Tree Density Research Articles

Investigating the effects of local climate zones on land surface temperature using spectral indices via linear regression model: a seasonal study of Sapanca Lake.

The formation of urban heat islands is a widespread issue in cities. However, the impact of spectral indices on land surface temperature (LST) with various urban forms, climates, and functions has not been sufficiently examined. Currently, the prevalent method for analyzing complex urban areas is the classification of local climate zones (LCZs). In this study, we aim to explore the urban thermal environment by utilizing GIS-based spatial analyses and statistical methods. We also examine LCZs and the temporal-spatial changes of LSTs in Sapanca Lake and its surroundings. A comparative analysis was conducted on the relationship between the normalized difference vegetation index (NDVI), the modified normalized difference water index (MNDWI), and the normalized difference built-up index (NDBI) spectral indices in different LCZs and LST using a linear regression model. The results showed that all LCZs experienced a warming effect with an increase in NDBI, while they exhibited a cooling effect with the influence of NDVI and MNDWI. Notably, NDVI demonstrated a strong cooling effect in LCZ A (Dense trees) during the summer season, with an R2 coefficient of 0.73. Similarly, MNDWI had an R2 coefficient of 0.73 in LCZ A during spring. Values calculated as a result of regression are found as MAE:0.72 and MSE:0.75. These findings indicate the cooling effect of urban areas characterized by dense trees and water surfaces, highlighting their role in reducing LST. As a result, the research revealed the role of urban green systems and water surfaces in reducing the heat island effect, which is a problem, especially in urban centers. Overall, the study's results contribute to a better understanding of the thermal environmental characteristics in complex urban settings.

Factors Influencing Emergence Timing Patterns of Long-Tailed Bats in Exotic and Native Forest in New Zealand.

Understanding temporal behavioural patterns in animals can be crucial to their conservation management. Emergence timing in bats, that is, the decision on when to depart day-roosts for foraging, is one such example and is well studied in Northern Hemisphere bats. The emergence timing of New Zealand long-tailed bats (Chalinolobus tuberculatus) is not yet fully understood, including when and where they may be vulnerable to threats. We investigated factors influencing long-tailed bat emergence timing in the Kinleith Forest (exotic plantation, 38° S) and the Eglinton Valley (native beech forest, 45° S). We recorded emergence times during late pregnancy through post-lactation (October to March), to determine whether the month, temperature at sunset, tree density, cloud cover, presence of rain and the number of bats within a roost influenced emergence timing. Most long-tailed bats emerged after sunset in the Kinleith Forest, whilst 80% of first emerging bats departed before sunset in the Eglinton Valley where nights are much shorter in summer, reducing foraging time. Month, temperature at sunset, and roost population size were the most important predictors of emergence timing at both sites. Long-tailed bats in the Kinleith Forest also emerged earlier as tree density increased, a pattern potentially associated with predator defence. The factors influencing long-tailed bat emergence timing are likely context dependent, namely latitude and habitat structure, which has implications for roost protection protocols, timing of bat surveys and interpretation of bat acoustic monitoring data.

Potential for Augmenting Water Yield by Restoring Longleaf Pine (Pinus palustris) Forests in the Southeastern United States

AbstractOver 95% of original longleaf pine (Pinus palustris) (LLP) forests have been converted to other land uses, including loblolly pine (Pinus taeda L) (LOP), croplands, urban uses during the past two centuries in the southeastern United States (U.S.) for socioeconomic developments. Restoring the LLP forests represents a contemporary forest management objective to improve wildlife habitat, water yield, and overall ecosystem services and resilience to a changing climate. Given the importance of understanding ecohydrological processes for guiding restoration efforts, this study compared evapotranspiration (ET) measurements at eight eddy covariance flux sites dominated by LLP or LOP forests in the southeastern U.S. In addition, we developed a “paired stands” approach to compare remote sensing based ET estimates and associated site biophysical properties for approximately 1,600 LLP‐LOP pairs. We found significant differences in ET, ET/Precipitation ratio, and water yield/precipitation ratio between the two types of pine forests, and these differences are explained by surface properties and management histories. Compared to LOP, the LLP forests generally had lower ET due to their significantly (p < 0.05) lower leaf area index but higher land surface temperature and albedo. Regionally, forest ET differences increased with the increase in atmospheric dryness index (reference ET/precipitation ratio). Therefore, we conclude that large‐scale restoration of LLP forests has the potential to reduce ET and augment water yield in the long run, especially in relatively drier watersheds. Maintaining low stand tree density and understory leaf area characteristic of natural LLP ecosystems through active forest management is critical for enhancing forest water supply. Our study provides the scientific basis for large scale restoration of a diminishing ecosystem for benefiting water resources in the southeastern U.S.

What is left in miombo woodlands? Rarity and commonness of woody species, commercial timber species, and lawful harvestable diameter classes.

Mozambican miombo woodlands (MWs) have been experiencing severe anthropogenic threats, recognized to have an impact on plant species distribution, occurrence, diversity, and rarity patterns. Based on 3725 0.1ha plots distributed across the country's MWs, this study aimed to assess the species rarity and commonness, protection status, and availability of commercial timber in MWs under varied environmental conditions. Results show that, out of the 515 tree and shrub species found, 45% were rare, while just 10% were highly protected. Nine of the 112 commercial miombo species were not observed, and 15 were rare. Commercial-sized trees of the top nine desired species were extremely rare, some species had only 1 tree per 20ha and stem forms unsuitable for sawmilling. Selective overharvesting has also affected trees with no minimum felling diameter. Brachystegia spiciformis, B. boehmii, and Julbernardia globiflora stood out among the few timber species with commercially viable populations. MWs in the semi-arid ecoregion have lower species richness, fewer commercially viable populations, and a higher number of poorly protected species (51%). The rainy ecoregion has the highest percentage of poorly protected species (61%). Based on the results obtained, it was recommended that (1) timber harvesting should be restricted to the humid ecoregion, prohibited for the timber species that were either absent or rare, and halted for the top nine desired species; (2) except B. spiciformis, B. boehmii, and J. globiflora, MWs should preferably undergo a forest closure period corresponding to at least one cutting cycle; (3) to ensure long-term viability, a minimum harvestable density for commercial-sized trees should be determined for each species.

Estimation of Carbon Density in Different Urban Green Spaces: Taking the Beijing Main District as an Example

Urban green spaces (UGS) are crucial urban elements that serve as direct carbon sequestration and contribute to indirect carbon emission reduction. Accurately calculating the carbon density of urban green spaces allows for scientific planning and design, thereby advancing efforts toward achieving carbon neutrality. This study has developed a workflow for estimating carbon density in urban green spaces through point cloud measurements and model simulations, using the UGS in the Beijing Main District as a case study. From the sample level, a calculation methodology was constructed based on the point cloud technology-model simulation method, which can obtain the carbon density at the plant level and the sample level. At the UGS level, remote sensing inversion was utilized to map the carbon density of urban green spaces. Ultimately, the research calculated and compared carbon density at different scales, including the carbon density of individual plants, the carbon density of sample plots, and the carbon density of various types of urban green spaces. It was found that the carbon density of trees in UGS was 9.87 kg/m2, while those of shrubs and herbaceous plants were 13.20 kg/m2 and 0.11 kg/m2. In urban green spaces, the carbon densities of the tree and herb layers were slightly lower than those in natural ecosystems, whereas the carbon density of the shrub layer was significantly higher. This highlights the substantial potential and value of shrubs in carbon sequestration and carbon storage. The average carbon density of all UGS types was 9.76 kg/m2, with the following descending order: Neighborhood Parks (10.31 kg/m2) > Attached Green Spaces (7.22 kg/m2) > Regional Parks (5.75 kg/m2). Based on these findings, the study proposed optimization strategies for different UGS types, focusing on high carbon-density plant community optimization. The goal is to provide a theoretical foundation for carbon storage calculations and plant arrangements in future UGS construction.

Forest Stem Extraction and Modeling (FoSEM): A LiDAR-Based Framework for Accurate Tree Stem Extraction and Modeling in Radiata Pine Plantations

Accurate characterization of tree stems is critical for assessing commercial forest health, estimating merchantable timber volume, and informing sustainable value management strategies. Conventional ground-based manual measurements, although precise, are labor-intensive and impractical at large scales, while remote sensing approaches using satellite or UAV imagery often lack the spatial resolution needed to capture individual tree attributes in complex forest environments. To address these challenges, this study provides a significant contribution by introducing a large-scale dataset encompassing 40 plots in Western Australia (WA) with varying tree densities, derived from Hovermap LiDAR acquisitions and destructive sampling. The dataset includes parameters such as plot and tree identifiers, DBH, tree height, stem length, section lengths, and detailed diameter measurements (e.g., DiaMin, DiaMax, DiaMean) across various heights, enabling precise ground-truth calibration and validation. Based on this dataset, we present the Forest Stem Extraction and Modeling (FoSEM) framework, a LiDAR-driven methodology that efficiently and reliably models individual tree stems from dense 3D point clouds. FoSEM integrates ground segmentation, height normalization, and K-means clustering at a predefined elevation to isolate stem cores. It then applies circle fitting to capture cross-sectional geometry and employs MLESAC-based cylinder fitting for robust stem delineation. Experimental evaluations conducted across various radiata pine plots of varying complexity demonstrate that FoSEM consistently achieves high accuracy, with a DBH RMSE of 1.19 cm (rRMSE = 4.67%) and a height RMSE of 1.00 m (rRMSE = 4.24%). These results surpass those of existing methods and highlight FoSEM’s adaptability to heterogeneous stand conditions. By providing both a robust method and an extensive dataset, this work advances the state of the art in LiDAR-based forest inventory, enabling more efficient and accurate tree-level assessments in support of sustainable forest management.

Sparse subalpine forest recovery pathways, plant communities, and carbon stocks 34 years after stand‐replacing fire

AbstractChanging global climate and wildfire regimes are threatening forest resilience (i.e., the ability to recover from disturbance). Yet distinguishing areas of “no” versus “slow” postfire forest recovery is challenging, and consequences of sparse tree regeneration for plant communities and carbon dynamics are uncertain. We studied previously forested areas where tree regeneration remained sparse 34 years after the large, stand‐replacing 1988 Yellowstone fires (Wyoming, USA) to ask the following questions: (1) What are the recovery pathways in areas of sparse and reduced forest recovery and how are they distributed across the landscape? (2) What explains variation in postfire tree regeneration density (total and by species) among sparse recovery pathways? (3) What are the implications of sparse recovery for understory plant communities? (4) How diminished are aboveground carbon stocks in areas of sparse postfire forest recovery? Tree densities and species‐specific age distributions, understory plant communities, and carbon stocks were sampled in 55 plots during summer 2022. We detected three qualitatively distinct sparse recovery pathways (persistent sparse or non‐forest, continuous tree infilling, and recent seedling and sapling establishment). Nearly half of the plots appeared “locked in” as persistently sparse or non‐forest, while the remaining may be on a slow path to forest recovery. Plots with nearby upwind seed sources as well as in situ seed pressure from young postfire trees appear likely to recover to forest. Where trees were sparse or absent, plant communities resembled those found in meadows, capturing compositional changes expected to become more common with continued forest loss. However, forest‐affinity species persisted in mesic locations, indicating mismatches between some plant communities and future forest change. Aboveground carbon stocks were low owing to minimal tree reestablishment. Almost all (96%) carbon was stored in coarse wood, a sharp departure from C storage patterns where forests are recovering. If not offset by future tree regeneration, decomposition of dead biomass will protract postfire aboveground carbon stock recovery. As global disturbance regimes and climate continue to change, determining the drivers of ecosystem reorganization and understanding how such changes will cascade to influence ecosystem structure and function will be increasingly important.

First Record of the Northern Spotted Owl Nesting in Forest Burned at the Highest Level of Severity

An instance of the Northern Spotted Owl (Strix occidentalis caurina) nesting successfully in severely burned forest indicates that under some circumstances, such habitat may indeed provide the species suitable habitat. Current forest-management approaches treat wildfire as the primary cause of habitat loss for both the Northern and California (S. o. occidentalis) Spotted Owls. Assumptions that severely burned forest does not provide any viable nesting or roosting habitat for these Spotted Owl subspecies has resulted in substantial post-fire logging and removal of burned trees throughout both owls’ ranges. In addition, forest management intended to prevent severe fires may entail thinning of unburned Spotted Owl habitat to reduce tree density and potential fuel loads. In the Mendocino National Forest of western Glenn County, California, I followed a pair of Northern Spotted Owls nesting and roosting deep within a large patch of severely burned forest two years after a fire, in a stand with no post-fire salvage logging, pre-fire thinning, fuels reduction, or attempts at restoration. A pair of Spotted Owls had used this location consistently since 1990, and the territory remained occupied with owls roosting and nesting successfully in 2022, despite 73% of the territory burning at high severity in 2020.

Shifting Cultivation—A Way of Life of Kandhas of Kandhamal: Is it Under Threat?

Forest is a complex phenomenon characterized by distinct configurations of vegetation and wildlife. Human interference shapes its development under specific climate conditions. The continuous practice of slashing and burning changes the patterns of vegetation and animal populations. Critics perceive shifting cultivation as an environmentally harmful practice, while others argue that it is a specific adaptation to forests and hill environments. This article examines the existing shifting cultivation practices of the Kandha tribe in Odisha, India. The Kandha contest the dominant narratives on shifting cultivation, or poduchas, and argue to assert their rights over the forest and nature. They claim themselves to be the “Sons of the Soil” and forest inhabitants. Their life-worlds and culture rely on their symbiotic relationship with nature. This worldview intertwines the practice of living in “nature” with agriculture, which is considered a separate activity. However, today economic “development” and sociocultural changes have broken down the relationships between the Kandha tribe and their natural habitat. They resent the presence of exploitative traders and governments who have forced poduchas to become their primary means of subsistence. Resistance to market-mediated relations and the resilience of traditional food collection methods characterize present-day living. As a result, the Kandhas continue living the way they are familiar with, favoring both the people and nature. The present article, based on ethnographic field research, examines the changing practices and worldviews embedded in the sociocultural as well as economic lives of the Kandhas.

Post-Fire Restoration of the Vegetation at the Cemetery of the Tatoi Estate Historical Site

The restoration of historical landscapes is crucial for preserving the cultural heritage. This study focuses on the cemetery of the former royal Tatoi estate, a historical site severely damaged by a wildfire in 2021. The fire almost completely eradicated the vegetation on Palaeokastro hill, necessitating a comprehensive vegetation restoration strategy. This research aims to restore the natural environment and historical landscape landmarks and improve future fire protection conditions. This study emphasizes creating a firebreak zone through thinning vegetation, aiding natural regeneration, and planting new seedlings, particularly Aleppo pines and cypresses. We recommend thinning interventions to reduce tree density, which improves the health of the remaining trees and lowers the fire risk. Additionally, the restoration of historical pathways, including cypress-lined routes, is proposed to preserve the cultural landscape. This study underscores the importance of maintaining the historical integrity and enhancing the resilience of the landscape against future fires.

Species Diversity, Biomass Production and Carbon Sequestration Potential in the Protected Area of Uttarakhand, India.

Ecosystem functioning and management are primarily concerned with addressing climate change and biodiversity loss, which are closely linked to carbon stock and species diversity. This research aimed to quantify forest understory (shrub and herb) diversity, tree biomass and carbon sequestration in the Binsar Wildlife Sanctuary. Using random sampling methods, data were gathered from six distinct forest communities. The study identified 271 vascular plants from 208 genera and 74 families. A notable positive correlation (r2 = 0.085, p < 0.05) was observed between total tree density and total tree basal area (TBA), shrub density (r2 = 0.09), tree diversity (D) (r2 = 0.58), shrub diversity (r2 = 0.81), and tree species richness (SR) (r2 = 0.96). Conversely, a negative correlation was found with the concentration of tree dominance (CD) (r2 = 0.43). The Quercus leucotrichophora, Rhododendron arboreum and Quercus floribunda (QL-RA-QF) community(higher altitudinal zone) exhibited the highest tree biomass (568.8 Mg ha-1), while the (Pinus roxburghii and Quercus leucotrichophora) PR-QL (N) community (lower altitudinal zone) in the north aspect showed the lowest (265.7 Mg ha-1). Carbon sequestration was highest in the Quercus leucotrichophora, Quercus floribunda and Rhododendron arboreum (QL-QF-RA) (higher altitudinal zone) community (7.48 Mg ha-1 yr-1) and lowest in the PR-QL (S) (middle altitudinal zone) community in the south aspect (5.5 Mg ha-1 yr-1). The relationships between carbon stock and various functional parameters such as tree density, total basal area of tree and diversity of tree showed significant positive correlations. The findings of the study revealed significant variations in the structural attributes of trees, shrubs and herbs across different forest stands along altitudinal gradients. This current study's results highlighted the significance of wildlife sanctuaries, which not only aid in wildlife preservation but also provide compelling evidence supporting forest management practices that promote the planting of multiple vegetation layers in landscape restoration as a means to enhance biodiversity and increase resilience to climate change. Further, comprehending the carbon storage mechanisms of these forests will be critical for developing environmental management strategies aimed at alleviating the impacts of climate change in the years to come.

Estimating Vegetation Density Dynamics, Tree Diversity, and Carbon Stock in the Agroforestry System of the Community Forest in Bogor Regency, Indonesia

Mitigation actions to address climate change are essential to prevent future adverse impacts, with woody species in forests playing a pivotal role in carbon storage, as exemplified by the agroforestry systems commonly practiced in community forests of Bogor Regency, which integrate woody species and crops. This study aimed to analyze changes in vegetation density using the Normalized Difference Vegetation Index (NDVI) approach, analyze stand structure and composition, and estimate above-ground carbon stocks in the agroforestry land of community forest in Tenjolaya Sub-District, Bogor Regency. The methods used were spatial analysis with NDVI, vegetation analysis, and carbon stock estimation using allometric and destructive methods. The plot size was 50 m × 50 m, totaling 21 plots. NDVI analysis resulted in low density (0.59–0.67), moderate density (0.67–0.78), and high density (0.78–0.85). This study found 178 plant species across 40 families, with Fabaceae and Myrtaceae being the most dominant. The carbon stock is 27.69 tons carbon/ha. Carbon stock is significantly influenced by tree density, number of species, and basal area values. A well-managed community forest has high ecological, economic, and social potential through the development of agroforestry, which can maintain biodiversity and environmental sustainability while storing carbon stocks. Keywords: above-ground carbon, agroforestry, community forest, normalized difference vegetation index, vegetation density

A Stocking Diagram for Even-aged Mixed Pine-Fir Stands of Kastamonu Region

Forest stand density diagrams help forest managers and practitioners more effectively manage stand density and tree occupancy to meet specific silvicultural goals. Therefore, creating such auxiliary silvicultural tools for different stands is essential. To our knowledge, no relative density graphs or diagrams have been developed for mixed stands in Türkiye. This study aimed to develop a stocking diagram for mixed Scots pine (Pinus sylvestris L.)-Kazdağı fir (Abies nordmanniana subsp. equi-trojani) stands. In the study, statistical relations between stocking percent and diameter increment in selected sample plots were also determined, and these statistical relations were compared with the "stand basal area-diameter increment relations" in the same sample plots. Stand stocking percent was found to be more descriptive than absolute density measurement units (i.e., basal area) in defining stand density in mixed Scots pine-Kazdağı fir stands. The resulting stock diagram may allow more effective use of stand growing space to achieve various silvicultural goals, including regeneration, thinning, and wildlife protection in mixed Scots pine- Kazdağı fir stands. Depicting various density measures including basal area, trees per ha, and stand stocking percent, the findings of this study would facilitate the tree density management in mixed Scots pine- Kazdağı fir stands.

Enhancement of Vegetation Cover through Farmer Managed Natural Regeneration in the Central Rift, Kenya

Purpose: This paper discusses the contribution of Kenya Central Rift Farmer-Managed Natural Regeneration Scale-up project (CRIFSUP) to enhanced vegetation cover through promotion of Farmer Managed Natural Regeneration concept among farmers in central rift region, Kenya. The project ran between July 2017 and June 2021, when it transitioned to a further five-year phase. The goal of this paper is to assess and compare changes in vegetation cover and species composition through FMNR and other evergreen agricultural practices in CRIPSUP and outside project areas in Central Rift Kenya. Methodology: The study was undertaken in three counties that included; Elgeyo-Marakwet, Nakuru and Baringo. The Study sites were Ndabibi sub-County in Nakuru County, Marigat sub-County in Baringo County, and sub-County Ng’oswet in Elgeyo Marakwet. This study employed cross-sectional study design where there was evaluation of changes in tree density and tree species composition before and after the Intervention of CRIFSUP project in Central Rift, Kenya. Both qualitative and quantitative data were used to investigate and analyse the critical study findings. The data collection methods included surveys, focus group discussions, key informant interviews, and observations. Multi-stage sampling was applied in this study. In total, 402 households out of a sample size 426 participated in the household survey in the study. Findings: The total acreage of land under FMNR managed in the project area increased from 500 acres at inception in 2017 to 4,588 acres in 2019 then to 6,938 acres in project year 2021. This was attributed to farmers recognising benefits of FMNR such as increased pasture, firewood, honey, milk production and training to replicating farmers. The average number of trees per hectare in areas practising FMNR was 115.9; significantly higher compared to areas where there was no FMNR practice such as community land allocated to individual households where average number of trees per hectare was 69.89. Farm boundaries recorded the lowest number of tree populations at 12.47 trees/ha and 14.5 trees/ha before and after project intervention, respectively. There was however, no significant difference in tree densities along the boundaries and among the control farmers before and after project intervention (p = 0.08). To the contrary, tree densities for farmlands, communal land and overall, in the area of project operation were significantly higher after intervention of CRIFSUP project (p = 0.02). This was attributed to increased knowledge on FMNR practices as where 45.0 % (n =181) of farmers indicated knowledge on natural regeneration of trees, while 27.9% (n = 112) displayed knowledge on protection of naturally regenerated trees and seedlings. In conclusion, FMNR and other evergreen methods were found to enhance vegetation cover and through enhanced tree densities and tree diversity in the three regions. Unique Contribution to Theory, Practice and Policy: The study recommends expanding FMNR training to raise awareness and adoption among farmers. Efforts should be made to overcome challenges affecting tree densities on farm boundaries. Additionally, scaling up FMNR practices to other regions and monitoring long-term impacts on biodiversity and ecosystem services are suggested.

Carbon and nutrient solubility in live and dead Betula pubescens leaves across a boreal retrogressive chronosequence

Leaching – the release of elements from organic matter through dissolution in water – plays an important role in biogeochemical cycling and ecosystem processes. However, our limited understanding of the patterns and underlying drivers of element solubility in leaves hinders accurate predictions of leaching over space and time in terrestrial ecosystems. In this study, we quantify the solubility of carbon (C), nitrogen (N) and phosphorus (P) from leaves of Betula pubescens – a widespread boreal tree species – across a post‐fire retrogressive chronosequence. We then relate solubility to variation in leaf‐level traits and ecosystem properties (e.g. soil chemistry, tree density and productivity) across the chronosequence to quantify micro‐ and macro‐scale determinants of leaching. We find that P is much more soluble than C and N and is released in solution mainly in readily accessible mineral form. Solubility patterns are strongly related to foliar chemical and structural traits, particularly for green leaves. Metrics related to ecosystem properties exert a stronger influence over solubility from senesced leaf litter. Overall, our results indicate that leaching could constitute an important flux of nutrients to the soil, particularly for P. The rate and spatio‐temporal pattern of this leaching flux may be predicted from foliar traits and ecosystem properties. Further application of the method should allow for rapid integration of leaching‐related foliar traits into broader plant trait frameworks and models of ecosystem biogeochemical cycling.

Effects of Stand Structural Characteristics, Diversity, and Stability on Carbon Storage Across Different Densities in Natural Forests: A Case Study in the Xiaolong Mountains, China

The carbon storage in forest ecosystems is closely linked to biomass, and its dynamic changes are of significant importance for assessing forest structure and function, as well as their response to global climate change. Recently, the research on the influencing mechanism of forest carbon storage has been a hotpot in the field of forest ecology. However, it remains unclear on the relationships among stand structure, stand stability, and carbon storage. The issues needed to be answered are as follows: How are tree density, tree species diversity, stand structural characteristics, stand stability, and carbon storage correlated? Is there a direct or indirect effect between tree density, tree species diversity, stand structural characteristics, stand stability, and carbon storage? Do these factors have an impact on stand stability, and, subsequently, carbon storage? What is the crucial factor in the mechanism that influences carbon storage? Here, the natural Quercus mongolica forests in the Xiaolong Mountains were taken as the research object. Several methods, including Pearson’s correlation, the best-fitting SEM, and multiple regression, were used to examine the relationships among tree density, tree species diversity, stand structural characteristics, stand stability, and carbon storage. Our results show that there were correlations between tree density, tree species diversity, stand structural characteristics, stand stability, and carbon storage. Tree density not only directly affects stand stability but also indirectly influences it through the mediation of tree species diversity and stand structural characteristics. Meanwhile, tree density also indirectly influences carbon storage through the mediation of tree species diversity, stand structural characteristics, and stand stability. Crown volume exerts the greatest influence on stand stability, while carbon storage is mostly impacted by stand stability. Overall, the combination of tree density, tree species diversity, stand structural characteristics, and stand stability influences carbon storage (66.4%). Therefore, it is important to consider stand stability when assessing carbon sequestration potentials; furthermore, the importance of tree density, tree species composition, and stand structural characteristics should be emphasized. Our research provides a scientific basis for conservation and management decision-making in natural forests and offers novel insights as well as a scientific reference for future large-scale carbon storage investigations.

Invariant Spatial Pattern Across Mediterranean Scrublands in the Iberian Pear (Pyrus bourgaeana).

The spatial distribution pattern of plant species is frequently driven by a combination of biotic and abiotic factors that jointly influence the arrival, establishment, and reproduction of plants. Comparing the spatial distribution of a target plant species in different populations represents a robust approach to identify the underlying mechanisms. We mapped all reproductive individuals of the Iberian pear (Pyrus bourgaeana) in five plots (1.39-8.57 km2) differing in the activity of seed dispersers and vertebrate herbivores in southern Iberian Peninsula. We used Thomas point process models to quantify the consistency in the spatial pattern and the level of spatial aggregation of this mammal-dispersed tree among the five populations. We tested two hypotheses: (i) because the clumped defecation behavior of some dispersers can lead to local tree aggregation, and because denser groups of fruiting trees can limit seed dispersal by attracting frugivores to specific sites, we expected a consistent small-scale aggregation pattern across all populations; and (ii) because ungulates reduce recruitment by preying on seeds and seedlings, we hypothesize that ungulate activity will show negative relationships with tree density and level of aggregation. Our spatial analysis revealed consistent and highly aggregated small-scale patterns of all Iberian pear populations, with one critical scale aggregation, a low density of clusters and high variability in the number of trees per cluster. Ungulate activity and the number of trees per cluster showed a marginally significant negative correlation, suggesting that in areas with higher ungulate activity, trees tend to form less dense clusters. Although several of the underlying processes varied greatly among the five study sites, the Iberian pear showed a relatively consistent spatial pattern with just quantitative nuances throughout the entire region. This result has significant implications for the reproductive success of the species, management strategies, and ultimately the long-term persistence of populations.

Initial Stand Volume and Residual Live Trees Drive Deadwood Carbon Stocks in Fire and Harvest Disturbed Boreal Forests at North-Central Alberta.

Retention forestry involves leaving single or groups of unharvested trees within harvest areas. Patch retention, which resembles structures such as unburned patches remaining after wildfire, is one practice implemented within the framework of Ecosystem-based Forest Management (EBM), which seeks to use natural forests as a model and minimize differences in natural and managed forests. Despite the widespread adoption of patch retention practices, few comparisons of the attributes of postfire and postharvest islands, or their drivers, have been made. Given the importance of deadwood in forests to a variety of ecosystem functions, we sought to compare the local bioenvironmental drivers of deadwood (snags, CWD) C stocks in islands remnants in postfire and postharvest forests a decade after disturbance. We also determined whether their relative effects are consistent across deadwood types (snags, CWD) and disturbance regimes using generalized additive mixed models with study site as random factor in all cases. A candidate model with initial stand volume (ISV), basal area of live trees, and size heterogeneity of live trees best predicted snag and CWD C stocks in both disturbance types, but their relative importance was inconsistent. The ISV had significantly (p < 0.05) positive effects on C stocks in snags and CWD across disturbance types, but its relative effects was higher in retention islands than fire islands. In all cases, stand density of remnant live trees was negatively related to deadwood C stocks. Conversely, the size heterogeneity of remnant live trees significantly boosted deadwood C stocks in fire islands but not in harvest islands. The results imply consideration for the stocking level of candidate forest areas for retention patches as this drives the evolution of deadwood accumulation in the postharvest islands.

Mechanism for Achieving Balance between Ecological Conservation and Community Forest Products Benefits: A Case Study of a Typical National Park in China

Abstract The establishment of national nature reserves has led to the protection of ecosystem diversity. In the context of China’s ecological protection system, controversies have arisen over the guarantee of dwellers’ well-being from forestland. This study uses Wuyi Mountain National Park (WYMNP) in China as an example to discuss the balance between ecological conservation and forest community benefits from forest products. Based on a cross-sectional survey, a logit regression method was adopted to explore factors influencing the ability of forestland holders within WYMNP to make productive financing decisions for forest production without policy intervention. Additionally, the government’s integrated management strategy that accelerates positive social externalities was explored. The results reveal that: before the establishment of WYMNP, forestland holders in this region that operated in the nontimber forest product (NTFP) industry had more incentives to make proactive productive financing decisions on forest production; second, enterprise forestland holders were more motivated to expand their forest products operations than individual forestland holders; finally, after the establishment of WYMNP, the government departments conducted adaptive policies including redemption of forestland and classifying the extent to which production activities could be performed. The government provides a compromise solution that supplies long-running payments in core ecological conservation areas to secure dwellers’ livelihoods, while in regular control areas, the opportunity to operate the NTFP industry is finitely provided with regular monitoring. This strategy provides insight that holistic optimization for the development of forest communities and dwellers could be incorporated into the mechanisms for the management of national parks globally.

Langue Durée of More-than-Human-Sociality of Gorski Kotar Forests and Contemporary Environmental Challenges

The article analyzes contemporary environmental challenges in the forests of Gorski Kotar through the prism of more-than-human sociality. It delves into the impact of human forest management dating back to the 19th century which initiated a complex series of adaptations of plants and insects to new circumstances. This has led to contemporary environmental issues, such as the fir moth infestation and the correlated damage from ice storms. The sociality of Gorski Kotar forests is approached from the perspective of dynamic relationships between species that create a forest meshwork of social relationships, including the fir moth, beech, fir, and humans. This perspective also includes nature's response to changes in environmental conditions (climate change), and a critical description of human activities because they frame the subject of research (forest management). The text shows that certain forest disasters, such as an infestation of the fir moth (including the correlated damage from ice storms), occur as a result of a complex set of interconnected relationships between several species that were initiated several centuries ago. The text also asserts that if humans wish to remain a part of the vital forest ecosystem, they must align their interests and techniques with other forest inhabitants and start to consider the ecological, economic, and symbolic values of the forest with equal importance.