scholarly journals Mitigation of Deer Herbivory in Temperate Hardwood Forest Regeneration: A Meta-Analysis of Research Literature

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1220
Author(s):  
Caleb H. Redick ◽  
Douglass F. Jacobs

Ungulate herbivory poses global challenges to forest regeneration. Deer, in combination with other biotic and abiotic factors, threaten to shift forest composition away from palatable hardwoods, such as oaks (Quercus spp.), and cause regeneration failure in some cases. Many studies have assessed methods to reduce or manage browse, but comprehensive analyses of the relative effectiveness of these techniques among published experiments are lacking. We synthesized the literature describing the results of methods to reduce deer browsing impacts, and assessed the effectiveness of deer browse management methods in controlling damage to hardwood forest regeneration. Specifically, we systematically analyzed results from 99 studies that used repellents, physical barriers, lethal population control, timber harvests, facilitation by neighboring plants, or fertilizer to affect browse, survival, or height growth of hardwood seedlings. Across studies, browse was reduced (mean effect size and confidence intervals) with the following: Fencing −3.17 (CI: −4.00–−1.31), shelters −1.28 (CI: −2.02–−0.67), cages −1.48 (CI: −3.14–−0.62), facilitation from neighboring plants −0.58 (CI: −1.11–−0.13), repellents −0.45 (CI: −0.56–−0.21), hunting −0.99 (CI: −1.51–−0.26). These methods each had positive effects on seedling height growth (except for repellents), and cages, timber harvests, fences, and mesh sleeves had positive effects on survival. Logging slash had no effect on browse incidence (−0.05, CI: −0.97–0.19). Fertilizer applied during seedling establishment increased browse (0.13, CI: 0.11–0.21), and did not affect height growth. We conclude that fences or other physical barriers best control for the effects of deer, but facilitation by surrounding vegetation, logging slash, hunting, habitat management through timber harvest, and certain repellents may also be moderately effective. Discrepancies between browse effectiveness and relative costs suggest that economic analyses should be developed to help to guide prescriptions for management.

1956 ◽  
Vol 185 (1) ◽  
pp. 195-200 ◽  
Author(s):  
R. Carl Millican ◽  
Edward F. Stohlman

The therapeutic effectiveness of chlorpromazine, dibenamine, l-norepinephrine, 1-ethylsulfonyl-4-ethyl-piperazine hydrochloride, serotonin, ascorbic acid, human plasma cholinesterase and a bacterial polysaccharide (Piromen), has been studied in experimental tourniquet and burn shock in mice. Employing survival as an indication of therapeutic effect, simultaneous comparisons were made of the survival of groups of animals receiving these agents in saline and control groups receiving saline alone. Chlorpromazine pretreatment (8–20 mg/kg) produced reproducible positive effects on survival whether given alone or in conjunction with saline replacement therapy. Dibenamine pretreatment (5–25 mg/kg) produced positive effects on survival but this response was not always reproducible. No beneficial effect was demonstrable following administration of the remainder of these agents when compared to control groups given saline alone.


1988 ◽  
Vol 64 (4) ◽  
pp. 315-319 ◽  
Author(s):  
Z. Chrosciewicz

An experimental burn in conjunction with a seed-tree system was successful in regenerating jack pine (Pinus banksiana Lamb.) on a fresh to somewhat moist upland, loamy till, cutover site in central Saskatchewan. About 20 well-formed, uniformly spaced seed trees per hectare were left standing during timber harvest. The ignition of logging slash was carried out under preselected weather and fuel conditions so that favorable seedbeds and adequate seed dispersal from the seed trees were produced. Four growing seasons after burning, jack pine stocking by 4-m2 quadrats was 90% with 12 195 seedlings/ha. Aspen (Populus tremuloides Michx.), to a lesser degree black spruce (Picea mariana [Mill.] B.S.P.), and other companion tree species also regenerated with the pine. Various seedbed and regeneration characteristics as well as height growth rates are discussed. Key words: Pinus banksiana, slash burning, seed-tree system, forest regeneration, growth rates, central Saskatchewan.


Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 778 ◽  
Author(s):  
Lingyan Li ◽  
Jiachen Qu ◽  
Xiaoyue Xin ◽  
Shuxin Yin ◽  
Yongli Qu

The present experiment was carried out to assess the effects of reconstituted milk (RM), acidified reconstituted milk (ARM), and acidified fresh milk (AFM) on growth performance, diarrhea rate, and hematological parameters of preweaning dairy calves. For this purpose, a total of 27 Holstein female calves (one month of age) with initial body weight of (67.46 ± 4.08) kg were divided into three groups in such a way that each group contained nine calves. Calves were housed individually, and starter was offered ad libitum to each calf. The dietary treatments were RM, ARM, and AFM. The highest milk intake was observed in calves receiving AFM as compared to other treatments (p < 0.01). Calves fed AFM had more feed intake than those fed ARM and RM (p < 0.01). Feed efficiency was significantly lower for calves offered ARM than those offered RM and AFM (p < 0.01). A lower withers height growth was found for calves fed RM than those fed ARM and AFM (p <0.05). Diarrhea rate and white blood cell (WBC) and lymphocytes (LYM) counts were greater for calves fed RM than those fed ARM and AFM (p < 0.05). These findings suggested that ARM and AFM had positive effects on growth performance and health status of the preweaning dairy calves.


Author(s):  
Diego Sánchez-González ◽  
Fermina Rojo-Pérez ◽  
Vicente Rodríguez-Rodríguez ◽  
Gloria Fernández-Mayoralas

Background: The academic literature contains little information regarding the interventions that create age-friendly cities and communities in order to promote active ageing. Objectives: A systematic review was carried out to determine the available empirical evidence in relation to the characteristics, content and effectiveness of interventions aimed at improving environmental and psychosocial risk factors for older people, from the perspective of age-friendly communities and the promotion of active ageing. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the studies retained in this review were identified through a systematic search of the academic literature in selected electronic databases including Web of Science and Scopus. Independent critical appraisal and data extraction were conducted by two reviewers. The checklist was used to assess the quality of the articles. Findings: The search identified 1020 potentially eligible documents, of which 11 satisfied the established criteria. Non-exhaustive practices prevailed over rigorous investigations, with a high proportion of studies observed to be of low methodological quality and at high risk of bias. This reflected the predominance of uncontrolled interventions. Environmental interventions were focused on reducing risk and adapting the everyday environmental setting, while psychosocial interventions prioritised social strategies (behavioural changes, promotion of participation) and training. Interventions were more effective in certain domains of age-friendly cities and communities such as transportation and housing, followed by increased participation as a lifestyle-related behavioural change. The inferred changes were associated with providing information and enhancing skills; modifying access, barriers, exposures, and opportunities; enhancing services and support; continuity and effectiveness of changes over time; and modifying policies based on the bottom-up approach of age-friendly cities and communities (AFCC). Discussion and conclusion: Interventions focused on personal and organisational aspects might have positive effects in the longer term. However, fewer changes would be observed in interventions revolving around changing lifestyles owing to the impact of complex multi-causal factors. The relative effectiveness in terms of health calls into question the design of interventions and the supposed “friendliness” of certain communities. There is a need to encourage sound longitudinal research aimed at providing key knowledge for the implementation and evaluation of public policies, and to encourage age-friendly community programmes to promote active ageing.


Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 146 ◽  
Author(s):  
Vernon S. Peters ◽  
Darcy R. Visscher

Research Highlights: When biotic interactions such as disease alter both the seed production capacity of stands, and seedling survivorship, the relative importance of seed availability versus substrate specificity may alter future regeneration opportunities for plant populations. Background and Objectives: We investigated the importance of disease severity, seed availability, and substrate limitation to the regeneration dynamics of the endangered limber pine, Pinus flexilis, in two ecosystems with varying forest composition, and different histories of white pine blister rust infection (WPBR; Cronartium ribicola). Materials and Methods: A total of 17 stands from the montane ecoregion (Alberta, Canada) were sampled for seed production between 2007–2010, seedling density, and age structure. Model selection using an information theoretic approach compared a series of a priori models and their combinations, based on our hypotheses on the role biotic variables play in the regeneration process. Results: Despite higher rates of WPBR infection, 2.3 times more seed was available for avian dispersers in the southern ecosystem. Recent seedling regeneration did not correspond to seed production (83 versus 251 seedlings/ha, in southern versus northern ecosystems, respectively), resulting in a seven-fold difference in seed to seedling ratios between ecosystems. Models suggest that disease and vegetation cover were important factors explaining the absence of regeneration in 79.4% of the plots sampled, while basal area (BA) of live limber pine, rocky substrates, ecosystem, South aspects, and slope enhanced limber pine regeneration. Seedling age structures suggest that recent regeneration is less likely in more diseased landscapes, than it was historically (40% versus 72.8% of seedlings < 20 years old, respectively, in southern versus northern ecosystems). Conclusions: At the northern limits of limber pine’s range, seed availability does not ensure regeneration, suggesting that other environmental or biotic factors hinder regeneration. Regeneration was consistently predicted to be lower in the southern ecosystem than in the northern ecosystem, suggesting that natural regeneration and the potential for population recovery are ecosystem dependent. We recommend that monitoring recent seedlings will aid the identification of biotic and abiotic factors affecting regeneration.


2010 ◽  
Vol 40 (3) ◽  
pp. 500-510 ◽  
Author(s):  
Timothy B. Harrington ◽  
Stephen H. Schoenholtz

Although considerable research has focused on the influences of logging debris treatments on soil and forest regeneration responses, few studies have identified whether debris effects are mediated by associated changes in competing vegetation abundance. At sites near Matlock, Washington, and Molalla, Oregon, studies were initiated after timber harvest to quantify the effects of three logging debris treatments (dispersed, piled, or removed) on the development of competing vegetation and planted Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii ). Each debris treatment was replicated with initial and annual vegetation control treatments, resulting in high and low vegetation abundances, respectively. This experimental design enabled debris effects on regeneration to be separated into effects mediated by vegetation abundance and those independent of vegetation abundance. Two to three years after treatment, covers of Scotch broom ( Cytisus scoparius (L.) Link) at Matlock and trailing blackberry ( Rubus ursinus Cham. & Schltdl.) at Molalla were over 20% greater where debris was piled than where it was dispersed. Debris effects on vegetation abundance were associated with 30% reductions in the survival of Douglas-fir at Matlock (r2 = 0.62) and the stem diameter at Molalla (r2 = 0.39). Douglas-fir survival and growth did not differ among debris treatments when effects were evaluated independent of vegetation abundance (i.e., with annual vegetation control), suggesting negligible short-term effects of debris manipulation on soil productivity.


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