RELATIONSHIPS BETWEEN WATER-BEETLE DISTRIBUTIONS AND CLIMATIC VARIABLES - A POSSIBLE INDEX FOR MONITORING GLOBAL CLIMATIC-CHANGE

The role of climate in determining water beetle species' distribution was investigated using data from 495 10-km national grid squares in no rthern England and southern Scotland. Four climatic variables (tempera ture, rainfall, sunshine and windspeed) were ordinated to produce a cl imate index and this was used in logistic regression with incidence of water beetle species. The distribution of eighty-seven species was co rrelated with the climate index. The probable occurrence of two specie s before and after a supposed climate change was investigated. Other f actors affecting water beetle species distributions are discussed but it can be envisaged that if climatic influences can be separated from other environmental factors, the distribution of water beetle species may be used as an index for monitoring climate change.