Search Results (37)

Rapid urbanization reduces green space and increases urban stressors, yet the mechanisms linking urban forests to residents’ subjective well-being remain incompletely understood. This study examines how perceived access, perceived quality, visitation frequency, and satisfaction with urban forests relate to citizens’ subjective well-being in Tehran. Using an online survey of 672 residents and structural equation modeling, this study estimates direct and indirect pathways among the constructs. The results show perceived access is the strongest predictor, raising visitation, satisfaction, and well-being, while perceived satisfaction is the most powerful direct driver of subjective well-being. Perceived quality positively affects well-being but with a smaller effect, and visitation frequency alone does not significantly improve well-being, underscoring that positive experiential factors such as satisfaction matter more than visit counts. The model explains 69.8% of variance in subjective well-being. This study refines the current theoretical foundation by integrating access, quality, frequency, and satisfaction within a single conceptual framework in a megacity context and directly comparing the relative strengths of accessibility versus quality as pathways to well-being. In the context of current knowledge it is among the first to test these comparative pathways using a large Tehran sample. Practically, these findings suggest that urban policy should prioritize equitable access and design that fosters satisfying experiences, not just increasing visit counts. Future research should use longitudinal or experimental designs, incorporate objective measures, compare multiple cities and types of green spaces, and explore moderators such as perceived safety, motivations for visiting, and place attachment to refine causal understanding and policy guidance. Full article

Urban green spaces are increasingly recognized for their capacity to support mental health and enhance positive affect through interaction with nature. As a significant component of urban green infrastructure, urban forests provide restorative environments that contribute to individuals’ subjective well-being. This study investigates the effects of quality of experience in urban forest visits on individuals’ restorative experiences and subjective well-being levels. Data were collected via a structured questionnaire from 385 participants who visited an urban forest and analyzed using structural equation modeling (SEM). The findings reveal that quality of experience exerts both direct and indirect positive effects on subjective well-being, with restorative experience serving as a partial mediator in this relationship. Full article

Driven by climate change and human activities, the expansion of highly invasive moso bamboo (Phyllostachys edulis) into coniferous forests induces a serious ecological imbalance. Its rapidly spreading underground roots significantly alter soil structure, yet the mechanisms by which this expansion affects soil detachment capacity (Dc), a key soil erosion parameter, remain unclear. While bamboo expansion modifies soil physicochemical properties and root characteristics, influencing Dc and, consequently, soil erosion resistance, the underlying mechanisms, particularly stage-specific variations, are not thoroughly understood. In this study, we examined Japanese white pine (Pinus parviflora Siebold & Zucc.) forest (CF), moso bamboo–Japanese white pine mixed forest (MF), and moso bamboo forest (BF) as representative stages of bamboo expansion. By integrating laboratory-controlled measurements of soil physicochemical properties and root traits with field-based flume experiments, we comprehensively investigate the effects of moso bamboo expansion into CF on soil detachment capacity. The results of the study can be summarized as follows: (1) Expansion of moso bamboo significantly changed soil physicochemical properties and root characteristics. Soil bulk density was the highest in the MF (1.13 g·cm⁻³), followed by the CF (1.08 g·cm⁻³) and BF (1.03 g·cm⁻³); non-capillary porosity increased significantly with expansion (CF 0.03% to MF 0.10%); and although the stability of aggregates (MWD) increased by 24.5% from the CF to MF, root mass density (RMD) in the MF (0.0048 g·cm⁻³) was much higher than that in the CF (0.0009 g·cm⁻³). This intense root competition between forest types, combined with increased macroporosity development, compromised overall soil structural integrity. This weakening may lead to a looser soil structure during the transition phase, thereby increasing erosion risk. (2) There were significant stage differences in Dc: it was significantly higher in the MF (0.034 kg·m⁻²·s⁻¹) than in the CF (0.023 kg·m⁻²·s⁻¹) and BF (0.018 kg·m⁻²·s⁻¹), which revealed that the MF was an erosion-sensitive stage. (3) Our Partial Least Squares Structural Equation Modeling (PLS-SEM) results revealed that soil physicochemical properties (soil moisture content and soil total nitrogen) dominated Dc changes through direct effects (total effect −0.547); in comparison, root properties indirectly affected Dc by modulating soil structure (indirect effect: −0.339). The results of this study reveal the dynamics and mechanisms of Dc changes during bamboo expansion, and for the first time, we identify a distinct Dc peak during the mixed forest transition phase. These findings provide a scientific basis for moso bamboo forest management, soil erosion risk assessment, and optimization of soil and water conservation strategies. Full article

The priming effect (PE), a microbially mediated process, critically regulates the balance between carbon sequestration and mineralization. This study used soils from different soil depths (0–20 cm, 20–40 cm, and 40–60 cm) under Picea schrenkiana forest in the Tianshan Mountains as the research object. An indoor incubation experiment was conducted by adding three concentrations (1% SOC, 2% SOC, and 3% SOC) of ¹³C-labelled glucose. We applied ¹³C isotope probe-phospholipid fatty acid (PLFA-SIP) technology to investigate the influence of readily labile organic carbon inputs on soil priming effect (PE), microbial community shifts at various depths, and the mechanisms underlying soil PE. The results indicated that the addition of ¹³C-labeled glucose accelerated the mineralization of soil organic carbon (SOC); CO₂ emissions were highest in the 0–20 cm soil layer and decreased trend with increasing soil depth, with significant differences observed across different soil layers (p < 0.05). Soil depth had a positive direct effect on the cumulative priming effect (CPE); however, it showed negative indirect effects through physico-chemical properties and microbial biomass. The CPE of the 0–20 cm soil layer was significantly positively correlated with ¹³C-Gram-positive bacteria, ¹³C-Gram-negative bacteria, and ¹³C-actinomycetes. The CPE of the 20–40 cm and 40–60 cm soil layers exhibited a significant positive correlation with cumulative mineralization (CM) and microbial biomass carbon (MBC). Glucose addition had the largest and most significant positive effect on the CPE. Glucose addition positively affected PLFAs and particularly microbial biomass. This study provides valuable insights into the dynamics of soil carbon pools at varying depths following glucose application, advancing the understanding of forest soil carbon sequestration. Full article

The nitrogen (N) and phosphorus (P) additions were commonly used to improve plantation quality. However, the balance between nutrient uptake in the underground part and nutrient utilization in the aboveground part of Pinus elliottii (Slash pine) plantation in subtropical regions after N and P addition is still unclear. We conducted the experiment using a randomized complete block design with four treatments: N (50 kg N ha⁻² yr⁻¹, P (100 kg P ha⁻² yr⁻¹), NP (N + P), and a control (CK). Nutrient transport dynamics of underground (rhizosphere soil and roots) and aboveground (twigs and needles) parts of a 10-year-old Pinus elliottii plantations were evaluated. The trial was maintained for three consecutive growing seasons. The results showed that N and P additions significantly increased the N, P, and potassium (K) contents of soils and plant tissues in subtropical slash pine plantation forests, and showed a significant and gradual increase in interannual variations over the observation period (except for TN in soils, which increased first and then decreased). In terms of nutrient transport and reabsorption efficiency, N addition promoted the transport of elemental P from the translocating root system to the twigs, whereas P addition inhibited this process. P addition significantly increased the nitrogen reabsorption efficiency (NRE) of the needles, but decreased the phosphorus reabsorption efficiency (PRE), showing an element-specific response to the nutrient reabsorption process. Structural equation modeling further revealed that N or P addition had direct positive effects on soil N, P, and K content (path coefficients r: 0.54, 0.71, 0.41). N addition indirectly negatively affected N resorption efficiency (NRE) and K resorption efficiency (KRE) (r: −0.62, −0.51) but positively affected PRE (r: 0.44). Conversely, P addition had an indirect negative effect on PRE (r: −0.59). These results reveal that in subtropical regions, slash pine plantations adapt to N or/and P addition by adjusting nutrient absorption, transport, and resorption efficiency. This provided new insights into nutrient transport and distribution strategies in underground and aboveground parts of plants under N or/and P additions. Full article

Solar desalination systems turn saltwater water into freshwater, which helps to overcome water scarcity. In this study, the effects of direct (contact) and indirect (non-contact) interactions with water in solar desalination were evaluated. The emphasis was on changing water depths to better understand the performance variances. Contact systems have a direct interface between thermal absorption materials and water, whereas non-contact systems avoid material–water contact to increase longevity. The experiments at two elevated water depths (3 cm and 4 cm) were conducted in a single-slope solar desalination system. The productivity of both touch and non-contact systems was investigated in June, August, and October 2024 to gather sufficient data for the training and testing of various machine learning models used to predict the distillate. Surprisingly, the non-contact structure system produced 15% and 8% more distillate than the contact system at 3 and 4 cm water depths, respectively. This insightful result will aid in building efficient and sustainable solar desalination technologies. The comparative study gives information on the trade-off between contact and non-contact techniques, with implications for future advances in solar-powered desalination technology. Among all the machine learning techniques, random forest regression achieved the highest coefficient determination (R² train of 0.89 and R² test of 0.95 for the non-contact structure system and R² of train 0.85 and R² test of 0.98 for the contact structure system). Machine learning techniques improve solar desalination by allowing for predictive insights and efficient maintenance, ultimately leading to sustainable water production. Full article

As a key component of the ecosystem, soil seed banks (SSBs) play a vital role in the evolution and renewal of plant communities. Although the pattern and mechanisms of influence of SSBs along the altitudinal gradient have been reported, most studies have focused on forest, grassland and alpine meadow ecosystems. The pattern and factors of SSBs across the altitudinal gradient in sedge peatlands remain largely unknown. Through vegetation surveys and seed germination experiments, we studied the changes in aboveground vegetation and SSBs in sedge peatlands at altitudes ranging from 300 m to 1300 m in the Changbai Mountains, China, and discussed the direct and indirect effects of climatic factors, soil properties and aboveground vegetation on SSBs. The results showed that the richness and density of the SSBs of sedge peatlands decreased with the altitude. Similarly, aboveground vegetation richness and density declined with altitude. A Spearman correlation analysis showed that SSB richness and density were mainly correlated with mean annual temperature, soil total phosphorus and ammonia nitrogen and the plant composition and richness of aboveground vegetation. A structural equation model analysis showed that climatic factors and aboveground vegetation directly affected seed bank richness, while soil properties indirectly affected it by directly affecting aboveground vegetation. Climatic factors, soil properties and aboveground vegetation directly affected SSB density, and soil properties indirectly affected it by directly affecting aboveground vegetation. This finding enhances our understanding of the altitude patterns of the SSBs in sedge peatlands and the response to future climate and environmental changes. Full article

This study used a double machine learning model (based on the random forest algorithm) and spatial Durbin DIDs model to conduct quasi-natural experiments. The results are as follows: (1) innovation and reform policy regarding regional industrial chains as well as their resilience can significantly and positively address the development of China’s impossible triangle coupling of energy; (2) implementing the innovation and reform policy for regional industrial chains in other regions can have a significant positive spatial transmission effect on the impossible triangle coupling coordinated development of energy in the region; (3) regional industrial chain resilience can produce a significant positive mediating effect between the innovation and reform policy of regional industrial chains and the safety, reliability, and economic feasibility of green and clean energy systems; (4) under the counterfactual framework, the mechanism path “innovation and reform policy of the regional industry chain→regional industry chain resilience→coordination degree of impossible triangle coupling of energy” has significantly positive direct and indirect effects in both the treatment group and the control group. However, “innovation and reform policy of the regional industrial chain→regional industrial chain resilience→the energy sector’s impossible triangle coupling coordination degree” and “innovation and reform policy of the regional industrial chain→leading power of the regional industrial chain→the energy sector’s impossible triangle coupling coordination degree” have significantly positive direct and indirect effects in the treatment group, but only the direct effect is significant in the control group. Full article

Previous studies have reported that exposure to forest landscapes has many benefits on human physiological and psychological health, as well as effectiveness in reducing stress and improving mood depending on different types of landscape. This study examined the effects of different types of forest landscapes for indirect visual experiences on the physical and mental health of college students (N = 33). Three types of landscape images were selected, in which forest landscapes included vegetated landscapes and water features, and as a control, we set up images of urban landscapes without natural elements. Physiological and psychological assessment was performed before the experiment for each student, followed by each student being exposed consecutively to nine landscape images for 3 min (each type) and assessed after each exposure. The results showed that both forest landscapes decreased stress (p < 0.05 for all) and improved mood and self-esteem (p < 0.01 for all). In contrast, water landscapes showed a slightly higher impact on physical and mental health than vegetated landscapes, but there was no significant difference. Conversely, only for self-esteem, the response after viewing vegetated landscapes (VL, SD = 29.06 ± 3.38) was better than after water views (WL, SD = 28.21 ± 2.48). Despite significant differences between the two types of forest landscapes not being found in our findings, the benefits of forest landscapes were observed through understanding the health-promoting capacities of different forest landscapes. Full article

As an important component of forest parameters, forest canopy height is of great significance to the study of forest carbon stocks and carbon cycle status. There is an increasing interest in obtaining large-scale forest canopy height quickly and accurately. Therefore, many studies have aimed to address this issue by proposing machine learning models that accurately invert forest canopy height. However, most of the these approaches feature PolSAR observations from a data-driven viewpoint in the feature selection part of the machine learning model, without taking into account the intrinsic mechanisms of PolSAR polarization observation variables. In this work, we evaluated the correlations between eight polarization observation variables, namely, T11, T22, T33, total backscattered power (SPAN), radar vegetation index (RVI), the surface scattering component (Ps), dihedral angle scattering component (Pd), and body scattering component (Pv) of Freeman-Durden three-component decomposition, and the height of the forest canopy. On this basis, a weighted inversion method for determining forest canopy height under the view of structural equation modeling was proposed. In this study, the direct and indirect contributions of the above eight polarization observation variables to the forest canopy height inversion task were estimated based on structural equation modeling. Among them, the indirect contributions were generated by the interactions between the variables and ultimately had an impact on the forest canopy height inversion. In this study, the covariance matrix between polarization variables and forest canopy height was calculated based on structural equation modeling, the weights of the variables were calculated by combining with the Mahalanobis distance, and the weighted inversion of forest canopy height was carried out using PSO-SVR. In this study, some experiments were carried out using three Gaofen-3 satellite (GF-3) images and ICESat-2 forest canopy height data for some forest areas of Gaofeng Ridge, Baisha Lizu Autonomous County, Hainan Province, China. The results showed that T11, T33, and total backscattered power (SPAN) are highly correlated with forest canopy height. In addition, this study showed that determining the weights of different polarization observation variables contributes positively to the accurate estimation of forest canopy height. The forest canopy height-weighted inversion method proposed in this paper was shown to be superior to the multiple regression model, with a 26% improvement in r and a 0.88 m reduction in the root-mean-square error (RMSE). Full article

The positive behaviors that urban forest parks encourage in urban residents (such as recommendations, repeat visits, etc.) are important considerations in the planning and construction of such forest parks. Recreators’ environmental preferences and perceived satisfaction with urban forest parks are responses to individuals’ perceptions and attitudes toward the external environment. Clarifying the interactive relationship between the two is of great significance to improving positive behavioral intentions in urban forest parks. In this paper, the concept of the urban forest park recreational environment is proposed, and in this concept, the three dimensions of the spatial physical environmental preference, regional cultural characteristics, and service experience that the urban forest park recreational environment has on tourists’ perception are separated out. A model of the structural relationship between park environment perception, perceived satisfaction, and post-tour behavioral intention was tested using Tongzhou Grand Canal Forest Park as an example. The psychological path of tourists’ behavioral intention after visiting the urban forest park can be divided into two categories: the direct influencing path is “urban forest park recreation environment → post-tour behavioral intention”; the indirect influencing path is “urban forest park recreation environment → perceived satisfaction → behavioral intention after the trip”. This shows that tourists’ preference for the urban forest park recreation environment will promote the generation of perceived satisfaction and then stimulate in-depth comprehensive experience evaluation after visiting. By enhancing tourists’ experience of the urban forest park recreational environment through their environmental preference perception and improving tourists’ perceived satisfaction with the urban forest park recreational environment, urban forest parks can improve tourists’ positive behavioral intentions. Clarifying these complex psychological processes provides a new perspective for understanding people’s cognition of urban forest parks, the physiological and psychological benefits produced, and the resulting behavioral tendencies. At the same time, it also provides a new perspective for the planning and design of similar types of urban forest parks. It provides a certain reference value for forest park management. Full article

Insect outbreaks are major drivers of natural disturbances in forest ecosystems. Outbreaks can have both direct and indirect effects on the composition of soil arthropod communities through canopy opening, nutrient addition and predator-prey interactions. In this study, we aimed to understand the effects of forest tent caterpillar (Malacosoma disstria; FTC) outbreaks through cascading effects on ant communities in both temperate and boreal forests in Canada. Pitfall traps and Berlese funnels were used to compare the ant communities, as well as the surrounding arthropod communities, between control and outbreak sites in boreal and temperate forests (in Quebec, Canada). Using the Sørensen dissimilarity index, we determined the alpha and beta diversity of the ant community. Other arthropods collected in the traps were counted to evaluate the richness and abundance of potential prey for the ants and other potential predators of the FTC. We used an indicator species analysis to examine the species associated with sites defoliated by the outbreak. In the boreal forest, we found that FTC outbreaks caused decreases in species richness and increases in the evenness of ant communities in defoliated sites. In the boreal forest sites, species composition varied significantly between control and outbreak sites. This pattern was driven in part by the presence of other predators. A similar, but weaker pattern was observed in the temperate forest. We saw no changes in the beta diversity in the boreal forest, but did see a significant decrease in the temperate forest between the outbreak sites and the control sites. Ant species in the boreal forest tended to exhibit a more marked preference for either control or previously defoliated sites than species in the temperate forest. Our study showed that disturbances such as insect outbreaks can drive changes in the ant community. While we saw small effects of outbreaks, manipulation experiments using resource addition could help us validate the mechanisms behind these relationships. Full article

Forestry workers endure highly physical workloads. Japanese forestry workers experience additional up-and-down movements due to geographical features. Fatigue is a common cause of injury. This pilot study aimed to determine an appropriate method for estimating energy expenditure while moving across inclined ground to simulate a Japanese forest. Six participants wore a portable indirect calorimeter ($\dot{\mathrm{V}}$O₂), heart rate (HR) monitor (17 g), accelerometer (20 g; vector magnitude; VM), and a global navigation satellite system (GNSS) device. They walked shouldering 20 kg of weight on flat, 15°- and 30°-slopes. The time course of HR was similar to that of $\dot{\mathrm{V}}$O₂, but that of VM and the vertical movement varied from that of $\dot{\mathrm{V}}$O₂. GNSS cannot correctly detect vertical movements. The HR index (HRI), indicating the ratio of activity HR to resting HR, was significantly correlated with the metabolic equivalent of the task (MET) calculated from $\dot{\mathrm{V}}$O₂ (r = 0.932, p < 0.0001), which fit the previously proposed formula for METs (METs = HRI × 6 − 5). However, VM was not correlated with VM (r = 0.354, p = 0.150). We can use HRI to measure the workload of Japanese forestry workers with a small burden in the field. Full article

Soil biodiversity and fuction have been altered by the increasing levels of nitrogen as a result of fertilization and atmospheric deposition. Although soil microarthropods are a crucial component of soil biodiversity and play a key role in a diverse range of soil functions, our understanding of the mechanisms by which N addition affects them remains limited. Using a long-term nitrogen addition experiment (2012–2016) in poplar plantations (Populus deltoides L. CL‘35′) located along the coast of Yellow Sea Forest Park in northern Jiangsu, eastern China (32°52′ N and 120°49′ E), where the soil was entisols, we examined the response of soil microarthropods across three soil depths (0–15 cm, 15–25 cm, 25–40 cm) to five N input levels (0, 5, 10, 15, 30 g N m⁻² year⁻¹) over four seasons. We found that the number of microarthropods per unit area initially grew and then dropped as more nitrogen was added to soils. Soil organic carbon (positive correlation, R² = 0.53) and pH (negative correlation, R² = 0.19) were the two dominant factors driving the effects of nitrogen addition on soil microarthropod densities at all soil depths. These results suggest that nitrogen input enhances the density of soil microarthropods via the increase in fresh organic matter input. However, the increase in organic matter may be offset by an indirect increase in acidity under high levels of N addition, providing one possible explanation for the reduced density of microarthropods in heavily fertilized soils.71 Full article

Nitrogen enters the soil surface along with the deposition and destroys the element balance of an ecosystem, which has an important impact on underground ecological processes. As active interfaces with the environment, fine roots play a key role in the processes of underground ecosystems and nutrient cycles. Nitrogen in deposition is mainly in two forms, namely organic nitrogen and inorganic nitrogen, which may have different responses to the ecological balance of fine roots and the soil environment; however, in Picea schrenkiana Fisch. et Mey., as a dominant species in the Tianshan Mountains of Xinjiang, it is not clear how different proportions of nitrogen deposition affect the element balance and interactions between fine roots and soil. In this study, from May 2018 to October 2020, five groups of in situ control experiments with different proportions of exogenous nitrogen addition (different ratios of ON–IN, CK = 0:0, N1 = 10:0, N2 = 7:3, N3 = 5:5, N4 = 3:7, and N5 = 0:10, were mixed and then used with equal total amounts of 10 kg·N·ha⁻¹·a⁻¹) were conducted on Picea schrenkiana. The results showed that inorganic nitrogen had a stronger effect on the carbon, nitrogen, and phosphorus contents of fine roots under different proportions of exogenous nitrogen addition, indicating that the fine roots of Picea schrenkiana had a greater response to inorganic nitrogen sources. In a mixed organic–inorganic nitrogen source with the same proportion of organic and inorganic nitrogen, the reaction between fine-root nitrogen (TN = 7.6 g·kg⁻¹−10.8 g·kg ⁻¹) and soil phosphorus (TP = 0.99 g·kg⁻¹−1.93 g·kg⁻¹) was stronger, indicating that the Picea schrenkiana ecosystem may be a nitrogen-limited forest ecosystem. In addition, different proportions of nitrogen source inputs have an indirect impact on the fine-root stoichiometry and biomass of different root sequences through the impact on soil environmental factors and stoichiometry. Therefore, our research provides insights into the impact of increases in nitrogen on the nutrient cycling of mountain forests in arid areas and provides small-scale support for a research database of forest ecosystem responses to nitrogen deposition. Full article