| Popis: |
The aims of this study were to investigate the structure and composition of the invertebrate community during the detritus decomposition (colonization features) of the two most abundant aquatic macrophytes Typha domingensis Pers. and Nymphaea ampla in Jurubatiba Lagoon and verify if the chemical composition of the substratum has any influence on invertebrate colonization and which are the functional groups possibly affected by these compounds. The substratum T. domingensis had higher percentages of cell wall fraction (F= 108.33; p < 0.0001) and organic matter (F= 225.77; p < 0.0001), while nitrogen (F= 408.61; p < 0.0001) and phosphorus (F= 224.59; p < 0.0001) contents were higher in N. ampla. These differences in the chemical composition of the substrata influenced the decomposition rate, and the detritus of N. ampla(4.37% DW day−1) decomposed approximately 26 times faster than the T. domingensis(0.17% DW day−1) detritus. The main groups of invertebrates that colonized both substrate were Chironomidae, with more than 50% of the total, followed by Oligochaeta, Nematoda, Copepoda and Cladocera. The results showed that the slow breakdown rate of T. domingensis detritus provided a higher probability for colonization and that the main driving force structuring the invertebrates' community was degradative ecological succession (DES). |
