Forest Climate Research Articles

Soil organic matter diagenetic state informs boreal forest ecosystem feedbacks to climate change

Abstract. The fate of soil organic carbon (SOC) in boreal forests is dependent on the integrative ecosystem response to climate change. For example, boreal forest productivity is often nitrogen (N) limited, and climate warming can enhance N cycling and primary productivity. However, the net effect of this feedback on the SOC reservoir and its longevity with climate change remain unclear due to difficulty in detecting small differences between large and variable carbon (C) fluxes needed to determine net changes in soil reservoirs. The diagenetic state of SOC – resulting from the physicochemical and biological transformations that alter the original biomolecular composition of detrital inputs to soil over time – is useful for tracing the net response of SOC at the timescales relevant to climate change not usually discernible from fluxes and stocks alone. Here, we test two hypotheses using a mesic boreal forest climate transect: (1) the SOC diagenetic state is maintained across this climosequence, and (2) the maintenance of the SOC diagenetic state is a consequence of coupled soil C and N cycling, signifying the role of enhanced N cycling supporting SOC inputs that maintain SOC stocks within the warmer-climate forests. Shifts in nonvascular to vascular plant inputs with climate observed in these and other boreal forests highlighted the need to carefully separate biogeochemical indicators of SOC source from those signifying diagenetic alteration. We thus evaluated and applied lignin biomarkers to assess the diagenetic alteration of SOC in these boreal forest organic soils and directly compared the lignin diagenetic state with that of soil organic nitrogen (SON) assessed through amino acid composition. The lignin diagenetic state remained constant across the climate transect, indicating a balance between the input and removal of lignin in these mesic boreal forests. When combined with previous knowledge of these forest ecosystems, including the diagenetic state of SON and direct measures of C fluxes and stocks, the results indicate a coupled increase in C and N cycling with climate warming that supports forest productivity and maintains SOC stocks. This balance could markedly shift as other factors begin to limit forest productivity (e.g., trace nutrients, water) with further climate change or affect forest nutrient allocation (e.g., forest age or compositional change). Further application of the approach presented here could be used to detect the limits of this and other ecosystem–climate feedbacks, by providing a tractable and parameterizable index of the lignin state across large spatial scales, necessary for ecosystem-scale parameterizations.

Wood density variations of E. urophylla clone among growth sites are related to climate

The Eucalyptus genus is extensively planted in Brazil for industrial use, and with the expansion of forest frontiers and climate changes, studies are needed on how these changes affect wood density (WD). The aim of this study was to evaluate the effect of some climate variables on WD of an Eucalyptus urophylla clone for a 4–5 year period. WD from trees collected in 12 sites were evaluated. Five growth rings were identified using a magnifying glass, X-ray densitometry, and forest inventory. WD was correlated with temperature ( T), precipitation ( P), soil water deficit, ring width, and current annual increment. There was no variation in WD in the first 20 months among sites. From that age on, WD was mainly correlated with T ( r > 0.6). The 1 °C increase in T resulted in a WD reduction of 0.014 g cm−1, and increases of 10 m³ ha−1 in the final volume were related to an increase of 0.004 g cm−1 in WD. Researchers and managers should continue to put efforts into broad experimental networks to assess the effects of climate change on the adaptation and wood quality of Eucalyptus clones. Highlights The influence of climate on E. urophylla wood density was greater after the third year of growth. The mean air temperature was the best correlated climatic variable with E. urophylla wood density. The cross-site climatic gradient was more important in wood density variation of E. urophylla than the variability among the years.

Hug a tree, hug a building: Reflections on the management of natural and built heritage

A veteran forester refuses to cut down a mammoth, millennium-old Douglas fir on British Columbia’s Vancouver Island. The city council in nearby Victoria designates the stately Empress Hotel as heritage property. The former was an act of environmental conservation; the latter, of built heritage conservation. This essay looks at the two events in the contexts of forest management, historic preservation, climate change, and sustainability. It describes the increasing threats to old-growth and heritage trees, discusses the mitigative tools that are available, and reflects on analogies between safeguarding natural heritage and built heritage. A new management and legislative approach is needed, one that balances science with Indigenous Traditional Knowledge. Until then, advocacy will continue to lead the way. The theme may have been expressed best by an Aboriginal writer from Australia, who reacted to a proposed freeway’s threat to destroy dozens of 800-year-old trees: “Their survival and our fight to keep them alive and safe are a cultural obligation and an assertion of our sovereignty.” The present article unpacks the issues, focusing on stories from British Columbia and California, while looking at parallel experiences elsewhere.

EVALUATION OF DIFFERENT PARAMETERS FOR PLANT CLASSIFICATION BY PRE-TRAINED DEEP LEARNING MODELS WITH BIGEARTHNET DATASET

Abstract. Vegetation monitoring and mapping are essential for a diverse range of environmental problems such as forest management, food resources, and climate change assessment. Several methods have been developed to classify different vegetation types based on remote sensing (RS) data. Land use classification has been revolutionized with the advent of neural networks. Various vegetation types were classified using multispectral Sentinel-2 satellite images due to their high spatial resolution and spectral information. Deep Convolutional Neural Network is considered a promising method for classifying remote sensing images with high spatial resolution due to its powerful feature extraction capabilities. However, large labeled datasets are required for better classification performance, so we have used pre-trained ResNet networks with 152 layers, 50 layers, and 101 layers trained on Big Earth Net (BEN). In order to obtain the best network performance and evaluate the sensitivity of the parameters in this study, we have performed two experiments: 1) the effect of different patch sizes and 2) increasing the number of images. The results demonstrate that ResNet 152 shows the highest accuracy with patches of 120 × 120 pixels, with an accuracy of 76.62%, and ResNet 50 is the best with an accuracy of 76.2% since the process of this network does not take much time.

Short term variation in leaf level water use efficiency in a tropical forest.

The representation of stomatal regulation of transpiration and CO2 assimilation is key to forecasting terrestrial ecosystem responses to global change. Given its importance in determining the relationship between forest productivity and climate, accurate and mechanistic model representation of the relationship between stomatal conductance (gs ) and assimilation is crucial. We assess possible physiological and mechanistic controls on the estimation of the g1 (stomatal slope, inversely proportional to water use efficiency) and g0 (stomatal intercept) parameters, using diurnal gas exchange surveys and leaf level response curves of six tropical broadleaf evergreen tree species. g1 estimated from ex-situ response curves averaged 50% less than g1 estimated from survey data. While g0 and g1 varied between leaves of different phenological stages, the trend was not consistent among species. We identified a diurnal trend associated with g1 and g0 that significantly improved model projections of diurnal trends in transpiration. The accuracy of modelled gs can be improved by accounting for variation in stomatal behavior across diurnal periods, and between measurement approaches, rather than focusing on phenological variation in stomatal behavior. Additional investigation into the primary mechanisms responsible for diurnal variation in g1 will be required to account for this phenomena in land surface models.

Future supply of boreal forest ecosystem services is driven by management rather than by climate change.

Forests provide a wide variety of ecosystem services (ES) to society. The boreal biome is experiencing the highest rates of warming on the planet and increasing demand for forest products. To foresee how to maximize the adaptation of boreal forests to future warmer conditions and growing demands of forest products, we need a better understanding of the relative importance of forest management and climate change on the supply of ecosystem services. Here, using Finland as a boreal forest case study, we assessed the potential supply of a wide range of ES (timber, bilberry, cowberry, mushrooms, carbon storage, scenic beauty, species habitat availability and deadwood) given seven management regimes and four climate change scenarios. We used the forest simulator SIMO to project forest dynamics for 100 years into the future (2016-2116) and estimate the potential supply of each service using published models. Then, we tested the relative importance of management and climate change as drivers of the future supply of these services using generalized linear mixed models. Our results show that the effects of management on the future supply of these ES were, on average, 11 times higher than the effects of climate change across all services, but greatly differed among them (from 0.53 to 24 times higher for timber and cowberry, respectively). Notably, the importance of these drivers substantially differed among biogeographical zones within the boreal biome. The effects of climate change were 1.6 times higher in northern Finland than in southern Finland, whereas the effects of management were the opposite-they were three times higher in the south compared to the north. We conclude that new guidelines for adapting forests to global change should account for regional differences and the variation in the effects of climate change and management on different forest ES.

Indigenous knowledge and sustainability concerns in an era of climate change: the Sahariya Adivasi and salai trees (Boswellia serrata) in central India

ABSTRACT Boswellia serrata, or salai is a prominent NTFP species of the Kuno forests in Central India. The Sahariya tribe primarily uses it for its gum-resin (chir). A major share of household income comes from the sale of chir. Long-term association with the Kuno forests, in particular with the salai trees, has allowed the Sahariya to build a repository of indigenous knowledge, which plays a pivotal role in their livelihoods. Indigenous knowledge systems are gaining increasing attention globally, and the wisdom of indigenous communities is getting acknowledged. Using qualitative tools and long-term ethnographic engagement with the Sahariya, this study aims to document their holistic process of management of salai forests and collection of chir. It documents their management practices and belief systems regarding salai. It also highlights sustainability concerns of the community and their perception of how climate change affects salai. The study emphasizes the relevance of situated knowledge systems for a better understanding of sustainability concerns about the forest resources, and the associated impacts on local communities. Recognizing indigenous knowledge of forests and trees can facilitate and improve sustainable forest management and climate change mitigation policies.

毛竹扩张对杉木林土壤微生物残体碳积累的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 毛竹扩张对杉木林土壤微生物残体碳积累的影响 DOI: 10.5846/stxb202202030289 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 浙江省"尖兵""领雁"研发攻关计划项目（2022C02036）；浙江省教育厅基金项目（Y202045039）；浙江省自然科学基金项目（LZ22C160001）；浙江农林大学科研发展基金-人才启动项目（2019FR067） Effects of Moso bamboo expansion on accumulation of soil microbial residual carbon in Chinese fir forest Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:亚热带毛竹扩张对杉木林土壤微生物残体碳积累的影响及机制尚不清楚。以毛竹向杉木林扩张带（包括杉木林、杉木-毛竹混交林和毛竹林）的凋落物（O层）和不同发生层土壤（A层、B层和BC层）为研究对象，通过分析凋落物和土壤样品中的氨基糖含量来表征微生物残体碳累积效应，并进一步评价微生物在土壤有机碳（SOC）形成过程中的作用。结果表明：毛竹扩张使杉木林凋落物数量和碳含量显著降低，但是凋落物中真菌残体碳（MRC-f）、细菌残体碳（MRC-b）和微生物残体碳（MRC）含量均显著增加；毛竹扩张显著提高了杉木林SOC、MRC-f、MRC-b和MRC含量，而且在毛竹扩张初期（杉木林演替为杉木-毛竹混交林） MRC-f、MRC-b和MRC在SOC中的比例也显著增加，说明毛竹扩张增强杉木林土壤MRC累积效应的同时，也提高了微生物对有机碳的贡献。而毛竹扩张后期MRC-f、MRC-b和MRC占SOC比例并没有显著变化，意味着毛竹扩张后期MRC和植物源残体碳对SOC含量的提升均有贡献，且两者贡献的相对比例保持不变。土壤MRC含量随着剖面深度的加深逐渐下降，而MRC占SOC比值却随着土壤深度的增加而逐渐升高，说明深层土壤中微生物对有机碳贡献高于表层土壤。研究结果对于理解微生物在亚热带森林SOC形成过程中的作用，科学评估毛竹扩张对亚热带森林生态系统及气候变化的影响，并采取合理的营林措施提升亚热带森林土壤碳汇功能具有重要理论意义。 Abstract:The effects of subtropical Moso bamboo expansion on carbon accumulation in soil microbial residues in Chinese fir forests and its mechanisms were not clear. In this study, the litter (O layer) and soils of different pedogenic horizons (A horizon, B horizon, BC horizon) in the expansion zone of Moso bamboo to Chinese fir forest (including Chinese fir forest, Chinese fir and Moso bamboo mixed forest, and Moso bamboo forest) were studied. We analyzed the amino sugar content in litter and soil samples to characterize accumulation of the microbial residual carbon and further evaluated the role of microorganisms in soil organic carbon (SOC) formation. The results showed that Moso bamboo expansion significantly reduced the amount and carbon content of litter in Chinese fir forests, but significantly increased the content of fungal residual carbon (MRC-f), bacterial residual carbon (MRC-b), and total microbial residual carbon (MRC). Moso bamboo expansion significantly increased SOC, MRC-f and MRC-b and MRC in Chinese fir forests, and the proportion of MRC-f and MRC-b and MRC in SOC increased significantly at the beginning of Moso bamboo expansion (when Chinese fir forests evolved into Chinese fir and Moso bamboo mixed forest). These results indicate that Moso bamboo expansion enhanced the cumulative effect of soil MRC in Chinese fir forests and also increased the microbial contribution to SOC. However, in the late stage of Moso bamboo expansion, the proportion of MRC-f, MRC-b, and MRC to SOC did not change significantly, implying that the contribution of MRC and plant-derived carbon to the SOC content increased at the later stage of Moso bamboo expansion, and the relative proportion of their contribution remained unchanged. The content of MRC gradually decreased with soil depth, while the proportion of MRC to SOC gradually increased with the depth of the soil, implying that the microbial contribution to SOC was higher in deep soils than in surface soils. The results of the study have important theoretical implications for understanding the role of microorganisms in SOC formation in subtropical forests, scientifically assessing the impact of Moso bamboo expansion on the subtropical forest ecosystems and climate change, and adopting reasonable forestry measures to enhance the soil carbon sink function in subtropical forests. 参考文献 相似文献 引证文献

Carbon Sequestration Decision-Making Management Based on Model Construction

Nowadays, forests are integral to mitigating climate change. Fully exerting the carbon sequestration capacity of forests is related to whether the concentration in the atmosphere can be reduced and the trend of global warming can be restrained. Because forest composition, climate, population, interests, and values vary widely around the world, it is impractical to develop a model of forest management that applies to all regions, and the optimal management strategy for each forest is different. Modeling the carbon footprint of forest areas, from which the carbon sequestration of trees, understory vegetation and forest litter per unit area can be obtained, and trees can be further divided into young forests, middle-aged forests, and near-mature forests according to their age , mature forest and over-mature forest, comprehensively evaluate the established indicators through the entropy weight method, establish 3 first-level indicators and 6 second-level indicators, and combine the Pearson correlation coefficient to formulate the most relevant indicators. The maintenance of ecological balance is a forest management plan in Carbon dioxide sequestration in the Greater Khingan Range is the most efficient.

The strategy of low-carbon development of Russia and the role of forests in its implementation

The article analyzes the role of increasing greenhouse gas absorption in the Land Use, Land Use Change, Forestry (LULUCF) sector to achieve carbon neutrality in Russia. Recommendations are given for improving the text of the “Strategy for the socioeconomic development of the Russian Federation with low greenhouse gas emissions until 2050” (LCDS). The interest of the business community in investing in climate projects in LULUCF, especially in forest climate projects, is shown. The latest changes in legal regulation are presented, opening up the possibility of increasing the return on investment in forest climate projects, and a detailed analysis of the content of the operational plan for the implementation of the LCDS in the LULUCF sector (LCDS OP) is carried out. A prospective assessment of the balance of greenhouse gases in Russian forests in 2050 is given, assuming a constant volume of logging and the area of burned areas. The ratio of public and private investment in the implementation of activities and climate projects in LULUCF proposed in the LCDS OP was calculated (4: 1), which indicates an unjustified bias in the direction of public financing. The authors justify the need for significant refinement of the LCDS OP and continuation of work to find an optimal scenario for decarbonization of the Russian Federation using the LULUCF potential.

Subtropical high-montane forest climate refuges in Brazil

Subtropical high-montane forest climate refuges in Brazil

Soil Carbon Fluxes and Sensitivity Analysis – A Study in Pinus roxburghii Forest

The predicted increasing atmospheric carbon dioxide (CO2) level is responsive to altering the future climate, and a small change in the soil carbon may significantly affect the forest carbon cycle and climate system. Soil respiration (SR) and its influencing factors like soil temperature (ST), soil water content (SWC) and surface litter-fall were measured monthly over one year in a sub-tropical Pine (Pinus roxburghii) forest of Bhaktapur district located in central Nepal to determine the SR of the forest and, its variations and sensitivity. The results showed that SR varied to the changes in ST by an exponential significant positive correlation between them. The optimum SR was observed between 10 and 22ºC, and the highest SR were obtained above ST at 20ºC. The temperature sensitivity value of SR (Q10) was estimated at Q10 = 2.13. The significant exponential curve represented the effect of SWC on SR. The higher SR rate was mostly measured between 10 and 25% SWC. The monthly and seasonal variations of the SR rate were consistent with the ST, SWC and litter-fall variations. The study showed that the combined effect of temperature and precipitation might be the major cause of SR variations; however, ST is adequate for increasing SR. Hence, the warming further enhances carbon emission from the forest floor and inversely increases carbon to contribute to climatic change through this pine-dominated forest stand structure.

ЭКОНОМИЧЕСКАЯ ОЦЕНКА ПРОЕКТНЫХ МЕР НАПРАВЛЕННЫХ НА СОКРАЩЕНИЕ ВЫБРОСОВ ПАРИКОВЫХ ГАЗОВ И УВЕЛИЧЕНИЕ ИХ ПОГЛОЩЕНИЯ В ЛЕСАХ РОССИИ

Forest climate projects have very strict criteria for successful verification, recognition, and these criteria are additionality, permanence and leakage control. The presence of these criteria creates serious problems for the effective implementation of forest climate projects on the lands of the forest fund, that is, where the forest exists and where it grows on its own. The article provides a quantitative assessment of the potential of project activities (forest climate projects) aimed at reducing greenhouse gas emissions and increasing carbon sequestration in forests according to the forms of maintaining the state forest registry. To form the most general picture of areas suitable for the implementation of forest-climatic projects, we grouped forest and non-forest lands that are most suitable for project activities and allow implementing the principles of climate projects by types of project activities. As a result of the study, it was proved that climate projects designed for afforestation, organization of intact forest areas and reforestation have significant potential. It has been established that the diversity of conditions, land categories, and the protection of forests in the Russian Federation create prerequisites for the implementation of various climate projects and adaptation measures in the country's forest fund. The implementation of these additional targeted climate-oriented activities will ensure, in the long term, the low-carbon development of forestry in regional systems, which makes it possible to evaluate the prospects for implementation positively and creates conditions for the growth of their investment attractiveness.

International agreements and entry points to adaptation and adoption of modern forest technologies, ecological restoration, climate change, ecotourism and agroforest enterprise based advanced materials of Sri Lanka and Regional Countries

Sri Lanka showed proven history of conserving richly endowed habitable natural capital that offers many eco-system services and essential launching pad for fast –track growth. This endowment could bring in desired economic and ecological improvements to living standards and for the well- being of future generations by sensibly put into sustainable use. Under the present development activities, country is facing major challenges of increasing severe climate change impacts, energy insecurity and ecological scarcity. Thus, present use of natural capital, carbon sequestration cyclic activities and forest enterprise are not fulfilling the conditions necessary for sustainability. International initiatives that have been taken and entry points for sustainable forest management and establishing of modern forest technologies are briefly discussed in this position paper to scope expansion of forestry enterprise development strategies. Thus, right policies for setting up right institutions of “Forest Development Authority” and “Forest Exchange System” and inter institutional set up of “Modern Forest Technology” for action in plan is justified.

Effect of Type of Forest Growth Conditions and Climate Elements on the Dynamics of Radial Growth in English Oak (Quercus robur L.) of Early and Late Phenological Forms

The pattern of annual radial growth is influenced by various factors: the local growth conditions, the age structure, and the ecotypes or provenances of trees. A more in-depth approach to the study of specific growth patterns of tree forms is needed to predict the further genesis of forests. This research was carried out on healthy English oak trees of early (EF) and late (LF) phenological forms in Shipov Forest, Voronezh Region. The dendroclimatic analysis was performed on permanent sample plots in wet, dry, and very dry oak stands grown on different soil types. The effect of precipitation on annual ring width was assessed using a one-way ANOVA. The LF showed higher radial growth rates on wet sites than the EF did on dry ones. Their annual radial growth was less stable and more variable compared with the LF. For both phenoforms, the most important radial growth factors are the composite indicators reflecting the ratio of temperature and moisture (Selyaninov’s hydrothermal coefficient and Lang’s rain factor). Generally, the radial growth minima coincided in time on dry and wet sites, and the periods of maximum growth were associated with high-water years.

From One Project to Another: Unintended Consequences and People’s Expectation of Climate Mitigation Project in Central Kalimantan

This paper discusses the dynamics of environmental interventions supported by aid projects and community responses as the subject of intervention. Drawing on ethnographic fieldwork, I looked into how connections between local and global entities occurred, between the local villagers in Central Kalimantan and the climate mitigation project of REDD +. Both of these entities met when the global discourse on climate change started to gain ground. This paper discusses how environmental interventions lead to different expectations and unintended consequences. I see community responses as choices and decisions which were historically constructed. These choices, expectations, and decisions are related to people’s experience with previous intervention agents and local livelihood dynamics. This local-global interaction has yielded unintended outcomes and led to different expectations for a REDD+’s demonstration activities project. When these two entities - local people and KFCP (Kalimantan Forest Climate Partnership) - meet in the global agenda to mitigate climate change, friction emerges due to a variety of interests in the village. My findings demonstrate how a reforestation program could lead to a socio-economic inequality. Land conflicts are likely to occur because of alternative livelihood programs which introduced rubber seeds.

Site occupancy by American martens and fishers in temperate deciduous forests of Québec.

Interspecific interactions can mediate site occupancy of sympatric species and can be a key factor in habitat use patterns. American martens (Martes americana) and Fishers (Pekania pennanti) are two sympatric mesocarnivores in eastern North American forests. Due to their larger size, fishers have a competitive advantage over martens. We investigated site occupancy of martens and fishers in temperate deciduous forests of Québec, an environment modified by forest management and climate change. We formulated hypotheses on the spatial distribution of the studied species based on the knowledge of local trappers and on the scientific literature regarding forest cover composition, habitat fragmentation, and competitive relationships. We used a network of 49 camera traps monitored over two fall seasons to document site occupancy by both species. We used two-species site occupancy models to assess habitat use and the influence of fishers on martens at spatial grains of different sizes. None of the habitat variables that we considered explained site occupancy by fishers. Availability of dense old coniferous stands explained the spatial distribution of martens both at the home range grain size and at the landscape grain size. We identified the characteristics of habitat hotspots based on the knowledge of trappers, which highlighted the importance of stand composition, height, age, and canopy closure. The characteristics of habitat hotspots for martens in temperate deciduous forests refine the habitat suitability model for American martens that was originally developed for boreal forests of Québec.

Monetized Estimates of the Ecosystem Service Value of Urban Blue and Green Infrastructure and Analysis: A Case Study of Changsha, China

Urban blue-green infrastructure (BGI) forms the basis of a regional ecosystem. Quantitative calculations can identify the weak points of a typical ecological environment, which is helpful for providing a basis for the spatial planning and ecological environment protection of developing cities. Currently, assessment of BGI ecosystem services focuses on local temperature, climate, and entertainment aesthetics, and the integrity of ecological indicators needs improvement. The assessment is usually conducted within large blue-green areas such as parks and rivers, and street greening is typically ignored. Roof gardens and unmanaged blue-green spaces also have ecosystem service functions. Therefore, our study aimed to extract the basic design distribution of urban blue-green spaces more accurately and monetize the value of its ecosystem services. Changsha, one of the top ten ecologically competitive cities in China, was the research focus. First, four types of BGI, forest, grassland, wetland, and waterbody, were extracted using remote sensing images and ArcGIS10.8. Second, the adjusted value coefficient was used to quantify the service value and geographic spatial distribution of the four BGI ecosystems in monetary terms. The results showed that in 2020, the total economic value of ecosystem services (ESV) generated by BGI in the study area was CNY 36.25 billion. Among ecosystem services, forest land climate regulation and waterbody hydrological regulation accounted for the largest proportion, at CNY 6.543 and 15.132 billion, respectively. The urban center had the weakest climate regulation capacity, and the Xiangjiang River Basin had the strongest hydrological regulation capacity. The urban center had the lowest ESV, thus requiring the attention of urban planners in the future. This study evaluated and optimized the distribution of BGI in Changsha according to the ESV of the existing BGI to help improve the ESV of the city center and create a green, ecological, and healthy city.

Effect of forest structures and tree species composition on common tick (Ixodes ricinus) abundance—Case study from Czechia

Tick-borne diseases are a significant health problem worldwide and have become even more pervasive in Europe due to the increasing abundance of tick species, especially the common tick (Ixodes ricinus L.). Moreover, in recent years, there have been changes in tick geographical distribution, the occurrence of new tick species, and an expansion in abundance driven by changes in forest management and climate change. Therefore, this paper’s objective is to determine the effect of tree species composition and forest structure on the abundance of I. ricinus in various forest stands in Czechia. Altogether, we analyzed 4195 collected ticks on 56 monitored research plots, of which 4182 individuals were I. ricinus, 4 individuals were Dermacentor reticulatus Fabricius, and 7 individuals were Haemaphysalis concinna C. L. Koch. The average density reached 1.21 ticks per 10 m2. The highest I. ricinus abundance was observed in coniferous stands (especially in Scotch pine—Pinus sylvestris L.) and forest edges with a high incidence of wild ungulate habitat signs. Contrarily, the lowest tick numbers were in clear-cut biotopes and mixed stands. Increasing vertical structure had a significant (p < 0.05) negative effect on I. ricinus abundance, similar to tree species diversity (richness, evenness, heterogeneity) and complex stand diversity on nymph stage abundance. Close-to-nature silviculture of mixed forests, which are resistant to climate extremes, could reduce the tick abundance, as well as the presence of tick-borne diseases compared to standard coniferous monocultures, which are receding now due to climate change. Based on this knowledge, it should be possible to predict the I. ricinus abundance under changing environmental conditions in the Central European region.

Spatiotemporal Assessment of Forest Fire Vulnerability in China Using Automated Machine Learning

Frequent forest fires cause air pollution, threaten biodiversity and spoil forest ecosystems. Forest fire vulnerability assessment is a potential way to improve the ability of forests to resist climate disasters and help formulate appropriate forest management countermeasures. Here, we developed an automated hybrid machine learning algorithm by selecting the optimal model from 24 models to map potential forest fire vulnerability over China during the period 2001–2020. The results showed forest aboveground biomass (AGB) had a vulnerability of 26%, indicating that approximately 2.32 Gt C/year of forest AGB could be affected by fire disturbances. The spatiotemporal patterns of forest fire vulnerability were dominated by both forest characteristics and climate conditions. Hotspot regions for vulnerability were mainly located in arid areas in western China, mountainous areas in southwestern China, and edges of vegetation zones. The overall forest fire vulnerability across China was insignificant. The forest fire vulnerability of boreal and temperate coniferous forests and mixed forests showed obviously decreasing trends, and cultivated forests showed an increasing trend. The results of this study are expected to provide important support for the forest ecosystem management in China.