Effects of forest management on vertebrates: synthesizing two decades of data from hardwood forests in Missouri, USA.

Modern forest management seeks to balance multiple social, economic, and ecological goals. Different management approaches create different types of disturbances in a forest ecosystem and thus also differ in their impacts on plants, animals, and insects. Understanding these impacts is important for conservation of forest ecosystem function, but challenging due to the large spatial and temporal scale over which management occurs. Most past research has focused on relatively small areas, short time scales, and/or a small number of species. To address this, we examined the effects of two common silvicultural systems (even and uneven aged) on abundance and richness of three vertebrate taxa (birds, small mammals, and herpetofauna) over a two-decade period in a temperate hardwood forest in Missouri, USA. The two systems removed a similar amount of biomass overall, but differed in the intensity, number, and configuration of harvests applied. We found that vertebrate population responses varied by taxa, occurred at multiple spatial scales, and were concentrated in the period following the first harvest entry. Birds generally had the largest changes in relative abundance, both positive and negative, following management. Small mammals and reptiles had smaller, but generally positive, responses; amphibians were mixed. Bird species tended to respond in the same way to both silvicultural systems, while small mammals and herpetofauna did not respond consistently. Thus, for birds, the total amount of harvest disturbance across the landscape drives population responses, while for others the size and configuration of individual harvests is likely more important. Synthesizing results across the vertebrate community at large spatial and temporal scales allows managers to better understand trade-offs when making decisions that will affect wildlife in contrasting ways.

Simulated data and code for analysis of herpetofauna response to forest management in the Missouri Ozarks.

We present predictor variables and R and Stan code for simulating and analyzing counts of Missouri Ozark herpetofauna in response to three forest management strategies. Our code performs four primary purposes: import predictor variables from spreadsheets; simulate synthetic response variables based on imported predictor variables and user-supplied values for data-generating parameters; format synthetic data for export to Stan; and analyze synthetic data.

Effect of Clonal Selection on Daphnia Tolerance to Dark Experimental Conditions.

Recent studies have demonstrated substantial effects of environmental stress that vary among clones. Exposure to ultraviolet radiation (UV) is an important abiotic stressor that is highly variable in aquatic ecosystems due to diel and seasonal variations in incident sunlight as well as to differences in the UV transparency of water among water bodies, the depth distribution of organisms, and the ability of organisms to detect and respond to UV. In contrast to the convention that all UV is damaging, evidence is accumulating for the beneficial effects of exposure to low levels of UV radiation. Whereas UV has been frequently observed as the primary light-related stressor, herein we present evidence that dark conditions may be similarly "stressful" (reduction of overall fitness), and stress responses vary among clones of the freshwater crustacean Daphnia parvula. We have identified a significant relationship between survivorship and reduced fecundity of clones maintained in dark conditions, but no correlation between tolerance of the clones to dark and UV radiation. Low tolerance to dark conditions can have negative effects not only on accumulated stresses in organisms (e.g. the repair of UV-induced damage in organisms with photolyase), but potentially on the overall physiology and fitness of organisms. Our results support recent evidence of the beneficial effects of low-level UV exposure for some organisms.