Tree architecture is an important component of forest community dynamics - taller trees with larger crowns often outcompete their neighbors, but they are generally at higher risk of wind-induced damage. Yet, we know little about wind impacts on tree architecture in natural forest settings, especially in complex tropical forests. Here, we use airborne light detection and ranging (LiDAR) and 30 yr of forest inventory data in Puerto Rico to ask whether and how chronic winds alter tree architecture. We randomly sampled 124 canopy individuals of four dominant tree species (n = 22-39). For each individual, we measured slenderness (height/stem diameter) and crown area (m2) and evaluated whether exposure to chronic winds impacted architecture after accounting for topography (curvature, elevation, slope, and soil wetness) and neighborhood variables (crowding and previous hurricane damage). We then estimated the mechanical wind vulnerability of trees. Three of four species grew significantly shorter (2-4 m) and had smaller crown areas in sites exposed to chronic winds. A short-lived pioneer species, by contrast, showed no evidence of wind-induced changes. We found that three species' architectural acclimation to chronic winds resulted in reduced vulnerability. Our findings demonstrate that exposure to chronic, nonstorm winds can lead to architectural changes in tropical trees, reducing height and crown areas. La arquitectura de los & aacute;rboles es un componente importante de la din & aacute;mica de la comunidad forestal: los & aacute;rboles m & aacute;s altos con copas m & aacute;s grandes suelen sobrepasar a sus vecinos, pero por lo general corren m & aacute;s riesgo de sufrir da & ntilde;os inducidos por el viento. Sin embargo, es poco lo que se sabe sobre el impacto del viento en la arquitectura de los & aacute;rboles en entornos forestales naturales, sobre todo en bosques tropicales complejos. En este caso, utilizamos LiDAR y 30 a & ntilde;os de datos de campo en Puerto Rico para preguntarnos si los vientos cr & oacute;nicos alteran la arquitectura de los & aacute;rboles. Se tom & oacute; una muestra aleatoria de 124 individuos del dosel de cuatro especies arb & oacute;reas dominantes (n = 22-39). De cada individuo, medimos la esbeltez (altura/di & aacute;metro) y el & aacute;rea de la copa (m2) y evaluamos si la exposici & oacute;n a vientos cr & oacute;nicos influ & iacute;a en la arquitectura teniendo en cuenta la topograf & iacute;a (curvatura, elevaci & oacute;n, pendiente, humedad del suelo) y las variables del vecindario (aglomeraci & oacute;n y da & ntilde;os previos por huracanes). Luego, estimamos la vulnerabilidad mec & aacute;nica de los & aacute;rboles al viento. En los lugares expuestos a vientos cr & oacute;nicos, tres de las cuatro especies crecieron mucho menos (2-4 m) y tuvieron & aacute;reas de copa m & aacute;s peque & ntilde;as. Cecropia schreberiana, en cambio, no mostr & oacute; indicios de cambios inducidos por el viento. La aclimataci & oacute;n arquitect & oacute;nica de tres especies a los vientos cr & oacute;nicos llevaba a una reducci & oacute;n de la vulnerabilidad. Nuestros hallazgos demuestran que la exposici & oacute;n a vientos cr & oacute;nicos puede provocar cambios arquitect & oacute;nicos en los & aacute;rboles tropicales, reduciendo su altura y la superficie de sus copas.

Protecting the environment is essential because a healthy ecosystem purifies air and water, maintains the soil, regulates the temperature, recycles nutrients, and provides food. However, when nations experience fast growth, they pay the utmost attention to their development and disregard the environmental and development-related consequences. The BRICS economies are examples of nations that have achieved high economic growth rates while polluting their environment via industrial expansion. Hence, this study aims to scrutinise the effects of forest rent, agricultural production, economic growth, and energy consumption on BRICS economies' carbon emissions and ecological footprint from 1995 to 2017. We adopted panel spatial correlation consistent least-squares dummy variables (PSCC-LSDV) estimation and panel quantile regression (PQR) techniques to perform the above-mentioned comparative analysis. The first-hand empirical consequences revealed that agricultural production, renewable energy consumption, and financial development condense the carbon discharge, and the rest of the variables trigger the carbon emission. In addition, GDPC, forest rents, non-renewable energy consumption, and domestic investment damage the environmental prominence by instigating an ecological footprint, whereas the remaining variables oblige to moderate the ecological footprint. Finally, this study recommends rigorous policies to mitigate pollution emissions to help reinstate environmental eminence.

Overgrazing is the primary human-induced cause of soil degradation in the Caatinga biome, intensely threatening lands vulnerable to desertification. Grazing exclusion, a simple and cost-effective practice, could restore soils' ecological functions. However, comprehensive insights into the effects of overgrazing and grazing exclusion on Caatinga soils' multifunctionality are lacking. This study examines (i) how overgrazing impacts multiple soil indicators, functions, and overall soil health (SH) and (ii) whether natural early forest growth post-grazing exclusion enhances critical soil functions for ecosystem restoration. We compared preserved dense forests, longterm overgrazed pastures (over 30 years), and young fenced-off open forests (three years old) along a longitudinal transect in the Caatinga biome: 36 degrees W (Sao Bento do Una), 37 degrees W (Sertania), and 40 degrees W (Araripina). Soil samples from the 0-20 cm layer were analyzed for thirteen physical, chemical, and biological indicators for a structured SH assessment, calculating index scores based on soil functions. Forest-to-pasture transition and subsequent overgrazing consistently compacted the soils and decreased nitrogen, carbon (C), microbial biomass C, and glomalin protein, thus degrading the soil's physical, chemical, and biological functions. Regionally, this conversion depleted 14.7 Mg C ha(-1) and reduced overall SH scores by 18%, severely impacting biological functions ( e.g.,-43% for sustaining biological activity). No significant differences in functions or SH were found between grazed pastures and open forests. SH scores and C stocks were highly interrelated (r > 0.5; p < 0.001), suggesting that C losses and SH deterioration were closely aligned. We conclude that overgrazing degrades soil multifunctionality and health across the Caatinga biome, with biological functions most severely damaged and legacies obstructing soil recovery for up to three years of grazing exclusion. Future SH studies should include open forest chronosequences with older ages and active restoration practices ( e.g., planting trees or green manure) to enhance Caatinga's ecological restoration knowledge and efforts.

AimHigh temperatures during forest fires can cause significant damage to tropical dry forest areas and alter their ecological stability, particularly by affecting seed viability and seedling emergence. This study evaluates the seedling emergence response of 18 dry forest species to fire-simulated temperatures, aiming to assess their potential for restoration in fire-prone Colombian ecosystems.LocationThe seeds used in this study were obtained from three tropical dry forests in Colombia.MethodsA total of 9832 seeds from 18 dry forest species were collected directly from the soil seed bank in three tropical dry forests in Colombia. These seeds were then exposed to simulated forest fire temperatures (100 degrees C, 150 degrees C, and 200 degrees C) for 10 min. Seed viability was analyzed using the 2,3,5-triphenyl tetrazolium chloride reagent (tetrazolium test) and assessed using a generalized linear model. Seedling emergence and mean emergence time were evaluated using one-way analysis of variance (ANOVA) with temperature treatments as factors.ResultsThe study revealed that seedling emergence significantly decreased with higher heat shock temperatures. Notably, Hura crepitans and Parkinsonia aculeata tolerated temperatures up to 100 degrees C, while Caesalpinia pulcherrima and Enterolobium cyclocarpum showed increased emergence at that temperature. Based on their emergence responses, species were classified as stimulated, tolerant, sensitive, or vulnerable. Seed viability declined with rising temperatures, and the mean emergence time increased in species like Cordia alba, Crescentia cujete, and Lonchocarpus violaceus.ConclusionsThis study shows that heat shocks at 150 degrees C and 200 degrees C significantly reduced seed bank viability for most Colombian dry forest species. However, Caesalpinia pulcherrima and Enterolobium cyclocarpum were stimulated by 100 degrees C heat shocks, while Hura crepitans and Parkinsonia aculeata showed no adverse effects. Vulnerable species like Coccoloba acuminata and Pithecellobium dulce exhibited no viable seeds at higher temperatures, suggesting potential local extinctions. These results emphasize the need to focus on heat-tolerant species for restoration efforts in fire-prone ecosystems.

Pine wilt disease (PWD) severely damages the health, stability, and functions of pine forests. However, empirical evidence regarding the impact of PWD on multiple ecosystem services in these forest ecosystems remains limited. This study investigated five ecosystem services, namely carbon sequestration, water conservation, soil nutrient accumulation, biomass nutrient accumulation and understory plant diversity in subtropical Masson pine (Pinus massoniana) forests, and quantified their trade-offs along varying ages of PWD infection (uninfected (0 years), 6, 10, and 16 years). The results showed that PWD infection significantly affected ecosystem services in Masson pine forests, with decreased carbon sequestration, water conservation, and biomass nutrient accumulation in 6 years of PWD infection forests. As the duration of PWD infection increased, the composite score of ecosystem services initially decreased, then increased, and finally decreased again. In contrast, soil conservation and understory plant diversity showed an initial increase, followed by a decline. Moreover, PWD infection increased the trade-offs among ecosystem services, with the highest trade-offs for 10 years of infected forests. PWD infection altered the trade-offs between understory plant diversity and other ecosystem services from low to high levels. Our results suggest that forest management should be strengthened to accelerate the recovery of ecosystem services while controlling PWD infection in these disturbed forests.

Forests provide multiple ecosystem services including water and soil protection, biodiversity conservation, carbon sequestration, and recreation, which are crucial in sustaining human health and wellbeing. Global changes represent a serious threat to Mediterranean forests, and among known impacts, there is the spread of invasive pests and pathogens, often boosted by climate change and human pressure. Remote sensing can provide support to forest health monitoring, which is crucial to contrast degradation and adopt mitigation strategies. Here, different multispectral and SAR data are used to detect the incidence of ink disease driven by Phytophthora cinnamomi in forest sites in central Italy, dominated by chestnut and cork oak respectively. Sentinel 1, Sentinel 2, and PlanetScope data, together with ground information, served as input in Random Forests to model healthy and disease classes in the two sites. The results indicate that healthy and symptomatic trees are clearly distinguished, whereas the discrimination among disease classes of different severity (moderate and severe damage) is less accurate. Crown dimension and sampled spectral regions are a critical factors in the selection of the sensor; better results are obtained for the larger chestnut crowns with Sentinel 2 data. In both sites, the red and near infra-red bands from multispectral data resulted well suited to monitor the spread of the ink disease.

Forest parks in megacities are pivotal in boosting biodiversity, purifying air, and offering essential green areas for community leisure and mental health amidst the hustle and bustle of cities. Yet, these vital oases encounter severe difficulties, including habitat degradation, contamination, and urbanization pressures, jeopardizing their preservation and the crucial ecological advantages they offer. The soil 's characteristics and its microbial inhabitants are fundamental in the cycling of nutrients and the well-being of plants, positioning them as central elements in restoration efforts. Nonetheless, the complex interplay among plant, soil, and microbial relationships during the restoration of forest ecosystems in megacities is still not well comprehended. This study aimed to investigate the interactions between plant-soil-microbial dynamics in different ecological restoration modes and construct assessment systems to evaluate the quality of restoration modes in the forest parks. The study identified a total of 25 distinct types of forests damaged by three main factors (farmland, highway, and quarrying) in Chongqing Taisiya Forest Park, and found that long-term natural restoration significantly increased soil properties in these forests. Additionally, an in-depth microbial sequencing analysis showed that Proteobacteria and Ascomycota were the major bacterial and fungal phyla dominant in the restoration process in the urban forests. Further correlation analysis showed that soil microbial diversity positively correlated with plant diversity, with a stronger correlation observed for bacterial communities compared to fungi. The comprehensive evaluation index results for the different forest types revealed varying degrees of restoration success. Collectively, our findings underscore the importance of forest attributes and soil microbial diversity in forest ecosystem restoration and provide valuable insights for designing effective restoration strategies in similar ecosystems.

We tested the hypothesis that the number of seedlings from the soil seed bank (SSB) in forests polluted by heavy metals and disturbed by recent fires decreases. It was also assumed that the consequences of pollution and fires for the soil seed bank are additive. We estimated the number of seedlings from the SSB of pine forests located near the Karabash copper smelter (KCS) (contaminated by Cu, Zn, Pb, and Cd) and from uncontaminated forests of the Ilmen State Reserve (ISR). In both areas, samples of the forest litter and humus horizon were taken from forests recently exposed to ground fires and long-term unburned forests. Samples were exhibited from June to September, conducting seven rounds of counting seedlings. Small peculiarities of the emergence of seedlings on the samples of the forest litter and the humus horizon were established. However, the regularities of the reaction of SSB to pollution and fire disturbances did not depend on the soil horizon. The number of seedlings on substrates from contaminated forests was 5-8 times lower than the number of seedlings on substrates from background forests. A decrease in the number of seedlings on polluted substrates was accompanied by an increase in the share of dicots in the total number of seedlings. The relationship between the number of seedlings and the age of fires was not found. The additivity of the consequences of pollution and fires has also not been established. Of the two types of damage, pollution and fires, the pollution factor is of leading importance for SSBs. The results indicate a low recovery capacity of the herb-shrub layer of polluted forests.

Accurate knowledge of site conditions and their effects on regeneration establishment is important for selecting the most appropriate tree species and regeneration methods for a given regeneration site. This study examined the response of the first-year field performance of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.) and silver birch (Betula pendula Roth.) seedlings in boreal forests to variables available in open forest and natural resources datasets. Survival, height increment and damage of planted tree seedlings and the success of direct seeding of pine were analysed on a total of 284 plots (1000 m(2)) in 18 regeneration experiments established in 2020-2022 in southern and central Finland. The height increment of silver birch was higher than that of conifers, while the lowest mortality rate was found for spruce. In the generalised linear mixed models, topographic wetness index, soil texture, site type and growing stock at clearcut explained the species-specific survival and height increment of planted seedlings and the success of pine seeding. Low-cost, open geospatial data effectively provide useful details on the site conditions suitable for diversifying tree species composition in boreal forests instead of monocultures.

Wood density (WD) is a key functional trait for its importance in tree performance and in biomass calculations of forests. Yet, the variation of WD among different woody tree parts, how this varies across ecosystems, and how this influences estimates of forest carbon stocks remains little understood, particularly for diverse tropical forests such as the Amazon. We assembled a dataset on stem and twig wood density from 119 tree species in three different Amazonian ecosystem types that differ considerably in soil nutrition and flooding: non-flooded forest (Terra Firme), white-water floodplain forest (V & aacute;rzea) and black-water floodplain forest (Igap & oacute;) to investigate (i) variation of stem and twig wood density across ecosystems, (ii) the relationships between stem and twig wood density and how these relationships vary across ecosystems. Wood density varied substantially across ecosystems. V & aacute;rzea species showed lower mean WD for stems compared to Terra firme, while Igap & oacute; species showed higher WD for twigs compared to the other ecosystems. Twig and stem wood density were positively related (R2adj = 0.47) with similarly increasing rates across ecosystems, although average WD values differed between Terra firme and Igap & oacute;. For any given twig density, stem density tends to be lower in floodplain environments but higher in Terra firme, a habitat-specific pattern of wood density variation within trees that may emerge from differences in the function of stem and twig wood for growth and survival in ecologically differentiated environments. Our results show how ecosystem has strong impacts on how trees allocate resources to different woody tissues, suggesting contrasting ecological strategies linked to ecosystem constraints. Our results suggest that greater consideration of the variation of WD within trees and how these changes across ecosystems might lead to more accurate estimates of above-ground biomass in Amazonia.Read the free Plain Language Summary for this article on the Journal blog. A densidade da madeira (WD) & eacute; um tra & ccedil;o funcional chave devido a sua import & acirc;ncia na performance das & aacute;rvores e para os c & aacute;lculos de biomassa em florestas. Entretanto, pouco se conhece sobre a varia & ccedil;& atilde;o da WD entre diferentes partes das plantas, se tal varia & ccedil;& atilde;o muda entre ecossistemas, e como isto influencia as estimativas de estoque de carbono, principalmente em florestas tropicais muito diversas como a Amaz & ocirc;nia. N & oacute;s utilizamos um conjunto de dados de densidade da madeira do tronco e do ramo de 119 esp & eacute;cies de & aacute;rvores de tr & ecirc;s tipos de ecossistemas amaz & ocirc;nicos: florestas de terra firme, florestas alag & aacute;veis de & aacute;guas brancas (V & aacute;rzea) e florestas alag & aacute;veis de & aacute;guas pretas (Igap & oacute;s) e investigamos (i) a variabilidade da densidade da madeira do tronco e do ramo entre ecossistemas, (ii) e a rela & ccedil;& atilde;o entre a densidade da madeira do tronco e a do ramo, e como esta rela & ccedil;& atilde;o varia entre os ecossistemas. A densidade da madeira variou consideravelmente entre os ecossistemas. As esp & eacute;cies de V & aacute;rzea tiveram WD m & eacute;dia do tronco menor comparada a Terra firme, enquanto as esp & eacute;cies de Igap & oacute; tiveram WD m & eacute;dia do ramo maior comparada aos outros ecossistemas. A densidade do ramo e do tronco tiveram correla & ccedil;& atilde;o positiva (R(2)adj = 0.47) e taxas de aumento similares entre os ecossistemas, mas com diferen & ccedil;a nos valores m & eacute;dios de densidade entre Terra firme e Igap & oacute;. Para um dado valor de WD do ramo, a WD do tronco tende a ser menor nas florestas alag & aacute;veis, por & eacute;m maior na Terra firme, um padr & atilde;o de varia & ccedil;& atilde;o na densidade das & aacute;rvores espec & iacute;fico do habitat, que pode surgir de diferen & ccedil;as nas fun & ccedil;& otilde;es do tronco e do ramo para o crescimento e sobreviv & ecirc;ncia das esp & eacute;cies em ambientes ecologicamente distintos. N & oacute;s mostramos como os ecossistemas impactam a aloca & ccedil;& atilde;o de recursos das & aacute;rvores em diferentes tecidos da madeira, sugerindo a exist & ecirc;ncia de estrat & eacute;gias ecol & oacute;gica contrastantes associadas as restri & ccedil;& otilde;es ambientais. Nossos resultados sugerem que considerar a varia & ccedil;& atilde;o da WD de uma & aacute;rvore e como tal varia & ccedil;& atilde;o muda entre ecossistemas pode propiciar estimativas mais acuradas de biomassa na Amaz & ocirc;nia. Read the free Plain Language Summary for this article on the Journal blog.image