Yanoviak Stephen P
Department of Zoology, University of Oklahoma, Norman, OK 73019-0235, USA e-mail:
Oecologia. 1999 Jul;120(1):147-155. doi: 10.1007/s004420050843.
Detritus quality and quantity affect macroinvertebrate productivity and distribution in many freshwater ecosystems. This study experimentally investigated the effects of leaf litter from Ceiba pentandra, Dipteryx panamensis, Ficus yoponensis, and Platypodium elegans on macroinvertebrate species composition, richness, and abundance in artificial water-filled tree holes in a lowland moist forest of Panama. Species composition was similar among treatments, but species richness and longevity differed among litter types and were consistently highest with Platypodium litter. Similar patterns were observed in natural tree holes of the focal tree species. The mosquito Culex mollis was the most abundant species in the field experiment. Average conductivity and dissolved oxygen concentration differed among leaf species, but pH did not. Leaf toughness was positively correlated with mean macroinvertebrate abundance and cumulative species richness. A laboratory experiment measured C. mollis yield and pupation time in tree hole microcosms containing the four litter species. Cumulative mosquito mass and time to pupation differed among leaf litter species, with Platypodium litter supporting the greatest yield. Pupation was slowest on Ceiba litter. Grazing by mosquito larvae facilitated leaf decomposition in all treatments. Results suggest that differences in macroinvertebrate species richness and mosquito yield can be attributed to differences in nutritional quality among litter species.
碎屑的质量和数量会影响许多淡水生态系统中大型无脊椎动物的生产力和分布。本研究通过实验调查了吉贝、巴拿马油楠、小叶榕和雅致阔盘豆的落叶对巴拿马低地湿润森林中人工蓄水树洞大型无脊椎动物物种组成、丰富度和丰度的影响。各处理间的物种组成相似，但落叶类型间的物种丰富度和寿命不同，雅致阔盘豆落叶的相关指标始终最高。在目标树种的天然树洞中也观察到了类似模式。在野外实验中，软体库蚊是最丰富的物种。不同叶片物种间的平均电导率和溶解氧浓度存在差异，但pH值无差异。叶片韧性与大型无脊椎动物的平均丰度和累积物种丰富度呈正相关。一项实验室实验测量了包含这四种落叶物种的树洞微观世界中软体库蚊的产量和化蛹时间。不同落叶物种间的累积蚊虫质量和化蛹时间存在差异，雅致阔盘豆落叶的产量最高。在吉贝落叶上化蛹最慢。在所有处理中，蚊虫幼虫的啃食都促进了叶片分解。结果表明，大型无脊椎动物物种丰富度和蚊虫产量的差异可归因于落叶物种间营养质量的差异。
