Rain forest on Maracá Island, Roraima, Brazil: soil and litter process response to artificial gaps

摘要: Abstract Artificial canopy gaps were made by felling trees in rain forest on Maraca Island. There three replicates of each gap size: small (c. 40 m 2 ), medium 150 large 350 very 2500 and unfelled controls (2500 ). Changes microclimate, soil chemistry, biological processes including decomposition measured for up to 12 months. Higher maximum lower minimum air temperatures occurred with increasing size but there was little consistent effect chemistry. Microbial biomass, respiration, nitrogen mineralization nitrification investigated gaps. No differences found between the forest, all had their lowest values dry season. Within higher these variables `under crown' position (where crowns felled fallen under surrounding canopy). Three litter-bag experiments over 217 d. relationship nutrient release rates or within it no clear trend along a central trunk gap, weight loss trees. It is concluded that are not influenced way size. may be areas high can caused local addition quantities substrate, even though process remain unaltered. Because additions readily decomposable substrate most likely occur closed canopy, support from data growth responses will involve an interaction enhanced supply increased light.