Forest Definitions Research Articles

Analysis of Wildfire Susceptibility by Weight of Evidence, Using Geomorphological and Environmental Factors in the Marche Region, Central Italy

Fires are a growing problem even in temperate climate areas, such as those in Central Italy, due to climate change leading to longer and longer periods of drought. Thus, knowing the fire susceptibility of an area is crucial for good planning and taking appropriate countermeasures. In this context, it was decided to use only causal factors of a geomorphological and environmental nature in order to obtain a fire susceptibility analysis that can also be applied to climatically under-sampled areas. Vector data of fires in Central Italy from 2005 to 2023 were collected, and the correct areal extent was calculated for each. At the same time, six factors were selected that could have an influence on fire development, such as ecological units, topographic wetness index (TWI), geology, slope, exposure, and altitude. The model was obtained by means of the weight of evidence statistical method, which takes into account past data by reinterpreting them in a future-oriented way on the basis of the identified factors and classes. The model was validated with a test sample and shows an area under the curve (AUC) value of 0.72 with a reliability that can be described as good considering the total absence of climatic factors that are known to play a major role in fire development. Furthermore, the identified causal factors were divided into classes, and these were carefully weighted in order to define their relative influence in the study area. Particularly Ecological Units with characteristic and well-defined contrast (C) values, which could lead to a more complete definition of forests that tend to increase fire susceptibility and those that tend to decrease it, allowing the latter to be exploited as a hazard mitigation agent.

A large non-parasitic population of Savalia savaglia (Bertoloni, 1819) in the Boka Kotorska Bay (Montenegro)

The golden coral Savalia savaglia is a long-living ecosystem engineer of Mediterranean circalittoral assemblages, able to induce necrosis of gorgonians’ and black corals’ coenenchyme and grow on their cleaned organic skeleton. Despite its rarity, in Boka Kotorska Bay (Montenegro) a shallow population of more than 1000 colonies was recorded close to underwater freshwater springs, which create very peculiar environmental conditions. In this context, the species was extremely abundant at two sites, while gorgonians were rare. The abundance and size of S. savaglia colonies and the diversity of the entire benthic assemblage were investigated by photographic sampling in a depth range of 0–35 m. Several living fragments of S. savaglia spread on the sea floor and small settled colonies (< 5 cm high) suggested a high incidence of asexual reproduction and a non-parasitic behaviour of this population. This was confirmed by studying thin sections of the basal portion of the trunk where the central core, generally represented by the remains of the gorgonian host skeleton, was lacking. The S. savaglia population of Boka Kotorska Bay forms the unique Mediterranean assemblage of the species deserving the definition of animal forest. Recently, temporary mitigation measures for anthropogenic impact were issued by the Government of Montenegro. Nevertheless, due to the importance of the sites the establishment of a permanent Marine Protected Area is strongly recommended.

Navigating EU-Sweden forestry disputes

This meta-empirical study delves into the conflicts between Sweden and its forestry industry in response to the EU-commission's demands for sustainable forest management. Combining theoretical foundations with empirical analysis of existing research, this study grounds itself in a clear definition of forests as intricate, adaptive, and ever-evolving systems. The central research question revolves around the efficacy of Sweden's guiding principle, "freedom under responsibility," in shaping forest policy and fostering long-term sustainability.To dissect the core of this conflict, two fundamental hypotheses are explored. The first centers on the clash of interests between the Swedish government and forest industry stakeholders, while the second delves into the tension between monetarily valued ecosystem services and those without a market value, a natural market being absent. These questions are scrutinized using a novel method tailored for conflict analysis. A model article and two specific analysis articles are developed, each focusing on distinct facets of forest management, and are subsequently compared to reveal insightful contrasts.This contrasting approach unveils a comprehensive socio-economic framework underlying these conflicts—a framework that often remains concealed due to deeply ingrained patterns of thought and behavior within homogeneous groups. The method's greatest strength lies in its ability to render the invisible visible and the "silent" audible. It clarifies what might be obscured in the model article, bringing the contours of the conflict into sharp relief.The study findings affirm the value and democratic nature of the "freedom under responsibility" principle. However, for it to yield the intended outcomes, substantial and continuous educational efforts directed at relevant forest management stakeholders are imperative. This meta-empirical study highlights the necessity of a robust educational campaign to ensure the principle's success.Moreover, this study contributes theoretical insights that could serve as a foundation for conflict resolution:•Forests are complex, adaptive, and dynamic systems.•Human intervention prompts responses and adaptations within this system.•The choice of management strategies plays a pivotal role in achieving specific outcomes, whether biomass production or the preservation of natural forest characteristics.•The production of forest ecosystem services necessitates active management and does not occur automatically.

Annual maps of forest cover in the Brazilian Amazon from analyses of PALSAR and MODIS images

Abstract. Many forest cover maps have been generated by using optical and/or microwave images, but these forest cover maps have large area and spatial discrepancies. To date, few studies have assessed forest cover maps in terms of two biophysical parameters used in forest definition: canopy height and canopy coverage. We generated annual forest cover maps from 2007 to 2010 and evergreen forest cover maps from 2000 to 2021 in the Brazilian Amazon using the images from the Phased Array type L-band Synthetic Aperture Radar and the time series images from the Moderate Resolution Imaging Spectroradiometer, using the forest definition of the Food and Agriculture Organization of the United Nations (&gt;5 m tree height and &gt;10 % canopy coverage) as the reference. We used the canopy height and canopy coverage datasets from the Geoscience Laser Altimeter System during 2003–2007 to assess annual forest cover maps from 2007 to 2010 and annual evergreen forest cover maps from 2003 to 2007, and the results show high accuracy of these forest cover and evergreen forest cover maps. These annual forest cover maps and annual evergreen forest cover maps provide data support for the analyses of the causes, processes, and consequences of forest cover changes in the Brazilian Amazon (https://doi.org/10.6084/m9.figshare.21445626; Qin and Xiao, 2022a; https://doi.org/10.6084/m9.figshare.21445590; Qin and Xiao, 2022b).

Estimating forest extent across Mexico

Information on forest extent and tree cover is required to evaluate the status of natural resources, conservation practices, and environmental policies. The challenge is that different forest definitions, remote sensing-based (RSB) products, and data availability can lead to discrepancies in reporting total forest area. Consequently, errors in forest extent can be propagated into forest biomass and carbon estimates. Here, we present a simple approach to compare forest extent estimates from seven regional and global land or tree cover RSB products at 30 m resolution across Mexico. We found substantial differences in forest extent estimates for Mexico, ranging from 387 607 km2 to 675 239 km2. These differences were dependent on the RSB product and forest definition used. Next, we compared these RSB products with two independent forest inventory datasets at national (n = 26 220 plots) and local scales (n = 754 plots). The greatest accuracy among RSB products and forest inventory data was within the tropical moist forest (range 82%–95%), and the smallest was within the subtropical desert (range <10%–80%) and subtropical steppe ecological zones (range <10%–60%). We developed a forest extent agreement map by combining seven RSB products and identifying a consensus in their estimates. We found a forest area of 288 749 km2 with high forest extent agreement, and 340 661 km2 with medium forest extent agreement. The high-to-medium forest extent agreement of 629 410 km2 is comparable to the official national estimate of 656 920 km2. We found a high forest extent agreement across the Yucatan Peninsula and mountain areas in the Sierra Madre Oriental and Sierra Madre Occidental. The tropical dry forest and subtropical mountain system represent the two ecological zones with the highest areas of disagreement among RSB products. These findings show discrepancies in forest extent estimates across ecological zones in Mexico, where additional ground data and research are needed. Dataset available at https://doi.org/10.3334/ORNLDAAC/2320.

ПРАВОВЫЕ И СОЦИАЛЬНЫЕ АСПЕКТЫ ИСПОЛЬЗОВАНИЯ ГОРОДСКИХ ЛЕСОВ МОСКВЫ

The subject of the article is both legal and social aspects of the use of urban forests in Moscow among which are the destruction of urban forests, the uncertainty of the definition and status of urban forests. The article considers the question of how the urban forests of the capital of the country are used and how this correlates with legal norms and social needs of citizens.&#x0D; The concentration of population in cities is becoming a global trend. The level of urbanization is reaching higher and higher indicators every day. Living in urban agglomerations isolated from nature leads to many health problems of citizens. The task of increasing the comfort of the urban environment could be solved by arrays of urban forests. It is known that forest vegetation has a huge positive impact on human health and emotional state. However, their use does not always correspond to legal norms and the interests of citizens.&#x0D; The article aims to investigate the relationship between the state of urban forests and the level of comfort of the urban environment, to identify specific factors that negatively affect the state of green spaces as well as to analyze social opinion about the problem. The article reveals the ecological significance of urban forests: they are a place for recreation, recreation, sports, and walks, in addition, they perform an important ecological function, maintaining balance in the natural environment and improving air quality, and describes the features of the dangerous state in which they are located.&#x0D; To study the legal and social aspects of the use of urban forests, the following methods were used: analysis of legislative acts regulating the use of urban forests and the study of the practice of their application, the study of expert opinions in the field of ecology law and sociology monitoring the use of urban forests in Moscow (identification of social aspects of forest use) a survey of residents of Moscow to find out their opinion about the use of urban forests and to assess the social significance of forests for city residents, analysis of statistical data on the importance of urban forests for city residents. &#x0D; As a result of the research legal and managerial problems were identified and practical solutions were proposed. Futhermore, it is important not to forget about the cooperation of city authorities, environmental organizations and the public in order to create an effective urban forest management system that would take into account the interests of all stakeholders and allow preserving this important resource for urban ecology and the health of residents. The results of the study can be used to develop recommendations for improving the use of urban forests, additionally for making decisions in the field of management and protection of the urban environment.&#x0D; The forest as an ecosystem located within a megalopolis is under threat of destruction. It is important that the use of urban forests is regulated by legislation and carried out within the framework of established rules and regulations. The use of Moscow's urban forests should be carried out taking into account their legal status and social significance, which will help ensure the preservation of these valuable environmental resources. The problem requires an integrated approach, including management measures, public involvement, scientific research and information campaigns. The sum of these decisions and the changes associated with them will help ensure the preservation of valuable environmental resources for future generations.

Scale dependence of forest fragmentation and its climate sensitivity in a semi-arid mountain: Comparing Landsat, Sentinel and Google Earth data

Landscape fragmentation is generally viewed as an indicator of environmental stresses or risks, but the fragmentation intensity assessment also depends on the scale of data and the definition of spatial unit. This study aimed to explore the scale-dependence of forest fragmentation intensity along a moisture gradient in Yinshan Mountain of North China, and to estimate environmental sensitivity of forest fragmentation in this semi-arid landscape. We developed an automatic classification algorithm using simple linear iterative clustering (SLIC) and Gaussian mixture model (GMM), and extracted tree canopy patches from Google Earth images (GEI), with an accuracy of 89.2% in the study area. Then we convert the tree canopy patches to forest category according to definition of forest that tree density greater than 10%, and compared it with forest categories from global land use datasets, FROM-GLC10 and GlobeLand30, with spatial resolutions of 10 m and 30 m, respectively. We found that the FROM-GLC10 and GlobeLand30 datasets underestimated the forest area in Yinshan Mountain by 16.88% and 21.06%, respectively; and the ratio of open forest (OF, 10% < tree coverage < 40%) to closed forest (CF, tree coverage > 40%) areas in the underestimated part was 2:1. The underestimations concentrated in warmer and drier areas occupied mostly by large coverage of OFs with severely fragmented canopies. Fragmentation intensity of canopies positively correlated with spring temperature while negatively correlated with summer precipitation and terrain slope. When summer precipitation was less than 300 mm or spring temperature higher than 4 °C, canopy fragmentation intensity rose drastically, while the forest area percentage kept stable. Our study suggested that the spatial configuration, e.g., sparseness, is more sensitive to drought stress than area percentage. This highlights the importance of data resolution and proper fragmentation measurements for forest patterns and environmental interpretation, which is the base of reliable ecosystem predictions with regard to the future climate scenarios.

Quantifying old-growth forest of United States Forest Service public lands

Old-growth forests are globally valued for their ecological attributes, cultural significance, and in many cases their rarity. Yet, defining and quantifying these forests has been a difficult task. This study developed an approach to consistently estimate extent of old-growth forest on United States Department of Agriculture (USDA) Forest Service National Forest System (NFS) lands, using NFS regional old-growth definitions applied to the US national forest inventory (conducted by the USDA Forest Service Forest Inventory and Analysis [FIA] program). This method was developed in response to a presidential order (EO#14072, April 22, 2022) and federal laws (e.g., Infrastructure Investment and Jobs Act, 2021; Inflation Reduction Act, 2022). We worked with NFS experts to obtain regionally approved criteria for establishing old growth status based on NFS definitions, assessments, and related documents. NFS regional old growth definitions focus on structural characteristics of forests with criteria for old growth status commonly including minimum abundance of large live trees (in eight of nine regions), tree or stand age (in eight of nine regions), and dead large tree density (in three of nine regions). Determining the regional criteria to use was straightforward for some NFS regions where old-growth forest definitions were specific, and in some cases, had already been applied to FIA data to quantify old-growth forest area. In other NFS regions, such as where definitions have never been applied in an operational manner, or where there were merely assessments of remnant old-growth forest conditions, determining exact criteria was more difficult. We estimate that there are approximately 10 million ha of old growth across NFS forests, as defined by NFS criteria, with the preponderance in the western US states. This study produces the first old-growth forest assessment at the national scale based on NFS definitions and FIA’s statistically-rigorous national forest inventory of the US. These methods can be repeated with future inventories or modified when definitions change to produce updated estimates of old-growth forest attributes, and such work is already underway.

Current state of mixed forests available for wood supply in Finland and Sweden

ABSTRACT This study’s objectives were to suggest harmonised criteria for the definition of mixed forests for two Nordic countries, describe their principal mixture types, and provide an overview of their current extent. We used national forest inventory data compiled in Finland and Sweden, considering the forest available for wood supply (FAWS), excluding seedling and sapling plots before canopy closure. The definition of the mixed forest was based on the threshold criteria, which indicate the basal area proportion of the dominant tree species of the total in a stand. The proportion of mixed forests increased with higher threshold criteria: 21% to 42% in Finland and 24% to 49% in Sweden, as the threshold criterion was changed from 65% to 85%. With a threshold criterion of 75%, the area of mixed FAWS was 5.6 million ha (31% of FAWS) in Finland and 6.5 million ha (36%) in Sweden. The dominant mixture type was the pine-spruce-birches mixture (31%) in Finland and the pine-spruce mixture (29%) in Sweden. The proportion of peatland forest of mixed forests was similar in the countries: 9–10%. The mixed forests proportion increased from north boreal to hemiboreal, increasing with more mature development classes.

A Comparison of Six Forest Mapping Products in Southeast Asia, Aided by Field Validation Data

Currently, many globally accessible forest mapping products can be utilized to monitor and assess the status of and changes in forests. However, substantial disparities exist among these products due to variations in forest definitions, classification methods, and remote sensing data sources. This becomes particularly conspicuous in regions characterized by significant deforestation, like Southeast Asia, where forest mapping uncertainty is more pronounced, presenting users with challenges in selecting appropriate datasets across diverse regions. Moreover, this situation impedes the further enhancement of accuracy for forest mapping products. The aim of this research is to assess the consistency and accuracy of six recently produced forest mapping products in Southeast Asia. These products include three 10 m land cover products (Finer Resolution Observation and Monitoring Global LC (FROM-GLC10), ESA WorldCover 10 m 2020 (ESA2020), and ESRI 2020 Land Cover (ESRI2020)) and three forest thematic mapping products (Global PALSAR-2 Forest/Non-Forest map (JAXA FNF2020), global 30 m spatial distribution of forest cover in 2020 (GFC30_2020), and Generated_Hansen2020, which was synthesized based on Hansen TreeCover2010 (Hansen2010) and Hansen Global Forest Change (Hansen GFC) for the year 2020). Firstly, the research compared the area and spatial consistency. Next, accuracy was assessed using field validation points and manual densification points. Finally, the research analyzed the geographical environmental and biophysical factors influencing consistency. The results show that ESRI2020 had the highest overall accuracy for forest, followed by ESA2020, FROM-GLC10, and Generated_Hansen2020. Regions with elevations ranging from 200 to 3000 m and slopes below 15° or above 25° showed high spatial consistency, whereas other regions showed low consistency. Inconsistent regions showed complex landscapes heavily influenced by human activities; these regions are prone to being confused with shrubs and cropland and are also impacted by rubber and oil palm plantations, significantly affecting the accuracy of forest mapping. Based on the research findings, ESRI2020 is recommended for mountainous areas and abundant forest regions. However, in areas significantly affected by human activities, such as forest and non-forest edges and mixed areas of plantations and natural forests, caution should be taken with product selection. The research has identified areas of forest inconsistency that require attention in future forest mapping. To enhance our understanding of forest mapping and generate high-precision forest cover maps, it is recommended to incorporate multi-source data, subdivide forest types, and increase the number of sample points.

Development and preliminary application of a Nature Value index to identify High Nature Value forests in the Republic of Ireland

High Nature Value (HNV) forests contribute to maintaining European biodiversity and public good supply. This study aimed to a) develop an objective and quantitative Nature Value (NV) index for the identification of HNV forests in the Republic of Ireland; and b) apply and validate the index using available data from the Irish National Forest Inventory (NFI).Following recent European definitions of HNV forest, a six-step framework was adapted from literature and used for assessing forest naturalness. The reference forest (in an Irish context) and its naturalness traits were first described. Six indicators were selected to construct a NV index and three categories (low, medium and high NV) were defined based on the range of NV scores. Using data from the Irish NFI, the approach was implemented by calculating the indicators’ values and the NV score for 1,676 forest plots. The selected indicators were tested for redundancy and the NV index was validated with available floristic variables and with forest sub-type classes. A sensitivity analysis was conducted on the weighting values of the indicators.Approximately 11% of the NFI plots were categorised as HNV. There was no redundancy between the selected indicators. The NV index was significantly positively correlated with data from the floristic variables collated by the NFI. The averages of the floristic variables per NV category were significantly different. NFI plots classified as HNV had a higher percentage of natural/semi-natural forest types than medium NV and low NV plots. The sensitivity analyses showed little effect of changes to the indicators' weighting values on a) the correlation coefficients between the floristic variables’ data and the new NV scores obtained and b) on the proportion of natural/semi-natural forests in HNV plots.This work provides an approach for the development of a NV index to identify HNV forests in a European country following the naturalness concept exclusively. The selected indicators and their weighting should be tailored to each country’s particular conditions, especially due to potential differences in the reference level of naturalness of forests and differences within NFIs.

More than one quarter of Africa’s tree cover is found outside areas previously classified as forest

The consistent monitoring of trees both inside and outside of forests is key to sustainable land management. Current monitoring systems either ignore trees outside forests or are too expensive to be applied consistently across countries on a repeated basis. Here we use the PlanetScope nanosatellite constellation, which delivers global very high-resolution daily imagery, to map both forest and non-forest tree cover for continental Africa using images from a single year. Our prototype map of 2019 (RMSE = 9.57%, bias = −6.9%). demonstrates that a precise assessment of all tree-based ecosystems is possible at continental scale, and reveals that 29% of tree cover is found outside areas previously classified as tree cover in state-of-the-art maps, such as in croplands and grassland. Such accurate mapping of tree cover down to the level of individual trees and consistent among countries has the potential to redefine land use impacts in non-forest landscapes, move beyond the need for forest definitions, and build the basis for natural climate solutions and tree-related studies.

Natural Forests or Cultural Forests? Forest Changes within Italian Protected Areas in the Last 85 Years

The cultural dimension of many forests is not adequately considered by current forest definitions, policies, inventories, and management. Moreover, the concept of “protected area” as a synonym of “natural area” ignores that many forests today included in protected areas (PAs) have been managed and exploited for centuries. The abandonment of rural areas that occurred in the last 60 years in EU countries caused the expansion of forests, with the risk of a homogenization of forest typologies, the loss of cultural features, and the loss of biodiversity at the landscape scale. The aim of this study is to investigate the origin and evolution of forests within Italian PAs in the last 85 years through GIS-based spatial analyses. In 1936, only a minority of the surface included in current PAs was covered by forests, ranging from 32% in Natura 2000 sites to 35% in regional PAs. Forest surface in Italian PAs increased in the last 85 years (from +33.1% in regional PAs to +45.2% in national PAs), mainly due to secondary successions, with a growth rate in Natura 2000 sites equal to 8709 ha/year. In regional PAs, 40.1% of the current forest cover originated after 1936, and this percentage increases to 43% in Natura 2000 sites and to 44.7% in national PAs. The altitudinal range of 500–1000 m a.s.l. is the one most affected by forest spread. In addition, most of the forests in 1936 were regularly managed as coppice: 44% in national PAs, 56% in Natura 2000 sites, and 62% in regional PAs. The study confirms that most of the forest surface included in Italian PAs has a clear cultural origin and is the consequence of the abandonment of pastures and/or cultivations that occurred in the last 85 years. PA management should take into consideration that open areas are shrinking and that the diversity of habitats and forest communities is strongly linked to the persistence of traditional human activities. The current forest characteristics (species composition, vertical and horizontal structure) are also the result of past management, and only active management of forest resources can counteract the homogenization of forest communities and landscape structure.

¿Qué es un bosque nativo en la Argentina? Marco conceptual para una correcta definición de acuerdo con las políticas institucionales nacionales y el conocimiento científico disponible

Native forests are the natural ecosystems with the greatest social concern in terms of conservation and management. The scope of the definition of native forest has changed over time, which has influenced the adoption of different forest management instruments carried out by different institutions (e.g., the forest cover obtained from forest inventories in jurisdictions of Argentina). This leads to different results and misunderstandings, which often leads to incomparable outputs (e.g., native forest cover). The objective of this work was to analyse the current definition of the native forest implemented by the Argentine Government within the framework of Law 26331/07, which regulates the implementation of institutional policies. We propose a new definition based on the available scientific knowledge, and try to correct the conceptual gaps identified in the aforementioned law. The proposed definition differs from the original one in the inclusion of the minimum patch size, as well in the assessment of the connectivity and composition of the surrounding landscape. Other main aspects for its implementation are discussed, as well as the impacts at different spatial scales.

Accuracy of COVID-19-Like Illness Diagnoses in Electronic Health Record Data: Retrospective Cohort Study.

Electronic health record (EHR) data provide a unique opportunity to study the epidemiology of COVID-19, clinical outcomes of the infection, comparative effectiveness of therapies, and vaccine effectiveness but require a well-defined computable phenotype of COVID-19-like illness (CLI). The objective of this study was to evaluate the performance of pathogen-specific and other acute respiratory illness (ARI) International Statistical Classification of Diseases-9 and -10 codes in identifying COVID-19 cases in emergency department (ED) or urgent care (UC) and inpatient settings. We conducted a retrospective observational cohort study using EHR, claims, and laboratory information system data of ED or UC and inpatient encounters from 4 health systems in the United States. Patients who were aged ≥18 years, had an ED or UC or inpatient encounter for an ARI, and underwent a SARS-CoV-2 polymerase chain reaction test between March 1, 2020, and March 31, 2021, were included. We evaluated various CLI definitions using combinations of International Statistical Classification of Diseases-10 codes as follows: COVID-19-specific codes; CLI definition used in VISION network studies; ARI signs, symptoms, and diagnosis codes only; signs and symptoms of ARI only; and random forest model definitions. We evaluated the sensitivity, specificity, positive predictive value, and negative predictive value of each CLI definition using a positive SARS-CoV-2 polymerase chain reaction test as the reference standard. We evaluated the performance of each CLI definition for distinct hospitalization and ED or UC cohorts. Among 90,952 hospitalizations and 137,067 ED or UC visits, 5627 (6.19%) and 9866 (7.20%) were positive for SARS-CoV-2, respectively. COVID-19-specific codes had high sensitivity (91.6%) and specificity (99.6%) in identifying patients with SARS-CoV-2 positivity among hospitalized patients. The VISION CLI definition maintained high sensitivity (95.8%) but lowered specificity (45.5%). By contrast, signs and symptoms of ARI had low sensitivity and positive predictive value (28.9% and 11.8%, respectively) but higher specificity and negative predictive value (85.3% and 94.7%, respectively). ARI diagnoses, signs, and symptoms alone had low predictive performance. All CLI definitions had lower sensitivity for ED or UC encounters. Random forest approaches identified distinct CLI definitions with high performance for hospital encounters and moderate performance for ED or UC encounters. COVID-19-specific codes have high sensitivity and specificity in identifying adults with positive SARS-CoV-2 test results. Separate combinations of COVID-19-specific codes and ARI codes enhance the utility of CLI definitions in studies using EHR data in hospital and ED or UC settings.

Solutions to fire and shade: resprouting, growing tall and the origin of Eurasian temperate broadleaved forest.

Tree species of Eurasian broadleaved forest possess two divergent trait syndromes with contrasting patterns of resource allocation adapted to different selection environments: short-stature basal resprouters that divert resources to a bud bank adapted to frequent and severe disturbances such as fire and herbivory, and tall trees that delay reproduction by investing in rapid height growth to escape shading. Drawing on theory developed in savanna ecosystems, we propose a conceptual framework showing that the possession of contrasting trait syndromes is essential for the persistence of broadleaved trees in an open ecosystem that burns. Consistent with this hypothesis, trees of modern Eurasian broadleaved forest bear a suite of traits that are adaptive to surface and crown-fire regimes. We contend that limited opportunities in grassland restricts recruitment to disturbance-free refugia, and en masse establishment creates a wooded environment where shade limits the growth of light-demanding savanna plants. Rapid height growth, which involves investment in structural support and the switch from a multi-stemmed to a monopodial growth form, is adaptive in this shaded environment. Although clustering reduces surface fuel loads, these establishment nuclei are vulnerable to high-intensity crown fires. The lethal effects of canopy fire are avoided by seasonal leaf shedding, and aerial resprouting enhances rapid post-fire recovery of photosynthetic capacity. While these woody formations satisfy the structural definition of forest, their constituents are clearly derived from savanna. Contrasting trait syndromes thus represent the shift from consumer to resource regulation in savanna ecosystems. Consistent with global trends, the diversification of most contemporary broadleaved taxa coincided with the spread of grasslands, a surge in fire activity and a decline in wooded ecosystems in the late Miocene-Pliocene. Recognition that Eurasian broadleaved forest has savanna origins and persists as an alternative state with adjacent grassy ecosystems has far-reaching management implications in accordance with functional rather than structural criteria. Shade is a severe constraint to the regeneration and growth of both woody and herbaceous growth forms in consumer-regulated ecosystems. However, these ecosystems are highly resilient to disturbance, an essential process that maintains diversity especially among the species-rich herbaceous component that is vulnerable to shading when consumer behaviour is altered.

Importance, Tools, and Challenges of Protecting Trees

Trees are the most important landscape architects of our planet, not only in forests but also in countless other ecosystems, including human-fabricated habitats. Due to their significance in the majority of terrestrial ecosystems, trees play an important role in maintaining biodiversity and providing food and habitat for countless microorganisms, fungi, climbers, invertebrates, and vertebrates. Trees are also indispensable for the development of human societies and are important for our survival today and in the future. Trees therefore have an inestimable scientific, economic, social, cultural, and aesthetic value. In addition, they were and are playing an essential role in myths, rituals, and cultures of nearly all indigenous and modern societies. Despite these facts, the protection of trees is insufficient, both globally due to climate change and deforestation, but also locally, for example in the big cities through deterioration of soils or improper care. In industrialized countries, only recently has the need for targeted protection efforts for tree species or even for individual trees been recognized. Our review starts with the differentiation and definitions of forests and trees. Furthermore, we present the main categories and subcategories of trees, each of them possessing different functions in their ecosystems and for human societies and thus needing specific legal protection measures. The second part of our review presents the most important tools for improving the protection of trees. On the one hand, there exist a series of international initiatives, conventions, and agreements, and on the other hand, there are numerous legal tools, such as red lists, lists of protected species, and legislation for the protection of monument and habitat trees. The main challenge of the 21st century is to find a solution to make the development and growth of modern human societies compatible with the protection of natural resources such as forests. The large number of tree species, as well as the large proportion of threatened tree species, makes this problem even larger. Finally, the most recent and controversial approach of attributing trees the rights as legal persons is discussed.

Mapping forest in the Swiss Alps treeline ecotone with explainable deep learning

Forest maps are essential to understand forest dynamics. Due to the increasing availability of remote sensing data and machine learning models like convolutional neural networks, forest maps can these days be created on large scales with high accuracy. Common methods usually predict a map from remote sensing images without deliberately considering intermediate semantic concepts that are relevant to the final map. This makes the mapping process difficult to interpret, especially when using opaque deep learning models. Moreover, such procedure is entirely agnostic to the definitions of the mapping targets (e.g., forest types depending on variables such as tree height and tree density). Common models can at best learn these rules implicitly from data, which greatly hinders trust in the produced maps. In this work, we aim at building an explainable deep learning model for forest mapping that leverages prior knowledge about forest definitions to provide explanations to its decisions. We propose a model that explicitly quantifies intermediate variables like tree height and tree canopy density involved in the forest definitions, corresponding to those used to create the forest maps for training the model in the first place, and combines them accordingly. We apply our model to mapping forest types using very high resolution aerial imagery and lay particular focus on the treeline ecotone at high altitudes, where forest boundaries are complex and highly dependent on the chosen forest definition. Results show that our rule-informed model is able to quantify intermediate key variables and predict forest maps that reflect forest definitions. Through its interpretable design, it is further able to reveal implicit patterns in the manually-annotated forest labels, which facilitates the analysis of the produced maps and their comparison with other datasets.

Rethinking forest monitoring for more meaningful global forest landscape change assessments.

Forest ecosystems play an indispensable role in addressing various pressing sustainability and social-ecological challenges such as climate change, biodiversity loss, and ecosystem services deterioration, hence the monitoring of the world's forests is crucial. As part of the global forest assessment workflow, a forest is generally classified and mapped based on land use and/or using a tree canopy cover threshold. In this paper, we examine the limitations of this approach and argue that the use of a land use-based forest definition and tree canopy cover thresholds can overlook forest degradation and enhancement, disguise the actual status of forest landscapes, and misinform management planning. These limitations can delay the development and implementation of forest restoration and conservation measures. To help overcome these issues, we propose some enhancements to the global forest assessment workflow, including the sharing of spatial data and inclusion of tree canopy cover estimates in assessment reports. Such enhancements are needed to achieve more meaningful forest monitoring and reporting in the context of global environmental initiatives, such as those related to climate change mitigation and adaptation, forest restoration, biodiversity conservation, and ecosystem services monitoring.

The evolution of forest restoration in India: The journey from precolonial to India's 75th year of Independence

AbstractThis paper examines the history of forest restoration in India. While contemporary literature often emphasizes the novelty of forest restoration programmes as exemplified in large‐scale global pledges such as the Bonn Challenge or the Trillion Trees initiative, we show that forest restoration has thousands of years of history in India. Furthermore, this history plays an important role in shaping current restoration efforts, in ways that often undermine restoration goals. We find four themes in this history: the definitions of forests changed as the national administration metamorphosed, the philosophy behind the afforestation practices transitioned from commercial to a focus on forest cover that still underemphasizes ecological and subsistence values of forests, the involvement of forest‐dependent people in forest restoration has been limited by government policies through much of this period, and current restoration practice draws more from the history of commercial timber production than from contemporary restoration science. Drawing on these insights, we argue that restoration programmes need to be reconsidered in India.