Effects of Precommercial Thinning on Snowshoe Hares, Small Mammals, and Forest Structure in Northern Maine

The extent of precommercial thinning (PCT) to manipulate stand density in overstocked, regenerating stands and to accelerate growth, yield, and the rate of development of crop trees has been increasing within the Acadian forest of northeastern North America. Although the silvicultural responses of crop trees to thinning are well studied, few studies have evaluated the effects of PCT on forest-dependent wildlife and their habitat. I investigated the effects of PCT and stand succession on snowshoe hares, small mammals, and forest structure on 38 stands (25 treated with PCT, 13 unthinned stands) from 1 to 16 years post-treatment within 7 townships in the commercial forests of northern Maine. Forest stands were clearcut from 1967-1983, treated with an aerial herbicide during 1977-1988, and treatment stands were manually thinned from 1984-1999. Densities of snowshoe hares were examined by establishing approximately 46 km of pellet transect across 30 stands and live-trapping a subset of 8 stands to determine the relationship between densities of pellets and estimated densities of hares. Densities of hares were linearly related to pellet densities from 0-3 hareslha (P \u3c 0.001). Two similar pellet x hare density regressions developed outside Maine did not perform well (AICc, \u3e 10) and predictions from these regressions underestimated densities of hares. Unthinned stands had approximately 2x greater densities of hares than similar stands treated with PCT across stand ageclasses, 2 years of sampling, and during leaf-off (October -May) and leaf-on (June - September) seasons (P \u3c 0.10). Although densities of hares were lower in stands treated with PCT, thinned stands still maintained densities greater than stands managed using some alternative silvicultural regimes. I examined the temporal effects of PCT on small mammals by live-trapping within 37 stands (24 treated with PCT) during June-August 2000 and 2001. Thinning increased [red-backed voles (Clethrionomys gapperi), P = 0.008; masked shrews (Sorex cineus), P \u3c 0.0011 or produced no detectable effect [deer mice (Peromyscus maniculatus), P = 0.544; short-tailed shrews (Blarina brevicauda), P = 0.5171 on the 4 - most abundant species of small mammals captured on my study areas; therefore, PCT was compatible with maintaining or enhancing densities of common species of forest-dwelling small mammals in regenerating conifer stands. \u27 Dominant changes in forest structure were described from 1 to 11 years post-treatment between herbicide treated clearcuts with and without PCT, to predict wildlife responses to thinning and stand succession. During summers 2001 and 2002,29 structural characteristics were quantified across 30 forest stands (17 treated with PCT). Variables with either significant effects of treatment or thinning class were incorporated into a principal components analysis (PCA) to reduce the dimensionality of data. Nearground cover, overhead cover, and understory structure described approximately 80% of variation between thinned and unthinned stands. Horizontal cover, an overstory to understory contrast, and a gradient of herbaceous vegetation accounted for 75% variation in forest structure among thinning classes of stands. Wildlife associated with dense, early successional habitat, such as snowshoe hares, have been negatively affected by PCT, but thinning could positively influence species that use more mature forest with a more open understory (i.e. red-backed voles)

eDNA as a tool for identifying freshwater species in sustainable forestry: A critical review and potential future applications

Environmental DNA (eDNA) is an emerging biological monitoring tool that can aid in assessing the effects of forestry and forest manufacturing activities on biota. Monitoring taxa across broad spatial and temporal scales is necessary to ensure forest management and forest manufacturing activities meet their environmental goals of maintaining biodiversity. Our objectives are to describe potential applications of eDNA across the wood products supply chain extending from regenerating forests, harvesting, and wood transport, to manufacturing facilities, and to review the current state of the science in this context. To meet our second objective, we summarize the taxa examined with targeted (PCR, qPCR or ddPCR) or metagenomic eDNA methods (eDNA metabarcoding), evaluate how estimated species richness compares between traditional field sampling and eDNA metabarcoding approaches, and compare the geographical representation of prior eDNA studies in freshwater ecosystems to global wood baskets. Potential applications of eDNA include evaluating the effects of forestry and forest manufacturing activities on aquatic biota, delineating fish-bearing versus non fish-bearing reaches, evaluating effectiveness of constructed road crossings for freshwater organism passage, and determining the presence of at-risk species. Studies using targeted eDNA approaches focused on fish, amphibians, and invertebrates, while metagenomic studies focused on fish, invertebrates, and microorganisms. Rare, threatened, or endangered species received the least attention in targeted eDNA research, but are arguably of greatest interest to sustainable forestry and forest manufacturing that seek to preserve freshwater biodiversity. Ultimately, using eDNA methods will enable forestry and forest manufacturing managers to have data-driven prioritization for conservation actions for all freshwater species

Crossing boundaries in conservation physiology

Abstract not available.Sean Tomlinson, Jodie L. Rummer, Kevin R. Hultine and Steven J. Cook

Fecal Glucocorticoid Metabolites as Biomarkers in Equids: Assay Choice Matters

From Wiley via Jisc Publications RouterHistory: received 2020-05-06, rev-recd 2021-03-29, accepted 2021-04-09, pub-electronic 2021-06-01Article version: VoRPublication status: PublishedFunder: Royal Society; Id: http://dx.doi.org/10.13039/501100000288; Grant(s): UF110641Funder: Chester Zoo; Id: http://dx.doi.org/10.13039/501100005359; Grant(s): Conservation FellowshipABSTRACT: Free ranging animals are exposed to environmental, demographic, and ecological challenges over time, which can affect their health and fitness. Non‐invasive biomarkers can provide insight into how animals cope with these challenges and assess the effectiveness of conservation management strategies. We evaluated how free ranging ponies (Equus ferus caballus) on the Carneddau Mountain range, North Wales respond to 2 stimuli: an acute stressor of an annual roundup event in November 2014, and spatial and temporal variation in ecological factors in 2018. We evaluated fecal glucocorticoid metabolites using 2 enzyme immunoassays (EIAs): an 11‐oxoetiocholanolone EIA (measuring 11,17‐dioxoandrostanes [11,17‐DOAs]) and a corticosterone EIA. The former assay has been validated in equids, whereas there is limited evidence for the suitability of the latter. We used an additional parent testosterone EIA to measure fecal androgen metabolites in response to the ecological challenges. Following the roundup, the metabolite concentrations measured by the 2 glucocorticoid EIAs were not correlated. The 11,17‐DOAs were elevated from the second day following the roundup and then slowly returned to pre‐round levels over the next 2 weeks. In contrast, the metabolites measured by the corticosterone assay showed no response to the roundup. For the ecological data, all 3 assays detected a positive correlation between metabolites and social group size in males but not in females. The metabolite concentrations measured by the testosterone and corticosterone assays were highly correlated and were temporally associated with the onset of the breeding season, whereas the 11,17‐DOAs were not. The co‐variance of metabolites measured by the corticosterone and testosterone assays, and the lack of an acute response in the corticosterone assay to the roundup, suggests that metabolites detected by the corticosterone assay were not primarily associated with increased glucocorticoid production. We recommend using well‐validated fecal biomarker assays of hypothalamus‐pituitary‐adrenal axis activity to evaluate and compare the effect of different management interventions and environmental change. © 2021 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society

Slow Lives in the Fast Landscape: Conservation and Management of Plethodontid Salamanders in Production Forests of the United States

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

Correction: Homyack, J.A. and Kroll, A.J. Slow Lives in the Fast Landscape: Conservation and Management of Plethodontid Salamanders in Production Forests of the United States. Forests 2014, 5, 2750–2772

The authors wish to correct a statement in the published paper [1], doi:10.3390/f5112750, website: http://www.mdpi.com/1999-4907/5/11/2750/htm. After publication, we discovered that two numbers were mistakenly switched. Section, 4.1, should read “Oregon slender salamanders were detected in 144/420 (34%) plots and 101/378 (27%) plots in 2013 and 2014, respectively; ensatina salamanders were detected in 53/420 (13%) plots and 73/378 (19%) plots in 2013 and 2014, respectively”. The authors would like to apologize for any inconvenience caused to the readers by these changes.[...

Short-term grazing exclusion effects on riparian small mammal communities

Grazing of livestock in streams and associated riparian habitats (hereafter referred to as riparian zones) may affect small mammal communities by influencing vegetation, water quality, and other site characteristics. To better understand these effects, we compared vegetation structure, and abundance and richness of small mammals in grazed riparian zones and similar areas where livestock had recently (1-2 years) been excluded in southwest Pennsylvania, 1998 and 1999. Mammalian species richness and abundance (all species combined, meadow voles [Microtus pennsylvanicus Ord], and meadow jumping mice [Zapus hudsonius Zimmermann]) were greater on sites where livestock had been excluded than grazed areas. These findings are likely the result of greater litter cover and increased vertical vegetation obstruction observed on these sites. Because small mammal communities respond quickly to relaxation of grazing in riparian zones, subsidy programs exist to partially pay for fencing, and landowners may potentially benefit from fencing these areas through improved water quality, erosion control, and livestock health, fencing may be an effective wildlife and grazing management tool.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202