Senescent leaves of Inga laurina, Protium spruceanum and Rircheria grandis (2 ± 0.1 g dry mass) were individually placed in litter bags (30 × 30 cm: 10 mm coarse mesh and 0.5 mm fine mesh) and submerged in the study stream before and after fire. This study evaluates short-term post-fire effects on leaf litter breakdown, the invertebrate community and fungal biomass of litter from three different vegetal species in a tropical stream.
Wildfire is a natural pulsed disturbance in landscapes of the Savannah Biome. Programa de Pós-graduação em Ciências Ambientais, Universidade Comunitária da Região de Chapecó – UNOCHAPECÓ, Rua Servidão Anjo da Guarda, 295-D, Efapi, CEP, Chapecó, SC, Brasil José Francisco Gonçalves-JúniorĪquaRiparia, Departamento de Ecologia, Universidade de Brasília – UnB, Asa Norte, Campus Universitário Darcy Ribeiro, CEP, Brasília, DF, Brasil About the authors Renato Figueiro Varella, s/n, Bairro Olaria, CEP, Nova Xavantina, MT, Brasil Paulino BambiĪquaRiparia, Departamento de Ecologia, Universidade de Brasília – UnB, Asa Norte, Campus Universitário Darcy Ribeiro, CEP, Brasília, DF, Brasil Natália GuedesĪquaRiparia, Departamento de Ecologia, Universidade de Brasília – UnB, Asa Norte, Campus Universitário Darcy Ribeiro, CEP, Brasília, DF, Brasil Cássia Alves Lima-Rezende Programa de Pós-graduação em Ecologia e Conservação, Universidade do Estado de Mato Grosso – UNEMAT, Av. Renato Figueiro Varella, s/n, Bairro Olaria, CEP, Nova Xavantina, MT, Brasil Helena Soares Ramos Cabette Renato Figueiro Varella, s/n, Bairro Olaria, CEP, Nova Xavantina, MT, Brasil Ricardo Keichi Umetsu Renato Figueiro Varella, s/n, Bairro Olaria, CEP, Nova Xavantina, MT, Brasil Paulo Fernandes Roges Souza Silva Francisco Mota, 572, Bairro Costa e Silva, CEP, Mossoró, RN, Brasil Andrezza Sayuri Victoriano Hirota Programa de Pós-graduação em Ecologia e Conservação, Universidade Federal Rural do Semi-Árido – UFERSA, Av. Although natural concentrations of glucose were low, the high turnover of enzymatically-released glucose probably means that β-glucosidase activity could be regulated by product concentration.*e-mail: Cristiano Queiroz de Albuquerque Increasing concentrations of glucose in the perfusion water resulted in a progressive inhibition of β-glucosidase activity. V max was uninfluenced by whether ground or stream water was perfused through the sediments, but K m was higher in cores perfused with groundwater. V maxand K mboth increased when the perfusion rate was raised, although naturally-low substrate concentrations could mean that variability in perfusion rates has little effect on enzyme activity in the field. Substrate affinity( Km)was higher in the suspended sediments.
At low rates of perfusion, maximum β-glucosidase activity ( V max) in perfused sediments was similar to that in suspended (unperfused) sediments.
β-glucosidase activity quantified from the release of fluorescent MUF in water discharge from the cores. In a perfused core technique, water containing MUF-β-Glc was perfused up through sediment cores. Β-Glucosidase activity was investigated in stream-bed sediments using 4-methylumbelliferyl-β- d-glucopyranoside (MUF-β-Glc) as a model substrate.
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