Shrub community development and annual productivity trends over a 100-yearperiod on an industrial forest of Northern Idaho

Understory community structure of conifer plantations and naturally regener ated stands on north and south aspects is assessed in stands up to 100 year s following initial overstory removal on an industrial forest of northern I daho. Industrial forests differ from other forests as they are managed for timber production, yet these forests maintain substantial wildlife populati ons and provide recreational opportunities. Species occurrence, stem densit y, twig density and height were compared between north and south aspects an d between plantation and natural regeneration stands. Differences were dete cted relative to aspect and stand type but variation among sites was also s ignificant. Annual shrub productivity, biomass of current year's twigs, was estimated for all shrub species in 77 different stands. Productivity curve s were developed for plantation and natural regeneration type stands on bot h north and south aspects which predict total stand annual productivity fro m time of initial cutting to over 100 years after overstory removal (R-2 > 0.90). Maximum annual shrub productivity occurred between 7 and 14 years af ter overstory removal and broadcast burning. The findings of the study indi cate that early successional stages across the landscape can, by forest man agement, be maintained to produce forage and influence animal distribution. (C) 2001 Elsevier Science B.V. All rights reserved.