盐沼中凋落物分解的研究主要集中在分解速率的测量上,作为垃圾质量,微生物分解器的类型及其胞外酶活性,很少考虑。此外,这些研究大多是在禾本科和节草科物种中进行的,关于藜科物种的文献很少,在地中海盐沼中丰富。在这里,我们分析了两种藜科(Fruticosa和HalimionePortulacoides)和一种禾本科(Elytrigiaatherica)的凋落物分解过程,将S.fruticosa归入一个嗜盐的灌木丛栖息地,将其他两个归入地中海盐沼的盐田栖息地。对于每个物种,我们分析了垃圾分解率,凋落物质量,真菌和细菌生物量以及潜在的胞外酶活性。为了拥抱空间异质性,在每个栖息地内考虑了两个区域。E.Aatherica的凋落物分解速度比S.fruticosa和H.马齿菌慢7倍和13倍,分别,这表明该物种是最有利于碳封存到土壤中的物种。不同的分解速率可以通过较高的初始木质素和纤维素含量来解释。此外,酶效率,与酶活性相比,更好地有助于解释观察到的不同分解速率。细菌在整个凋落物分解过程中占主导地位,无论物种如何,但是真菌在后期增加了它们的相关性,当相对木质素凋落物含量增加时。凋落物分解受微生境空间差异的影响,尽管反应取决于物种。因此,洪水(在S.fruticosa的栖息地)或土壤质地(在E.Aatherica和H.Migulacoides的栖息地)可能已经调节了分解过程,是H.mapulacoides对盐草甸栖息地的空间差异最敏感的物种。
Studies of litter decomposition in salt marshes have been mainly focused on the measurement of decomposition rates, being litter quality, the type of microbial decomposers and their extracellular enzyme activity, rarely considered. Moreover, most of these studies have been conducted in Poaceae and Cyperaceae species, being scarce the literature on Chenopodiaceae species, which are abundant in Mediterranean salt marshes. Here we analyse the litter decomposition process of two Chenopodiaceae (Sarcocornia fruticosa and Halimione portulacoides) and one Poaceae (Elytrigia atherica) species, belonging S. fruticosa to a halophilous scrub habitat and the other two to a salt meadow habitat of a Mediterranean salt marsh. For each species, we analysed litter decomposition rates, litter quality, fungal and bacterial biomass and potential extracellular enzymes activities. In order to embrace the spatial heterogeneity, two zones were considered within each habitat. Litter of E. atherica decomposed 7- and 13-fold slower than those of S. fruticosa and H. portulacoides, respectively, suggesting that this species is the one that would favour most the carbon sequestration into the soil. The different decomposition rates would be explained by the higher initial lignin and cellulose content of E. atherica rather than by the initial carbon and nitrogen content and C/N ratio. Moreover, enzyme efficiency, compared to enzyme activity, better contributes to explain the different decomposition rates observed. Bacteria dominated throughout the litter decomposition process regardless the species, but fungi increased their relevance in the later stages, when the relative lignin litter content increased. Litter decomposition was affected by microhabitat spatial differences, although the responses depended on the species. Hence, flooding (in the habitat of S. fruticosa) or soil texture (in the habitat of E. atherica and H. portulacoides) might have modulated the decomposition process, being H. portulacoides the most sensitive species to the spatial differences of the salt meadow habitat.