Studies examining how wildlife populations perceive and respond to habitat are common, and many attempt to understand how the quality of available habitats influences population processes such as survival and recruitment. Traditional methods to estimate habitat quality (e.g. population density) have not led to great advancement in our understanding of relationships between habitat and fitness in recent years. Metrics from the discipline of conservation physiology could help researchers to address these difficulties and to meet the challenges that habitat alteration poses to biodiversity. Incorporating physiological metrics that relate energetics or environmental stress to habitats may be powerful measures of habitat quality. By quantifying field metabolic rates, body condition, or concentrations of stress hormones in individual organisms, researchers may identify mechanisms associated with habitat that underlie observed patterns in vital rates (survival and fecundity). Physiological metrics offer useful tools that may identify mechanisms of habitat quality and detect the causes of declines in biodiversity. However, integration among physiologists, ecologists and conservation biologists will require new partnerships and approaches to respond to complex ecological issues.
13 July 2011 in The Journal of Wildlife Management
Intensively-managed forest (IMF) ecosystems support environmental processes, retain biodiversity and reduce pressure to extract wood products from other forests, but may affect species, such as plethodontid salamanders, that are associated with closed canopies and possess limited vagility. We describe: (1) critical aspects of IMF ecosystems; (2) effectiveness of plethodontid salamanders as barometers of forest change; (3) two case studies of relationships between salamanders and coarse woody debris (CWD); and (4) research needs for effective management of salamanders in IMF ecosystems. Although plethodontid salamanders are sensitive to microclimate changes, their role as ecological indicators rarely have been evaluated quantitatively. Our case studies of CWD and salamanders in western and eastern forests demonstrated effects of species, region and spatial scale on the existence and strength of relationships between plethodontid species and a “critical” microhabitat variable. Oregon slender salamanders (Batrachoseps wrighti) were more strongly associated with abundance of CWD in managed second growth forests than ensatina salamanders (Ensatina eschscholtzii). Similarly, CWD was not an important predictor of abundance of Appalachian salamanders in managed hardwood forest. Gaining knowledge of salamanders in IMF ecosystems is critical to reconciling ecological and economic objectives of intensive forest management, but faces challenges in design and implementation.