Moderate Thinning Research Articles

Stand characteristics regulate forest water use efficiency in the Three-North Shelterbelt Forest Program region of China

Abstract The Three-North Shelter Forest Program (TNSFP) of China, one of the largest forestry ecological projects, serves as a nature-based solution to addressing ecological, social, and economic challenges and issues. This program, mainly situated in arid and semi-arid regions, critically focuses on improving water use efficiency (WUE) - maximizing carbon sequestration per unit of water consumed - as a key strategy for optimizing water resource utilization and ensuring the long-term success of vegetation restoration efforts. However, the regulatory mechanisms of forest WUE in this region remain unclear. Here, we adopted an interpretative machine-learning method to investigate the influence of main environmental elements, topographical conditions, and stand characteristics on forest WUE in the TNSFP region from 2001 to 2022 based on remote sensing products, ground monitoring data, and forest inventory data. Our study identified soil moisture (SM) as the primary factor influencing forest WUE across the TNSFP region, with higher SM levels generally leading to improved WUE in forests. However, stand characteristics strongly mediated their relationship. Specifically, forest WUE initially increases against forest density before peaking at about 1000 trees hm–2 for needle-leaved forests and 800 trees hm–2 for broad-leaved forests, respectively, then gradually declining due to water competition. When SM is relatively adequate, moderate thinning could significantly enhance forest WUE. Furthermore, implementing management strategies to improve WUE is crucial as needle-leaved forests mature. This study emphasizes the significant impacts of stand characteristics on forest WUE in the TNSFP region, offering essential insights for optimizing water resource management in managed forests across arid and semi-arid regions.

Response of Fuel Characteristics, Potential Fire Behavior, and Understory Vegetation Diversity to Thinning in Platycladus orientalis Forest in Beijing, China

Objective: Active fuel management operations, such as thinning, can minimize extreme wildfire conditions while preserving ecosystem services, including maintaining understory vegetation diversity. However, the appropriate thinning intensity for balancing the above two objectives has not been sufficiently studied. Methods: This study was conducted to assess the impact of various thinning intensities (light thinning, LT, 15%; moderate thinning, MT, 35%; heavy thinning, HT, 50%; and control treatment, CK) on fuel characteristics, potential fire behavior, and understory vegetation biodiversity in Platycladus orientalis forest in Beijing using a combination of field measurements and fire behavior simulations (BehavePlus 6.0.0). Results: A significant reduction in surface and canopy fuel loads with increasing thinning intensity, notably reducing CBD to below 0.1 kg/m3 under moderate thinning, effectively prevented the occurrence of active crown fires, even under extreme weather conditions. Additionally, moderate thinning enhanced understory species diversity, yielding the highest species diversity index compared to other treatments. Conclusions: These findings suggest that moderate thinning (35%) offers an optimal balance, substantially reducing the occurrence of active crown fires while promoting biodiversity. Therefore, it is recommended to carry out moderate thinning in the study area. Forest managers can leverage this information to devise technical strategies that simultaneously meet fire prevention objectives and enhance understory vegetation species diversity in areas suitable for thinning-only treatments.

Investigating the Effects of Dietary Supplementation and High-Intensity Motor Learning on Nutritional Status, Body Composition, and Muscle Strength in Children with Moderate Thinness in Southwest Ethiopia: A Cluster-Randomized Controlled Trial.

In Ethiopia, moderate thinness (MT) is a persistent issue among children. Yet, evidence on the effects of dietary supplementation and motor skills training in these children is limited. This study aimed to assess the effect of Ready-to-Use Supplementary Food (RUSF), whether or not combined with high-intensity motor learning (HiML), on weight, height, body composition, and muscle strength in children 5-7 years old with MT living in Jimma Town, Ethiopia. A cluster-randomized controlled trial was carried out among 69 children (aged 5-7) with MT assigned to receive RUSF (n = 23), RUSF + HiML (n = 25), or no intervention (control group, n = 21). A multivariable Generalized Estimating Equations model was used and the level of significance was set at alpha < 0.05. At baseline, there were no significant differences in the outcome measurements between the RUSF, RUSF + HiML, and control groups. However, after 12 weeks of intervention, there were significant mean differences in differences (DIDs) between the RUSF group and the control arm, with DIDs of 1.50 kg for weight (p < 0.001), 20.63 newton (N) for elbow flexor (p < 0.001), 11.00 N for quadriceps (p = 0.023), 18.95 N for gastrocnemius sup flexor of the leg (p < 0.001), and 1.03 kg for fat-free mass (p = 0.022). Similarly, the mean difference in differences was higher in the RUSF + HiML group by 1.62 kg for weight (p < 0.001), 2.80 kg for grip strength (p < 0.001), 15.93 for elbow flexor (p < 0.001), 16.73 for quadriceps (p < 0.001), 9.75 for gastrocnemius sup flexor of the leg (p = 0.005), and 2.20 kg for fat-free mass (p < 0.001) compared the control arm. RUSF alone was effective, but combining it with HiML had a synergistic effect. Compared to the control group, the RUSF and RUSF + HiML interventions improved the body composition, height, weight, and muscle strength of the studied moderately thin children. The findings of this study suggest the potential that treating moderately thin children with RUSF and combining it with HiML has for reducing the negative effects of malnutrition in Ethiopia. Future research should explore these interventions in a larger community-based study. This trial has been registered at the Pan African Clinical Trials Registry (PACTR) under trial number PACTR202305718679999.

Managing both overstory and understory vegetation mitigates the impact of drought on soil nematode communities in a Mediterranean pine forest

Forest management strategies can effectively mitigate the impacts of drought on tree species, but their effects on soil fauna remain largely unexplored. Among soil organisms, soil nematodes can serve as valuable bioindicators to assess the impact of forest management on soil biodiversity and soil functioning. Consequently, we investigated two related questions in a Mediterranean Pinus halepensis Mill. forest located in southeastern France. First, how do soil nematodes respond to forest management practices? Second, can forest management practices help modulate the effects of Mediterranean summer drought on these soil organisms? We conducted a field experiment in which we explored the influence of two forest management techniques—tree thinning (intense, moderate, or absent) and understory removal (shrubs present or absent)—on soil nematodes before and after the summer drought. We found that only total and bacterivorous nematode abundances were positively influenced by the forest management practices. The highest values were observed under conditions of intense thinning combined with shrub presence, with an average of 97,509 individuals per kg of dry soil. In contrast, the abundances of all nematodes, with the exception of predaceous nematodes, were lower after the summer drought with a reduction ranging from −55 % to −82 %. Total, bacterivorous, and fungivorous nematode abundances were less negatively affected by the summer drought under conditions of moderate thinning when shrubs were present versus absent. More generally, we discovered that bacterivorous and fungivorous nematodes were particularly sensitive to the forest management practices and the summer drought. It is thus apparent that habitat alterations induced by forest management can strongly affect nematode community structure and could therefore prompt shifts in ecosystem functioning. Finally, this study highlights that, in forests, understory vegetation can have significant positive impacts on soil nematode populations when severe dry periods occur.

Determinants of carbon sequestration in thinned forests

Given global climate change and the projected increases in the greenhouse effect, enhancing the carbon storage capacity of forest ecosystems is especially critical. To fully realize the potential carbon sequestration, it is imperative to understand the drivers affecting carbon storage in forest ecosystems, particularly with disturbances that disrupt existing balance. In this study, we explored the effects of stem-only harvest at various thinning intensities on forest structure and carbon density in middle-aged natural secondary forests, located in the northern temperate zone. Carbon density included aboveground carbon density (ACD), soil organic carbon stocks (SOCD), and total carbon density (TCD), which was the sum of ACD and SOCD. We employed the random forest analysis method to identify significant variables influencing changes in carbon density. Structural equation modelling (SEM) was then used to determine the drivers of changes in forest carbon density. The results showed that moderate thinning (20 %–35 % trees removed), is an effective management practice for increasing the TCD in forests. Although heavy thinning (35.1 %–59.9 % trees removed) accelerated individual growth, it did not fully offset the carbon removed due to thinning. It is noteworthy that light thinning (0–19.9 % trees removed) not only reduced the species richness but also caused a significant number of tree deaths. Large live trees were an important direct determining factor of ACD, but not the only one. In addition, thinning indirectly influenced ACD by reducing canopy density and deformed tree density. The increase in dead tree density had an adverse impact on SOCD, and this phenomenon increased with the passage of recovery time. Conversely, greater thinning intensity enhanced SOCD. Moreover, TCD was directly influenced by tree height, large live trees, and stand density. Furthermore, thinning altered the conifer ratio, thereby influencing tree growth and indirectly controlling the TCD. We believe that this knowledge will be highly beneficial for successful forest management and enhancing the carbon sequestration capacity of forest ecosystems.

Effectiveness of thinning in mitigating post-drought legacy effects on Chinese fir in subtropical plantation forests, Southeastern China

Legacy effects following drought are widely detected across worldwide forests, significantly affecting the growth recovery and susceptibility of trees after droughts. Thinning is a common forest management practice used to alter tree growth and climate-growth relationships. Although the effects of thinning on tree response during drought have been investigated, how thinning modulates post-drought legacy effects remains largely unknown. In this study, based on tree-ring data of 140 trees, we examined the effects of thinning on post-drought legacy effects using the quantile mixed effect model for Chinese fir (Cunninghamia lanceolata) in Southeastern China. The tree-ring data were stratified sampling from a thinning experiment applied 10 years ago in 8-year-old plantations, and included four thinning intensities (20 %, 25 %, 33 %, and 50 % reduction of tree number) and an unthinned control treatment. Drought legacy effects of tree growth positively depended on tree social status with the magnitudes and variations larger in higher status classes. Dominant large trees without thinning management had the greatest drought legacy effects. Although the effects of thinning varied slightly at different quantiles, they all indicated that thinning mitigated the growth legacies after drought and the reduction effect was more pronounced with increasing thinning intensity. Thinning could also reduce post-drought climate sensitivities, but only after moderate thinning (20 % and 25 % thinning intensity). Heavier thinning (33 % and 50 % thinning intensity) instead enhanced tree growth responses to climate changes following drought. Thinning intensity needs to be carefully considered to really reap the post-drought benefits of forest thinning management. Our findings suggested that mild thinning offered an alleviation of climate dependency following drought in addition to reducing drought legacy effects on growth, benefiting tree recovery from drought. The results of this study are useful to inform management adaptive strategies for drought-vulnerable plantations under increasingly frequent droughts.

The effects of thinning on carbon and nutrient fluxes input into forest floor via litterfall in black pine afforestation sites.

As a component of the biogeochemical cycle, litterfall contributes carbon and nutrients to forest ecosystems by transferring organic material to mineral soil. Litterfall therefore serves as an important indicator for soil fertility and ecosystem health. This study aimed to determine the impact of different levels of thinning (light, moderate, and heavy) on litterfall quantity (needles, branches, bark, cones, and miscellaneous parts) and on the amount of carbon and nutrients entering the ecosystem in black pine afforestation areas. Three levels of low thinning, namely light, moderate, and heavy thinning (15%, 25%, and 35% of breast height area, respectively), were applied as treatments. Additionally, a control plot was included in the experiment. Litterfall samples were collected four times per year (once per season) from 12 treatment plots for three years. In the laboratory, dry weight measurements and analyses of carbon and macro-micro nutrient elements (N, P, K, Ca, Mg, S, Na, Fe, Cu, Zn, and Mn) were performed on litterfall samples taken from the field. Differences between treatments in terms of litterfall and the amount of carbon and nutrient elements entering the ecosystem were evaluated through variance analysis and the Duncan test. According to the findings, the quantity of litterfall input into the forest floor was highest in the control treatment, at 6,543kgha-1year-1 and lowest in the heavy treatment, at 4,378kgha-1year-1, showing a significant variation in litterfall quantity. The input of C to the soil ranged between 2,233kgha-1year-1 and 3,347kgha-1year-1 depending on thinning treatment. Although thinning treatment reduced C input to the soil, there was no significant difference among treatments. This also applied to nutrient elements such as N, P, K, Mg, and S. Needles constituted the majority of litterfall components (60%) and had the highest C density among all components, at 51.2%. The weighted carbon ratio for litterfall was calculated at 50.8%. Considering carbon-focused planning, performing moderate thinning interventions in the study area or similar pine-afforested areas may be a suitable option for maintaining the sustainability and health of the forest.

Temporal change in prevalence of BMI categories in India: patterns across States and Union territories of India, 1999–2021

BackgroundThe problem of overweight/obesity often coexists with the burden of undernutrition in most low- and middle-income countries. BMI change in India incorporating the most recent trends has been under-researched.MethodsThis repeated cross-sectional study of 1,477,885 adults in India analyzed the prevalence of different categories of BMI among adults (age 20–54) in 4 rounds of National Family Health Surveys (1998–1999, 2005–2006, 2015–2016, and 2019–2021) for 36 states/UTs. State differences across time were harmonized for accurate analysis. The categories were Severely/Moderately Thin (BMI < 17.0), Mildly Thin (17.0-18.4), Normal (18.5–24.9), Overweight (25.0-29.9), and Obese (≥ 30.0). We also estimated change in Standardized Absolute Change (SAC), ranking of states, and headcount burden to quantify the trend of BMI distribution across time periods for all-India, urban/rural residence, and by states/UTs.ResultsThe prevalence of thinness declined from 31.7% in 1999 to 14.2% in 2021 for women, and from 23.4% in 2006 to 10.0% in 2021 for men. Obesity prevalence increased from 2.9% (1999) to 6.3% (2021) for women, and from 2.0% (2006) to 4.2% (2021) for men. In 2021, the states with the highest obesity prevalence were Puducherry, Chandigarh, and Delhi. These states also had a high prevalence of overweight. Dadra and Nagar Haveli and Diu, Gujarat, Jharkhand, and Bihar had the highest prevalence of severe/moderately thin. Prevalence of extreme categories (severely/moderately thin and obese) was larger in the case of women than men. While States/UTs with a higher prevalence of thin populations tend to have a larger absolute burden of severe or moderate thinness, the relationship between headcount burden and prevalence for overweight and obese is unclear.ConclusionsWe found persistent interstate inequalities of undernutrition. Tailored efforts at state levels are required to further strengthen existing policies and develop new interventions to target both forms of malnutrition.

Impact of abandonment on leaf morphology traits and nutrient utilization strategies of dominant tree seedlings in Moso bamboo forests

The restoration of ecological functions in abandoned Moso bamboo forests facilitates positive succession in evergreen vegetation. Nevertheless, there is a limited understanding regarding the leaf functional traits and nutrient utilization strategies of understory vegetation after abandonment. This study investigated the impact of abandonment duration (9 and 21 years) on leaf morphological traits, soluble sugars characteristics, carbon (C), nitrogen (N), phosphorus (P), and their ratios in dominant tree seedlings (Lithocarpus brevicaudatus and Schima superba) within Moso bamboo forests. Leaf sizes increased significantly with prolonged abandonment in both species, accompanied by a consistent decrease in leaf thickness and leaf tissue density. These morphological indices were more pronounced in L. brevicaudatus compared to S. superba (P < 0.05), and they showed a positive correlation with tree sizes. Moreover, leaf soluble sugars, C, and C: N: P ratios of both tree species decreased over duration abandonment, while N and P contents increased. Specifically, L. brevicaudatus exhibited elevated levels of fructose, glucose, N, and P, whereas S. superba displayed higher sucrose, C, and C: N: P ratios. Our findings reveal that both species, with extended abandonment, enlarged their leaf area and improved carbon utilization, facilitating adaptation to competitive resource habitats. Particularly, L. brevicaudatus exhibited a propensity to augment leaf sizes, as well as N, and P contents, suggesting a strategy to enhance carbon assimilation through additional N and P nutrient supplementation. Conversely, S. superba primarily focused on bolstering carbohydrate reserves, indicating that moderate thinning or pruning of bamboo forests could boost sunlight penetration, along with the appropriate nutrient supplementation. These insights significantly contribute to the scientific understanding necessary for the classification and management of mixed stands in abandoned bamboo forests.

Integrating Dendrochronological and LiDAR Data to Improve Management of Pinus canariensis Forests under Different Thinning and Climatic Scenarios

Thinning focused on achieving growth and diameter management objectives has typically led to stands with reduced climate sensitivity compared to unthinned stands. We integrated dendrochronological with Airborne Laser Scanner (LiDAR) data and growth models to assess the long-term impact of thinning intensity on Canary pine (Pinus canariensis) radial growth. In 1988, 18 permanent treatment units were established in 73-year-old Canary pine plantations and three thinning treatments were applied (C–control-unthinned; 0% basal area removal; MT–moderate thinning: 10% and 15% basal area removal, and HT–heavy thinning: 46% and 45% basal area removal on the windward and leeward slopes, respectively). Dendrochronological data were measured in 2022 and expressed as basal area increment (BAI). The impact of climate on growth was examined by fitting linear regression models considering two different Representative Concentration Pathway (RCP) climate scenarios, RCP 2.6 and RCP 4.5. Finally, LiDAR data were used for standing segmentation to evaluate changes in overall growth under different climatic scenarios. The LiDAR–stand attributes differed between aspects. The BAI of the most recent 20 years (BAI20) after thinning was significantly higher for the moderate and heavy treatments on the leeward plots (F = 47.31, p &lt; 0.001). On the windward plots, BAI decreased after moderate thinning. Considerable thinning treatments resulted in stronger changes in growth when compared to RCP climatic scenarios. From a silviculture perspective, the mapping of canopy structure and growth response to thinning under different climatic scenarios provides managers with opportunities to conduct thinning strategies for forest adaptation. Combining dendrochronological and LiDAR data at a landscape scale substantially improves the value of the separate datasets as forecasted growth response maps allow improving thinning management plans.

The Seasonal Impact of Thinning Intensities on Soil Carbon Cycling in the Lesser Xing’an Range, Northeast China

Forest degradation, driven by human and natural factors, diminishes ecological functions and carbon storage. Understanding the complex dynamics of soil carbon pools is crucial for the global carbon cycle, although these dynamics are poorly understood. This study examines how different thinning intensities influence seasonal soil carbon cycling in degraded forests. ANOVA revealed significant differences in soil properties across treatments (p &lt; 0.05). Redundancy analysis and random forest analyses were used to explore relationships among thinning intensities, soil properties, and carbon sequestration. Thinning significantly altered soil attributes, as revealed by field experiments and data analysis. Moderate thinning (20% intensity) significantly enhanced litter retention and soil nutrient levels year-round (p &lt; 0.05). Seasonal variations affected soil carbon dynamics and lower thinning intensities improved carbon sequestration in spring and summer. Conversely, higher thinning intensities led to carbon loss in autumn and winter. Litter carbon, fine root carbon, and correction factor significantly respond to thinning intensities year-round as examined through redundancy analysis and random forest analyses. Findings indicate moderate thinning effectively enhances soil carbon sequestration in degraded forests. Strategically planned thinning could aid climate change mitigation by boosting forest soil carbon storage, influencing forest management and conservation.

Productivity of Clonal Teak Plantation Under Different Spacing and Thinning Intensity in Java Monsoon Forest

Intensive silviculture plays a crucial role in selecting superior clones with high productivity. The use of superior clones needs to be accompanied by appropriate environmental conditions. The arrangement of growing space is one way for teak clones to grow optimally and produce quality wood products. It can choose initial spacing in the early growth phase and thinning intensity in the later growth phase. This study aims to assess and determine the growth of superior teak clones with different thinning intensities at different planting distances to optimize the growing space. Optimizing growth space also has the potential for intercropping under the stand to produce more diverse products. The research design was a Split-plot design with three blocks as replications. The main plots had four spacings, including 3 m x 3 m, 6 m x 2 m, 8 m x 2 m, and 10 m x 2 m. Subplots were thinning intensity, including 0% thinning (control), 25% thinning (moderate thinning), and 50% thinning (heavy thinning). The results showed that spacing could significantly affect diameter growth. Silvicultural thinning showed significant differences in diameter growth, CADI, height, and volume per hectare. The diameter growth showed higher growth at larger spacing and higher thinning intensity, while the volume per hectare was low. The tree height parameter increased with the thinning intensity. The CADI after two years of thinning increased by 14–42% at 25% thinning intensity and increased by about 35–48% at 50% thinning intensity compared to no thinning at each spacing. Meanwhile, the volume per hectare was lower at wider spacing and decreased at a high thinning intensity. These results indicate an increase in spacing, and thinning accelerates diameter growth and provides better-growing space for intercrops.

DEEP REFLECTION SEISMIC DATA FOR IMPROVED IMAGING OF CRUST STRUCTURE: 2D CASE STUDY OF THE SOUTHWEST SUB-BASIN IN THE SOUTH CHINA SEA

Seismic imaging of crustal structures becomes difficult in the presence of rough basements or complex bathymetry. Here, we present a 900 km deep seismic reflection profile collected across the Southwest Sub-basin (SWSB) of the South China Sea. By analyzing the types and distinctions of noise and effective signals, we employed deep structure migration techniques to improve crustal structure imaging, wide-line processing to predict 3D space multiples, and F-K domain time-space variable adaptive de-ghosting and different offset stacking to enhance the weak signals reflected from deep strucutures. The imaged continental crustal structure in the Penxi Bank exhibits moderate thinning, down to 15 km, and is intersected by continental-ward low-angle normal faults. Within the limitations of the OBS P-wave velocity model, we detected sub-horizontal lower crustal reflections that may be indicative of a weak lower crust. Two small-scale rollover structures along detachment faults rooted and rafted to the top of these weak lower crust. Based on the presence of narrow continent-ocean transitions(COTs), continental-ward detachment faults, and high lithosphere heat flow, we deduced that the mantle lithosphere breakup occurred earlier than the crust in the SWSB. Moreover, the continent-ocean transitions and oceanic crust domains demonstrate rough basements with numerous faults and approximately 20% diffuse or weak Moho reflections. From the southern COT to the initial oceanic domain, the thickness of the crust gradually reduces to only 3-5 km. This suggests a relatively low magmatic budget and protracted tectonic extension from the continental breakup to the onset of seafloor spreading. Within the oceanic crust domain, the crust thickness ranges from approximately 4-6 km, indicating a thinner oceanic crust than normal crust. Lower crustal reflections with a ridge-ward dipping pattern terminate at the Moho reflections and are partly connected to syn-spreading faults, hinting at their possible generation through syn-spreading faulting.

Assessment of Nutritional Status of 3–8-Year Mawasi Tribal Children Using Anthropometric Indices

Nearly 45 lakh children, mostly tribal suffer from stunted growth in Madhya Pradesh. Hence a cross sectional study was undertaken in two villages of Majhgawan block in which height, weight, and mid upper arm circumference of 112 Mawasi tribal were measured and recorded via standard techniques. Body mass index was computed using the conventional method, the data was then analysed using anthro plus software of WHO. The overall prevalence of stunting among tribal children (3-5 years) was 60.65%, with 47.54% moderate and 13.11% severe stunting. The prevalence of underweight among these children was 59.03% (47.55% moderate and 11.48% severe). The prevalence of wasting among these children was 26.24% (22.26% moderate acute malnutrition (MAM) and 3.28% severe acute malnutrition (SAM)). Among 6–8-year children it was found that the prevalence of stunting and underweight was 64.36% and 83.5% respectively. 20.13% of children were thin (1.81% had severe thinness, and 18.02% had moderate thinness) in 6-8 years. The prevalence of thinness among 6,7- and 8-year children was 15.38%, 20.0% and 23.50% respectively. Thus, the overall results indicate high level of underweight and stunting, therefore based on the results, it can be stated that there is a urgent need for lot of work to be done on improvement of nutritional and health status of Mawasi children. The hand in hand support of government and the local bodies for upliftment of tribal community can make a huge difference in current scenario.

Drivers of spatial structure in thinned forests

BackgroundAs is widely known, an increasing number of forest areas were managed to preserve and enhance the health of forest ecosystems. However, previous research on forest management has often overlooked the importance of structure-based. AimsOur objectives were to define the direction of structure-based forest management. Subsequently, we investigated the relationships between forest structure and the regeneration, growth, and mortality of trees under different thinning treatments. Ultimately, the drivers of forest structural change were explored. MethodsOn the basis of 92 sites selected from northeastern China, with different recovery time (from 1 to 15 years) and different thinning intensities (0–59.9%) since the last thinning. Principal component analysis (PCA) identified relationships among factors determining forest spatial structure. The structural equation model (SEM) was used to analyze the driving factors behind the changes in forest spatial structure after thinning. ResultsLight thinning (0–20% trees removed) promoted forest regeneration, and heavy thinning (over 35% of trees removed) facilitated forest growth. However, only moderate thinning (20%–35% trees removed) created a reasonable spatial structure. While dead trees were clustered, and they were hardly affected by thinning intensity. Additionally, thinning intensity, recovery time, and altitude indirectly improve the spatial structure of the forest by influencing diameter at breast height (DBH) and canopy area. ConclusionCreating larger DBH and canopy area through thinning will promote the formation of complex forest structures, which cultivates healthy and stable forests.

Scaling up tree growth to assess forest resilience under increasing aridity: the case of Iberian dry-edge pine forests

ContextMediterranean managed dry-edge pine forests maintain biodiversity and supply key ecosystem services but are threatened by climate change and are highly vulnerable to desertification. Forest management through its effect on stand structure can play a key role on forest stability in response to increasing aridity, but the role of forest structure on drought resilience remains little explored.ObjectivesTo investigate the role of tree growth and forest structure on forest resilience under increasing aridity and two contrasting policy-management regimes. We compared three management scenarios; (i) “business as usual”-based on the current harvesting regime and increasing aridity—and two scenarios that differ in the target forest function; (ii) a “conservation scenario”, oriented to preserve forest stock under increasing aridity; and (iii), a “productivity scenario” oriented to maintain forest yield under increasingly arid conditions.MethodsThe study site is part of a large-homogeneous pine-covered landscape covering sandy flatlands in Central Spain. The site is a dry-edge forest characterized by a lower productivity and tree density relative to most Iberian Pinus pinaster forests. We parameterized and tested an analytical size-structured forest dynamics model with last century tree growth and forest structure historical management records.ResultsUnder current management (Scenario-i), increasing aridity resulted in a reduction of stock, productivity, and maximum mean tree size. Resilience boundaries differed among Scenario-ii and -Scenario-iii, revealing a strong control of the management regime on resilience via forest structure. We identified a trade-off between tree harvest size and harvesting rate, along which there were various possible resilient forest structures and management regimes. Resilience boundaries for a yield-oriented management (Scenario-iii) were much more restrictive than for a stock-oriented management (Scenario-ii), requiring a drastic decrease in both tree harvest size and thinning rates. In contrast, stock preservation was feasible under moderate thinning rates and a moderate reduction in tree harvest size.ConclusionsForest structure is a key component of forest resilience to drought. Adequate forest management can play a key role in reducing forest vulnerability while ensuring a long-term sustainable resource supply. Analytical tractable models of forest dynamics can help to identify key mechanisms underlying drought resilience and to design management options that preclude these social-ecological systems from crossing a tipping point over a degraded alternate state.

2000–2020年喀喇昆仑山洪扎河流域冰川高程变化数据集

Under the influence of climate warming, glaciers in High Mountain Asia (HMA) have undergone significant recession in recent decades. However, stable or even positive glacier mass budgets have been found in the Karakoram Mountains in the past decades, which is termed as “Karakoram anomaly”. The Hunza Basin, located in the western Karakoram, is a region with concentrated glacier development along the Sino-Pakistan Economic Corridor. The glacier mass balance in Hunza Basin plays an important role in water resource utilization and infrastructure construction. In this study, we used the SRTM DEM (2000) and ZY3-02 stereo images (2020) to obtain the glacier height changes in the Hunza Basin by employing the method of Geodetic (GeoTIFF format with a resolution of 30 m). This study covers an area of around 7600 km2, within the spatial extent of 36°N–37°N, 74°E–76°E. The statistical analysis of the residual movement in the non-glacial region indicates an overall accuracy of about 1.1 m. The findings suggest that glaciers experienced a moderate thinning during the early 21st century, with significant spatial variations. Factors such as debris cover, crevasses, supraglacial lake, ice cliff and glacier surge have distinct influences on glacier height changes. This dataset can be used as basic data for the research on glacier mass balance in the Karakoram, as well as water resources utilization, glacier disaster warning and climate change in the Sino-Pakistan Economic Corridor.

Undernutrition in older children and adolescents in peri-urban Zambia.

Adolescents make up roughly a quarter of the population in Zambia; however, most nutrition-related programming is targeted at the under-five population. Understanding the scale of undernutrition in older children and adolescents is fundamental to alleviating food insecurity and addressing undernutrition across all age groups. A cross-sectional survey was performed in four low-income, peri-urban compounds in Chilanga District which included anthropometric measurements of children between ages 6 months-19 years and a household-level diet diversity and food security questionnaire. Wasting was used for children under 5 and thinness for children 5-19 years. Descriptive analysis and multivariate logistic regression were conducted to quantify the prevalence and distribution of malnutrition and understand the impact of food security. We surveyed 393 households and 1,004 children between the ages of 6 months and 19 years. Children aged 6-9 years had the highest prevalence of severe thinness (5.2%) and adolescents (10-19 years) had the highest rates of moderate thinness (6.5%). Across all age groups, more than 75% of children were in households that worried about running out of food in the previous month. 24.9% of adolescents and 28.4% of older children were in households were more likely to go a whole day without eating compared to 16.9% of children under 5. Our survey indicated that malnutrition in adolescents and older children living in Chilanga district was comparable to those under 5. Interventions to address undernutrition must be targeted at older children and adolescents in order to ameliorate this burden.

Nutrient pools and loss due to the removal of harvesting residue in cedar plantations (a case study from Türkiye).

Determining the nutrient stocks and revealing the extent to which these stocks will be affected by the interventions in forest ecosystems are crucial for sustainable forest management. This study aimed to determine the nutrient stock of cedar (Cedrus libani A. Rich.) plantations at different stands with various diameter classes and estimate the nutrient stock to be removed from the forest due to harvesting. Soil and plant samples were collected from 40 plots in Eskişehir and Afyonkarahisar provinces in Turkey. The variation in the nutrient concentrations and stocks of different components of the ecosystem were evaluated by analysis of variance and the decrease via harvesting by regression analysis. The results showed that the concentrations of N, P, K, Mg, S, Fe, Zn, and Mn were highest in the needles, Ca in the bark, Cu in the needles, dead branches, and root. In the large-diameter forest (LDF), dbh=20.0-35.9 cm, the highest P stock was found in the trees, Fe stock in the forest floor, and S stock in the soil and trees. As a result, the forest floor should be protected as it is the crucial component of both the nutrient cycle and the Fe stock in the ecosystem. In LDF, 28.4-37.3% of the nutrient stored in the trees would be removed from the ecosystem in the case of moderate thinning with whole-tree harvesting, while only 5.9-14.1% of the nutrient stock in the case of stem-only harvesting. For these reasons, leaving logging residues after harvesting in the forest would minimize nutrient loss. The study results showed that improved nutrient management in a forest ecosystem will make a significant contribution to the sustainability of forests.

Seasonal Variation and Soil Texture-Related Thinning Effects on Soil Microbial and Enzymatic Properties in a Semi-Arid Pine Forest

Thinning is a practice that reduces competition for available soil resources, thereby promoting vegetation growth and affecting soil, which is involved in important ecosystem processes. Soil quality is directly influenced by various aspects such as ground cover, regional climate, and local microclimate, which can further be modified by forest thinning. In this study, the effect of tree thinning and climate on microbiological and enzymatic soil properties was investigated in an Aleppo pine (Pinus halepensis M.) forest more than a decade after silvicultural treatments. The treatments included were clear-felling (100% of mean basal area (BA) removed), moderate thinning (60% BA removed), and control (no thinning). Soil organic carbon (SOC), water-soluble organic carbon (WSOC), basal soil respiration (BSR), microbial biomass carbon (MBC), soil enzymes (β-glucosidase, acid phosphatase, urease, and dehydrogenase), general soil characteristics, soil temperature and humidity, and precipitation were compared seasonally for over two years by analysis of variance and multivariate analysis. Results showed that the effect of 60% thinning improved soil microbial and enzymatic soil properties with variable results, mainly depending on soil organic matter content and soil texture. SOC, WSOC, and MBC were highly correlated with BSR and enzymatic activities. The main reason for the observed differences was water availability, despite a large seasonal variation. In conclusion, microbial activity was strongly affected by soil characteristics and climate, which in turn were influenced by the silvicultural treatments applied. Moderate thinning can be used as a useful practice to improve soil quality in the Mediterranean area.