Wpływ suszy na ściółkowo-glebowe zgrupowania skoczogonków (Collembola, Hexapoda) w lesie mieszanym

The resilience of forest ecosystems to climate changes such as elevated temperature and frequent drought episodes, strongly depends on how the soil subsystems and its inhabitants responds to these perturbation. The epigeic soil Collembola communities of mature mixed deciduous forest and adjacent young plantation on moderately humid soil were compared in two consecutive years, out of which the second one was marked by significant deficiency of precipitation in growing− −season. The study plots were established on the area of experimental forests of Warsaw University of Life Science−SGGW in Rogów (central Poland). The objectives of the study was to assess the sensitivity of forest Collembola communities to drought stress and to check if the reaction depends on stand age. We also aimed to test if an indicator species of climate changes can be appointed. The results showed that three months drought episode had negative impact on forest Collembola communities of mature stands, while communities of young plantation were not affected. The reduction of total abundance of Collembola and clear changes in communities structure in mature stand was detected in the year of lower precipitation. The Collembola communities of young plantation were also significantly transformed, but in result of clear cutting and soil preparation. Therefore, the successional changes were the most evident process in these communities and there were no signs of drought influence. Among the most numerous species in Collembola communities of mature forest Isotomiella minor was appointed as an indicator of drought, because its abundance was drastically reduced in the year of lower precipitation. The small number of specimen of this species in young plantation may also prove its sensitivity to deficiency of humidity in soil. The significantly negative response to drought episode was documented also for Psuedosinella horaki, Micraphorura absoloni and Megalothorax minimus. Our study provided strong evidence that the drought, which lasted only three months, had a detrimental effect on forest Collembola commu− nities.