Leaf litter decomposition and macroinvertebrate communities in headwater streams draining pine and hardwood catchments

摘要: Benthic invertebrates, litter decomposition, andlitterbag invertebrates were examined in streamsdraining pine monoculture and undisturbed hardwoodcatchments at the Coweeta Hydrologic Laboratory thesouthern Appalachian Mountains, USA. Bimonthlybenthic samples collected from a stream draininga catchment during 1992, comparedto previously (1989–1990) benthic data froma draining an adjacent hardwood catchment. Litter decomposition litterbag wereexamined by placing litterbags filled with ormaple streams catchments andhardwood 1992–1993 1993–1994. Total invertebrate abundance biomass inthe was ca. 57% 74% that of thehardwood stream, respectively. Shredder wasalso lower but, as result ofhigher Leuctra spp. abundance, shredderabundance higher than stream. Decomposition rates both andred maple significantly faster pinestreams (p<0.05). shredder biomass, production weresimilar bags streams. However, trichopteran biomass,and some taxa such asLepidostoma spp., maplelitterbags streams(p<0.05). In contrast, plecopteran shredders(mainly Tallaperla sp.) more important inmaple Shredderswere well represented pinestreams, but low values obtained frompine Resultssuggest conversion forest to pinemonoculture influences taxonomic composition streaminvertebrates dynamics. Although impact this landscape-leveldisturbance on communitiesappeared somewhat subtle, significant differences indecomposition dynamics indicate vital ecosystem-levelprocesses are altered pinecatchments.