Search Results (53)

Haloxylon ammodendron plays a pivotal role in combating aeolian desertification and restoring degraded arid ecosystems. Strategic afforestation protocols for this xerophytic species offer dual benefits in ecological stabilization and socioeconomic development, particularly in ecotonal zones between desert and oasis ecosystems, as exemplified by the Jilantai Salt Lake region. This investigation employs allometric scaling analysis to elucidate biomass allocation strategies in H. ammodendron plantations under three distinct silvicultural approaches: soil moisture retention afforestation, water flushing afforestation, and mechanical hole afforestation. Key findings demonstrate that water flushing afforestation treatment induced significant biomass enhancement (total biomass: 1718.69 ± 214.28 g), with phylloclade (photosynthetic branch) and vegetative organ biomass increasing by 29.03% and 60.34%, respectively, compared to conventional methods. Conversely, soil moisture retention afforestation preferentially promoted lignification processes, maximizing biomass allocation to structural components (stems: 15.2% increase) and reproductive structures (inflorescences: 22.7% elevation). Standardized major axis regression revealed differential scaling exponents among organ pairs under varying treatments (stem-phylloclade: 1.798; inflorescence-phylloclade: 1.752; vegetative-reproductive: 1.672; p < 0.001), indicating treatment-specific allometric allocation patterns. Notably, soil moisture retention afforestation induced lateral crown expansion through enhanced meristematic activity in secondary branches (p < 0.01), contrasting with the apical dominance observed in water flushing afforestation and mechanical hole afforestation specimens. These morphological divergences suggest resource allocation trade-offs between vertical exploration and horizontal exploitation strategies. The differential growth trajectories were strongly correlated with edaphic moisture redistribution patterns (R² = 0.83, p < 0.001), as quantified using soil water potential measurements. This study provides mechanistic insights into phenotypic plasticity responses to silvicultural interventions. These findings advance our understanding of allometric growth regulation in a psammophyte and establish an empirical basis for optimizing desert afforestation strategies in arid transitional ecotones. Full article

Wildfires increasingly threaten forest ecosystems, particularly in arid Mediterranean regions impacted by climate change. This study presents a novel quantitative framework for optimizing silvicultural interventions to reduce combustion energy loads and enhance resource conservation. Using dendrometric equations, biomass removal calculations, and geospatial modeling (Ordinary Kriging, SAGA-GIS and Q-GIS), the methodology evaluates the spatial distribution of calorific energy before and after thinning interventions. The results show that a 20% thinning intervention reduced calorific energy by 13.45% and water demand by 8.38%, while thinning at 30% and 40% intensities achieved even greater reductions. Specifically, thinning reduced the higher calorific potential by 14,000 kJ/m² and saved approximately 861,390 L of water across the study area. These findings provide actionable insights for forest managers to balance ecological health, optimize thinning practices, and mitigate wildfire risks in vulnerable ecosystems. Full article

Coppicing has been neglected in recent decades, leaving gaps in knowledge on silvicultural interventions, especially the long-term effects on coppices of Southeast Europe. The recent economic crisis, the sudden increase in energy prices, and the increased demand for assorted wood products have initiated higher interest in coppices in Croatia. Thus, our work aims to define the long-term effects of thinning in sessile oak (Quercus petraea (Matt.) Liebl.) and European beech (Fagus sylvatica L.) sub-mountainous thermophilic low coppices in the Croatian Dinarides. The experiment includes two localities with thinning and control plots. Thinning was performed in 2002, with 17.71% of wood volume removed in the European beech coppice and 26.09% in the sessile oak coppice. In 2020, 1276 trees were marked, measured (DBH, tree height, number of stems per stump), and assessed for vitality, origin, and six silvicultural features revealing tree quality. In 2022, trees were again measured (DBH, tree height) to gain data on tree growth. Conventional data analysis methods were used. The results show a statistically significant positive long-term effect of thinning on tree growth, stem, and crown features and support findings that thinning, by increasing growth and quality, is a necessary intervention in European beech and sessile oak low coppices. Thinning promoted the healthiest and best quality trees/stems, resulting in a more valuable range of wood products and the potential for higher income. It had a positive impact on tree growth regardless of the tree’s origin (seed or stump) and improved the growth and quality of trees among the supporting tree species. Short-term effects of thinning in trial plots suggested that thinning supported tree species diversity, but this effect diminished over time, showing no positive effect after twenty years. The study points to the need for more frequent thinning in coppices to support tree species diversity (i.e., to allow growth to less competitive tree species) but underlines the need for further research. Full article

Castanea sativa is a high-value tree species whose stands have faced significant threats over the past century. The occurrence of one such threat, Chestnut Red Stain—a heartwood discoloration caused by the fungus Fistulina hepatica—has recently increased. This disease devalues the timber by up to 70% due to the rejection of stained wood by the industry. This study aimed to evaluate the effects of three management strategies on the occurrence of F. hepatica in chestnut coppice stands. Additionally, the co-occurrence of F. hepatica and Cryphonectria parasitica, both highly prevalent in the study area, was assessed. In 2013, three different silvicultural treatments were applied to five plots. Seven years later, the stand characteristics were measured, and the incidence of F. hepatica was evaluated using molecular tools. Data modeling revealed that the quadratic mean diameter before the interventions was related to the incidence of F. hepatica. Our results suggest that the thinning at earlier stand stages may be more critical than the type or intensity of the thinning in reducing the incidence of the fungus in the mid-term. This finding provides forest managers with new guidance to improve silvicultural treatments and prevent F. hepatica damage. Full article

In the Mediterranean basin, coniferous reforestation mainly comprises forest stands highly susceptible to fires. When silvicultural treatments have not been performed for decades after plantation, these stands often exhibit high vertical and horizontal tree density, along with a significant occurrence of lying and standing deadwood, thereby increasing the fuel load. On average, these pine forests are characterized by high values of above-ground biomass, ranging from 175 to 254 Mg ha⁻¹ for the younger and the older ones, respectively. The theoretical heat energy produced per surface unit, in the case of the total combustion of the above-ground biomass, is also high, varying from 300 to 450 MJ ha⁻¹ depending on the stage of stand development. In this study, we demonstrated the importance of silvicultural interventions in reducing the pyrological potential in pine reforested stands located in southern Italy, also giving attention to the water savings needed during extinction phases. In detail, we applied a preliminary mathematical reaction-diffusion model aimed at predicting the development of forest fires. The model was applied using data obtained through the estimation of the pyrological potential in terms of heat energy produced per surface unit (1 hectare) and the variation in the critical surface intensity. We verified that, when silvicultural interventions are applied, they induce a reduction of heat energy ranging between 17 and 21%, while the extinguishing water saved ranges between 600 and 1000 Mg ha⁻¹. Moreover, when the silvicultural interventions are implemented, the probability of the transition from surface fire to crown fire can be reduced by up to 31%. The most effective results on fire risk mitigation are mainly obtained when thinning aimed at reducing canopy and tree density is carried out in the younger phases of the reforested pine stands. Full article

This study examines the impact of silvicultural and land-use management practices on carbon sequestration in peri-urban forest ecosystems, with a particular focus on human-induced carbon dynamics. The study area’s complex profile spans from a compact native forest to varying degrees of fragmentation. This included areas undergoing secondary succession forest without silvicultural interventions (No-SI) alongside sites subjected to high-intensity (High-SI) and low-intensity silvicultural interventions (Low-SI). The research assessed carbon stocks and sequestration in different carbon pools (living biomass, dead organic matter and soil) using field data, allometric equations and laboratory analysis. Findings reveal a significant correlation between the intensity of anthropogenic interventions and variations in carbon stocks. The CASMOFOR model facilitated the reconstruction of carbon stock and carbon-stock change dynamics over four decades (1980–2022), showing disparities in carbon storage capabilities linked to the structural characteristics of the sites. The Low-SI site had the highest carbon stock in all carbon pools (378 tonnes C ha⁻¹), which is more than double compared to High-SI (161 tonnes C ha⁻¹) or No-SI sites (134 tonnes C ha⁻¹). However, the secondary succession forest (No-SI) demonstrated the highest annual carbon stock change (4.4 tonnes C ha⁻¹ year⁻¹), two times higher than the Low-SI mature stand (2.2 tonnes C ha⁻¹ year⁻¹), emphasising the resilience of forest ecosystems to recover and sustain carbon sequestration capacities after harvesting if forest land use remains unchanged. The study underscores the significant importance of anthropogenic interventions on carbon dynamics, especially for living tree biomass, which has consequences in enhancing carbon sequestration and contributing to emission reduction targets. Full article

The maritime pine (Pinus pinaster Ait.) forest is an essential element of the Portuguese forest landscape due to its social, economic, and environmental importance. The sustainability of these forests in the Mediterranean region faces challenges due to recurrent forest fires and the absence of or delayed management. The species has a high capacity for regeneration, but the perpetuation of pine forests in sustainable conditions depends on adequate management to achieve high biomass production and assure fire resilience. This study aimed to analyse four management scenarios (C1 to C4) for the natural regeneration of maritime pine in six areas with stand ages ranging from 6 to 16 years and densities varying from 15,000 to circa 93,000 trees per ha. The same four scenarios were implemented in each of the six areas. The scenarios considered the evolution of forest growth according to different management prescriptions and were simulated using Modispinaster and PiroPinus models. Scenario C1 considered no intervention, with only the final cut. Scenario C2 considered a thinning schedule to maintain the stand within the 50–60% range of the Stand Density Index (SDI). Scenario C3 followed the area’s Forest Management Plan (PGF), which typically includes two or three thinning operations throughout the cycle. Scenario C4 was adapted from the MS1 silvicultural model of the National Institute for Nature Conservation and Forests—ICNF, which involves opening strips at earlier ages (3 and 6 years), with the selection of trees to remain in the wooded area carried out between 4 and 10 years of age and performing thinning whenever the Wilson Spacing Factor (FW) reaches 0.21. The final cutting age was assumed to be 45 years but could be lowered to 35 years in Scenario 3 if defined in the plan. Based on the indicators generated by the simulators, the results showed variations in the total volume of timber produced at the time of harvest depending on the silvicultural guidelines. Scenario C4 was the most effective in generating the highest individual tree volume at the end of the cycle and the total volume of timber collected throughout the cycle. The ability of the forest to resist fire was evaluated before and after the first treatment for density reduction. The treatments performed did not decrease the resistance to fire control. Full article

This study focuses on the natural regeneration of Nothofagus glauca, a critical component of temperate forests in the Mediterranean region of the Southern Hemisphere in Chile. Various harvesting and canopy opening methods were evaluated to understand their impact on the regeneration of this species. A “mast seeding” behavior was observed in seed production, with alternating years of high and low production. Seed viability was affected by lepidopteran infestation and extreme weather events. The results indicate variable seed quantity and quality, influencing regeneration. First-year seedling mortality was significant, reaching up to 95%, and regeneration decreased annually. Additionally, changes in canopy opening and solar radiation transmission were analyzed, revealing significant post-harvest modifications. This study provides valuable insights for the sustainable management of Mediterranean forests, emphasizing the importance of considering seed production variability and regeneration dynamics in decision-making processes. Full article

Forest soils contain a large amount of organic carbon (OC); therefore, small changes in these ecosystems have effects on climate. In this study, variation in the quantity of C pools that occurred in one year in the soil of temperate forests managed by two farms in the Apennine chain (Emilia-Romagna Region) was investigated using elemental and isotopic C analyses of soil samples collected in 2020 and 2021. In one year, soil from the Branchicciolo (BRA) farm lost organic matter as shown by the decrease in C contents and the less negative C isotopic signatures (¹³C/¹²C), whereas the C contents and C isotopic signatures remained almost stable during time in the soil from the Beghelli (BEG) farm. This cannot be related to thinning interventions, as much more forest material was removed from the BEG forest than from the BRA forest (60% and 25%, respectively). Therefore, other causes should be considered. The BRA forest was at a lower altitude than the BEG forest; thus, it was more affected by C depletion due to the warmer temperature. Moreover, the sandy soil in the BRA forest was less prone to sequestering organic matter than the soil in the BEG forest, which was characterized by phyllosilicates (including vermiculite) and zeolites (clinoptinolite) having high C sequestration capacity. This work showed the different impacts of the pedo-climatic conditions in two nearby farms, which should be considered in planning appropriate silvicultural management for OC sequestration. Full article

The American beech (Fagus grandifolia Ehrh.) has been impacted by the beech bark disease (BBD) complex throughout the northeastern United States for over 100 years, but the disease has been present in the Great Lakes region only for around 20 years, requiring acknowledgement of the evolving context surrounding F. grandifolia. This disease threatens to remove a foundational tree species which is especially important ecologically for wildlife habitat and mast, and as a climax successional species. We review advances in propagation techniques of F. grandifolia with the goal of addressing their use in the rehabilitative restoration of forests affected by BBD. Natural regeneration and artificial methods of propagation are addressed, along with how they may be applied for mitigation. Silvicultural interventions are discussed that may be necessary to protect and release resistant seedlings to promote persistence. An existing framework is used to explore context necessary for decision making in restoration. Nucleated seed orchards of resistant trees may currently be the most effective and practical method for introduction of BBD-resistant F. grandifolia into affected northern hardwood forests. Full article

Despite the sharply growing interest in the disturbances occurring in primary forests, little is known about the response of European virgin forests to anthropogenic disturbance. The present study investigated the effect of the first silvicultural interventions that took place nine years earlier in a former virgin forest (FVF). Changes in the stand structure, environmental characteristics, and diversity of ground vegetation were studied in comparison with a nearby virgin forest (VF), both consisting of a mixture of European beech and silver fir. While the tree density did not differ significantly between the two forests, the number of large trees, the basal area, and the stand volume were significantly reduced in the FVF. The deadwood volume was twice as great in the VF as in the FVF and was found in both forests, particularly from silver fir. Despite significantly better light conditions in the FVF, natural regeneration was not significantly higher than in the VF. However, a slight improvement in the proportion of silver fir and other tree species into total regeneration was reported. The soil temperature was significantly higher in the FVF, independent of the measurement season, while the soil moisture showed a higher value in the VF only in spring. The FVF is characterized by a greater soil CO₂ emission, which is especially significant in summer and fall. The diversity of the ground vegetation did not yet react significantly to the silvicultural intervention. These preliminary findings are important in drawing suitable forest management practices that need to be applied in mixed beech–silver fir stands, especially in terms of maintaining species diversity. However, the short time frame since the intervention obliges further research on this VF–FVF pair over the next 10–20 years, at least regarding silver fir dynamics. Full article

Firewood extraction by mule forwarding is still common in oak coppices in Central and Southern Italy. This is due to the scarce presence of aerial extraction systems such as cable yarders. Considering the importance of forest soil for all ecosystem services, the evaluation of the disturbance that a given extraction system has on the forest soil is a fundamental aspect in the framework of sustainable forest management. Therefore, this study was developed to assess the disturbance caused to the physicochemical and biological features of soil and to coppice after mule logging according to the standards of silvicultural treatment, as well as the recovery time needed after the logging intervention. Four cutting blocks located in Central Italy represented the study area, one cutting block represented the unharvested control, while the others were logged 3 years (CB-2019), 8 years (CB-2014) and 10 years (CB-2012) prior to the field surveys. In each harvested cutting block the soil was subdivided into disturbed soil (DIST—mule trails) and low disturbance soil (LD—area within the harvested cutting block not affected by mule passage). This experimental design assessed the disturbance caused by logging operations by mules (DIST soil) and the silvicultural treatment (LD soil) to soil physicochemical (bulk density, penetration resistance, shear resistance, and soil organic matter) and biological properties (soil microarthropod community evaluated with the QBS-ar index). The results revealed a significant disturbance in the mule trails for all the investigated variables. The disturbance was particularly strong for the QBS-ar index, with values which were lower than half of those of the control area. Furthermore, no recovery process was evident even after 10 years from the logging interventions. Instead, values of the various parameters became worse with time after harvesting. On the other hand, no marked disturbance was revealed in LD soil, except for a significant decrease in soil organic matter. Although this is a preliminary evaluation that needs to be confirmed with further study, this trial suggested that mule logging cannot be considered a fully low-impact approach to forest operations and that studies with a longer time span after harvesting are needed to assess the recovery process in the mule trails. Full article

An appropriate management and valuation of Pyrenean oak (Quercus pyrenaica Willd.) forests are essential in order to ensure their multiple functions and uses. Many coppice forests of Pyrenean oak have been converted into high forests mostly due to changing demands. This work presents a 20-year study conducted with Pyrenean oak coppices, providing results from an experimental trial where silvicultural improvement interventions for coppice conversion were applied. In addition to control, selective thinning and 3-strip thinning with 2 × 2 m, 3 × 3 m, and 3 × 6 m (the latter also included selective thinning) were examined. The study analyzed tree growth, vertical stratification dynamics, and epicormic branching. It was found that the silvicultural interventions promoted tree development differently according to social crown class. The results have shown a significantly different response in tree diameter growth and live crown length, while height growth has been less accentuated. The study also examined the temporal effect of the interventions on diameter growth. Changes in tree crown position and structural characteristics varied among the cutting interventions. Regarding epicormic branching, the results have revealed that the number of shoots does not differ significantly among the treatments but shows differences in length. Management issues regarding Pyrenean oak coppice conversion have also been addressed. Full article

Socio-economic status, technologies, and policies are key factors affecting forest management planning and forest ecosystem functions. This study applied shared socioeconomic pathways (SSPs) to a forest-management model framework. The potential timber yields and carbon sinks of spatially allocate alternatives were examined by quantifying their consequent changes at the regional tree species level in Chinese commercial forests (CFs) under the harvest and afforestation restrictions. The results indicate that the annual carbon sequestration rate of China’s CFs over the next 50 years is estimated to be 152.0–162.5 Tg/a, which can offset approximately 5% of the anthropogenic CO₂ emissions identified in 2019. Newly planted and regenerated forests can contribute more than 80% of this offset. The annual timber supply capacity is estimated to be 119.2–142.4 million m³/a with current policy interventions, which is not enough to meet the demand for China’s timber market. Although most existing forests are managed as the primary source for forest goods and carbon service, the total commercial forest area changes are not as large as expected, resulting in only 2.0–10.6% differences. Our results also demonstrate that socioeconomic factors (e.g., social preference, carbon price, and forest logging and silvicultural practices) have a strong impact on carbon sinks but a minor impact on timber yields timber, except for improving harvesting and processing technologies. Establishing local long-term effective forest management systems and making afforestation and regeneration as a priority at the national level are suggested to comprehensively enhance the carbon sequestration and timber-supplying abilities of regional CFs. Full article

The studies of spatial-temporal land use and land cover (LULC) change patterns, supported by future scenarios and simulation methods based on the assumption of natural socio-economic and territorial driving forces, allow us to go beyond an accurate diagnosis of the dynamics that have occurred so far, providing a picture of possible alternative futures, and are fundamental in assisting with the planning and policy-making in the territory. In this paper, we use LULC maps and explanatory variables aggregated in five dimensions (physical/natural, economic, sociocultural, technological, and demographic) to identify which are the main drinving forces in the evolution process and the simulation of LULC dynamics for 2036, using as a case study the Chapecó River ecological corridor (Chapecó EC) area. The Chapecó EC was created by the state government in 2010 with the goal of combining nature conservation with local and regional development. In this region, in the last two decades, the loss of areas of natural grassland and forest was on average five times higher than the average recorded in the state. Based on scenario-building methods using artificial neural networks, six predictive scenarios were elaborated, based on three socioeconomic scenarios (current conditions, growth, and socioeconomic recession) and two territorial intervention options (actions). This includes an action based on maintaining the current LULC, and another action of a conservationist nature with the recovery of forest and natural grassland areas to the proportions of areas found in 1990. The results indicate that if the current LULC is maintained, forest, pasture and agriculture areas tend to increase, while silviculture and natural grassland areas decrease, driven by economic and physical/natural driving forces. If there is a conservationist action, natural grassland and pasture areas tend to increase and silviculture and agriculture tend to lose area due to economic, technological, and physical/natural driving forces. These trends have revealed that the natural grassland preservation/restoration, the encouragement of conservationist agricultural practices combined with economic strategies, and the technological development of the rural sector seem to form the basis of economic development combined with biodiversity conservation. Full article