Evaluating the effects of ecosystem management: A case study in a MissouriOzark forest

Many federal and state management agencies have shifted from commodity-base d management systems to multiple resource-based management systems that emp hasize sustainable ecosystem management. Long-term sustainability of ecosys tem functions and processes is at the core of ecosystem management, but a b lueprint for assessing sustainability under different management strategies does not exist. Using the Missouri Ozark Forest Ecosystem Project (MOFEP) as a case study, we present one approach to evaluating the landscape-scale, short-term (one and two years posttreatment) consequences of even-aged and uneven-aged forest management treatments on community-level biological div ersity. We chose changes in density of ecological species groups, represent ing groups of species with similar resource requirements, as our response v ariable. Changes in density are detectable before species completely disapp ear from an area, and these changes may be an early indicator of significan t alterations to community structure and ecosystem function. Meta-analysis was used to statistically combine changes in densities across multiple spec ies groups and assess the overall impacts of management treatments on the a nimal community. We also separately examined changes in density for each ec ological species group. Our findings demonstrated that, in the short-term, even-aged and uneven-aged forest management treatments caused changes in an imal community density in Missouri Ozark forests. Even-aged management site s showed greater changes than uneven-aged management sites after harvesting , and changes in species' densities were larger two years posttreatment (19 98) than one year posttreatment (1997). Evaluation of treatment effects on individual ecological groups revealed that toads, forest interior birds, an d edge/early successional birds were significantly affected by management t reatments. We did not expect most species groups to exhibit treatment effec ts because relatively little forest biomass was removed per experimental si te (only 10%), forest cover at the regional landscape level did not change and was generally high during the study, and the time scale was relatively short. The challenges facing ecosystem management evaluation parallel the c hallenges of ecological science in general: identifying appropriate variabl es, spatial and temporal scales, and experimental/management treatments. Th e integrative approach demonstrated in this paper is a first step toward th e analysis of the effects of management treatments on multiple organisms wi thin an ecosystem.