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Lianas are major contributors to tropical forest dynamics, yet we know little about their mortality. Using overlapping censuses of the lianas and trees across a 50 ha stand of moist tropical forest, we contrasted community-wide patterns of liana mortality with relatively well-studied patterns of tree mortality to quantify patterns of liana death and identify contributing factors. Liana mortality rates were 172% higher than tree mortality rates, but species-level mortality rates of lianas were similar to trees with 'fast' life-history strategies and both growth forms exhibited similar spatial and size-dependent patterns. The mortality rates of liana saplings (<2.1 cm in diameter), which represent about 50% of liana individuals, decreased with increasing disturbance severity and remained consistently low during post-disturbance stand thinning. In contrast, larger liana individuals and trees of all sizes had elevated mortality rates in response to disturbance and their mortality rates decreased over time since disturbance. Within undisturbed forest patches, liana mortality rates increased with increasing soil fertility in a manner similar to trees. The distinct responses of liana saplings to disturbance appeared to distinguish liana mortality from that of trees, whereas similarities in their patterns of death suggest that there are common drivers of woody plant mortality. [ABSTRACT FROM AUTHOR]

The timing, location, intensity, and drivers of forest disturbance and recovery are crucial for developing effective management strategies and policies for forest conservation and ecosystem resilience. Although many algorithms and improvement methods have been developed, it is still difficult to guarantee the detection accuracy for forest disturbance and recovery patterns in southern China due to the complex climate and topography, faster forest recovery after disturbance, and the low availability of noise-free Landsat images. Here, we improved the LandTrendr parameters for different provinces to detect forest disturbances and recovery trajectories based on the LandTrendr change detection algorithm and time-series Landsat images on the GEE platform, and then applied the secondary random forest classifier to classify the forest disturbance and recovery patterns in southern China during 1990–2020. The accuracy evaluation indicated that our approach and improved parameters of the LandTrendr algorithm can increase the detection accuracy for both the spatiotemporal patterns and multiple events of forest disturbance and recovery, with an overall accuracy greater than 86% and a Kappa coefficient greater than 0.91 for different provinces. The total forest loss area was 1.54 × 105 km2 during 1990–2020 (4931 km2/year); however, most of these disturbed forests were recovered and only 6.39 × 104 km2 was a net loss area (converted to other land cover types). The area with two or more times of disturbance events accounted for 11.50% of the total forest loss area. The total forest gain area (including gain after loss and the afforestation area) was 5.44 × 105 km2, among which, the forest gain area after loss was 8.94 × 104 km2, and the net gain area from afforestation was 4.55 × 105 km2. The timing of the implementation of forestry policies significantly affected the interannual variations in forest disturbance and recovery, with large variations among different provinces. The detected forest loss and gain area was further compared against with inventory and other geospatial products, and proved the effectiveness of our method. Our study suggests that parameter optimization in the LandTrendr algorithm could greatly increase the accuracy for detecting the multiple and lower rate disturbance/recovery events in the fast-regrowing forested areas. Our findings also offer a long-term, moderate spatial resolution, and precise forest dynamic data for achieving sustainable forest management and the carbon neutrality goal in southern China. [ABSTRACT FROM AUTHOR]

Natural regeneration after mining activities depends largely on the soil seed bank (SSB) and aboveground vegetation (AGV) richness and composition. We evaluated the species diversity pattern of the SSB and AGV on soil and technosol across second‐growth Atlantic Forests (SGFs) after mining tailings deposition in Mariana, southeastern Brazil. Two second‐growth Atlantic seasonal semideciduous forests of different stand ages were selected: a 3‐year‐old stand of SGF re‐growing on tailings (SGF tailings) and a 30‐year‐old stand of native reference forest not affected by tailings (SGF nontailings). Overall, the results showed significant differences in forest attributes (species richness and composition) in the SSB and AGV between the two forest patches evaluated (SGF tailings and SGF nontailings). Moreover, both nonzoochoric and zoochoric dispersed species of AGV showed significant differences between second‐growth forests, with higher variability of community‐weighted mean in SGF tailings. The result shows smaller differences in species richness between forest types for both SBB (ranging 85 and 90 species) and AGV (~55 species). Despite the time difference between the secondary forest and the absence of zoochoric species in the tailings seed bank, the AGV that are re‐growing on mining tailings presented a high proportion of zoochoric species. This pattern of species richness and community composition variability observed in the technosol seed bank, and AGV that are re‐growing after the deposition of mining tailings are important recovery indicators for plant communities affected. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China Normal University (Natural Science Edition) / Huanan Shifan Daxue Xuebao (Ziran Kexue Ban) is the property of Journal of South China Normal University (Natural Science Edition) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Questions: Agricultural expansion is one of the dominant drivers of forest and biodiversity loss, and shifting cultivation is the most widely used form of agriculture in many tropical forest regions. Where forests have been cleared, they have the potential to recover once the land is abandoned. However, legacies of land use are often overlooked in successional studies, and a deeper understanding of this legacy effect is needed to define efficient restoration practices using natural or assisted regeneration. Here, we analysed how land‐use history affects soil properties and early succession on abandoned agricultural fields in two contrasting Mexican socio‐ecological systems. Location: Mexico, Oaxaca and Chiapas. Methods: We sampled soil and monitored vegetation for 2 years after agricultural abandonment, and interviewed landowners about their land‐use practices. Results: Land‐use practices were clearly influenced by landowners' social context (residence time, rural or urban origin), and topography and soil type also constrained or facilitated land‐use practices. Soil characteristics were strongly affected by three land‐use practices: mechanical tillage decreased soil N and K; frequent herbicide and pesticide use increased N and K; and for pasture systems, stocking density increased soil bulk density and decreased pH and N. High‐intensity land management practices, specifically use of machinery, had the highest impact on early forest succession. When machinery was not used, the frequency of land‐use practices, particularly weeding frequency, is the main factor influencing tree cover and sapling diversity. Conclusions: To facilitate post‐agricultural forest recovery, we recommend restoration efforts using natural regeneration in areas with low previous land‐use intensity and frequency. [ABSTRACT FROM AUTHOR]

Tropical tree species are increasingly being pushed to inhabit deforested landscapes. The habitat amount hypothesis posits that, in remaining forest patches, species diversity in equal‐sized samples decreases with decreasing forest cover in the surrounding landscape. We tested this prediction by taking into account three important factors that can affect species responses to forest loss. First, forest loss effects can be linear (proportional) or nonlinear, as there can be threshold values of forest loss beyond which species extirpation may be accelerated. Second, such effects are usually scale dependent and may go unnoticed if assessed at suboptimal scales. Finally, species extirpation may take decades to become evident, so the effects of forest loss can be undetected when assessing long‐lived organisms, like adult old‐growth forest trees. Here, we evaluated the linear and nonlinear effects of landscape forest loss across different spatial scales on site‐scale abundance and diversity of old‐growth forest trees, separately for four plant‐life stages (seeds, saplings, juveniles, and adults) in two rainforest regions with different levels of deforestation. We expected stronger (and negative) forest loss effects on early plant‐life stages, especially in the region with the highest deforestation. Surprisingly, in 13 of 16 study cases (2 responses × 4 life stages × 2 regions), null models showed higher empirical support than linear and nonlinear models at any scale. Therefore, the species richness and abundance of local tree assemblages seem to be weakly affected by landscape‐scale forest loss independently of the spatial scale, life stage, and region. Yet, as expected, the predictive power of forest cover was relatively lower in the least deforested region. Our findings suggest that landscape‐scale forest loss is poorly related to site‐scale processes, such as seed dispersal and seedling recruitment, or, at least, such effects are too small to shape the abundance and diversity of tree assemblages within forest patches. Therefore, our findings do not support the most important prediction of the habitat amount hypothesis but imply that, on a per‐area basis, a unit of habitat (forest) in a highly deforested landscape has a conservation value similar to that of a more forested one, particularly in moderately deforested rainforests. [ABSTRACT FROM AUTHOR]

Amazon rainforests are critical for providing a wide range of ecosystem services. In the Southeastern Peruvian Amazon; however, goldmining activities are causing severe soil degradation and forest loss. We analyzed aboveground biomass (AGB), forest structure, and species diversity recovery during secondary succession in 179 forest plots. Our study provides the first field-based quantification of AGB recovery following the abandonment by two types of goldmining (heavy machinery and suction pumping) in Madre de Dios (Peru). We found that successional secondary forests in areas subjected to suction pumping were more resilient than those in areas subjected to heavy machinery. After 20 years, mean AGB in suction pumping mining areas had reached 56% of reference forest AGB, while in areas of heavy machinery mining it was only 18%. Mining type, stand age, and distance from the forest edge had a significant effect on AGB. The influence of the distance from the forest edge on AGB varies according to mining type because the effects of species diversity on AGB are mediated by the distance from the forest edge. Our results clearly showed the dynamics of AGB recovery across a secondary succession after goldmining, and the contrasting responses of AGB between the two mining types. Our study disentangles the importance of key factors in forest recovery after mining and improves understanding of the resilience of biomass accumulation in these highly degraded ecosystems. [ABSTRACT FROM AUTHOR]

Disturbance and recovery dynamics are characteristic features of many ecosystems. Disturbance dynamics are widely studied in ecology and conservation biology. Still, we know less about the ecological processes that drive ecosystem recovery. The ecological processes that mediate ecosystem recovery stand at the intersection of many theoretical frameworks. Range expansion theory is one of these complementary frameworks that can provide unique insights into the population‐level processes that mediate ecosystem recovery, particularly fauna recolonization. Although the biodiversity patterns that follow the fauna recolonization of recovering forests have been well described in the literature, the ecological processes at the population level that drive these patterns remain conspicuously unknown. In this study, we tested three fundamental predictions of range expansion theory during the recolonization of recovering forests in Puerto Rico by a shade specialist anole, Anolis gundlachi. Range expansion theory predicts that individuals at the early stages of recolonization (i.e., younger forests) would have a high prevalence of dispersive traits, experience less density dependence, and suffer less parasitism. To test these predictions, we conducted a chronosequence study applying space‐for‐time substitution where we compared phenotypic traits (i.e., body size, body condition, and relative limb size), population density, population growth rates, and Plasmodium parasitism rates among lizard populations living in young (<30 years), mid (~40–70 years), and old‐growth forests (>75 years). Lizard populations in younger forests had lower densities, higher population growth rates, and lower rates of Plasmodium parasitism compared with old‐growth forests. Still, while we found that individuals had larger body sizes, and longer forelimbs in young forests in one site, this result was not consistent among sites. This suggests a potential trade‐off between the traits that provide a dispersal advantage during the initial stages of recolonization and those that are advantageous to establish in novel environmental conditions. Overall, our study emphasizes the suitability of range expansion theory to describe fauna recolonization but also highlights that the ecological processes that drive recolonization are time‐dependent, complex, and nuanced. [ABSTRACT FROM AUTHOR]

Climate change has accelerated the frequency of catastrophic wildfires; however, the drivers that control the time‐to‐recover of forests are poorly understood. We integrated remotely sensed data, climate records, and landscape features to identify the causes of variability in the time‐to‐recover of canopy leaf area in southeast Australian eucalypt forests. Approximately 97% of all observed burns between 2001 and 2014 recovered to a pre‐fire leaf area index (±0.25 sd) within six years. Time‐to‐recover was highly variable within individual wildfires (ranging between ≤1 and ≥5 years), across burn seasons (90% longer January to September), and year of fire (median time‐to‐recover varying four‐fold across fire years). We used the logistic growth function to estimate the leaf area recovery rate, burn severity, and the long‐term carrying capacity of leaf area. Time‐to‐recover was most correlated with the leaf area recovery rate. The leaf area recovery rate was largest in areas that experienced high burn severity, and smallest in areas of intermediate to low burn severity. The leaf area recovery rate was also strongly accelerated by anomalously high post‐fire precipitation, and delayed by post‐fire drought. Finally we developed a predictive machine‐learning model of time‐to‐recover (R2: 0.68). Despite the exceptionally high burn severity of the 2019–2020 Australian megafires, we forecast the time‐to‐recover to be only 15% longer than the average of previous fire years. Plain Language Summary: Australian eucalypt forests have evolved different strategies to recover from fire. While the meteorological drivers of bushfire are reasonably well understood, the various processes explaining how long a forest takes to recover from fire are not. We investigated a range of static (landscape) and dynamic (vegetation condition or meteorological) factors that could influence how long a forest's canopy leaf area would take to recover from fire. "Time‐to‐recover" after fire is highly variable, ranging from less than 1 year to more than 5 years even within an individual burn location. More intense fires cause greater forest canopy damage and generally (but not always) lead to longer recovery times, whereas wetter conditions after the fire can accelerate recovery. Using these factors and others, we developed a model capable of predicting the time‐to‐recover and applied it to the 2019–2020 Australian megafires. Our analysis suggests the canopy damage caused by these fires was far more severe than fires in years prior. This would normally lead to a prolonged time‐to‐recover, however we predict that anomalously high rainfall in the year following the fires will shorten recovery time, compensating for the high burn severity. Ultimately we predict the time‐to‐recover will be only slightly longer than average. Key Points: Pre‐fire leaf area, burn severity, and post‐fire meteorological conditions combine to determine time‐to‐recover after fireLarge geographic variation in time‐to‐recover can be explained by mean climate and landscape differencesTime‐to‐recover can be predicted with high accuracy using information limited to the first year following fire [ABSTRACT FROM AUTHOR]

Wildfires are increasing in frequency, intensity, and extent globally due to climate change and they can alter forest composition, structure, and function. The destruction and subsequent regrowth of young vegetation can modify the ecosystem evapotranspiration and downstream water availability. However, the response of forest recovery on hydrology is not well known with even the sign of evapotranspiration and water yield changes following forest fires being uncertain across the globe. Here, we quantify the effects of forest regrowth after catastrophic wildfires on evapotranspiration and runoff in the world's tallest angiosperm forest (Eucalyptus regnans) in Australia. We combine eddy covariance measurements including pre‐ and post‐fire periods, mechanistic ecohydrological modeling and then extend the analysis spatially to multiple fires in eucalypt‐dominated forests in south‐eastern Australia by utilizing remote sensing. We find a fast recovery of evapotranspiration which reaches and exceeds pre‐fire values within 2 years after the bushfire, a result confirmed by eddy covariance data, remote sensing, and modeling. Such a fast evapotranspiration recovery is likely generalizable to tall eucalypt forests in south‐eastern Australia as shown by remote sensing. Once climate variability is discounted, ecohydrological modeling shows evapotranspiration rates from the recovering forest which reach peak values of +20% evapotranspiration 3 years post‐fire. As a result, modeled runoff decreases substantially. Contrary to previous research, we find that the increase in modeled evapotranspiration is largely caused by the aerodynamic effects of a much shorter forest height leading to higher surface temperature, higher humidity gradients and therefore increased transpiration. However, increases in evapotranspiration as well as decreases in runoff caused by the young forest are constrained by energy and water limitations. Our result of an increase in evapotranspiration due to aerodynamic warming in a shorter forest after wildfires could occur in many parts of the world experiencing forest disturbances. [ABSTRACT FROM AUTHOR]

Abstract Climate change has accelerated the frequency of catastrophic wildfires; however, the drivers that control the time‐to‐recover of forests are poorly understood. We integrated remotely sensed data, climate records, and landscape features to identify the causes of variability in the time‐to‐recover of canopy leaf area in southeast Australian eucalypt forests. Approximately 97% of all observed burns between 2001 and 2014 recovered to a pre‐fire leaf area index (±0.25 sd) within six years. Time‐to‐recover was highly variable within individual wildfires (ranging between ≤1 and ≥5 years), across burn seasons (90% longer January to September), and year of fire (median time‐to‐recover varying four‐fold across fire years). We used the logistic growth function to estimate the leaf area recovery rate, burn severity, and the long‐term carrying capacity of leaf area. Time‐to‐recover was most correlated with the leaf area recovery rate. The leaf area recovery rate was largest in areas that experienced high burn severity, and smallest in areas of intermediate to low burn severity. The leaf area recovery rate was also strongly accelerated by anomalously high post‐fire precipitation, and delayed by post‐fire drought. Finally we developed a predictive machine‐learning model of time‐to‐recover (R2: 0.68). Despite the exceptionally high burn severity of the 2019–2020 Australian megafires, we forecast the time‐to‐recover to be only 15% longer than the average of previous fire years.

Background: Individual pioneer tree species often dominate early tropical dry forest succession and thereby affect possible successional pathways. Mimosa acantholoba var. eurycarpa is a highly dominant species in the tropical dry forest in Mexico. Hypothesis: Mimosa acantholoba var. eurycarpa exerts an inhibitory effect on the germination, establishment, survival, and early growth of light-demanding pioneers, while facilitating these processes for shade-tolerant old-growth forests species. Studied species: Lonchocarpus torresiorum, Lysiloma divaricatum, Mimosa acantholoba var. eurycarpa and Vachellia farnesiana. Study site and dates: Nizanda, Oaxaca, Mexico, 2020-2021. Methods: In 12 early successional plots, we applied three levels of crown cover removal (100, 50, and 0 %) of established trees of the dominant pioneer legume (M. acantholoba var. eurycarpa). We sowed seeds of the four study species in each experimental plot and recorded their germination, establishment, survival, and early growth over a 2-mo period. Results: The removal of crown cover of established M. acantholoba var. eurycarpa trees did not significantly affect germination. Lysiloma divaricatum had the highest germination probability, the fastest germination, and the highest establishment probability regardless of treatment. Lonchocarpus torresiorum had the highest establishment probability in plots where the crown cover of established M. acantholoba var. eurycarpa trees was removed The survival probability of both shade-tolerant species was highest in the 100 % removal treatment. Conclusions: Despite successful germination of shade-tolerant species, their survival is inhibited under the dense canopy of the dominant legume. Therefore, interventions to reduce the crown cover area of this dominant legume may stimulate forest recovery.

Abstract People have modified landscapes throughout the Holocene (the last c. 11,700 years) by modifying soils, burning forests, cultivating and domesticating plants, and directly and indirectly enriched and depleted plant abundances. These activities also took place in Amazonia, which is the largest contiguous piece of rainforest in the world, and for many decades was considered to have very little human impact until the modern era. The compositional shift caused by past human disturbances can alter forest traits, creating ecological legacies that may persist through time. As the lifespan of most Amazonian tree species is more than 200 years, forests that were modified over the last centuries to millennia are likely still in a mid‐successional state. Ecological legacies resulting from past human activity may also affect modern forest resilience to ongoing anthropogenic and climatic changes. Current estimates of resilience assume that forests are in equilibrium, and long‐term successional trajectories are not considered. We suggest that disturbance histories, generated through palaeoecological and archaeological surveys, should be paired with field‐based and remotely sensed estimates of forest resilience to recent drought events, to determine whether past human activities affect modern forest resilience. We have outlined how this can be accomplished in future research. Read the free Plain Language Summary for this article on the Journal blog.

The timing, location, intensity, and drivers of forest disturbance and recovery are crucial for developing effective management strategies and policies for forest conservation and ecosystem resilience. Although many algorithms and improvement methods have been developed, it is still difficult to guarantee the detection accuracy for forest disturbance and recovery patterns in southern China due to the complex climate and topography, faster forest recovery after disturbance, and the low availability of noise-free Landsat images. Here, we improved the LandTrendr parameters for different provinces to detect forest disturbances and recovery trajectories based on the LandTrendr change detection algorithm and time-series Landsat images on the GEE platform, and then applied the secondary random forest classifier to classify the forest disturbance and recovery patterns in southern China during 1990–2020. The accuracy evaluation indicated that our approach and improved parameters of the LandTrendr algorithm can increase the detection accuracy for both the spatiotemporal patterns and multiple events of forest disturbance and recovery, with an overall accuracy greater than 86% and a Kappa coefficient greater than 0.91 for different provinces. The total forest loss area was 1.54 × 105 km2 during 1990–2020 (4931 km2/year); however, most of these disturbed forests were recovered and only 6.39 × 104 km2 was a net loss area (converted to other land cover types). The area with two or more times of disturbance events accounted for 11.50% of the total forest loss area. The total forest gain area (including gain after loss and the afforestation area) was 5.44 × 105 km2, among which, the forest gain area after loss was 8.94 × 104 km2, and the net gain area from afforestation was 4.55 × 105 km2. The timing of the implementation of forestry policies significantly affected the interannual variations in forest disturbance and recovery, with large variations among different provinces. The detected forest loss and gain area was further compared against with inventory and other geospatial products, and proved the effectiveness of our method. Our study suggests that parameter optimization in the LandTrendr algorithm could greatly increase the accuracy for detecting the multiple and lower rate disturbance/recovery events in the fast-regrowing forested areas. Our findings also offer a long-term, moderate spatial resolution, and precise forest dynamic data for achieving sustainable forest management and the carbon neutrality goal in southern China.

Transboundary forests in the Himalayas are one of the world’s biodiversity hotspots, but exploring the patterns and influencing factors related to forest disturbance-recovery is still limited. In this study, we used a random forests model, a LandTrendr temporal segmentation algorithm and geographical detector to investigate the spatial and temporal evolution characteristics of forest disturbance and recovery and their influencing factors in the central Himalayas from 1995 to 2018. The results showed that forest disturbance was dominant (∼2.94 × 104 km2) and greater than recovery (∼0.56 × 104 km2). Both disturbance and recovery showed a significant decreasing trend (p

Understanding accurate and continuous forest dynamics is of key importance for forest protection and management in the Greater Khingan Mountains (GKM). There has been a lack of finely captured and long-term information on forest disturbance and recovery since the mega-fire of 1987 which may limit the scientific assessment of the GKM's vegetation conditions. Therefore, we proposed a rapid and robust approach to track the dynamics of forest disturbance and recovery from 1987 to 2021 using Landsat time series, LandTrendr, and random forests (RF) models. Furthermore, we qualified the spatial characteristics of forest changes in terms of burn severity, topography, and distances from roads and settlements. Our results revealed that the integrated method of LandTrendr and RF is well adapted to track forest dynamics in the GKM, with an overall accuracy of 0.86. From 1987 to 2021, forests in the GKM showed a recovery trend with a net increase of more than 4.72 × 104 ha. Over 90% of disturbances occurred between 1987 and 2010 and over 75% of recovery occurred between 1987 and 1988. Mildly burned areas accounted for 51% of forest disturbance and severely burned areas contributed to 45% of forest recovery. Forest changes tended to occur in zones with elevations of 400–650 m, slopes of less than 9°, and within 6 km of roads and 24 km of settlements. Temporal trends of forest disturbance and recovery were mainly explained by the implementation timelines of major forestry policies. Our results provide high-resolution and time-series information on forest disturbance and recovery in the GKM which could support scientific decisions on forest management and sustainable utilization. [ABSTRACT FROM AUTHOR]

Information about post-disturbance regeneration success and successional dynamics is critical to predict forest ecosystem resistance and resilience to disturbances and climate change. Our objective was to identify and classify post-disturbance empirical research conducted by the Canadian Forest Service (CFS) of Natural Resources Canada and their collaborators to provide guidance on future research needs, improving our understanding of post-disturbance recovery in a Canadian context. To achieve our objective, we collected and classified peer-reviewed and non-published literature produced by the CFS between 1998 and 2020 that concerned post-disturbance ecology. We focused on research addressing natural or anthropogenic disturbances, such as wildfires, pest outbreaks, windthrows, forest management, seismic lines, and those that studied processes related to soil, vegetation, fauna, hydrology, and microbial communities. We found that forest harvesting was the disturbance most studied by CFS between 1998 and 2020, followed by fire. Despite the fact that large, forested areas are affected annually by pests, studies on recovery after pest outbreaks were scarce. Other disturbances, such as mining and seismic lines or other abiotic disturbances were rare in CFS literature. Most studies (70%) examined changes in vegetation related to forest management and fire and they were mainly focussed on post-disturbance tree regeneration success. Post-disturbance changes in understory species diversity were also well-studied. Our results provide a geographic overview of CFS research on post-disturbance recovery in Canada and enable the identification of key knowledge gaps. Notably, research focusing on recovery after natural disturbances was underrepresented in the assessed literature compared to studies centered around harvesting. Long-term research sites, chronosequences that substitute space for time, and studies focused on consecutive disturbances are especially important to maintain and establish sustainable forest management strategies in the face of climate change. [ABSTRACT FROM AUTHOR]

Copyright of People & Nature is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ecological corridors are effective strategies to address the environmental consequences of forest fragmentation by connecting fragmented areas through various techniques. This study aims to propose the implementation of an ecological corridor in the Itapemirim River basin in Espírito Santo, Brazil. The specific objectives of this study are as follows: delimiting the Permanent Preservation Areas (APPs) in the Itapemirim River watershed and comparing land use and land cover within these areas. The MapBiomas platform and Landsat 8 satellite images were utilized to map land use and land cover, while the criteria set by Law No. 12.651 were followed to define the APP boundaries. The calculation of the landscape ecology indices and the identification of the forest fragments with the highest potential for ecological corridor implementation were conducted using the Fuzzy logic. The QGIS 3.26 application, along with the LecoS 3.0.1 plugin and Fragstats 4.2, were employed to characterize and quantify landscape ecology indices. The costs assessment and determination of the optimal route for implementing the ecological corridor were performed, considering bothdistance and physical impediments. The least cost path algorithm was utilized, taking into account land use and land cover, APP, fragment potential, slope, and subnormal clusters. Evaluating land costs and expropriation expenses required to define the ecological corridor in the study area. The identified forest fragments for inclusion in the ecological corridor were the Caparaó National Park, the Serra das Torres State Natural Monument, and other selected fragments based on the application of Fuzzy logic to landscape ecology indices. The corridor route was determined using the least cost path algorithm, considering various factors. This study revealed that the predominant land use and land cover class in the area is pasture, and a significant portion (68.58%) of the designated Permanent Preservation Areas were in conflict with legal regulations. The bare land value per hectare for pasture was the second highest among the land use and land cover categories, accounting for 64.28% of the total. The priority area analysis indicated that 31.86% of the region had high or very high importance for forest restoration, while 42.97% had low or very low priority. The findings demonstrate that the least cost path algorithm, coupled with a multi-criteria decision-making approach using the Analytic Hierarchy Process (AHP), is a valuable tool for planning and implementing ecological networks. These methods effectively consider critical factors in decision-making processes related to the optimal location of the ecological corridor. In conclusion, this study provides insights into the implementation of an ecological corridor in the Itapemirim River basin, emphasizing the importance of considering multiple factors and utilizing appropriate methodologies for effective decision-making in ecological planning. [ABSTRACT FROM AUTHOR]

The decline of the forest cover due to deforestation and agricultural expansion in Sudan has reached a critical situation. Taungya agroforestry systems have been used as a strategy to safeguard against this process, allowing farmers to cultivate their subsistence crops at the early stage of tree plantations. The current study research tackled Nabag Forest Reserve (NFR) as a case study to assess and explore Taungya agroforestry system as a practice used for forest rehabilitation in the study area. Satellite images of Landsat 5 Thematic Mapper, and Landsat 8 Operational Land Imager/Thermal Infrared Sensor of 1991, 2001, 2011, and 2021 were used to generate forest cover maps. Both unsupervised and supervised classification, as well as ground truth points, were applied to classify the vegetation cover in NFR as dense forest (DF), light forest (LF), agricultural field (AF), and bare land (BL). The results showed that two trends of forest cover changes occurred in NFR between 1991-2001 and 2011-2021. It was well explored that through Taungya agroforestry, there was a considerable increase in forest cover over this period. This could be clearly detected by increasing dense forest and light forest cover by 1041.73 ha (24.95%) and 2.95 ha (0.07%), respectively and decreasing of bare land and agricultural field by 409.79 ha (9.81%) and 634.52 ha (15.15%) during the addressed period. The findings of the study indicated that Taungya agroforestry system could be a feasible land-use alternative for forest recovery in the dry land of Sudan.

Amazon rainforests are critical for providing a wide range of ecosystem services. In the Southeastern Peruvian Amazon; however, goldmining activities are causing severe soil degradation and forest loss. We analyzed aboveground biomass (AGB), forest structure, and species diversity recovery during secondary succession in 179 forest plots. Our study provides the first field-based quantification of AGB recovery following the abandonment by two types of goldmining (heavy machinery and suction pumping) in Madre de Dios (Peru). We found that successional secondary forests in areas subjected to suction pumping were more resilient than those in areas subjected to heavy machinery. After 20 years, mean AGB in suction pumping mining areas had reached 56% of reference forest AGB, while in areas of heavy machinery mining it was only 18%. Mining type, stand age, and distance from the forest edge had a significant effect on AGB. The influence of the distance from the forest edge on AGB varies according to mining type because the effects of species diversity on AGB are mediated by the distance from the forest edge. Our results clearly showed the dynamics of AGB recovery across a secondary succession after goldmining, and the contrasting responses of AGB between the two mining types. Our study disentangles the importance of key factors in forest recovery after mining and improves understanding of the resilience of biomass accumulation in these highly degraded ecosystems.

Abstract Ateleia glazioveana Baill. is a pioneer, rustic and can be used for forest recovery. This work aimed to study the process of physiological maturation of this species. The research was carried out in the city of Alegre - ES, the trees were identified in the floral anthesis and accompanied during the filling of the fruits and development of the seeds until the complete maturation. The fruits were harvested at the following stages 7, 14, 21, 28, 35 and 42 days after anthesis, and characterized according to: morphometry, moisture, fresh and dry mass of fruits and seeds, germination, germination speed index, shoot and root length and dry mass of seedlings. The regression equations were adjusted for the main characteristics analyzed as a function of the harvest period. The point of physiological maturity of timbó occurred at 42 days after anthesis.

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Oil sand mining in northern Alberta/Canada in the Athabasca region is a major intrusion into the otherwise pristine natural environment. The various types of oil sands mining, transport, and processing are causing large-scale discharge of pollutants. Accordingly, this study examined the gradual changes in the physically undisturbed vegetation, that occurred from 1984 to 2021 in the Athabasca oil sands monitoring region. First, the abrupt changes were masked out with the help of auxiliary and Landsat data. Subsequently, a normalized burn ratio Landsat time-series was applied to the LandTrendr algorithm on the Google Earth Engine. In order to interpret gradual changes, measurement criteria were used to describe vegetation development, vulnerability, and variability. In addition, the spatial and temporal relationship of these to oil sand opencast mines, processing facilities, and steam assisted gravity drainage (SAGD) mines was examined. The results showed that a major part of the vegetation in the Athabasca oil sand monitoring region underwent a positive development (65.9%). However, around the opencast mines a negative vegetation development and stability within a radius of 10 km could be observed. In the surroundings of processing facilities, the development and stability of vegetation was disturbed within a radius of 2 km. Thereby the analysis of land cover classes showed that deciduous, coniferous, and mixed forest are disproportionately affected. Conversely, no negative influences on neighboring vegetation could be detected around SAGD mines. The temporal analysis showed that vegetation disturbance was most pronounced between 1990 and 2000, but recovered in recent years.

The decline of the forest cover due to deforestation and agricultural expansion in Sudan has reached a critical situation. Taungya agroforestry systems have been used as a strategy to safeguard against this process, allowing farmers to cultivate their subsistence crops at the early stage of tree plantations. The current study research tackled Nabag Forest Reserve (NFR) as a case study to assess and explore Taungya agroforestry system as a practice used for forest rehabilitation in the study area. Satellite images of Landsat 5 Thematic Mapper, and Landsat 8 Operational Land Imager/Thermal Infrared Sensor of 1991, 2001, 2011, and 2021 were used to generate forest cover maps. Both unsupervised and supervised classification, as well as ground truth points, were applied to classify the vegetation cover in NFR as dense forest (DF), light forest (LF), agricultural field (AF), and bare land (BL). The results showed that two trends of forest cover changes occurred in NFR between 1991-2001 and 2011-2021. It was well explored that through Taungya agroforestry, there was a considerable increase in forest cover over this period. This could be clearly detected by increasing dense forest and light forest cover by 1041.73 ha (24.95%) and 2.95 ha (0.07%), respectively and decreasing of bare land and agricultural field by 409.79 ha (9.81%) and 634.52 ha (15.15%) during the addressed period. The findings of the study indicated that Taungya agroforestry system could be a feasible land-use alternative for forest recovery in the dry land of Sudan. [ABSTRACT FROM AUTHOR]

The long-term resilience of Pyrenean forests in the face of historical anthropogenic clearing remains largely unknown. In this paper, a high-resolution (decadal to subdecadal) paleoecological study of mid-elevation Pyrenean forests is presented that encompasses the last two millennia. This long-term record was obtained after sediment coring, dating (varve counting) and pollen analysis of annually laminated (varved) sediments from Lake Montcortès, situated at 1027 m elevation, in the transition between the Mediterranean and montane forest belts. This allowed the definition of three major deforestation/recovery cycles during the Roman, Medieval and Modern times. Each DR cycle is characterized considering three different levels: overall forest trends, forest type and individual taxa. Overall, the studied forests exhibited high resilience, as they recovered almost completely after each deforestation event (bulk resilience). The critical point of no return (tipping point) beyond which forests would have irreversibly disappeared from the region was never reached, even after deforestation magnitudes above 60%. The different forest types identified (conifer, sclerophyll and deciduous) persisted over time, showing similar heterogeneous patterns with minor spatial reorganizations (mosaic resilience). Individually, the main forest taxa underwent minor variations in their relative abundances, always within the same attraction domains (community resilience). The high levels of resilience documented in these Pyrenean forests are attributed to the action of metapopulation and metacommunity processes and mechanisms in a highly dynamic patchy environment. Conservation actions should be focused on the maintenance of these spatial patterns and the associated ecological dynamics. [ABSTRACT FROM AUTHOR]

Deforestation poses a major threat to the tropical montane forest ecosystems of East Africa. Montane forests provide key and unique ecological and socio-economic benefits to the local communities and host diverse flora and fauna. There is evidence of ongoing deforestation and forest clearance in these montane forests although estimates diverge among different sources suggesting rates of 0.4%–3% yr−1. Quantifying deforestation rates and forest disturbance is critical to design conservation and sustainable management policies for forest management. This study quantified the rate of deforestation and forest recovery over the last three decades for the Mau Forest Complex and Mount Elgon forests in Kenya and Uganda using Landsat time-series satellite imagery. With the analysis, classification accuracies of 86.2% and 90.5% (kappa 0.81 and 0.88) were achieved for the Mau Forest Complex and the Mt Elgon forests, respectively. 21.9% (88,493 ha) of the 404,660 ha of Mau forest was lost at an annual rate of −0.82% yr−1 over the period between 1986 and 2017. More positively, 18.6% (75,438 ha) of the forest cover that was disturbed during the same period and is currently undergoing recovery. In Mt Elgon forest, 12.5% (27,201 ha) of 217,268 ha of the forest cover was lost to deforestation at an annual rate of −1.03% yr−1 for the period between 1984–2017 and 27.2% (59,047 ha) of the forest cover disturbed is undergoing recovery. The analysis further demonstrated agriculture (both smallholder and commercial) was the main driver of forest cover loss in Mau forest, accounting for 81.5% (70,612 ha) of the deforestation, of which 13.2% was due to large scale and 68.3% was related to the smallholders. For the Mt Elgon forest, agriculture was also the main driver accounting for 63.2% (24,077 ha) of deforestation followed by the expansion of human settlements that contributed to 14.7% (5,597 ha) of forest loss. This study provides accurate and novel estimates of the rate of deforestation for the Mau forest complex and Mt Elgon forest ecosystems. These rates are higher than previously estimated and recent deforestation has been identified, which provides a quantitative basis for forest restoration programs and to design conservation policies.

Outbreaks of several bark beetle species can develop rapidly in response to drought and may result in large transfers of carbon (C) stored in live trees to C stored in dead trees (10s of Tg C yr-1 in the western U.S. alone), which over time will be released back to the atmosphere. The western pine beetle (WPB) outbreak incited by the 2012–2015 mega-drought in the Sierra Nevada, California, U.S., could portend more frequent and/or severe bark beetle outbreaks as the temperature warms and drought frequency and intensity increase in the future. However, changes in the frequency and/or severity (resultant levels of host tree mortality) of beetle outbreaks are difficult to predict as outbreaks are complex with non-linear and eruptive processes primarily driven by interactions among beetle populations, the demography of hosts and other tree species, and climate and weather. Using an insect phenology and tree defense model, we projected the future likelihood of WPB outbreaks in the Sierra Nevada with climate drivers from different Earth System Models. Our goal was to understand how host (ponderosa pine, PIPO) recovery and future warming and drought affect the frequency and severity of WPB outbreaks and their C consequences. Our projections suggested that by 2100 the C stored in live PIPO (mean: 1.98 kg C m-2, 95% CI: 1.74–2.21 kg C m-2) will not return to levels that occurred before the 2012–2015 drought (2012: ∼2.30 kg C m-2) due to future WPB outbreaks. However, differences in climate models indicate a wide range of possible WPB outbreak frequencies and severities. Our results suggest that total plot basal area is the most significant factor in the mortality rate of PIPO by WPB in any given year, followed by drought severity and temperature. High levels of host basal area, higher temperature, and extreme drought all contribute to the frequency and severity of future WPB outbreaks. While PIPO basal area may decline under increased drought and warming, limiting high-stand basal area (>60 m2 ha-1) may reduce the severity of future WPB outbreaks in the Sierra Nevada.

Wildfires are a common disturbance factor, while climate change is thought to be one of the main causes of the fires. The detection of disturbance and post-fire recovery monitoring are vital for ecological research. This article aims to provide a review of current research of post-fire recovery monitoring based on remotely sensed data. While a close relationship between vegetation indices (VIs) and physiological parameters of vegetation has been established, VIs have become the main tool for assessing and monitoring vegetation status. Research on the effects and recovery from fires has been conducted by a number of authors, with VIs being used mainly in the methodologies. Tasseled Cap Transformation (TCT) method is also used to assess the state of the ecosystem before and after a fire. When viewed in series, Disturbance Index (DI) images provide an immediate way to recognize the pixels of the forests affected by the fire, different from those characteristics of the normal state of forests. The incorporation of various remote sensing data with field data is able to support the monitoring of post-fire effects and forest recovery. [ABSTRACT FROM AUTHOR]

Wildfires simplify ecosystems, modifying the ecological niches of the fauna living in the recently burned areas. Small mammals respond rapidly to changes in habitat structure and composition after fire, but the effects of fire can be ameliorated by some management strategies (e.g., salvage logging). Hence, it is necessary to explore whether alternative management strategies may be able to return the ecosystem to its initial state. We studied the small mammal community by live trapping on eight plots under different post-fire treatments in Sant Llorenç del Munt i l'Obac Natural Park (Barcelona province, NE Spain). At the community level, an increase in overall relative abundance and species density was observed in the burned areas. Apodemus sylvaticus, the most abundant mammal in study area, used woody debris piles as a shelter against predators. Mus spretus was more abundant in post-fire sites with large open areas interspersed with woody debris piles. Crocidura russula steadily increased its presence in later successional stages when ground cover became more complex. Our results suggest that combining different management strategies may be appropriate to improve the habitat suitability and biodiversity of small mammals and other key open-land species throughout the burned area. [ABSTRACT FROM AUTHOR]

Transboundary forests in the Himalayas are one of the world's biodiversity hotspots, but exploring the patterns and influencing factors related to forest disturbance-recovery is still limited. In this study, we used a random forests model, a LandTrendr temporal segmentation algorithm and geographical detector to investigate the spatial and temporal evolution characteristics of forest disturbance and recovery and their influencing factors in the central Himalayas from 1995 to 2018. The results showed that forest disturbance was dominant (∼2.94 × 104 km2) and greater than recovery (∼0.56 × 104 km2). Both disturbance and recovery showed a significant decreasing trend (p < 0.01); disturbance occurred mainly at low elevations and the Gandaki basin, while recovery was in eastern Nepal. Disturbance rates were highest in Nepal (1.14%) and recovery rates in China (0.29%). The main influencing factors on forest dynamics were elevation, temperature and population. The interaction of all factors was synergistically enhanced. [ABSTRACT FROM AUTHOR]

This study is aimed at evaluating C and N stocks in fractions of soil organic matter (SOM) in an area of bauxite mining under recovery with tree species. We have analyzed the long-term recovery of C and N stocks of organic matter fractions from five types of forest cover (Eucalyptus, Anadenanthera peregrina, mixed plantation of 16 native species, a mined area without vegetation cover as a control site, and a natural forest cover as a reference site). The total organic C (TOC) and N (TN) stocks and also organic matter fractions, particulate organic matter (POM), mineral-associated organic matter (MAOM), microbial biomass (MB), and labile C (LC), were determined, as well as the C/N ratio and the carbon management index (CMI). Although the stocks of TOC and LC, CMI, and MB did not differ between the types of forest cover in the 0–60 cm layer, they were lower than the values in the native forest. Forest cover increases the stocks of TOC, LC, MB, and CMI in the area of bauxite mining compared to the control site. In addition, we found that the TOC C and TN stocks and also SOM fractions (LC, C-MAOM, C-POM, N-MAOM, and N-POM) are positively correlated (r ≥ 0.71 for all cases) with volume of roots larger than 2 mm. Therefore, Eucalyptus, A. peregrina, and a mixed of 16 native trees contribute for restoring stocks of soil C and N following bauxite mining in the Brazilian Atlantic Forest. [ABSTRACT FROM AUTHOR]

Seedling banks are very important in forest regeneration following forest disturbances such as crop cultivation. In 2011 and 2013 the Uganda National Forestry Authority (NFA) evicted encroachers from parts of Mabira Central Forest Reserve that had been under crop cultivation for over 40 years. This gave an opportunity for the vegetation to recover. In this study, we assessed the recovery process based on seedling bank diversity, richness and density in three blocks differing in recovery time. Two disturbed blocks, the Western Block (WB) (abandoned by encroachers 1–3 years), and the Eastern Block (EB) (abandoned 4–5 years) before this study and a nearby undisturbed area (intact) were included in the study. We recorded 48 seedlings species; 37 in WB, 30 in EB and 27 in intact. Differences in species richness were not statistically significant among blocks (F2, 88 = 1.2420, p = 0.294). All seedling species found in the intact were found in the EB and WB. There were statistically significant differences in species diversity (Shannon–Wiener: F2, 88 = 5.354, p = 0.006), density (P < 0.001) and composition (ANOSIM; R = 0.55, p = 0.001) among blocks. Apart from Broussonetia papyrifera, other species contributing to the dissimilarity (Acalypha neptunica, Antiaris toxicaria, Blighia unijugata, Funtumia elastica were late succession species. Animal dispersed species dominated intact. Seed-regenerating species were found in both WB and EB, but re-sprouts were more common in EB. These results show that proximity to intact forest aids forest recovery, even for areas with long-term cultivation history. [ABSTRACT FROM AUTHOR]

Tropical forests contribute a major sink for anthropogenic carbon emissions essential to slowing down the buildup of atmospheric CO2 and buffering climate change impacts. However, the response of tropical forests to more frequent weather extremes and long-recovery disturbances like fires remains uncertain. Analyses of field data and ecological theory raise concerns about the possibility of the Amazon crossing a tipping point leading to catastrophic tropical forest loss. In contrast, climate models consistently project an enhanced tropical sink. Here, we show a heterogeneous response of Amazonian carbon stocks in GFDL-ESM4.1, an Earth System Model (ESM) featuring dynamic disturbances and height-structured tree-grass competition. Enhanced productivity due to CO2 fertilization promotes increases in forest biomass that, under low emission scenarios, last until the end of the century. Under high emissions, positive trends reverse after 2060, when simulated fires prompt forest loss that results in a 40% decline in tropical forest biomass by 2100. Projected fires occur under dry conditions associated with El Niño Southern Oscillation and the Atlantic Multidecadal Oscillation, a response observed under current climate conditions, but exacerbated by an overall decline in precipitation. Following the initial disturbance, grassland dominance promotes recurrent fires and tree competitive exclusion, which prevents forest recovery. EC-Earth3-Veg, an ESM with a dynamic vegetation model of similar complexity, projected comparable wildfire forest loss under high emissions but faster postfire recovery rates. Our results reveal the importance of complex nonlinear responses to assessing climate change impacts and the urgent need to research postfire recovery and its representation in ESMs. [ABSTRACT FROM AUTHOR]

The capability of tropical forest to recover from extensive land-use remains a matter of debate, despite its importance for guiding conservation and restoration policies. This is especially the case for Southeast Asia. Fortunately, the Sunda Shelf was extensively exposed during the Last Glacial Maximum sea-level lowstand, providing a unique window to study the long-term and landscape-scale development of tropical forest in new accommodation spaces that may be analogous to those emerge after the cessation of human activities. Here we conduct pollen analyses on three sediment cores from the southern South China Sea – two located in front of the Sunda Shelf paleo-river mouths and one close to the northern Borneo – in order to evaluate the similarity/difference between the "primary" and "secondary" tropical forest of Southeast Asia. The assemblages of major pollen taxa and the life-form composition of identified plant types are found to be quite similar among the sites, indicating that well-structured rainforest should have expanded to the Sunda Shelf despite the sandy and potentially saline, nutrient-poor soils. The plant biodiversity, however, was obviously lower on the Sunda Shelf than on Borneo as inferred from the pollen richness. This indicates a loss of biodiversity during large-scale range expansions. Our findings suggest the potential of reforestation in the lowlands of Southeast Asia, but unfortunately the incapability of restoring biodiversity to pre-disturbance levels through natural regeneration alone. Moreover, the old forests in the mountainous northern Borneo appears to be irreplaceable and thus a priority of conservation efforts. • Effectivity of fossil pollen records in biodiversity reconstruction of Southeast Asia. • Spatial pattern of plant diversity over the northern Sundaland during the LGM. • Limiting factors of Southeast Asian rainforest to recover from large-scale disturbance. • Irreplaceability of primary rainforest in mountainous northern Borneo. [ABSTRACT FROM AUTHOR]

Understanding accurate and continuous forest dynamics is of key importance for forest protection and management in the Greater Khingan Mountains (GKM). There has been a lack of finely captured and long-term information on forest disturbance and recovery since the mega-fire of 1987 which may limit the scientific assessment of the GKM’s vegetation conditions. Therefore, we proposed a rapid and robust approach to track the dynamics of forest disturbance and recovery from 1987 to 2021 using Landsat time series, LandTrendr, and random forests (RF) models. Furthermore, we qualified the spatial characteristics of forest changes in terms of burn severity, topography, and distances from roads and settlements. Our results revealed that the integrated method of LandTrendr and RF is well adapted to track forest dynamics in the GKM, with an overall accuracy of 0.86. From 1987 to 2021, forests in the GKM showed a recovery trend with a net increase of more than 4.72 × 104 ha. Over 90% of disturbances occurred between 1987 and 2010 and over 75% of recovery occurred between 1987 and 1988. Mildly burned areas accounted for 51% of forest disturbance and severely burned areas contributed to 45% of forest recovery. Forest changes tended to occur in zones with elevations of 400–650 m, slopes of less than 9°, and within 6 km of roads and 24 km of settlements. Temporal trends of forest disturbance and recovery were mainly explained by the implementation timelines of major forestry policies. Our results provide high-resolution and time-series information on forest disturbance and recovery in the GKM which could support scientific decisions on forest management and sustainable utilization.

Forest harvesting can impact site quality by removing essential nutrients, exacerbating the effects of historic base cation losses associated with acid deposition. We studied the 30-year trajectory of forest recovery from clearcutting (whole-tree harvest (WTH)) in a forest originally dominated by sugar maple (Acer saccharum Marsh.). At both the watershed scale (21.9 ha) and the “detailed” plot scale (1 m2), a dramatic decline of sugar maple was observed, along with maintenance of American beech (Fagus grandifolia Ehrh.) and an increase in birch, mainly yellow birch (Betula alleghaniensis Britt.). Many of the “detailed” plots where sugar maple failed to recruit became unoccupied rather than being “won” by another species. The decline of sugar maple was most severe in the upper elevation zones of the watershed, where low base status (especially Ca) of the soils was a likely driver. The results support previous studies indicating that regeneration by sugar maple is severely compromised on base cation depleted soils. Lower survival of seedlings for sugar maple emphasized the importance of maintaining advance regeneration to favor desired species such as sugar maple. Foresters should consider that sites with low base saturation and exchangeable Ca are likely to exhibit regeneration failure for sugar maple in the long term, even those with initial dominance by this species.

Because of continuing degradation or deforestation in areas of undisturbed primary forest, there is a need to study the relative merit of strategies that mitigate their impacts on biodiversity and associated ecological functionality.Here, we provide a global synthesis of forest degradation or deforestation using 48 studies published in peer‐reviewed journals that use dung beetles as indicators given their sensitivity to anthropogenic disturbance and their relevance in performing essential ecological functions in terrestrial ecosystems.We evaluated forest cover associated with undisturbed primary forest degradation (i.e. degraded primary forest) and undisturbed primary forest deforestation (i.e. secondary forest, forestry plantations and forestry restoration implementation) on species richness, total abundance, biomass, functional groups' presence and ecological functions provided by dung beetles. Additionally, we determined whether if dung beetle responses to forest disturbances were geographically dependent.We found lower diversity and a decrease in ecological functions associated with all classes of disturbance in primary forest. However, the effects were less severe in the case of forest degradation compared to complete deforestation with natural regeneration of secondary forest, development of forest plantations or active forest restoration by planting indigenous trees. The Neotropical and Oriental regions are particularly vulnerable, given the elevated rates of undisturbed primary forest deforestation and its negative impact on their assemblages' diversity and ecological functions.Synthesis and applications. Our results show that efforts for the conservation of remaining undisturbed primary forests need to be prioritized, especially in tropical latitudes. However, in regions where primary forest conservation is not feasible, logging management programs in degraded primary forest may have a potential role in reducing negative impacts for dung beetle diversity and ecological functions. Moreover, we conclude that despite the negative effect of primary forest deforestation and implementation of secondary forest, forestry plantation and forestry restoration, they can be useful for partial recovery of diversity and ecological functions performed by dung beetles in areas lacking any primary forest (undisturbed or degraded) vegetation cover. [ABSTRACT FROM AUTHOR]

Two novel satellite LiDAR missions —GEDI and ICESat-2— are currently operational and combined provide near-global measurements of forest height and structure. Such data underpin a new era of large-area approaches for measuring forest height in regrowing forests of different ages and assessing associated regrowth rates. Two LiDAR missions further allow for comparing independently derived forest heights and regrowth rates. This study utilized both GEDI and ICESat-2 measurements to assess regrowth rates in regrowing forests of different ages for the Brazilian state Rondônia. We considered 19 data subgroups stratified by beam strength, light condition, beam sensitivity, and waveform processing algorithm to assess the retrieval uncertainty and identify data subgroups associated with the most reliable regrowth estimates. The quality assessment of GEDI and ICESat-2 forest heights over four 50 km long airborne LiDAR strips determined a root mean square error of 4.14 m (CV = 17%) and 5.91 m (CV = 19%) and a mean error of 0.04 m and −2.81 m, respectively. A linear calibration model between satellite- and airborne-LiDAR heights was then derived for each data subgroup and used to calibrate satellite heights. Forest regrowth rates were subsequently estimated for each satellite mission using a space-for-time imputation with forest heights’ medians per stand age class. The total growth of GEDI and ICESat-2 median forest heights after 33 years was 20.17 m (SE = 1.3 m) and 20.13 m (SE = 2.8 m), respectively. However, when growth was approximated with different non-linear models, the total growth differed by up to 6%, and the average regrowth rate even by up to 23%. The study revealed that omitting either the calibration step or the removal of secondary-forest-border pixels would result in an underestimation of the regrowth rate by more than 20%. Furthermore, the ICESat-2 weak beams were found unreliable for regrowth retrieval. The study showed that the novel satellite LiDAR data and the proposed methods could assess median forest height growth over large areas. However, forest age errors should also be accounted for in the retrieval uncertainty before comparing the growth estimates across different regions.Code and data necessary to reproduce the results are freely available on GitHub and Zenodo.

Wildfire is a natural disturbance in many forested biomes, with the loss of carbon to the atmosphere and mortality of trees actively sequestering carbon of global concern as a contribution to climate change. Natural regeneration is often successful at reestablishing a forest in ecosystems adapted to fire, but there is increasing concern that the changing size, frequency and severity of wildfire is causing regeneration failures or inadequate densities of trees that sequester and store carbon following these disturbances. It remains unclear whether the action of planting trees accelerates carbon storage following fire compared to forests established through natural regeneration. The central interior of British Columbia recently experienced multiple years of record-breaking fire activity. Rehabilitation planting focused on reestablishing trees in the managed forest but was also prescribed in previously unmanaged forests to initiate carbon sequestration. Planting is often accompanied by other stand treatments such as salvage harvesting or snag removal and debris clearing to ensure planter safety. Here, we determine carbon recovery and stores in 21 wildfires across a chronosequence from the early 1960s to 2015. We measured above and belowground carbon pools to determine the effect of time since fire and planting treatments on carbon. Tree planting did not increase total ecosystem carbon over time, but rather decreased carbon through the loss of dead wood from site preparation. All carbon pools were affected by time since fire except the mineral soil pool, which was best predicted by soil clay content and coarse fragments positive effects. Live tree carbon increased over time, with more stored in planted stands over 60 years compared to stands that were not planted. Projecting growth to 100 years since fire suggests we may see increasing divergence in carbon stores in planted stands over a full fire-return interval, but these differences remain relatively small [mean (sd): 140.8 (19.6) Mg⋅ha–1 in planted compared to 136.9 (27.5) Mg⋅ha–1 in not-planted stands], with 1.4 Mg⋅ha–1 year–1 sequestered in not-planted compared to 1.5 Mg⋅ha–1 year–1 in planted stands. To meet carbon objectives, replanting trees on average sites in burned forests of BC’s central interior would require preserving the carbon legacy of fire, including dead wood.

Tropical montane forests are diverse ecosystems often affected by uncontrolled human-induced fires causing tree mortality and creating large deforested areas. After fires, Pteridium spp. ferns (bracken) often dominate, and forest regeneration in these areas is slow. In this study, we evaluated the effects of bracken fronds and litter, as well as the micro-environmental conditions created by the fern, on the density and species diversity of naturally recruiting seedlings. At eight sites, 120 experimental plots were established among forest and bracken-dominated areas with the following treatments: (a) fronds and litter intact (F+L+); (b) fronds intact and litter removed (F+L-); (c) fronds removed and litter intact (F-L+); and (d) fronds and litter removed (F-L-). After one year, all seedlings were registered, identified and classified according to their life-form (tree, shrub, herb, vine), dispersal vector (wind- or animal-dispersed) and successional status (early-, mid-, and late-successional). For all treatments we assessed 12 micro-environmental variables. We identified 3649 naturally-recruiting seedlings corresponding to 278 species from 70 families. We found positive effects of bracken fronds particularly on tree seedling recruitment: treatments with fronds had greater densities of both animal- and wind-dispersed tree seedlings, 1.8 and 1.4 fold higher, respectively, compared to treatments without fronds. Similarly, the density of early-, mid- and late-successional tree species was 1.3, 1.7 and 1.9 times higher in treatments with than without fronds. Furthermore, species diversity of early-, mid- and late-successional tree species was higher in the treatments with fronds. The environmental conditions generated by bracken presence, such as photosynthetically active radiation, soil temperature, live bracken biomass and litter depth, had positive effects on seedling density of all, animal-dispersed and early-successional tree species, and negative effects on seedling recruitment of other life-forms, notably from early successional stages. To promote forest regeneration in bracken-dominated areas, active restoration measures such as direct seed addition and transplants of nursery-raised seedlings of mid- and late-successional species should be considered. Since bracken can hinder the establishment of some life forms and species but favor others, it is recommended to include a trait-based approach to understand species responses to environmental factors and select species that are optimally adapted to bracken-dominated habitat conditions to promote forest regeneration. [Display omitted] • Bracken facilitates seedling recruitment of mid- and late-successional tree species. • Bracken fronds' shade increases species diversity of tree seedlings. • Bracken litter decreases natural recruitment of herbs. • Animal-dispersed species have higher recruitment under bracken fronds and litter. [ABSTRACT FROM AUTHOR]

Natural disturbances play an important role in shaping the dynamics of mountain forests, yet their effects on essential ecosystem services, such as protection against natural hazards, can be significant. With the challenges posed by climate change and increasing disturbances, as well as the complexities of salvage logging, there is a growing interest in understanding post-disturbance development in unsalvaged mountain forests, alongside the advancement of decision support systems aimed at ensuring sustained provision of ecosystem services. In this study, we combined a space-for-time substitution approach with long-term monitoring data to evaluate regeneration processes and development of deadwood decay following three distinct windthrow events in Central European mountain forests that were locally unsalvaged (specifically Vaia in 2018, Kyrill in 2007, and Vivian in 1990). Our unique dataset additionally provided insights into the long-term effects of disturbance legacies and tree regeneration on protection against natural hazards. Deadwood cover gradually decreased with time since disturbance, from an average of 50% two years after Vaia to 25% twelve years after Kyrill and 15% thirty years after Vivian. Similarly, deadwood height above ground significantly decreased over time, with median values dropping from 1 to 2 m immediately after the disturbance to 25–30 cm three decades later. The decay stage and diameter of deadwood significantly influenced tree regeneration, with larger diameters of logs and deadwood in more advanced decay stage (especially less solid/soft to very loose stage), facilitating seedling establishment, thus a second wave of tree regeneration. About a quarter of saplings grew on deadwood thirty years after disturbance. The analysis of post-windthrow stand development showed an increase in tree cover and height with time since disturbance, with distinct patterns observed across different windthrow events and sites. Three decades post-disturbance, the number of trees had notably increased, with tree cover reaching 50%. Although Norway spruce remained the dominant species, the forest composition had shifted towards a predominance of broadleaves, particularly evident at lower elevations and areas with moderate browsing pressure. Our findings underscore the critical role of post-disturbance forest recovery and deadwood dynamics in promoting uneven-aged mixed forest structures, thereby enhancing forest regeneration, structural diversity, and protection against natural hazards. Emphasizing the vital importance of retaining deadwood, our study suggests that its role as a valuable substrate for enhancing resilience and ecosystem services is likely to grow in the future. • Deadwood cover and height above ground decreased with time since windthrow. • Decay stage and diameter of deadwood significantly influenced tree regeneration. • At lower elevations, windthrow led to higher shares of broadleaves. • Deadwood supports tree establishment and heterogeneity of forest structure. • Avoiding salvage logging enhanced forest recovery and avalanche protection. [ABSTRACT FROM AUTHOR]

Anthropogenic modification of montane forests to other land uses has significant effects on native vegetation and the ecological functions of plant communities, such as in the forests of Mount Kilimanjaro. This study was carried out in Kilimanjaro National Park at the former Engushai forest village, where local people were relocated for conservation in 2006. Forty 20 × 50 m plots were established in areas with different historical land use (former settlement, former cultivation, transition and natural forest). We recorded 132 plant species, representing 114 genera and 58 families. The highest tree species richness was recorded in the forest zone (11 ± 1 per plot), followed by in the transition zone (7 ± 1), former cultivation zone (4 ± 1) and former settlement zone (4 ± 0.4). The natural forest was more diverse in terms of tree species than other sites (H' = 1.83 ± 0.09, evenness of 0.48 ± 0.02). Analysis of variance showed significant variation in tree species richness, diversity index and evenness among previously disturbed sites and natural forests. The vegetation is at an early stage of succession in anthropogenically impacted areas. However, the domination of Vernonia lasiopus and Bothriocline longipes in the formerly degraded areas was crucial for restoring the microclimate and soil fertility vital for forest development. There is adequate potential for and patterns of natural regeneration of indigenous trees in the anthropogenically impacted areas. The current passive management by Kilimanjaro National Park facilitates forest recovery, indicating the high resilience of these montane forests. It is recommended to monitor the future recovery and succession of the lower montane forest. [ABSTRACT FROM AUTHOR]

Ecological restoration is considered a nature-based solution to reduce ecosystem degradation, biodiversity loss, and combat climate change. In this sense, the objective of this study was to identify the knowledge management practices that are present in an ecological restoration process in the tropical dry forest. The empirical study was developed using a mixed approach over an area of 11,079 ha in Huila, Colombia. At first, the qualitative study was supported by a documentary review and participant observation between 2018 and 2020. On the other hand, the quantitative study was carried out through the application of the Delphi method with the participation of 64 experts. Twenty-two knowledge management practices were identified with orientation towards human factors, organization, information technologies, strategy, and intellectual protection. These findings show that all the knowledge management practices identified have an impact on the six components of the ecological restoration process (planning, diagnosis, implementation, monitoring, participation, and consolidation). Likewise, these practices contribute to the generation, transformation, and mobilization of local and scientific knowledge in the components of the ecological restoration process of the tropical dry forest. [ABSTRACT FROM AUTHOR]

Extreme wind blowdown events can significantly modify the structure and composition of forests, and the predicted shift in tropical cyclone regimes due to climate change could strongly impact forests across the tropics. In this study, we coupled an individual-based and spatially-explicit forest dynamics model (TROLL) with a mechanistic model estimating wind damage as a function of tree size, traits, and allometry (ForestGALES). We assimilated floristic trait data and climate data from a subtropical forest site in Taiwan to explore the effect of wind regimes on forest properties. We found that the average canopy height and biomass stocks decreased as wind disturbance strength increased, but biomass stocks showed a nonlinear response. Above a wind intensity threshold, both canopy height and biomass drastically decreased to near-zero, exhibiting a transition to a non-forest state. Wind intensity strongly regulated wind impact, but varying wind frequency did not cause discernible effects. The implementation of within-stand topographic heterogeneity led to weak effects on within-stand forest structure heterogeneity at the study site. In conclusion, the intensity of wind disturbances can potentially greatly impact forest structure by modifying mortality. Individual-based modeling provides a framework in which to investigate the impact of wind regimes on mortality, other factors influencing wind-induced tree mortality, as well as interaction between wind and other forms of forest disturbance and human land use legacy.

Establishing diverse mycorrhizal fungal communities is considered important for forest recovery, yet mycorrhizae may have complex effects on tree growth depending on the composition of fungal species present. In an effort to understand the role of mycorrhizal fungi community in forest restoration in southern Costa Rica, we sampled the arbuscular mycorrhizal fungal (AMF) community across eight sites that were planted with the same species (Inga edulis, Erythrina poeppigiana, Terminalia amazonia, and Vochysia guatemalensis) but varied twofold to fourfold in overall tree growth rates. The AMF community was measured in multiple ways: as percent colonization of host tree roots, by DNA isolation of the fungal species associated with the roots, and through spore density, volume, and identity in both the wet and dry seasons. Consistent with prior tropical restoration research, the majority of fungal species belonged to the genus Glomus and genus Acaulospora, accounting for more than half of the species and relative abundance found on trees roots and over 95% of spore density across all sites. Greater AMF diversity correlated with lower soil organic matter, carbon, and nitrogen concentrations and longer durations of prior pasture use across sites. Contrary to previous literature findings, AMF species diversity and spore densities were inversely related to tree growth, which may have arisen from trees facultatively increasing their associations with AMF in lower soil fertility sites. Changes to AMF community composition also may have led to variation in disturbance susceptibility, host tree nutrient acquisition, and tree growth. These results highlight the potential importance of fungal-tree-soil interactions in forest recovery and suggest that fungal community dynamics could have important implications for tree growth in disturbed soils.

Planted woodland islets can provide seeds for restoring forest ecosystems in Mediterranean old fields lacking seed sources, but other factors than seed arrival can also hinder the establishment of woody species. We experimentally examined factors affecting the emergence, survival, growth and recruitment of holm oak (Quercus ilex) seedlings juveniles from 25-year-old 100-m2 oak woodland islets planted in a Mediterranean old field. Wet springs and summers increased seedling emergence and survival. Distance to the islets per se did not affect seedling performance. However, emergence and survival increased in microsites close to the islets in less sun-exposed orientations of the islets and far from the islets in more sun-exposed orientations. Damage by wild boar reduced emergence, and unsheltered seedlings had 26% lower survival than sheltered ones, reflecting herbivory. Herb community biomass and light reduction by herbs increased with distance from nearest islet; the sparse herb cover around islets was due to competition from woodland islets, not to herbivory. There was a mismatch between the pattern of seedling survival and how the abundance of naturally recruited oaks varied with distance from the nearest islet; this suggests that other drivers can counteract the spatial pattern of seedling survival. We conclude that natural regeneration of Q. ilex in old fields from planted woodland islets is slow (5.7 seedlings ha−1 yr−1) due to acorn and seedling predation, and drought during spring and summer. Despite their small size, planted islets affected survival of oak juveniles depending on the orientation and distance relative to the islets. [ABSTRACT FROM AUTHOR]