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Context: Wildfire and vegetation treatments affect mule deer (Odocoileus hemionus) populations across the western United States. However, the relative influence of fire and treatments on habitat use by mule deer in Arizona is not well defined. Aims: We examined locations of mule deer on the Kaibab Plateau in northern Arizona, so as to determine the influence of vegetation treatments and wildfire severity on deer habitat-use patterns across their winter range where fires and treatments had occurred previously. Methods: We used locations (n = 11 297) from 21 adult female mule deer fitted with global positioning system collars to model probability of use as a function of habitat covariates. Key results: The best model describing winter-range habitat use by mule deer on the Kaibab Plateau included covariates describing the age of vegetation treatments and fire severity. Increased deer use in winter was associated with areas of lower terrain ruggedness and reduced snow depths. Deer use also increased in areas that experienced a higher average fire severity, resulting in decreased vegetation heights. Among treatment age classes, deer use was greatest in areas containing vegetation treatments that were ≤6 years old, but negatively associated with treatments that were >6 years old. Conclusions: Vegetation treatments designed to remove or reduce less palatable tree and shrub species to improve forage conditions may increase the use of winter habitats by deer on the Kaibab Plateau. Similarly, prescribed fire and rangeland treatments designed to return areas to a more natural fire regime and, thereby, generate new plant growth, may improve winter-range habitat conditions for mule deer. Implications: Similar treatment strategies may also benefit mule deer populations throughout the western USA, by improving forage conditions on critical habitats and reducing the potential for catastrophic wildfire. Wildfire and prescribed burns are common across many mule deer habitats; yet, published literature is equivocal relative to how mule deer respond to burned habitats or treatments intended to improve them. On the Kaibab Plateau in northern Arizona, mule deer used winter-range areas where wildfires had reduced the overall plant height and where vegetation treatments intended to restore habitats were ≤6 years old. Wildfires may, thus, have positive effects on habitats for wildlife, provided that fire severity is not extreme, and particularly when efforts to recover native vegetation allow mule deer to move through successively productive areas. [ABSTRACT FROM AUTHOR]

• Zero to 118 aspen (Populus tremuloides) saplings were found at 92 sites in Arizona. • Conifers, drought, disease, and a lack of intense fire correlated with fewer aspen. • Elk, deer, and cattle were less likely to appear in the best supported model. • Conifer removal and prescribed fires may promote aspen recruitment. Poor recruitment in some quaking aspen (Populus tremuloides) stands has led to debate over which factors play the largest role in aspen forest persistence. Understanding the relative importance of the many relevant factors over a large landscape could inform management strategies regarding aspen recruitment by focusing efforts on the most important factors. Therefore, between 2011 and 2016 we collected data on 29 biotic and abiotic factors thought to affect aspen recruitment from 92 randomly-selected aspen stands growing along the southwestern limit of its distribution in Arizona, USA. We assessed the condition of selected aspen stands by quantifying the number of recently recruited aspen stems (saplings >2 m tall and <5 cm dbh) in each sampling plot. We used negative binomial regression to estimate the relationship between aspen recruitment and the measured covariates. We fit a balanced set of models, calculated AIC weights for those models, and summed the weights of the models containing each covariate as a measure of covariate relative importance. Six covariates had relative importance values that were significantly greater than random: fire severity in 2011, conifer encroachment, rust presence, fire severity in 2015, blight presence, and the standardized precipitation-evapotranspiration index. There were no significant differences in the ranking of these six covariates by relative importance. Although we estimated that cattle and elk had a significant negative impact on aspen recruitment, these factors were relatively unimportant. This seemingly counter-intuitive result arose because many sites lacked ungulates, but still failed to recruit aspen, indicating that other factors were more important for aspen recruitment. Our results indicate that conifer removal and increased fire activity could be among the most effective management tools to help promote aspen recruitment. [ABSTRACT FROM AUTHOR]

The article reports that simulation model introduced a very small amount of experimental noise compared to most real glasshouse experiments focused on soil biotic effects on plants. It mentions importance of background noise, and overestimate the importance of noise derived from soil biotic treatments. It states that plant–soil interactions involve randomly sampling a larger population.

Highlights: [•] We report a database of nutrient concentrations in tree component tissues. [•] We combined the nutrient database with the Heureka forest analysis model. [•] We evaluated the impact of forest management on BC pools in forest ecosystems. [•] K is the most sensitive BC and is removed from soil more quickly than others. [•] Estimates of mineral soil weathering rates need greater precision. [Copyright &y& Elsevier]

Studies evaluating plant-soil biota interactions in both native and introduced plant ranges are rare, and thus far have lacked robust experimental designs to account for several potential confounding factors., Here, we investigated the effects of soil biota on growth of Pinus contorta, which has been introduced from Canada to Sweden. Using Swedish and Canadian soils, we conducted two glasshouse experiments. The first experiment utilized unsterilized soil from each country, with a full-factorial cross of soil origin, tree provenance, and fertilizer addition. The second experiment utilized gamma-irradiated sterile soil from each country, with a full-factorial cross of soil origin, soil biota inoculation treatments, tree provenance, and fertilizer addition., The first experiment showed higher seedling growth on Swedish soil relative to Canadian soil. The second experiment showed this effect was due to differences in soil biotic communities between the two countries, and occurred independently of all other experimental factors., Our results provide strong evidence that plant interactions with soil biota can shift from negative to positive following introduction to a new region, and are relevant for understanding the success of some exotic forest plantations, and invasive and range-expanding native species. [ABSTRACT FROM AUTHOR]

Summary [ABSTRACT FROM AUTHOR]

Additions of nutrients, faster growing tree varieties, more intense harvest practices, and a changing climate all have the potential to increase forest production in Sweden, thereby mitigating climate change through carbon sequestration and fossil fuel substitution. However, the effects of management strategies for increased biomass production on soil resources and water quality at landscape scales are inadequately understood. Key knowledge gaps also remain regarding the sustainability of shorter rotation periods and more intensive biomass harvests. This includes effects of fertilization on the long-term weathering and supply of base cations and the consequences of changing mineral availability for future forest production. Furthermore, because soils and surface waters are closely connected, management efforts in the terrestrial landscape will potentially have consequences for water quality and the ecology of streams, rivers, and lakes. Here, we review and discuss some of the most pertinent questions related to how increased forest biomass production in Sweden could affect soils and surface waters, and how contemporary forestry goals can be met while minimizing the loss of other ecosystem services. We suggest that the development of management plans to promote the sustainable use of soil resources and water quality, while maximizing biomass production, will require a holistic ecosystem approach that is placed within a broader landscape perspective. [ABSTRACT FROM AUTHOR]

Abstract: Ectomycorrhizal (EM) fungi are abundant in temperate and boreal ecosystems and are understood to be an important means whereby plants can fulfill their nutrition requirements. The extent of the EM fungal involvement in accessing organic sources of N, however, remains unknown. Some EM fungi have been found to produce lignolytic and proteolytic enzymes which are necessary to depolymerize organic substrates, but this ability varies by species. Both EM fungal communities and the activities of lignolytic and proteolytic enzymes may be sensitive to changes in inorganic N availability such as through increased atmospheric deposition. Our objectives were to simulate an ecologically relevant increase in atmospheric N deposition in areas currently receiving very little exogenous N and examine changes in EM community composition, lignin degrading enzyme activity, and soil protein depolymerization. We found a distinct shift in the EM community composition following simulated atmospheric N deposition. Likewise, we found a significant decrease in the activity of lignin degrading enzymes, which could have important implications on ecosystem N and C cycling. Contrary to our hypotheses, proteolysis increased following N addition. The fact that lignolytic and proteolytic enzymes exhibit opposite responses is counterintuitive and suggests much is yet to be learned about how N addition affects global C storage by affecting the decomposition of organic matter. Our data suggest small increases in atmospheric N deposition could produce significant changes in communities of EM fungi and N and C cycles. [Copyright &y& Elsevier]

Abstract: We have much to learn about the roles of various groups of soil microorganisms in the decomposition of soil organic matter. Any changes in the type or amount of organic matter entering the soil, due to increasing atmospheric nitrogen (N) deposition and elevated carbon dioxide, could directly affect soil microbial community structure or the decompositional functions performed by the various microbial groups. We experimentally altered soil microbial communities using a factorial combination of trenching and in-growth bags crossed with fertilization treatments consisting of two forms of inorganic N and three N-containing organic molecules of increasing molecular weight and complexity. We tested three hypotheses: (1) Different components of soil microbial communities change in different ways following the application of fertilization treatments; (2) soil fungi decrease with increased inorganic N but increase following the application of organic molecules; and (3) activity of the extracellular enzymes peroxidase and phenol oxidase, which are important in lignin degradation, decrease following the addition of inorganic N. We found that the abundance of soil microbes and their composition (measured by lipid analysis) was significantly altered following the addition of glutamic acid, but not with inorganic N or more complex N-containing organic molecules. Lipids indicative of ectomycorrhizal fungi experienced the greatest increase in abundance. Extracellular enzyme activity, in contrast, changed very little and did not parallel changes in the structure of the soil microbial community that resulted from the isolation treatments. We conclude that small additions of N-containing organic compounds can cause changes in the structure of the soil microbial community but that community changes do not necessarily have an impact on extracellular enzyme activity. [Copyright &y& Elsevier]

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Background: DNA methylation of CpG sites on genetic loci has been linked to increased risk of asthma in children exposed to elevated ambient air pollutants (AAPs). Further identification of specific CpG sites and the pollutants that are associated with methylation of these CpG sites in immune cells could impact our understanding of asthma pathophysiology. In this study, we sought to identify some CpG sites in specific genes that could be associated with asthma regulation ( Foxp3 and IL10 ) and to identify the different AAPs for which exposure prior to the blood draw is linked to methylation levels at these sites. We recruited subjects from Fresno, California, an area known for high levels of AAPs. Blood samples and responses to questionnaires were obtained ( n  = 188), and in a subset of subjects ( n  = 33), repeat samples were collected 2 years later. Average measures of AAPs were obtained for 1, 15, 30, 90, 180, and 365 days prior to each blood draw to estimate the short-term vs. long-term effects of the AAP exposures., Results: Asthma was significantly associated with higher differentially methylated regions (DMRs) of the Foxp3 promoter region ( p  = 0.030) and the IL10 intronic region ( p  = 0.026). Additionally, at the 90-day time period (90 days prior to the blood draw), Foxp3 methylation was positively associated with NO 2 , CO, and PM 2.5 exposures ( p  = 0.001, p  = 0.001, and p  = 0.012, respectively). In the subset of subjects retested 2 years later ( n  = 33), a positive association between AAP exposure and methylation was sustained. There was also a negative correlation between the average Foxp3 methylation of the promoter region and activated Treg levels ( p  = 0.039) and a positive correlation between the average IL10 methylation of region 3 of intron 4 and IL10 cytokine expression ( p  = 0.030)., Conclusions: Short-term and long-term exposures to high levels of CO, NO 2 , and PM 2.5 were associated with alterations in differentially methylated regions of Foxp3 . IL10 methylation showed a similar trend. For any given individual, these changes tend to be sustained over time. In addition, asthma was associated with higher differentially methylated regions of Foxp3 and IL10 ., Competing Interests: All methods and procedures were approved by the Stanford University Institutional Review Board for the Protection of Human Subjects. Written informed consent was received from parents of subjects prior to inclusion in the study.Not applicableThe authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.