1. Changes in benthic invertebrate community structure following 16 years of forest succession after logging were examined by estimating benthic invertebrate abundance, biomass and secondary production in streams draining a forested reference and a recovering clear-cut catchment. Benthic invertebrate abundance was three times higher, and invertebrate biomass and production were two times higher...

this paper is concerned with the estimation of total factor productivity (tfp) growth for the iranian electric utilities during the period 1980-1993 on the basis of panel data. a translog cost function is used which accommodates firm - specific variability through a one - way error component model. the results show that the iranian electricity supply industry experienced increasing returns to s...