渓流における生葉の分解過程とシュレッダーの定着
Decomposition of fresh leaves and colonization by shredders in a small mountain stream

Kaori KOCHI
2002 Nihon Seitai Gakkaishi  
Decomposition of fresh leaves of deciduous trees and colonization by macroinvertebrate shredders were studied in a mountain stream inNagano Prefecture , central 亅apan 、 Decomposition experiments were carried out from late Juneto mid August ( ' ' summer experiment " )and from early October to late November ( 」 tautumn experimen ビ ' )in l998. Two types of litter bag ( 9 − mm mesh and O. 4 − mm mesh ) were used in these experiments to examine the role of shredders in leaf decomposition .
more » ... osition . Decomposition rates ( ks)of fresh leaves calculated using an exponential decay model were faster ( k = 0. 0073 − 0. 0935)than most of the known rates f ( )r senescent leaves . The 丘esh leaves were subjected to a higher degree of microbial and shredder processing because oftheir lower C / N ratio . Decomposition rates in the summer experiment were higher than in the autumn experiment f()r both types of mesh bag . Decomposing activities of microbes and / or small shredders wou 夏 d have been higher in the summer experiment , when the CIN ratio ofthe leaves was lower and the stream temperamre was higher . In the early stage of decomposition during the summer experiment , the biomass of shredders colonizing the coarse mesh bags was very large , due to co ] onization by many large , mature caddisfly larvae( i. e . Pseudostenophylax and Goerodes), while significant effects of mesh size on leaf decomposition were detected . These results suggest that in streams du [ing early summer , when several shredder species are often at a mature stage even Ihough coarse organic detritus is limited , input of high − quality fresh leaves is an important fbod resource fbr these shredders .
doi:10.18960/seitai.52.3_331 fatcat:qj355kvhuffq3msdhvd2hxgrji