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Forest change affects local and global climate by altering the physical properties of the land surface. Accurately assessing urban forest changes in local land surface temperature (LST) is a scientific and crucial strategy for mitigating regional climate change. Despite this, few studies have attempted to accurately characterize the spatial and temporal pattern of afforestation, reforestation, and deforestation to optimize their effects on surface temperature. We used the China Land Cover Dataset and knowledge criterion-based spatial analysis model to map urban forestation (e.g., afforestation and reforestation) and deforestation. We then analyzed the impacts of these activities on LST from 2010 to 2020 based on the moving window strategy and the spatial–temporal pattern change analysis method in the urban agglomerations of the Yangtze River Delta (YRD) and Pearl River Delta (PRD), China. The results showed that forest areas declined in both regions. Most years, the annual deforestation area is greater than the yearly afforestation areas. Afforestation and reforestation had cooling effects of −0.24 ± 0.19 °C and −0.47 ± 0.15 °C in YRD and −0.46 ± 0.10 °C and −0.86 ± 0.11 °C in PRD. Deforestation and conversion of afforestation to non-forests led to cooling effects in YRD and warming effects of 1.08 ± 0.08 °C and 0.43 ± 0.19 °C in PRD. The cooling effect of forests is more evident in PRD than in YRD, and it is predominantly caused by reforestation. Moreover, forests demonstrated a significant seasonal cooling effect, except for December in YRD. Two deforestation activities exhibited seasonal warming impacts in PRD, mainly induced by deforestation, while there were inconsistent effects in YRD. Overall, this study provides practical data and decision-making support for rational urban forest management and climate benefit maximization, empowering policymakers and urban planners to make informed decisions for the benefit of their communities. [ABSTRACT FROM AUTHOR]

Longleaf pine (Pinus palustris Mill.) is a conifer historically associated with an open forest ecosystem that extended across much of the coastal plain of the Southeastern United States. It now exists mainly in isolated fragments following the conversion of forests and the long-term disruption of the low-intensity fire regime upon which the species depends. Recent decades have seen efforts to restore longleaf pine forests by government and private landowners. This was reflected in analyses of national forest inventory data during two time periods, ca. 2009–2015 and 2016–2021, that showed increases in the estimated number of longleaf pine trees, the area of the longleaf pine forest type, and the number and area of planted longleaf pine, along with growth in mean plot-level longleaf pine carbon and importance value. At the same time, we found a decrease in the overall forest area containing longleaf pine, manifested across a variety of other forest types. These results point to a dynamic through which forests dominated by longleaf pine are becoming more widespread via restoration, while forests in which the species is a less important component are transitioning to other forest types or land uses. We also detected a decrease over time in the estimated number of longleaf seedlings across most states and forest types and a decline in naturally regenerated longleaf pine. To further assess regeneration trends in longleaf pine, we calculated the estimated proportion of small trees (seedlings and saplings) for the entire species and for seed zone sub-populations. We found a species-wide decrease in the proportion of small trees, from 82.1 percent to 75.1 percent. This reduction was most pronounced along the edges of the species distribution and could indicate less sustainable levels of regeneration in some areas. These results underscore the challenges of facilitating natural regeneration in this important species. [ABSTRACT FROM AUTHOR]

The editorial "Dynamics of Asia's and Australasia's forests in a changing world" published in Frontiers in Forests & Global Change discusses the pressures faced by forests due to climate change, anthropogenic disturbances, and biological invasions. The research topic explores various aspects of forest science in Asia and Australasia, focusing on carbon sequestration, ecosystem management, biodiversity conservation, and policy implications. The articles highlight the importance of interdisciplinary approaches to address the challenges of climate change and ecological degradation, aiming to inform policy and promote sustainable forest management practices in the region. [Extracted from the article]

Drought‐induced groundwater decline and warming associated with climate change are primary threats to dryland riparian woodlands. We used the extreme 2012–2019 drought in southern California as a natural experiment to assess how differences in water‐use strategies and groundwater dependence may influence the drought susceptibility of dryland riparian tree species with overlapping distributions. We analyzed tree‐ring stable carbon and oxygen isotopes collected from two cottonwood species (Populus trichocarpa and P. fremontii) along the semi‐arid Santa Clara River. We also modeled tree source water δ18O composition to compare with observed source water δ18O within the floodplain to infer patterns of groundwater reliance. Our results suggest that both species functioned as facultative phreatophytes that used shallow soil moisture when available but ultimately relied on groundwater to maintain physiological function during drought. We also observed apparent species differences in water‐use strategies and groundwater dependence related to their regional distributions. P. fremontii was constrained to more arid river segments and ostensibly used a greater proportion of groundwater to satisfy higher evaporative demand. P. fremontii maintained ∆13C at pre‐drought levels up until the peak of the drought, when trees experienced a precipitous decline in ∆13C. This response pattern suggests that trees prioritized maintaining photosynthetic processes over hydraulic safety, until a critical point. In contrast, P. trichocarpa showed a more gradual and sustained reduction in ∆13C, indicating that drought conditions induced stomatal closure and higher water use efficiency. This strategy may confer drought avoidance for P. trichocarpa while increasing its susceptibility to anticipated climate warming. Key Points: Dryland riparian cottonwoods used shallow soil moisture when available but ultimately relied on groundwater for survival during droughtSpecies had different water‐use strategies related to their distribution along a gradient of increasing aridity with distance from coastPopulus trichocarpa appears more susceptible to warming, and P. fremontii more vulnerable to groundwater decline due to high water demand [ABSTRACT FROM AUTHOR]

Monitoring the dynamics of land use and land cover (LULC) is imperative in the changing climate and evolving urbanization patterns worldwide. The shifts in land use have a significant impact on the hydrological response of watersheds across the globe. Several studies have applied machine learning (ML) algorithms using historical LULC maps along with elevation data and slope for predicting future LULC projections. However, the influence of other driving factors such as socio-economic and climatological factors has not been thoroughly explored. In the present study, a sensitivity analysis approach was adopted to understand the effect of both physical (elevation, slope, aspect, etc.) and socio-economic factors such as population density, distance to built-up, and distance to road and rail, as well as climatic factors (mean precipitation) on the accuracy of LULC prediction in the Brahmani and Baitarni (BB) basin of Eastern India. Additionally, in the absence of the recent LULC maps of the basin, three ML algorithms, i.e., random forest (RF), classified and regression trees (CART), and support vector machine (SVM) were utilized for LULC classification for the years 2007, 2014, and 2021 on Google earth engine (GEE) cloud computing platform. Among the three algorithms, RF performed best for classifying built-up areas along with all the other classes as compared to CART and SVM. The prediction results revealed that the proximity to built-up and population growth dominates in modeling LULC over physical factors such as elevation and slope. The analysis of historical data revealed an increase of 351% in built-up areas over the past years (2007–2021), with a corresponding decline in forest and water areas by 12% and 36% respectively. While the future predictions highlighted an increase in built-up class ranging from 11 to 38% during the years 2028–2070, the forested areas are anticipated to decline by 4 to 16%. The overall findings of the present study suggested that the BB basin, despite being primarily agricultural with a significant forest cover, is undergoing rapid expansion of built-up areas through the encroachment of agricultural and forested lands, which could have far-reaching implications for the region's ecosystem services and sustainability. [ABSTRACT FROM AUTHOR]

Forest discourses help identify forest-related issues. They aim to aid policy and decision-makers in understanding forest-related challenges and opportunities better so that they may initiate possible strategies and tactics to tackle them. Ideally, information requirements for the forest discourses would be translated into measurable variables, being the basis for collecting, analysing, and reporting data and information. Our study examined the connection between major international forest reporting processes and forest discourses. We analysed summaries and key findings for policy makers of five recent major forest reports. We compared their focus with forest discourses on climate change, forest conservation, deforestation, forest decline, illegal logging, industrial forestry/bioeconomy, traditional knowledge, woody biomass production, and innovative wood-based biofuels. The paper explores how the forest discourses are reflected in the surveyed documents and closely examines the specific focus areas in the summaries for policy makers. The results show that most forest discourses are generally well-represented, albeit with different foci. The discourse on illegal logging could not be identified in any investigated documents, even though it remains a significant concern for international forest policy. Keywords related to traditional knowledge and woody biomass production could not be found in two of the analysed findings. All analysed summaries and key findings mention issues related to the climate change discourse topic. However, they lack information on emissions from deforestation, carbon dioxide emissions and carbon budgets, which are high in political discussions. The paper highlights how discourse issues have gained in complexity both topic-wise and regarding the reporting obligations, as policy and decisionmakers require more timely and comprehensive information about the status' and trends of forests. [ABSTRACT FROM AUTHOR]

Rapid urbanization in Algeria is causing significant problems, such as the emergence of unplanned neighborhoods, and local authorities need to apply modern tools like geomatics to monitor and update spatial planning databases to support sustainable development. More to the point, these tools—geographic information systems (GIS) and remote sensing (RS) are of assistance to update the spatial planning and development database so as to support the decision-making. In fact, for understanding the purpose of the process of urban growth in the region of the interior high plateaus, we chose the city of Setif as it represents an urban and economic pole in the region. Besides, economic activities exacerbate the phenomenon of rapid and unplanned urban growth alongside the environmental impact thereof. In the light of the obtained results, there exists a significant increase in urban lands and a significant decline in forests and agricultural lands, as the urban area has tripled from 10.4% in 1985 to 20.3 in 2003 and to 29.7% in 2021. At the same time, the agricultural area has then shrunk from 76.4% in 1985 to 65.8 in 2003 and to 55.5% in 2021, while the forest areas have decreased from 5.04% in 1985 to 4.4 in 2003 and to 2.3% in 2021. [ABSTRACT FROM AUTHOR]

As one of the most serious health issues facing trees, the occurrence of decay and hollowing not only reduces the stability and quality of living trees but also leads to the deterioration of their eco-physiological functions, which creates great challenges to the conservation and sustainable management of forest resources. In recent years, the study of tree decay and hollow rot have attracted more and more attention from scholars at home and abroad. The relevant research results have a great significance for the prevention and control of affected living trees and the conservation and sustainable management of endangered species. However, there is a lack of systematic literature review and an insufficient understanding of research hotspots and trends in this field. This paper selects literature retrieved from the CNKI and Web of Science core databases as data sources, the number of publications, research topics, research status, hot spots, and trends, as well as the main research countries, institutions, and co-cited authors in the field of tree decay are visualized by using bibliometrics software CiteSpace (V.5.8.R3), and the current international research hotspots and development trends in this field were systematically summarized. The results showed that the number of papers in this field at home and abroad showed rapid growth in general, and the number of Chinese papers showed a slow growth after 2009. The number of papers published in English by Chinese authors was more than the number of papers published in Chinese in the field. From 2002 to 2021, the research hotspots in this field are constantly changing. Cluster analysis shows that the main themes of the relevant research are as follows: "Eastern Canada" tree species, "hydraulic vulnerability segmentation", "dead wood management", and "hydraulic safety". The advantages and disadvantages of hollow/dead wood on forest ecosystems were explored from different perspectives, providing a theoretical basis and scientific support for the forest health and sustainable management. The United States dominates the research in this field, while China is a relatively late comer but is catching up fast, and the Chinese Academy of Sciences is the most prolific publisher on this topic in China. The influence of Chinese research in this field on relevant international publications is gradually increasing. In short, the research in this field is still in the phase of rapid development, and both the breadth and depth of quantitative research are increasing. How to accurately diagnose and quantify the internal decay of tree trunks and its relationship with tree death and forest decline under the interference and pressure of climate change and human activities is still a hot and difficult issue in this field. [ABSTRACT FROM AUTHOR]

The management of regional eco-environmental risks is the key to promoting regional economic sustainability from the macro level, and accurate evaluation of the evolutionary trends of regional ecological risk in the future is of high importance. In order to clearly identify the possible impact of future development scenario selection for the Chengdu-Chongqing Economic Zone (C-C E Zone) on the evolution of landscape ecological risk (LER), we introduced the Patch-generating Land Use Simulation (PLUS) model to simulate land use data for the C-C E Zone from 2030 to 2050 for two scenarios: natural development (ND) and ecological protection (EP). Based on the ecological grid and landscape ecological risk index (LERI) model, the landscape ecological risk (LER) evolutionary trends seen in the C-C E Zone from 2000 to 2050 were analyzed and identified. The results showed that: (1) The PLUS model can obtain high-precision simulation results in the C-C E Zone. In the future, the currently increasing rate of land being used for construction will be reduced, the declining rates of forest and cultivated land area will also be reduced, and the amount of land being used for various purposes will remain stable going into the future. (2) This study found that the optimal size of the ecological grid in the LERI calculation of the mountainous area was 4 × 4 km. Additionally, the mean values of the LERI in 2030, 2040, and 2050 were 0.1612, 0.1628, and 0.1636 for ND and 0.1612, 0.1618, and 0.1620 for EP. (3) The hot spot analysis results showed that an area of about 49,700 km2 in the C-C E Zone from 2000 to 2050 belongs to high agglomeration of LER. (4) Since 2010, the proportions of high and extremely high risk levels have continued to increase, but under the EP scenario, the high and extremely high risk levels in 2040 and 2050 decreased from 14.36% and 6.66% to 14.33% and 6.43%. Regional analysis showed that the high and extremely high risk levels in most regions increased over 2010–2050. (5) Under the ND scenario, the proportions of grids with decreased, unchanged, and increased risk levels were 15.13%, 81.48%, and 3.39% for 2000–2010 and 0.54%, 94.75%, and 4.71% for 2040–2050. These trends indicated that the proportion of grids with changed risk levels gradually decreased going into the future. This study analyzed the evolutionary trends of LER at the C-C E Zone for the ND and EP scenario. On the whole, the LER for the C-C E Zone showed an upward trend, and the EP scenario was conducive to reducing the risk. These research results can serve as a valuable data reference set for regional landscape optimization and risk prevention and control. [ABSTRACT FROM AUTHOR]

Although forest areas have been growing in Europe, some forest types have been declining regionally. Since the 1980 s, there have been reports of defoliation and mortality in evergreen oak woodlands of the Iberian Peninsula. However, long-term and large-scale trends of Iberian oak decline are still poorly understood. We quantified trends in canopy cover for cork oak (Quercus suber) and holm oak (Q. rotundifolia) woodlands in mainland Portugal for a 50 year period (1965 to 2015). We considered loss of canopy cover a proxy of forest degradation and asked how it changed over time, in association with human activity and climate. Between 1965 and 2015, both cork oak and holm oak canopy cover showed declining trends (57.9% and 71.1% of sampling points, respectively). Canopy cover dynamics, however, differed across time. Between 1965 and 1990, canopy cover gains (over 35% of sampling points) prevailed over losses (under 20%), with larger differences for cork oak than holm oak. Between 1990 and 2015, canopy cover losses (over 70% of sampling points) were much higher than gains (under 9%). Oak canopy cover decrease was associated with flatter areas (usually having more intensive land use) for both oak species, higher cattle numbers (holm oak only) and higher mean temperature (cork oak only). Contrastingly, loss of holm oak canopy cover seems to have occurred in less hot and dry regions that enable more intensive land uses. Active restoration is urgently needed to reverse the current decline in canopy cover in Mediterranean evergreen oak woodlands. [ABSTRACT FROM AUTHOR]

Forests are a major natural resource of the state of California, where over a third of the land is forested, and provide a wide range of environmental, economic, and social benefits. Over the past decade, unprecedented drought, insect outbreaks and wildfires have resulted in large-scale tree mortality that greatly affects the forest ecosystem and poses significant threat to human health and welfare and to the environment. Forest thinning and management is considered imperative to improve forest health and resilience. Forest resources including dead and dying trees as well as the residues produced from forest thinning and timber harvesting operations could potentially be used to a greater degree than at present to generate electricity and other renewable energy to meet the increasing demand for more sustainable supplies and mitigate the risk of wildfires. However, efforts to construct new electricity generation capacity in the state at any scale over the last several decades have faced both economic and environmental challenges. As needs for alternative management approaches have become clear, opportunities have emerged for new bioenergy projects. These projects need to be effectively planned and potential economic and environmental performance carefully evaluated. Toward this purpose, an integrated framework model for lifecycle and technoeconomic assessment was developed to quantify environmental and economic impacts, initially for generating electricity using forest resources and with associated web services developed for an online application (forestdss.ucdavis.edu) that allows potential users to quickly estimate the economic and environmental performance of a potential facility at specified locations. • Tree mortality, past fire suppression practices, and high fuel loadings threaten forests and human health and welfare. • Forest resources including dead and dying trees as well as residues can be used for greater renewable energy production. • Bioenergy projects need to be effectively planned and potential economic and environmental performance carefully evaluated. • An integrated spatial framework model was developed to aid in decision making related to new project investments. [ABSTRACT FROM AUTHOR]

Temperate forests play a fundamental role in the provision, regulation, and support of hydrological environmental services, but they are subject to constant changes in land use (clearing, overgrazing, deforestation, and forest fires) that upset the hydrological balance. Through scenarios simulated with the Water Evaluation and Planning (WEAP) hydrological model, the present study analyzes the effects of forest fires and land use changes on the hydrological balance in the microwatersheds of central Mexico. The land use changes that took place between 1995 and 2021 were estimated, and projections based on the current scenario were made. Two trend scenarios were proposed for 2047: one with a positive trend (forest permanence) and the other with a negative trend (loss of cover from forest fires). The results show that with permanence or an increase in forest area, the surface runoff would decrease by 48.2%, increasing the base flow by 37% and the soil moisture by 2.3%. If forest is lost, surface runoff would increase up to 454%, and soil moisture would decrease by 27%. If the current forest decline trends continue, then there will be negative alterations in hydrological processes: a reduction in the interception of precipitation by the canopy and an increase in the velocity and flow of surface runoff, among others. The final result will be a lower amount of water being infiltrated into the soil and stored in the subsoil. The provision of hydrological environmental services depends on the maintenance of forest cover. [ABSTRACT FROM AUTHOR]