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Land cover is a crucial factor in controlling rainfall–runoff processes in mountain basins. However, various anthropogenic activities, such as converting natural vegetation to agricultural or urban areas, can affect this cover, thereby increasing the risk of flooding in cities. This study evaluates the hydrological behavior of two mountain basins in Loja, Ecuador, under varying land use scenarios. El Carmen small basin (B1), located outside the urban perimeter, and Las Pavas small basin (B2), within the urban area, were modeled using HEC-HMS 4.3 software. The results highlight the significant influence of vegetation degradation and restoration on hydrological processes. In degraded vegetation scenarios, peak flows increase due to reduced soil infiltration capacity, while baseflows decrease. Conversely, the conserved and restored vegetation scenarios show lower peak flows and higher baseflows, which are attributed to enhanced evapotranspiration, interception, and soil water storage. The study underscores the importance of ecosystem management and restoration in mitigating extreme hydrological events and improving water resilience. These findings provide a foundation for decision-making in urban planning and basin management, emphasizing the need for comprehensive and multidisciplinary approaches to develop effective public policies. [ABSTRACT FROM AUTHOR]

Multiplatform fusion point clouds can effectively compensate for the disadvantages of individual platform point clouds in forest parameter extraction, maximizing the potential of LiDAR technology. However, existing registration algorithms often suffer from insufficient feature extraction and limited registration accuracy. To address these issues, we propose a ULS (Unmanned Aerial Vehicle Laser Scanning)-TLS (Terrestrial Laser Scanning) point cloud data registration method based on Similar Distance Search (SDS). This method enhances coarse registration by accurately retrieving points with similar features, leading to high overlap in the rough registration stage and further improving fine registration precision. (1) The proposed method was tested on four natural forest plots, including Pinus densata Mast., Pinus yunnanensis Franch., Pices asperata Mast., Abies fabri (Mast.) Craib, and demonstrated high registration accuracy. Both coarse and fine registration achieved superior results, significantly outperforming existing algorithms, with notable improvements over the TR algorithm. (2) In addition, the study evaluated the accuracy of individual tree parameter extraction from fusion point clouds versus single-platform point clouds. While ULS point clouds performed slightly better in some metrics, the fused point clouds offered more consistent and reliable results across varying conditions. Overall, the proposed SDS method and the resulting fusion point clouds provide strong technical support for efficient and accurate forest resource management, with significant scientific implications. [ABSTRACT FROM AUTHOR]

Simple Summary: Climate change will cause a reduction in the provision of goods and services of Mediterranean forests, including those of stone pine (Pinus pinea), an economically important species. We used a dendrochronological approach to address climate impact on the growth of stone pine natural stands and plantations. Our results indicate that increasingly arid conditions will affect both natural stands and plantations in native and exotic countries. Adaptive management will be essential to ensure the maintenance of the stands and their multifunctionality. Pinus pinea is an important Mediterranean species due to its adaptability and tolerance to aridity and its high-quality pine nuts. Different forest types located in Mediterranean native and non-native environments provide the opportunity to perform comparative studies on the species' response to climate change. The aims of this study were to elucidate growth patterns of the species growing in native and exotic habitats and to analyze its response to climatic fluctuations, particularly drought, in both geographical contexts. Understanding stone pine (Pinus pinea) growth responses to climate variability in native and exotic habitats by comparing natural stands and plantations may provide useful information to plan adequate management under climate change. By doing so, we enhance the understanding of P. pinea's adaptability and provide practical approaches to its sustainable management. In this study, we reconstructed and compared the stem radial growth of seven stone pine stands, two in southern Spain and five in central–southern Chile, growing under different climatic conditions. We quantified the relationships between growth variability and climate variables (total rainfall, mean temperature, and SPEI drought index). Growth was positively correlated with autumn rainfall in plantations and with autumn–winter rainfall in natural stands. Growth was also enhanced by high autumn-to-spring rainfall in the driest Chilean plantation, whereas in the wettest and coolest plantation, such correlation was found in winter and summer. A negative impact of summer temperature was found only in one of the five Chilean plantations and in a Spanish site. The correlation between SPEI and tree-ring width indices showed different patterns between and within countries. Overall, exotic plantations showed lower sensitivity to climate variability than native stands. Therefore, stone pine plantations may be useful to assist in mitigating climate change. [ABSTRACT FROM AUTHOR]

The nitrogen (N) enrichment induced by atmospheric N deposition affects both soil physicochemical properties and bacterial communities. However, how N enrichment affects soil aggregate-associated bacterial communities remains largely unclear. In this study, we conducted a two-year N addition experiment (four N levels: 0, 5, 10, and 20 g N m−2 year−1, corresponding to normal N, low N, medium N, and high N, respectively) in a Quercus liaotungensis Koidz–dominated forest. The distribution, nutrient content, and bacterial community composition of the soil aggregates were measured under various N enrichment conditions. N enrichment changed the aggregate distribution, increased the content of nutrients in aggregates, and altered the aggregate-associated bacterial community composition. N enrichment reduced the complexity of the bacterial co-occurrence network and degraded the interactions between bacteria compared with those observed under the normal N level. Aggregate-associated bacterial community was determined to be primarily affected by N enrichment level but not by aggregate size. The litter properties are the key factors affecting the composition of bacteria in aggregates. These findings improve our understanding of aggregate-associated bacterial responses to N enrichment and the related influencing factors. [ABSTRACT FROM AUTHOR]

Researchers build growth models to predict the growth of forest stands and propose management measures to improve the overall quality of these stands. In this study, data collected from 91 sample plots from the eighth (2010) and ninth (2015) Chinese National Forest Inventories in Jiangxi Province were used to establish a transition-matrix growth model. Then, 12 potential equilibrium curves were set to guide forest management, and a transition-matrix growth model was used to predict stand growth in Jiangxi Province. In each 10-year management period, trees with diameters that exceeded the equilibrium curve were cut down. The results show that species diversity (H1), size diversity (H2), and basal area (B) have statistically significant influences on growth, mortality, and recruitment. Moreover, the high accuracy of the transition-matrix growth model is demonstrated. According to the simulation results, B = 35 m2/ha, the maximum diameter of retained trees Dmax = 45 cm and the adjacent diameter ratio q = 1.7 constitute the optimal equilibrium curve to guide forest management. The diameter distribution guided by the equilibrium curve is reverse J-shaped and is associated with significant increases in the hardwood stock volume and current annual growth. Under the guidance of the equilibrium curve, the forests in Jiangxi Province can be reasonably managed, produce more high-economic-value timber, and achieve a more stable species composition. This study will help maximize the ecological and economic benefits of forests and provide a reference for the realization of the sustainable development of forestry. Furthermore, the results can be used to improve the facility and accuracy of natural forest harvesting. [ABSTRACT FROM AUTHOR]

Outbreaks of defoliator insects are important natural disturbances in boreal forests, but their increasing frequency under warming climate conditions is of concern. Outbreak events can shape ecosystem dynamics with cascading effects through trophic networks. Caterpillar defoliation can alter tree physiology, increase sunlight to the understory, and result in the deposition of large amounts of leaf litter and caterpillar frass to the forest floor. These modifications can thus affect soil organisms through direct (e.g., changes in soil temperature or moisture) or indirect (e.g., changes in detrital and root food webs) mechanisms. We assessed whether a recent (2015 to 2017) outbreak of the forest tent caterpillar (Malacosoma disstria) at the Lake Duparquet Teaching and Research Forest (Abitibi, QC, Canada) affected soil springtail communities, abundant microarthropods in forest soils. In 2018 and 2019, we sampled litter and soil (0–10 cm depth) at eight sites each in aspen-dominated (Populus tremuloides Michx) stands that were undefoliated or had a recent defoliation history. We found no significant difference in springtail abundance (specimens cm−2) or alpha diversity indices between undefoliated sites and those with defoliation history. However, we observed a transient change in springtail community composition 1 year after the outbreak (2018) with the absence of Folsomia nivalis, Anurophorus sp1, and Xenylla christianseni in sites with defoliation history, but no compositional differences were observed in 2019. Certain soil nutrients (P, C, Mg, Mn) were significant predictors of springtail community composition, but soil microbial biomass was not, despite its significant decrease in sites with defoliation history. Our results show that soil springtail communities respond in the short-term to the forest tent caterpillar outbreak with compositional shifts, but seem ultimately resilient to these events. [ABSTRACT FROM AUTHOR]

Forest ecosystems are an important component of the global carbon cycle. Carbon density (CD; carbon mass per unit area) elevational changes in the vegetation, litter, and soil of forest ecosystems, are poorly understood. We investigated CD variations in arbor, shrubs, herbs, litter, and soils in a Juniperus przewalskii Kom. (Przewalski's juniper) forest at 2900–3900 m above sea level (a.s.l.) in Qinghai Province, China. The average CD of vegetation (VCD) and litter (LCD) were 76.53 and 1.21 t hm−2, respectively, and the CD increased with increasing elevation, to maximum values of 114.02 and 1.39 t hm−2, respectively, at 3500–3700 m a.s.l., before decreasing at higher elevations. The soil carbon density (SCD) gradually decreased from 2900 to 3500 m a.s.l., sharply increased from 3500 to 3700 m a.s.l., peaking at 217.84 t hm−2, and then sharply decreased. The maximum ecosystem carbon density (ECD, 333.25 t hm−2) occurred between 3500 and 3700 m a.s.l. The VCD and ECD were significantly and positively correlated with elevation and annual average precipitation (AAP, p < 0.01), and negatively correlated with annual average temperature (AAT, p < 0.05). These may be key factors in determining CD distribution. This study reveals that conserving high-elevation forests is important for enhancing organic carbon accumulation in the ecosystem. [ABSTRACT FROM AUTHOR]

When forest fires occur, highly complex effects on soil properties and hydrological processes are activated. However, in countries such as Iran, these consequences are not widely studied and there is a lack of studies. Therefore, the main aim of this study was to investigate the effects of wildfire on soil quality characteristics in a representative forest area located in the Hyrcanian forests, specifically, in the Zarrinabad watershed of Sari. For this purpose, four different sites, including unburnt natural (UNF), burned natural (BNF), unburnt plantation (UPF), and burned plantation forests (BPF) were selected. Soil sampling was performed at each site using the random, systematic method at a depth from 0 to 30 cm. To investigate the effects of fire on physical and chemical properties indicators, 10 plots with dimensions of 0.5 × 0.5 m were placed at a distance of 1.5 m from each other at each site. Soil samples were transported to the laboratory and their physical and chemical properties were determined. The results showed that the percentage of sand, silt, aggregate stability, soil hydrophobicity, organic carbon, organic matter, soil total nitrogen, absorbable potassium and phosphorus, electrical conductivity, and pH, increased significantly when the soil surface is burned (p ≤ 0.01, p ≤ 0.05). However, clay percentage, initial, final, and average infiltration in the burned areas showed a decreasing trend in comparison with other forest statuses. Furthermore, no significant effects were observed on the true and bulk density, porosity, and soil moisture (p ≥ 0.05). These findings demonstrate that forest fire effects in Iran must be considered as a key topic for land managers because soil properties and hydrological processes are drastically modified, and land degradation could be irreparably activated. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicles (UAVs) have contributed considerably to forest monitoring. However, gaps in the knowledge still remain, particularly for natural forests. Species diversity, stand heterogeneity, and the irregular spatial arrangement of trees provide unique opportunities to improve our perspective of forest stands and the ecological processes that occur therein. In this study, we calculated individual tree metrics, including several multispectral indices, in order to discern the spectral reflectance of a natural stand as a pioneer area in Mexican forests. Using data obtained by UAV DJI 4, and in the free software environments OpenDroneMap and QGIS, we calculated tree height, crown area, number of trees and multispectral indices. Digital photogrammetric procedures, such as the ForestTools, Structure from Motion and Multi-View Stereo algorithms, yielded results that improved stand mapping and the estimation of stand attributes. Automated tree detection and quantification were limited by the presence of overlapping crowns but compensated by the novel stand density mapping and estimates of crown attributes. Height estimation was in line with expectations (R2 = 0.91, RMSE = 0.36) and is therefore a useful parameter with which to complement forest inventories. The diverse spectral indices applied yielded differential results regarding the potential vegetation activity present and were found to be complementary to each other. However, seasonal monitoring and careful estimation of photosynthetic activity are recommended in order to determine the seasonality of plant response. This research contributes to the monitoring of natural forest stands and, coupled with accurate in situ measurements, could refine forest productivity parameters as a strategy for the validity of results. The metrics are reliable and rapid and could serve as model inputs in modern inventories. Nevertheless, increased efforts in the configuration of new technologies and algorithms are required, including full consideration of the costs implied by their adoption. [ABSTRACT FROM AUTHOR]

The contribution of coarse woody debris (CWD) to forest carbon (C) and nitrogen (N) dynamics is poorly quantified. This study quantified total C and N content in CWD and estimated the decomposition rates of CWD at different decay stages in a 70-year-old naturally regenerated Korean red pine forest (Pinus densiflora S. et Z.). The N concentration in CWD varied among species and decay classes (from 0.15% to 0.82%), and exhibited a decreasing pattern in C:N ratios with increasing decay class. Total CWD amounts of 4.84 Mg C ha-1, dominated by pine logs (45.4%) and decay class III (40.0%), contained total N of 20.48 kg N ha-1, which was approximately nine times the N input from annual tree mortality. In addition, this study demonstrated that the decay constant rate k was 0.2497 for needle litter, whereas k values were 0.0438, 0.0693, 0.1054, and 0.1947 for red pine CWD of decay class I, II, III, and IV, respectively. The decay rates were significantly related to wood density, N concentration, and C:N ratio across the decay classes of CWD. The results suggest that the C:N ratio of CWD is a key factor affecting its decomposition. [ABSTRACT FROM AUTHOR]

In recent decades, the area and proportion of planted forests have increased; thus, understanding the responses of planted and natural forests to drought are crucial because it forms the basis for forest risk assessments and management strategies. In this study, we combined the moderate-resolution imaging spectroradiometer (MODIS) enhanced vegetation index (EVI), meteorological aridity indices, and standardized precipitation evapotranspiration indices (SPEI) to identify the drought responses of planted and natural forests. In particular, we used the EVI standard anomaly (ESA) as a physiological drought indicator and analyzed the applicability of SPEIs at time scales of 1-30 months, thereby determining the optimal time scale for the SPEI (SPEIopt), i.e., the SPEI that best represents the drought responses of forests in Yunnan. Next, we employed the optimal SPEI and the ESA as indices to statistically analyze the response characteristics of planted and natural forests under different drought intensities. The results indicated the following: (1) The SPEI in June and a time scale of five months (i.e., SPEIJun,5) comprise the optimal meteorological aridity indicator for forests in Yunnan Province, which had the strongest correlation with the EVI standard anomaly (ESAJun). (2) All forest types were affected by drought in Yunnan, but their responses varied according to the forest type, elevation, and drought intensity. In general, natural forests are more vulnerable and sensitive to drought than planted forests, especially natural coniferous forests at low (0-2000 m) and moderate (2000-4000 m) altitudes, and natural mixed forest at low altitudes (0-2000 m). (3) The remote sensing-based ESA (ESAJun) is sensitive to the intensity of water stress, which makes it a good indicator for drought monitoring. In addition, the forests' inventory survey revealed that 8.05% of forests were affected by drought; thus, we used this as a guide to estimate an approximate threshold to map forest responses to drought across the region. Below this approximate threshold (i.e., ESAJun < -3.85), severe drought-induced effects on forests may occur. Given that natural forests are more vulnerable and sensitive to drought than the planted forests, natural forests need more careful management, especially in the context of projected increases in extreme drought events in the future. [ABSTRACT FROM AUTHOR]

The depletion of soil organic matter (SOM) reserve after deforestation and subsequent management practices are well documented, but the impacts of land-use change on the persistence and vulnerability of storage C and N remain uncertain. We investigated soil organic C (SOC) and N stocks in a landscape of chrono-sequence natural forest, grazing/crop lands and plantation forest in the highlands of North-West Ethiopia. We hypothesized that in addition to depleting total C and N pools, multiple conversions of natural forest significantly change the relative proportion of labile and recalcitrant C and N fractions in soils, and thus affect SOM quality. To examine this hypothesis, we estimated depletion of SOC and N stocks and labile (1 & 2) and recalcitrant (fraction 3) C and N pools in soil organic matter following the acid hydrolysis technique. Our studies showed the highest loss of C stock was in grazing land (58%) followed by cropland (50%) and eucalyptus plantation (47%), while on average ca. 57% N stock was depleted. Eucalyptus plantation exhibited potential for soil C recovery, although not for N, after 30 years. The fractionation of SOM revealed that depletions of labile 1 C stocks were similar in grazing and crop lands (36%), and loss of recalcitrant C was highest in grazing soil (56%). However, increases in relative concentrations of labile fraction 1 in grazing land and recalcitrant C and N in cropland suggest the quality of these pools might be influenced by management activities. Also, the C:N ratio of C fractions and recalcitrant indices (RIC and RIN) clearly demonstrated that land conversion from natural forest to managed systems changes the inherent quality of the fractions, which was obscured in whole soil analysis. These findings underscore the importance of considering the quality of SOM when evaluating disturbance impacts on SOC and N stocks. [ABSTRACT FROM AUTHOR]

The occurrence of hydrological drought, caused by rainfall deficiency, poses a threat to forest areas—not only due to the danger of fire, but as a result of changes in habitat conditions. It is predicted that more frequent periods of drought and high temperatures will reduce the stability of forests and increase their susceptibility to industrial pollution, pressure from insect pests, fungal pathogens, and fires. The main aim of this study was to investigate the current streamflow droughts in the catchment area of the Narewka River as an indicator of hydrological droughts in the Białowieża Primeval Forest for the period 1951–2020. The research presented in this paper shows that low flows of surface waters have appeared as an indicator of hydrological droughts almost every year since 1983. The analysis of the trend over the past 70 years shows that the aggregated annual volumes of low flows and the number of days with low flows are increasing significantly. This indicates a significant and relatively permanent change in the seasonal structure of the river runoff in the event of low summer flow. [ABSTRACT FROM AUTHOR]

Vietnam's Payment for Forest Ecosystem Services (PFES) scheme has the goal of protecting remaining natural forests by providing financial support to people involved in forest protection. However, studying the case of Dak Lak province in the Central Highlands region of Vietnam shows that even after eight years of PFES implementation, achieving this goal remains a challenge. Although PFES does provide a stable income source and higher payments than state forest protection programs, enables the mobilization of more personnel resources for patrolling forest and relieves a great burden on the state budget in terms of investment in forest protection and development, forest cover in Dak Lak province is still decreasing, mainly due to conversion for other land uses, especially commercial agricultural and industrial crops. These drivers are rooted in national socio-economic planning aimed at boosting economic growth and in local people's need to sustain their livelihoods. In addition, our paper shows that illegal logging is still widespread in Dak Lak. Weak law enforcement in areas of forest managed by state forest authorities and state companies also contributes to deforestation. However, these drivers are neither fully recognized nor addressed, and instead, the blame for deforestation is laid on local communities. PFES alone cannot protect forests in Dak Lak province. It needs to be backed up by political commitment to address underlying drivers of deforestation, improved social programs to help local people diversify their income sources and clarity over land use. [ABSTRACT FROM AUTHOR]

Scientifically sound methods are essential to estimate the survival of trees, as they can substantially support sustainable management of natural forest resources. Tree mortality assessments have mainly been based on forest inventories and are mostly limited to planted forests; few studies have conducted age-based survival analyses in natural forests. We performed survival analyses of individual tree populations in natural forest stands to evaluate differences in the survival of two coniferous species (Abies sachalinensis (F. Schmidt) Mast. and Picea jezoensis var. microsperma) and all broad-leaved species. We used tree rings and census data from four preserved permanent plots in pan-mixed and sub-boreal natural forests obtained over 30 years (1989–2019). All living trees (diameter at breast height ≥ 5 cm in 1989) were targeted to identify tree ages using a Resistograph. Periodical tree age data, for a 10-year age class, were obtained during three consecutive observation periods. Mortality and recruitment changes were recorded to analyze multi-temporal age distributions and mean lifetimes. Non-parametric survival analyses revealed a multi-modal age distribution and exponential shapes. There were no significant differences among survival probabilities of species in different periods, except for broad-leaved species, which had longer mean lifetimes in each period than coniferous species. The estimated practical mean lifetime and diameter at breast height values of each coniferous and broad-leaved tree can be applied as an early identification system for trees likely to die to facilitate the Stand-based Silvicultural Management System of the University of Tokyo Hokkaido Forest. However, the survival probabilities estimated in this study should be used carefully in long-term forest dynamic predictions because the analysis did not include the effects of catastrophic disturbances, which might significantly influence forests. The mortality patterns and survival probabilities reported in this study are valuable for understanding the stand dynamics of natural forests associated with the mortality of individual tree populations. [ABSTRACT FROM AUTHOR]

Land degradation, especially natural forest land degradation (NFLD), is a severe environmental concern in China. This natural disaster itself and its derivative control policies have caused some impacts on surrounding farmers' livelihood level and strategies, but the literature on the sustainable livelihood of different households in NFLD vulnerability is limited, and there is an urgent need to bridge the gap and conduct studies on the sustainable livelihood of Changting, Libo, Lixian, Menghai and Wuxi, the typical NFLD-prone areas in China. A new livelihood sustainability index (LSI) including livelihood asset, livelihood strategy and sustainability engagement is constructed to assess the basic situation. The results showed that: (1) The overall LSI of five NFLD areas was not high, and the social, financial and natural assets, in particular, were relatively low. A disparity was found among the five areas, and the rank sequence of the LSI value was sorted in a descending order: Changting > Menghai > Libo > Lixian > Wuxi. (2) In detail, farmers in Changting had the relative highest LSI because of the inherent high value of livelihood assets, which constrain the scores of the livelihood strategy and sustainability engagement. (3) Households in Libo, Menghai and Lixian had middle level LSI scores. The relative low livelihood assets in Libo and Menghai drove parts of local farmers to carry out off-farm/forestry employment, leading to high scores of livelihood strategy, while farmers in Lixian had lower livelihood diversification scores and higher sustainability engagement due to their working content for the local forestry bureau. (4) The low scores of the livelihood asset and sustainability engagement restricted farmers in Wuxi. A discussion of LSI in the NFLD vulnerability was conducted to determine the characteristics and analyze the reasons. Accordingly, targeted policy recommendations were proposed to realize a sustainable livelihood in NFLD areas. [ABSTRACT FROM AUTHOR]

Manor parks are characteristic objects in the agricultural landscape of Poland. Lack of proper management after World War II, however, led to their devastation from a cultural point of view, but may allow the regeneration of rare and endangered species. The aim of our study was to determine if the presence of forests in the vicinity of manor parks will work as an accelerator of the regeneration process of oak-hornbeam and ancient forest species. Phytosociological analyses were conducted in manor parks adjacent to forests and not adjacent to the forest as well as natural forests. The total number of plant species, number and percentage share of ancient forest species, and plant species consistent with oak-hornbeam habitat were analyzed using a GLM model. Characteristic species were identified using detrended correspondence analysis. Parks adjacent to forests and natural forests showed higher numbers of total species, ancient forest species, and oak-hornbeam species compared with parks not adjacent to forests, but there were no differences in percentage shares of ancient forest species and oak-hornbeam species. For all three types of studied objects, characteristic species could be identified. We conclude that adjacent forests allow greater regeneration of ancient forest species and oak-hornbeam forest species in manor parks. [ABSTRACT FROM AUTHOR]

Many remote sensing studies do not distinguish between natural and planted forests. We combine C-Band Synthetic Aperture Radar (Sentinel-1, S-1) and optical satellite imagery (Sentinel-2, S-2) and examine Random Forest (RF) classification of acacia plantations and natural forest in North-Central Vietnam. We demonstrate an ability to distinguish plantation from natural forest, with overall classification accuracies of 87% for S-1, and 92.5% and 92.3% for S-2 and for S-1 and S-2 combined respectively. We found that the ratio of the Short-Wave Infrared Band to the Red Band proved most effective in distinguishing acacia from natural forest. We used RF on S-2 imagery to classify acacia plantations into 6 age classes with an overall accuracy of 70%, with young plantation consistently separated from older. However, accuracy was lower at distinguishing between the older age classes. For both distinguishing plantation and natural forest, and determining plantation age, a combination of radar and optical imagery did nothing to improve classification accuracy. [ABSTRACT FROM AUTHOR]

Invasive forest pests can cause environmental and economic damage amounting to billions of dollars (US) in lost revenues, restoration and response costs, and the loss of ecosystem services nationwide. Unfortunately, these forest pests do not stay confined to wildland forest areas and can spread into suburban and urban areas, imposing significant costs on local governments, homeowners, and management agencies. In this study, a contingent valuation experiment is used to estimate Florida residents' willingness to pay (WTP) a monthly utility fee that would protect urban forests from invasive pests by implementing a monitoring and prevention program for their early detection and eradication. On average, the respondents are WTP US $5.44 per month to implement the surveillance program, revealing an aggregate WTP in the order of US $540 million per year. The results also reveal that respondents are sensitive to the scope of the program, with higher rates of participation and higher WTP for a program that is more effective at preventing forest pest invasions. [ABSTRACT FROM AUTHOR]

Highly detailed and accurate forest maps are important for various applications including forest monitoring, forestry policy, climate change, and biodiversity loss. This study demonstrates a comprehensive and geographically transferable approach to produce a 12 category high-resolution land use/land cover (LULC) map over mainland Vietnam in 2016 by remote sensing data. The map included several natural forest categories (evergreen broadleaf, deciduous (mostly deciduous broadleaf), and coniferous (mostly evergreen coniferous)) and one category representing all popular plantation forests in Vietnam such as acacia (Acacia mangium, Acacia auriculiformis, Acacia hybrid), eucalyptus (Eucalyptus globulus), rubber (Hevea brasiliensis), and others. The approach combined the advantages of various sensor data by integrating their posterior probabilities resulting from applying a probabilistic classifier (comprised of kernel density estimation and Bayesian inference) to each datum individually. By using different synthetic aperture radar (SAR) images (PALSAR-2/ScanSAR, PALSAR-2 mosaic, Sentinel-1), optical images (Sentinel-2, Landsat-8) and topography data (AW3D30), the resultant map achieved 85.6% for the overall accuracy. The major forest classes including evergreen broadleaf forests and plantation forests had a user's accuracy and producer's accuracy ranging from 86.0% to 95.3%. Our map identified 9.55 × 106 ha (±0.16 × 106 ha) of natural forests and 3.89 × 106 ha (±0.11 × 106 ha) of plantation forests over mainland Vietnam, which were close to the Vietnamese government's statistics (with differences of less than 8%). This study's result provides a reliable input/reference to support forestry policy and land sciences in Vietnam. [ABSTRACT FROM AUTHOR]

We studied the distributional patterns of phoretic deutonymphs of the genera Oodinychus and Trichouropoda (Uropodina) on the longhorn beetles Monochamus sartor urussovii, Plagionotus detritus, Tetropium castaneum, and Te. fuscum, based on large samples of specimens (992 beetles and 25,587 mites) collected in the Białowieża Primeval Forest in Central Europe in the years 2008 and 2012–2016. All the studied phoretic phoront-host associations are characterized by different patterns of the attachment sites of mites on beetle's body. In the case of O. ovalis and M. sartor urussovii association, the deutonymphs were found mostly on the pronotum and dorsal surface of the elytra. This is the only instance in which phoronts were absent on the legs. Deutonymphs of T. sociata on P. detritus preferred the abdomnen (both tergites and ventrites) and the hindlegs. Only in this case the phoronts were attached inside the subelytral space. The highest number of deutonymphs of T. shcherbakae on both Tetropium species occurred on the legs. In the case of Te. castaneum, similar proportions of mites were recorded on all pairs of legs, while the preferred location of mites phoretic on Te. fuscum were the forelegs. Both the preferences of phoretic deutonymphs for specific parts of the host's body and the participation of carriers transporting deutonymphs on particular parts of their bodies were very consistent. [ABSTRACT FROM AUTHOR]

This paper proposes a method to classify individual tree species groups based on individual tree segmentation and crown-level spectrum extraction ("crown-based ITC" for abbr.) in a natural mixed forest of Northeast China, and compares with the pixel-based classification and segment summarization results ("pixel-based ITC" for abbr.). Tree species is a basic factor in forest management, and it is traditionally identified by field survey. This paper aims to explore the potential of individual tree classification in a natural, needle-leaved and broadleaved mixed forest. First, individual trees were isolated, and the spectra of individual trees were then extracted. The support vector machine (SVM) and spectrum angle mapper (SAM) classifiers were applied to classify the trees species. The pixel-based classification results from hyperspectral data and LiDAR derived individual tree isolation were compared. The results showed that the crown-based ITC classified broadleaved trees better than pixel-based ITC, while the classes distribution of the crown-based ITC was closer to the survey data. This indicated that crown-based ITC performed better than pixel-based ITC. Crown-based ITC efficiently identified the classes of the dominant and sub-dominant species. Regardless of whether SVM or SAM was used, the identification consistency relative to the field observations for the class of the dominant species was greater than 90%. In contrast, the consistencies of the classes of the sub-dominant species were approximately 60%, and the overall consistency of both the SVM and SAM was greater than 70%. [ABSTRACT FROM AUTHOR]

Various studies have established possible threats posed due to pollution using ecological risk indices, but most have focused strictly on anthropogenic areas, so the data from these studies are less comparable with those obtained from natural forest sites, which was the focus of this current study. The main reason for this focus could be attributed to the commonly agreed reference provided by natural forest parks, which are assumed to be uncontaminated. The aim of this research was to determine if the Kampinoski National Park (Poland) could be considered a geochemical referencing ecosystem for Pb, Cd, and Ni levels. The specific purpose was to conduct a soil-background-based evaluation of metal contamination with a focus on geochemical indices as normative tools for assessing similar forest ecosystems at local and international levels. The toxicity response factors indicated some specific metal features that seemed highly magnified for Cd compared with Pb and Ni. The use of geochemical indices when assessing the contamination status of various ecosystems, either natural or strongly anthropogenic, is recommended to enable worldwide comparison, rather than only assessing metal contents. This approach considers the background metal concentrations for local on-site targets as well as pre-industrial reference levels for international referencing. [ABSTRACT FROM AUTHOR]

It has been recognized that land use change affects soil organic carbon (SOC) dynamics and the associated microbial turnover. However, the contribution of microbial residue to SOC storage remains largely unknown in land use change processes. To this end, we adopted a "space for time" approach to examine the dynamics of SOC and amino sugars, which was a biomarker of microbial residue C, in different natural forest conversions. Three typical converted forests were selected: an assisted natural regeneration (ANR) and two coniferous plantations of Cunninghamia lanceolata (Lamb.) Hook (Chinese fir) and Pinus massoniana Lamb. (pine) each. All of these were developed at the same time after the harvest of an old natural forest and they were used to evaluate the effects of forest conversions with contrasting anthropogenic disturbance on SOC and microbial residue C, along with the natural forest. Natural forest conversion led to an approximately 42% decrease in SOC for ANR with low anthropogenic disturbance, 60% for the Chinese fir plantation, and 64% for the pine plantation. In contrast, the natural forest conversion led to a 32% decrease in the total amino sugars (TAS) for ANR, 43% for the Chinese fir plantation, and 54% for the pine plantation at a soil depth of 0–10 cm. The ratios of TAS to SOC were significantly increased following natural forest conversion, with the highest ratio being observed in the Chinese fir plantation, whereas the ratios of glucosamine to muramic acid (GluN/MurA) were significantly decreased in the two plantations, but not in ANR. The contents of SOC, individual amino sugar, or TAS, and GluN/MurA ratios were consistently higher at a soil depth of 0–10 cm than at 10–20 cm for all of the experimental forests. Redundancy analysis showed that microbial residue C was significantly correlated with SOC, and both were positively correlated with fine root biomass, annual litterfall, and soil available phosphorus. Taken together, our findings demonstrated that microbial residue C accumulation varied with SOC and litter input, and played a more important role in SOC storage following forest conversion to plantations with higher anthropogenic disturbance. [ABSTRACT FROM AUTHOR]

The Loess Plateau is an important region for vegetation restoration in China; however, changes in soil organic carbon (SOC), soil nutrients, and stoichiometry after restoration in this vulnerable ecoregion are not well understood. Typical restoration types, including orchardland, grassland, shrubland, and forestland, were chosen to examine changes in the stocks and stoichiometry of SOC, soil total nitrogen (TN), and soil total phosphorus (TP) at different soil depths and recovery times. Results showed that SOC stocks first increased and then stabilized in orchardland, grassland, and shrubland at 0–30 cm depths, while in forestland, SOC stocks gradually increased. Soil TN stocks first increased and then decreased in orchardland, shrubland, and forestland with restoration age at 0–30 cm depths, while soil TP stocks showed little variation between restoration types; at the same time, the overall C:N, C:P, and N:P ratios increased with restoration age. In the later stages of restoration, the stocks of SOC and soil TN at 0–30 cm soil depths were still lower than those in natural grassland and natural forest. Additionally, the SOC, soil TN, and soil TP stocks and the C:N, C:P, and N:P ratios decreased with soil depth. The forestland had the highest rate of change in SOC and soil TN stocks, at 0–10 cm soil depth. These results indicate a complex response of SOC, soil TN, and soil TP stocks and stoichiometry to vegetation restoration, which could have important implications for understanding C, N, and P changes and nutrient limitations after vegetation restoration. [ABSTRACT FROM AUTHOR]