Search Results (33)

This article describes a field- and laboratory-based framework that can be used to monitor the C balance in Mediterranean pine forest ecosystems under different management practices that determine their structure and function. By jointly monitoring stand structure, gas exchange, litter, and decomposition dynamics, this protocol enables the assessment of how management-driven changes regulate carbon uptake, turnover, and losses, thereby affecting carbon sequestration potential. As an example, we suggest the implementation of the protocol at ten (10) permanent monitoring plots across three study areas located in Greece. The first group of plots represents a post-fire chronosequence in pine stands with no management interventions. The second group includes pine stands that exhibit variation in overstory and understory density driven by differences in microclimate and management history. The third group consists of peri-urban pine stands subjected to thinning of varying intensity. The monitoring protocol is implemented across all plots and the collected data can be classified into three analytical domains: (a) demography, encompassing measurements of tree growth and mortality; (b) litter and decomposition dynamics, involving the quantification of litterfall and its seasonality and the estimation of its decomposition rates; and (c) gas exchange, focusing on measurements of leaf photosynthesis and respiration (including relevant leaf functional traits) and monitoring of soil respiration. These three data domains can be used to comparatively consider the effect of forest management on key ecosystem processes and to constrain local-scale vegetation dynamics models. Full article

Deep planting of young trees—defined as the burial of the root collar below soil grade—is widely recognized by practitioners as an improper technique that can impair tree development and establishment. Despite this knowledge, research has shown that urban trees are frequently planted too deeply. To better understand the impacts of planting depth on the urban forest, we conducted a literature review of peer-reviewed and professional studies relevant to the effects of planting depth in urban trees. Most studies reported effects on tree establishment (34%), growth (23%), and root development (22%). A general conclusion across reviewed articles was evident: trees planted too deep exhibited higher mortality, slower establishment, and reduced growth, primarily due to poor root development. Effects of planting depth were also species-specific—Norway Maple (Acer platanoides L.), Turkish Hazel (Corylus colurna L.), White Ash (Fraxinus americana L.), and Green Ash (Fraxinus pennsylvanica Marshall) showed minimal differences in performance when deeply planted, while Baldcypress (Taxodium distichum L. Rich), which tolerates anoxic conditions, performed better at or below grade than when planted above grade, although the findings in these studies only measured the effects of planting depth relative to limited measured parameters. We also compiled a reference table that links tree species to their performance based on planting depth. These findings highlight the critical role of planting depth in shaping root architecture and long-term success, emphasizing the need for adherence to best practices concerning proper planting, tree maintenance (e.g., mulching), and production in the nursery. Full article

Skilled Birth Attendance (SBA) is essential for reducing maternal and neonatal mortality, yet access remains limited in many low- and middle-income countries. This study used machine learning to predict SBA use among Ugandan women and identify key influencing factors. We analyzed data from the 2016 Uganda Demographic and Health Survey, focusing on women aged 15 to 49 who had given birth in the preceding five years. After preparing and selecting relevant features, six tree-based models (decision tree, random forest, gradient boosting, XGBoost, LightGBM, CatBoost) and logistic regression were applied. Class imbalance was addressed using cost-sensitive learning, and hyperparameters were tuned via Bayesian optimization. XGBoost performed best (F1-score: 0.52; recall: 0.73; AUC: 0.75). SHapley Additive Explanations (SHAP) were used to interpret model predictions. Key predictors of SBA use included education level, antenatal care visits, region (especially Northern Uganda), perceived distance to a healthcare facility, and urban or rural residence. The results demonstrate the value of interpretable machine learning for identifying at-risk populations and guiding targeted maternal health interventions in Uganda. Full article

Suburban forest patches can have important conservation value for birds. This is a hopeful trend because the extent of urbanization is increasing, many avian populations are declining, and urban areas are where most people interact with wildlife. There is evidence that, despite an increased density of potential predators, the breeding success of birds in urban or suburban forest patches is comparable to that in rural areas. However, extremely limited data exists on the fledgling life stage of birds in urban or suburban areas, even though it is known that the fledgling stage strongly influences population growth rates. We used radio telemetry to look at the survival, movement, and habitat use of fledgling Wood Thrushes (Hylocichla mustelina) originating from nests in suburban forest patches and in larger swaths of rural, undeveloped forests in western Massachusetts. We tracked 168 fledglings over four field seasons and found that survival was similar for rural and suburban fledglings. Fledglings had lower mortality as they aged. Force-fledging and being left outside the nest after radio-tagging had a negative effect on survival, and we developed techniques to minimize its occurrence. We also found that rural fledglings moved farther from their natal nests, at any given age, than suburban fledglings. Fledglings in both suburban and rural sites selected denser understory growth, and the use of non-forested land cover increased as they aged. Full article

Mediterranean forests are severely threatened by increasing seedling mortality due to harsh environmental conditions, especially drought. In this study, we investigate whether seedlings of Quercus ilex and Arbutus unedo, previously exposed to water deficit, acquired tolerance to summer drought. Seedlings of the two species were grown from April to September in a plastic tunnel greenhouse and exposed to two irrigation regimes (control, 100% water holding capacity; water-stressed, 50% of control). In mid-August, the irrigation of all plants was suspended for three weeks. The response of the species was analyzed to evaluate survival, growth, ecological, and anatomical traits of wood produced under stressful conditions and marked through the pinning technique. The results suggest that both species show pre-acclimation to drought, with Q. ilex demonstrating a marked increase in survival percentage. This is likely due to a reduction in vessel size in response to previous water stress. In contrast, in A. unedo, the higher frequency of narrower vessels allowed safer water transport compared to Q. ilex, thus explaining the slight increase in survival. Overall results indicated that the two species adopt different strategies to overcome drought, providing valuable insights for managing seedlings in natural ecosystems and urban green spaces. Full article

Elms (Ulmus spp.) are widely spread in the forest, shelter belts, and urban landscaping. This research aimed to reveal the trends of Ulmus sp. health in Ukraine under biotic damage. The tasks included: (i) analyzing the presence of Ulmus sp. in the forests; (ii) studying the dynamics of Ulmus sp. health for 2001–2015 in the monitoring plots in the frame of the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP-Forests); (iii) assessing the prevalence of the dominant biotic factors affecting elm health and the probability of tree death or recovery. As a result of research, elms were found in 3.58% of the area in the stands with other main forest-forming species in the forests subordinated to the State Specialized Forest Enterprise «Forests of Ukraine». Four elm species are present in the forests of all regions of Ukraine. In the Forest zone, U. minor predominates, U. glabra is more common in the western part of the country, and U. pumila in the southern and eastern regions. In the ICP-Forests monitoring plots for 2001–2015, a trend of elm deterioration in 2007–2012 was found. The highest incidence of trees with disease symptoms was recorded for U. pumila. In the sample plots for 2023–2024, the health of three elm species tended to deteriorate. In 2024, mortality occurred among all elm species with symptoms of Dutch elm disease (DED) and among U. pumila trees with symptoms of wetwood. However, several trees have recovered. The results show the gaps in our knowledge that need to be filled, particularly in identifying resistant individuals and using their progeny to create resistant stands. Full article

A review of 113 scientific and other publications on the smallest and most abundant deer in Lithuania, the roe deer (Capreolus capreolus), is presented, along with an analysis based on compound annual population growth rates of population numbers, hunting bags, and roadkill. This review covers the species’ history in the country from the last glaciation onwards, the changes in numbers from 1934 to 2023, hunting bag changes from 1965 to 2022, roadkill numbers from 2002 to 2022, data on roe deer reproduction, habitat selection, genetic diversity, pathogens, and damage to forest stands. It also provides an overview of species management and selection for trophies. Despite the exponential increase in roe deer numbers since 1990 and the dominance of this species in roadkill, even on urban roads, the number and density of animals and the damage they cause to forest stands are relatively low compared to other European countries. Within the observed period, drops in numbers were related to harsh winters in 1969/1970 and 1995/1996. Poaching, especially coinciding with weakened enforcement during the period of political–economic transition in the early 1990s, has also had a negative impact on population numbers, as have recent increases in the number of large predators. Population growth over the recent period does not correlate with hunting mortality, which has remained stable at an average of 16.9% since 2002. Full article

Habitat modification due to human activities threatens species survival. While some species can inhabit habitat patches in anthropogenic landscapes, their occurrence often depends on landscape structure. We assessed the effects of landscape structure on brown howler monkey (Alouatta guariba clamitans) occurrence in an urban scenario. We conducted censuses in 59 forest patches from 2014 to 2016 in Rio Grande do Sul State, Brazil. We evaluated patch occurrence (presence/absence) in response to landscape composition (forest cover, arboreal crops, urban areas, open areas, and water) and configuration (patch density), considering the scale of effect. Water, urban, and open areas were the most important predictors of howler presence. Their presence was notably higher in landscapes with more water, likely because these landscapes consist of rural areas with low urbanization, less farming, and relatively high forest cover. Presence of howlers was positively associated with forest cover and negatively related to urban areas, open areas, and arboreal crops. Resource scarcity and increased mortality risks from human pressures, such as domestic dog attacks, electrocution, and roadkill on these land covers may explain these relationships. We highlight the importance of conserving and increasing forest cover in anthropogenic landscapes to protect species reliant on forested habitats, like howler monkeys. Full article

Central Europe is not a typical wildfire region; however, an increasingly warm and dry climate and model-based projections indicate that the number of forest fires are increasing. This study provides new insights into the drivers of forest fire occurrence in the Czech Republic, during the period 2006 to 2015, by focusing on climate, land cover, and human activity factors. The average annual number of forest fires during the study period was 728, with a median burned area of 0.01 ha. Forest fire incidence showed distinct spring (April) and summer (July to August) peaks, with median burned areas of 0.04 ha and 0.005 ha, respectively. Relationships between the predictors (climate data, forest-related data, socioeconomic data, and landscape-context data) and the number of forest fires in individual municipality districts were analyzed using Generalized Additive Models (GAM) on three time scales (annually, monthly, and during the summer season). The constructed GAMs explained 48.7 and 53.8% of forest fire variability when fire occurrence was analyzed on a monthly scale and during the summer season, respectively. On an annual scale, the models explained 71.4% of the observed forest fire variability. The number of forest fires was related to the number of residents and overnight tourists in the area. The effect of climate was manifested on monthly and summer season scales only, with warmer and drier conditions associated with higher forest fire frequency. A higher proportion of conifers and the length of the wildland–urban interface were also positively associated with forest fire occurrence. Forest fire occurrence was influenced by a combination of climatic, forest-related, and social activity factors. The effect of climate was most pronounced on a monthly scale, corresponding with the presence of two distinct seasonal peaks of forest fire occurrence. The significant effect of factors related to human activity suggests that measures to increase public awareness about fire risk and targeted activity regulation are essential in controlling the risk of fire occurrence in Central Europe. An increasing frequency of fire-conducive weather, forest structure transformations due to excessive tree mortality, and changing patterns of human activity on the landscape require permanent monitoring and assessment of possible shifts in forest fire risk. Full article

Wildlife that inhabit urban landscapes face the dual challenge of negotiating their positions in their group while navigating obstacles of anthropogenically modified landscapes. The dynamics of urban environments can result in novel injuries and mortalities for these animals. However, these negative impacts can be mitigated through planning, and onsite veterinary care like that provided by the Ubud Monkey Forest in Bali, Indonesia. We examined 275 recorded injuries and mortalities among six social groups of long-tailed macaques (Macaca fascicularis) brought to the veterinary clinic from 2015–2018. We fit the probabilities of injury vs. death among macaques brought to the clinic using a multilevel logistic regression model to infer the relationship between injury vs. death and associated demographic parameters. Males were more likely to sustain injuries and females were more likely to die. The frequency of injuries and mortalities changed over the four-year study period, which was reflected in our model. The odds of mortality were highest among young macaques and the odds of injury vs. mortality varied across the six social groups. We categorized injuries and mortalities as “natural” or “anthropogenic”. Most injuries and mortalities were naturally occurring, but powerlines, motorized vehicles, and plastic present ongoing anthropogenic threats to macaque health. Most wounds and injuries were successfully treated, with healthy animals released back to their group. We suggest other sites with high levels of human–alloprimate interplays consider the Ubud Monkey Forest veterinary office as a model of care and potentially adopt their approaches. Full article

Urban forests provide considerable ecosystem services for city dwellers, yet the function of forest species is increasingly challenged by urban drought. Understanding drought tolerance of urban forest species would facilitate vegetation conservation and establishment within urban ecosystems. Here, we report on the drought resistance of leaves for two exotic and three indigenous tree species common to the Jing-Jin-Ji metropolitan region (covering Beijing, Tianjin, and Hebei province) of north China. Xylem vulnerability to drought-induced embolism and leaf gas exchange, together with various morphological and anatomical traits that potentially relate to plant water use, were measured for pot-grown seedlings. In addition, seedlings were subjected to dry-down at two different drought intensities until death, and the tree mortality rate was recorded. We found that species differ markedly in xylem embolism resistance, with indigenous species showing more negative P₅₀ (the water potential triggering 50% loss of xylem hydraulic conductivity), but less canopy leaf area at a given branch basal diameter, compared with exotic species. Furthermore, P₅₀ well predicted tree mortality rate under protracted drought stress. Species characterized by more negative P₅₀ also exhibited higher maximum leaf photosynthetic rates. In addition, leaf P₅₀ was found to correlate with specific leaf area, while the hydraulic safety margin was related to sapwood density and the thickness of the leaf upper epidermis. Collectively, these results highlight the role of embolism resistance in dictating drought response and the promise of morphological traits as proxies of plant physiological drought resistance. Our findings contribute to understanding drought response for urban tree species and will guide the establishment and management of urban forests. Full article

Urban forests are an essential part of adaptation and mitigation solutions for climate change. To understand the relationship between carbon storage, sequestration, and stand density in the most heavily-managed aspect of the urban forest—street trees—we modified the parameters and algorithms of a rural forest dynamics model, the perfect plasticity approximation (PPA), to reflect urban street tree conditions. The main changes in the new street tree PPA are the maintenance of a prescribed stand density via management of recruitment, the possibility of crown-roof overlap, and increased mortality rates. Using the street tree PPA, we explored overall productivity, crown allometry relative to stem diameter, and mortality rate to test each mechanism’s impact on urban street tree carbon storage and sequestration across a gradient of prescribed stand density, with the goal of finding conditions in which street tree carbon storage and sequestration are optimized. We compared the qualitative trends in storage from the street tree PPA to those found in the U.S. Forest Service’s Urban Forest Inventory Analysis data. We found that carbon storage and sequestration increase with prescribed density up to a point where carbon storage and sequestration saturate. Optimized carbon storage and sequestration result from a stand with high productivity, maximized crown allometry relative to stem diameter, and a low mortality rate. These insights can be used to inform urban street tree maintenance strategies that effectively increase carbon storage and sequestration within a given city, such as focusing afforestation campaigns on adequate areas with the lowest street tree densities. Full article

Objective: To analyze the factors associated with leishmaniasis in Peru, according to the cluster classification in the period 2017–2021. Methods: Quantitative approach, with an ecological, descriptive correlational, and cross-sectional design. The population was from the geographical region of Peru, where a total of 26,956 cases of leishmaniasis were registered by the Peruvian Ministry of Health from 2017 to 2021. Spearman’s Rho statistic was used to analyze the variables that are most associated with the cases of leishmaniasis reported per year, and, in addition, the multivariate technique of cluster analysis was applied. Results: Annual rainfall and areas with humid forest (climatic factors) and mortality from transmissible diseases (health factor) are directly associated with reported cases of leishmaniasis. Households with basic access to infrastructure, drinking water, drainage, and electric lighting; illiteracy, regional social progress, and unsatisfied basic needs (social factors); and percentage of urban population (demographic factor) are inversely and significantly associated with cases of leishmaniasis. Conclusions: Climatic and environmental factors contribute to the multiplication of the leishmaniasis disease vector. The incidence of leishmaniasis adds up to the mortality rates for transmissible diseases in Peru. As living conditions improve, the incidence of this pathology decreases. Full article

The urban heat island (UHI) is a critical issue in most urbanised areas. Spatial variation of urban air temperature and humidity influences human thermal comfort, the settling rate of atmospheric pollutants, and the energy demand for cooling. UHIs can be particularly harmful to human health and there are numerous studies that link mortality and morbidity with extreme thermal events, that can be worsened by UHIs. The temperature difference between city centres and the surrounding countryside, which is accentuated in the summer months and at night, is the result not only of a greater production of anthropogenic heat but is mainly due to the properties of urban surfaces. The use of vegetation, and in particular urban tree planting, is one of possible strategies to contrast the heat island effects. In order to analyse the mitigation effects produced by green spaces in the city of Padova, a municipality in the northeast of Italy, simulations of the air temperature variations and their spatial distribution were carried out using the i-Tree Cool Air model. High-resolution RGBir aerial photos were processed to produce a tree canopy and a permeability map and the model was applied on a 10 m × 10 m grid over the entire city, producing a raster map of the aboveground air temperatures. A particularly hot July day with recorded air temperatures of 35 °C at 3 p.m. and 28 °C at 10 p.m. at a reference weather station was chosen for the test. In the daytime, the results show temperature differences up to almost 10 °C between urban open spaces with impervious cover (squares, streets) and green areas under tree canopy. At night, the simulated air temperatures are only slightly cooler in areas with tree cover than those recorded at the reference station, while urban areas with sealed surfaces maintain air temperatures 4.4 °C higher. The study was aimed at testing the applicability of the model as a tool for predicting air temperatures in relation to land use and canopy cover. The results show that the model can potentially be used to compare different urban forest and urban greening planning scenarios, however, further research is necessary to assess the reliability of the temperature predictions. Full article

In the context of climate change, heat waves are a serious hazard having significant impacts on human health, especially vulnerable populations. Many studies have researched the association between extreme heat and mortality. In the context of urban planning, many studies have explored the cooling effect of green roofs, parks, urban forests and urban gardens. Nevertheless, few studies have analyzed the effect mechanism of specific ecosystem services (Ess) as mitigation measures to heat waves. This study aimed to determine the relationship among Ess, heat waves and the heat-related mortality risk of different groups by diseases, age and sex. The research was conducted in three cities in Jiangsu Province, including Nanjing, Suzhou and Yancheng. We quantified five ecosystem services, i.e., water supply service, carbon sequestration service, cooling service, biodiversity and cultural service. Based on the previous studies, we took the frequency of heat waves into account, extending the concept of the Heat Wave Magnitude Index (HWMI). A distributed lag nonlinear model (DLNM) was applied to estimate the effect of extreme heat on mortality. Then, the study used the process analysis method to explore the relationship among Ess, heat waves and heat-related mortality risks. The results indicated that (i) water supply service, carbon sequestration service, cooling service and biodiversity can reduce heat-related mortality while cultural service increases; (ii) the effects of carbon sequestration service and cultural service are stronger than other Ess; (iii) the effects of Ess on cardiorespiratory disease, stroke and chronic obstructive pulmonary disease (COPD) mortality risks are higher than others; and (iv) women and elderly heat-related mortality risks are more affected by the Ess. This study can provide a theoretical support for policy makers to mitigate heatwave events, thus limiting heat-related mortality. Full article