失超过50%。我们发现，系统发育距离的增加对凋落物质量损失或无脊椎动物分解者的丰度和多样性没有影响。然而，系统发育距离降低了微生物生物量，并增加了凋落物混合物的碳/氮（C/N）比。一致的是，四种凋落物性状显示出（略微）显著的系统发育信号，在其中三种性状中，性状差异的增加降低了微生物生物量并增加了C/N比。我们认为，由于资源集中效应，凋落物的系统发育接近有利于微生物分解者和凋落物的化学转化。这引出了一个新的假设：在同一生态位中出现的亲缘关系密切的植物物种应该会促进养分有效性的提高并从中受益。
