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Understanding the role of biocrust-forming mosses in soil recovery after wildfires is necessary for assessing the resilience of managed ecosystems. The purpose of this study was to investigate the mid-term impacts of two contrasting post-fire management strategies on soil recovery in eucalypt plantations in north-central Portugal, where a high cover of biocrust-forming mosses developed post-fire, contributing to erosion control. Six years after a wildfire, we examined the legacy effects of salvage logging and two rates of mulch application using logging residues (a standard rate of 8.0 Mg ha-1 and a reduced rate of 2.6 Mg ha-1) on soil properties, and explored the interaction between moss biocrusts and forest management practices on soils. Our findings reveal the resilience of soils to physical disturbance after logging operations, with no persistent negative effects on their physicochemical properties. Although forest residue mulches showed minimal influence on soils after six years, an interesting interaction with moss biocrusts was observed. In the absence of moss cover, direct contact of wood residues with soil at the standard mulch rate promoted higher nutrient content and biochemical activity, potentially attributed to accelerated decomposition processes. Regardless of the management applied, our study highlights the role of moss biocrusts in improving soil aggregation and biochemical processes in the mid-term. However, the severe water repellency observed in these soils may have impeded further biocrust expansion. Understanding the implications of forest management practices on soil recovery after wildfires is imperative for guiding strategies aimed at promoting ecosystem recovery and resilience in fire-prone managed forest ecosystems. • Soils show resilience to logging with no lasting physicochemical impacts. • Post-fire mulching increased soil nutrient content in the absence of moss biocrusts. • Biocrust proliferation may be conditioned by the severe soil water repellency. • Moss biocrust accelerated post-fire soil recovery and improved soil functions. [ABSTRACT FROM AUTHOR]

• Large high severity patches and salvage logging hinder post-fire tree regeneration. • Distance from seed trees was the most important driver of Scots pine regeneration. • Potential positive effects of AN and importance of site selection for plantation. • Integrating micro-scale site selection can improve the efficiency of plantation. Changes in disturbance regimes triggered by land use and climate change can significantly alter forest ecosystems by modifying the distribution of some species and hindering post-disturbance tree regeneration dynamics. Applied nucleation (AN) could be a valuable active restoration approach for promoting natural recovery in forest ecosystems affected by stand-replacing disturbances as it improves seed availability and microsite conditions. The study aimed to investigate the potential of AN under different scenarios in a mountain forest ecosystem of the Northwestern Italian Alps dominated by Scots pine (Pinus sylvestris L.). The area was affected by a large stand-replacing fire in 2005 and post-fire salvage logging that amplified ecosystem degradation and dampened natural tree regeneration. We assessed the main drivers guiding natural post-fire natural recovery and identified suitable sites for tree regeneration through a machine learning correlative model (Bayesian Additive Regression Tree, BART). Specifically, we used several environmental predictors (e.g., topography, wind direction, and distance from seed trees) to model the occurrence of natural tree regeneration. We predicted the probability of tree regeneration presence at landscape scale under the current situation (fire followed by salvage logging) and a set of AN scenarios characterized by an increase in nuclei density, since distance from seed trees emerged as the most important driver for natural tree regeneration. Starting from the situation 16 years after the fire, we reclassified the prediction raster into a binary map of intervention priority (priority and non-priority patches), using the probability value that maximized the model accuracy (true skill statistic; TSS) as threshold. Patches with scarce pine regeneration were considered as high intervention priority sites for AN. These predictions made it possible to assess the most efficient active management scenario in terms of promoting forest recovery. The simulations showed the positive effects of AN on natural tree regeneration and the importance of site selection for plantations, proving that AN could be a promising post-fire management technique that can minimize human interventions and their associated economic and ecological costs. To our knowledge, this work is the first AN simulation in a temperate mountain ecosystem. The selection of favorable sites can be further improved by considering fine-scale characteristics through field experiments and cross-scale integration. [ABSTRACT FROM AUTHOR]

• Organic matter and nutrients were different between treated and untreated soils. • Herbaceous plants were found only in UB and LEB sites. • Increases in OM and nitrogen are associated to more resprouting species. • Increases in pH and again OM are associated to more abundant tree and herbs. • The study indicates the most resilient plant species after post-fire restoration. The medium- and long-term studies about the effectiveness of post-fire management techniques on soil and plant ecology are scarce, although the effects of wildfire and subsequent management can be long lasting. This study has evaluated the changes in the main physico-chemical properties of soil and plant diversity six years after a wildfire and post-fire treatments using contour felled log debris (CFD) and log erosion barriers (LEB) in a Mediterranean pine forest in comparison to unburnt (UB), and burnt but untreated (BNA) sites. Soil texture and pH did not generally change after wildfire and treatments, while organic matter and nutrients were significantly different between the treated soils and the other sites. Herbaceous plants were found only in UB and LEB sites, the latter showing the lowest number of tree species. Shrubs were equally distributed among the four soil conditions. Resprouting and germinating plants increased in the treated sites compared to BNA area, which however showed a higher number of facultative resprouters. The analysis of relationships between soil properties and plant diversity showed that, when organic matter (CFD plots) and nitrogen (LEB plots) contents are noticeably higher compared to BNA soils, more resprouting species are detected. Moreover, significant increases in pH (UB and BNA plots) and organic matter (CFD plots) are associated to more abundant tree and herbaceous species. The study also indicates to forest managers the most resilient plant species after post-fire restoration several years after a wildfire under Mediterranean conditions. [ABSTRACT FROM AUTHOR]

• The effects of mulching on ecosystem multifunctionality (EMF) have been little explored. • EMF increased from burned and untreated to mulched and to unburned sites. • No significant difference in EMF between the two mulches was found. • Mulching only partially dampened the impact of fire on EMF. • Almost all ecosystem functions were associated to soil or vegetation parameters. Straw and wood chips have been widely used as mulch materials to control post-fire erosion in burned forests. However, their effects on ecosystem multifunctionality (EMF) have been little explored. This information is essential to give forest managers insight about the effectiveness of these strategies for restoration of severely-burned forests. To fill this gap, this study has evaluated the short-term (one year after wildfire) changes in ecosystem properties (associated to soil characteristics), structure (linked to plant diversity), individual ecosystem functions, and EMF in a Mediterranean forest. This delicate ecosystem was burned by a wildfire and then mulched with straw or wood chips, and EMF in these conditions was compared to burned and untreated, and unburned sites. The results have shown that: (i) neither wildfire nor mulching significantly changed soil properties with the exception of pH; (ii) in contrast, ecosystem structure significantly declined in mulched plots due to wildfire, and mulching did not limit the alteration in species richness; (iii) among the analysed ecosystem functions, waste decomposition and nutrient cycling, which were significantly higher in unburned soils compared to burned sites, showed intermediate and similar values in mulched plots, while water cycle and wood production (the latter with the exception of unburned plots) were similar among all soil conditions, and climate regulation was significantly higher only in soils mulched with wood chips compared to burned sites; (iv) EMF increased from burned and untreated soils to unburned sites; (v) mulching was effective at limiting the reduction in EMF due to wildfire, but only partially dampened the impact of the fire. Moreover, the combined analysis of ecosystem properties, structure and functions, and EMF revealed that: (i) all functions, except water cycle, were associated to one or more soil or vegetation parameters; (ii) species community composition noticeably influenced several ecosystem functions, and, therefore, EMF; (iii) species richness is a key driver of wood production; (iv) pH, which was found as the most influential soil property on ecosystem functions and EMF, may be considered as an important ecological predictor of forest functions in basic soils of Mediterranean forests. This study may be of practical importance for policymakers and land managers about the most effective actions to preserve the ecosystem EMF in fragile ecosystems, such as the Mediterranean wildfire-affected forest. [ABSTRACT FROM AUTHOR]

• Red alder shows promise to aid in soil health post-fire. • Mixed stands with red alder demonstrated increased site index. • Douglas-fir site index continued to increase after alders died out. • Airborne lidar can be used to compare tree height when updated field data unavailable. A forester set up a large-scale, 1600-m fire-break trial with red alder (Alnus rubra Bong.) inter-planted between Douglas-fir (Pseudotsuga menziesii Mirb Franco) , after the extensive 1927 Yacolt Burn in the Columbia Gorge. This now 90-year-old trial demonstrates dramatic effects of alder on soils and growth of Douglas-fir; it also provides a timely lesson for foresters deciding what to do after recent similar fires in western Oregon and Washington. We used 2015 airborne lidar to re-examine the trial effects. Douglas-fir trees in stands mixed with alder (Strip) continue to grow taller than those in adjacent pure stands (Controls), even though almost all alder died out 30–40 years ago. Site index in Strip stand continues to increase relative to Controls, now averaging 30–40 % higher than Controls. Basal area ha−1 is 2.1, and stem biomass is 2.8 times higher in Strip than Control stands. Implications and future studies are discussed. Before planting wall-to-wall Douglas-fir, foresters responding to new fires in this region might contemplate alder interplanting and crop rotation for their likely positive effect on future revenue, wildlife, and carbon sequestration rates and storage above and belowground. [ABSTRACT FROM AUTHOR]

• Topographic indices influence seedling survival. • This allows the extrapolation of these findings to the wider landscape, creating a probabilistic surface of seedling survival. • These methods to guide future plantings may increase conifer tree seedling survival in post-wildfire landscapes. Across the southwestern United States, high-severity wildfire is causing increasingly large areas of tree mortality and removing the seed sources required for the natural regeneration of these formerly conifer-dominated landscapes. Planting tree seedlings can accelerate reforestation, but in the semi-arid southwestern US, the survival of planted conifer seedlings is typically low. Our research examined how post-fire planting success is influenced by climate, topographic, biotic, and microclimate factors. We present data on a seedling planting experiment within the footprint of the 2011 Las Conchas Fire in northern New Mexico. We planted 768 tree seedlings of four species: ponderosa pine (Pinus ponderosa), piñon (P. edulis), southwestern white pine (P. strobiformis), and Douglas-fir (Pseudotsuga menziesii) in an area burned at high-severity and densely populated by New Mexico locust (Robinia neomexicana) and other shrub species. We established experimental plots stratified by aspect, either northerly or southerly, and cover, either planted under New Mexico locust or in the open, and collected topographical and microclimate measurements over three years. Mean survival over the 3-year period for all species in all treatments was 20%. Using microclimate variables and site-level topographical indices in a piecewise exponential model, we first determined how these factors influenced seedling survival of four conifer tree species, finding that topographical indices describing incoming solar radiation, variables related to vapor pressure deficit, i.e., seasonal maximums, and presence of New Mexico locust increased hazard for all species while variables related to shade, moisture availability, and slope reduced hazard. Following our planting experiment, an additional 1145 ponderosa pine seedlings, planted by USFS, were surveyed for survival and the topographical indices at their locations were recorded. Adding these seedlings' survival data to our experimentally planted ponderosa pine seedlings, we used boosted regression tree models to determine survival probability for ponderosa pine as a product of topographical indices, then extrapolated these findings to the wider landscape, producing a spatial projection of probabilistic seedling survival as a function of readily available topographical data, with a mean AUC value of 0.63. Both sets of analyses highlight the importance of landscape heterogeneity in shaping microclimatic environments and affecting seedling survival in a predictable manner, with areas receiving less solar radiation and more moisture promoting seedling survival. Our results demonstrate that by using fine-scale microtopography that shapes microclimatic environments, future plantings can increase conifer tree seedling survival in high-severity post-wildfire landscapes. [ABSTRACT FROM AUTHOR]

This study concerned the mid-term regeneration of the woody understory vegetation of pure and mixed stands of Pinus pinaster Ait. and Eucalyptus globulus Labill. in northern and central Portugal following wildfires in 2005 and 2006. Pine and eucalypt stands are the most widespread and most fire-prone forest types in Portugal. The main aim was to investigate the importance of biogeography, topography, forest type and post-fire management operations in explaining the patterns in shrub diversity (species richness) and abundance (cover). To this end, 284 study sites in four distinct biogeographic regions were sampled 5 to 7 years following the last wildfire. At each site, the presence and cover of individual shrub species were estimated using 4 sub-plot of approximately 10 m 2 each. The entire data set was analyzed by means of GLM using a total of seven explanatory variables: biogeographic region, forest type, three types post-fire management operations (soil tillage, tree harvesting, and shrub clearance), and two topographic variables (slope angle and elevation). The GLM analysis was also done for the individual biogeographic regions. Biogeographic region and slope steepness were key factors explaining shrub species richness, albeit the role of slope angle was possibly linked to the intensity of past land use. Biogeographic region equally played a significant role in explaining the cover of all shrubs together as well as of the shrubs of Leguminosae and Cistaceae. All three types of post-fire management operations appeared to hamper the recovery of resprouters and Leguminosae, whereas just tree harvesting and shrub clearance (but not soil tillage) negatively affected the cover of seeder species. These impacts of post-fire management operations had a noticeable region-specific component, being more relevant in the less productive biogeographic regions. Also the role of forest type depended strongly on biogeographic region. It was only significant in the South Mediterranean region, where pine plantations had a higher total shrub cover as well as higher covers of seeders and Cistaceae. Possibly, however, this significant role of forest type could be due to the lower incidence of shrub clearance in the pine stands. [ABSTRACT FROM AUTHOR]

Highlights: [•] Post-fire natural establishment of E. globulus occurred in 72% of the studied sites. [•] Occurrence was influenced by stand type, productivity region and understorey removal. [•] Occurrence, density and height were higher in good productivity regions. [•] Salvage logging had a positive effect on density. [•] Tillage had a negative effect on both density and height. [ABSTRACT FROM AUTHOR]

We evaluated the impact of different post-fire management options in a chestnut coppice on surficial processes by comparing splash erosion, mean weight diameter (MWD) and stability of soil aggregates, and the development of soil cover on the following three plots with an undisturbed forest plot: fire without post-fire treatment; fire followed by clear-cutting; fire followed by clear-cutting 1 year later. Splash erosion was monitored on an event basis (n=44) over two growing seasons with splashboards, MWD and stability of aggregates were determined by dry and wet sieving, respectively, of soil samples collected three times throughout the 14-month study period, and soil cover was estimated six times. In the first year, clear-cutting did not result in an increased rate of splash erosion compared with the untreated, burned coppice, nor did it result in a deterioration of aggregate stability, although both fire-affected plots showed a decrease in MWD compared to the control plot. In the second year, splash erosion decreased substantially on these two plots, whereas the freshly cleared plot maintained splash erosion rates characteristic for the first year without a concomitant deterioration of MWD or aggregate stability. The strongest decrease in splash erosion occurred on the plot subject to immediate clear-cutting, which also experienced the most rapid development of soil cover. We conclude that post-fire clear-cutting does not have any adverse effects, as judged by splash erosion and measures of soil aggregation, beyond the fire-related ones. Due to the persistence of the erosion in the first year, however, we recommend immediate intervention where justified by economic considerations. [Copyright &y& Elsevier]