Zooplankton species occurrence in arctic lakes in landscapes of very different ages

摘要

Over the past eight summers we have sampled over 165 lakes in the Toolik Lake Region (TLR) in arctic Alaska (68 deg 38 min 00 sea N, 148 deg 38 min 00 sea W). For each lake we have measured plant nutrients, water quality, physical attributes, and the species composition of the benthic, zooplankton and fish communities. We focus here on the relationships between zooplankton species richness and biotic and abiotic factors. The lakes varied in depth from less than 1 meter to 37 meters, varied in areafrom 1.3 to 7963.7 ha and were located on landscapes of four different ages (12.8-11.4 ka, 25-11.5 ka, 120-55 ka, and 780-125 ka). There are twelve species of crustacean zooplankton and 1 larval insect that may be found in the pelagic zones of these lakes. In lakes with fish, we found a positive relationship between the number of zooplankton species present and lake depth and area. We also found a positive relationship between the number of zooplankton species present and lake age, but no relationship between species richness and lake order.