Silvicultural Practices Research Articles

Inter-annual effects of potassium/sodium fertilization and water deficit on wood quality of Eucalyptus grandis trees over a full rotation

In Brazil, most Eucalyptus plantations are located in regions experiencing periods of water shortage, where fertilizers such as potassium (K) are intensively used to achieve high productivity. Recently, sodium (Na) has also been considered a potential nutrient in K-deficient soils. K and Na supply can increase water stress in Eucalyptus grandis trees, which could negatively impact forest productivity over prolonged droughts. Wood properties are determinants of the quality and yield of products. They are important factors to consider when measuring the impacts of silvicultural practices and water deficit on forest productivity. However, alterations in wood properties due to interactions between K/Na fertilization, water availability, and stand age are not well documented.Through annual sampling of E. grandis trees throughout a complete rotation (6 years) in Brazil, we evaluated the interactive effects of K/Na fertilization, water availability, and stand age on stem volume, sapwood/heartwood ratio, wood density, fiber, and vessel features. We also evaluated the relationships between growth rate, wood density, and fiber and vessel features. The split-plot experimental design consisted of two water supply regimes (37% throughfall reduction versus undisturbed throughfall) and three fertilization regimes (K, Na, and control).Until six years of age, K and Na fertilization increased stem volume by 3 and 2-fold, respectively, and only K-fertilized trees affected stem volume by 37% throughfall reduction. Both K and Na detrimentally affected wood density and beneficially affected fiber length. The sapwood/heartwood ratio was highly and negatively related to the growth rate of trees. Wall thickness was not affected by either K or Na. As expected, K and Na affected vessel size due to an increase in basal area growth. However, the effects of Na were more pronounced than those of K. Significant interactions between fertilization and water availability suggest that, under water deficit, wood density will not be affected by K fertilization. In contrast, the effect of Na and control treatments were invariable regardless of water availability.The effects of fertilization on wood properties changed over time, with non-significant effects in the first year and stronger effects from two years of age of trees. The variations in wood density were strongly related to variations in the fiber wall thickness. High increases in basal area growth promoted by K and Na were not related to significant decreases in wood density, but they were related to increases in fiber length. These findings highlight the significant effects of K addition on stem volume without significant losses in wood quality, even under water stress over a complete rotation. The negative impacts observed on wood density and lower productivity in commercial E. grandis plantations with the use of Na as a substitute for K should be considered.

Effects of timber harvest on epigeous fungal fruiting patterns and community structure in a northern hardwood ecosystem

Epigeous fungal fruiting has important impacts on fungal reproduction and ecosystem function. Forest disturbances, such as timber harvest, impact moisture, host availability, and substrate availability, which in turn may drive changes in fungal fruiting patterns and community structure. We surveyed mushrooms in 0.4 ha patch cuts (18 months post-harvest) and adjacent intact hardwood forest in northern New Hampshire, USA, to document the effects of timber harvest on summer fruiting richness, biomass, diversity, and community structure of ectomycorrhizal, parasitic, and saprobic mushroom taxa. Fungal fruiting richness, diversity, and community heterogeneity were greater in intact forests than patch cuts. Among functional groups, ectomycorrhizal fruiting richness, diversity, and biomass were greater in unharvested areas than in the patch cuts, but parasitic and saprobic fruiting did not differ statistically between the two forest conditions. Our findings suggest that timber harvest simplifies fungal fruiting communities shortly after harvest, in particular triggering declines in ectomycorrhizal taxa which are important symbionts facilitating tree establishment and regeneration. Multi-aged silvicultural practices that maintain mature forest conditions adjacent to and throughout harvested areas through deliberate retention of overstory trees and downed woody material may promote fungal fruiting diversity in regenerating stands.

Ensemble modeling of watershed‐scale hydrologic effects of short‐rotation woody crop production

AbstractShort‐rotation woody crop (SRWC) production involves a set of silvicultural practices that aim to produce large volumes of biomass over relatively short time frames. The area over which these practices are employed is likely to increase in the coming decades as the demand for bioenergy increases, but the potential effects of this change in land management, including the hydrologic effects, are largely unknown. Here we outline the results from an ensemble modeling study that was developed to forecast the range of potential hydrological responses to the implementation of SRWC production over areas that are large (>1000 ha) relative to the size of individual clearcuts. The three models, SWAT, MIKE‐SHE, and Envision‐SRS, a physically based model designed to represent watersheds with dynamic land cover, represent a range of simulation tools that include hydrological response to landcover change. Results suggest that SRWC production will affect the hydrologic balance, primarily through changes in the volume of transpired water associated with the rapidly growing young stands. In particular, average annual actual evapotranspiration (ET) rates tend to decline under SRWC production in response to the less mature vegetation. These reductions in ET are balanced in the hydrological cycle through elevated groundwater recharge, expressed in the model results as elevated annual stream discharge. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

Morphological Characteristics of Reproductive System of the Codling Moth Cydia Pomonella

Forest management system as a component of ungulate pest management. Wild ungulates are an important site factor in forests and landscapes. Impacts of ungulates on forest vegetation and the effect of hunting systems are often investigated and discussed. In contrast, the impact of silvicultural systems on forest damage by ungulates is much less conscious. Therefore, in a long-term research program in Central Europe since the 1990ies two questions were investigated additionally, (i) in which way can forest management systems and landscape structures influence the interactions between ungulates and forest vegetation, and (ii) how can silvicultural practices modify the susceptibility of forests to damage by ungulates. The results showed a strong impact of these factors on the emergence of game damage to forests. Factors that are often underestimated in practice. Recommendations for a coordinated management of different land users to avoid ungulate damage to forest vegetation and to preserve biodiversity were made.

Root Growth Potential and Microsite Effects on Conifer Seedling Establishment in Northern Idaho

Environmental conditions and seedling quality interact to produce complex patterns of seedling survival and growth. Root growth potential (RGP) is one metric of seedling quality that can be rapidly measured prior to planting, but the correlation of RGP and seedling performance is not consistent across studies. Site factors including microsite objects that cast shade and competing vegetation can also influence seedling performance. We examined the effects of RGP, presence/absence of a microsite object, and competition cover on the survival and growth of three native conifers to the Inland Northwest, USA, over 5 years. We found that RGP had no effect on the survival or growth of western larch (Larix occidentalis), Douglas fir (Pseudotsuga menziesii var. glauca), and grand fir (Abies grandis) at a mesic north aspect site and a xeric south aspect site. Comparatively, the presence of a microsite increased the odds of survival by 37% for western larch and 158% for grand fir, while the absence of forb cover increased the odds of survival of western larch by 72% and of grand fir by 26%. Douglas fir was less sensitive to microsites and competition. The strong effects of neighborhood conditions around seedlings help inform silvicultural practices to enhance the establishment of western larch and grand fir, including planting seedlings near shading objects and competition control, while these practices may not be as important for Douglas fir.

Climate change impacts on spatial distribution, tree-ring growth, and water use of stone pine (Pinus pinea L.) forests in the Mediterranean region and silvicultural practices to limit those impacts

Stone pine (Pinus pinea L.) has been cultivated since centuries in Mediterranean areas for its products and economic benefits, including edible pine nuts, timber, mushrooms, firewood, and grazing. However, current management objectives of stone pine stands also include recreational use, biodiversity conservation, protection from soil erosion, and CO2 fixation. Stone pine stands are considered to be among the ecosystems most vulnerable to climate change, and the current increase in drought frequency in the Mediterranean Basin has been shown to negatively impact their long-term establishment. Understanding the effects of climate change on the distribution, tree-ring growth and water use of stone pine forests can help assessing the adaptive capacity of the species, and developing management programs aimed at its conservation. This paper reviews the impacts of climate change on stone pine in the Mediterranean region. The high sensitivity of stone pine to climate change has been widely demonstrated in that: (i) climatic models predict the loss of suitable habitats and the shift of its geographical distribution in the next future; (ii) tree-ring analysis showed that winter and spring rainfalls have positive effects on growth, whereas high spring temperature has a negative effect; (iii) the strategy of stone pine to cope with water deficit affects the processes regulating its growth, including wood formation, leading to peculiar tree-ring anatomical features such as intra-annual density fluctuations. The silvicultural interventions and the most effective management strategies for stone pine forests are reviewed and discussed in the context of current climate change in the Mediterranean Basin.

A Dynamic Stand Growth Model System for Loblolly Pine Responding to Mid-Rotation Treatments

Intensive loblolly pine (Pinus taeda L.) plantation management in the southeastern United States includes mid-rotation silvicultural practices (MRSP) like thinning, fertilization, competitive vegetation control, and their combinations. Consistent and well-designed long-term studies considering interactions of MRSP are required to produce accurate projections and evaluate management decisions. Here we use longitudinal data from the regional Mid-Rotation Treatment study established by the Plantation Management Research Cooperative (PMRC) at the University of Georgia across the southeast U.S. to fit and validate a new dynamic model system rooted in theoretical and biological principles. A Weibull pdf was used as a modifier function coupled with the basal area growth model. The growth model system and error projection functions were estimated simultaneously. The new formulation results in a compatible and consistent growth and yield system and provides temporal responses to treatment. The results indicated that the model projections reproduce the observed behavior of stand characteristics. The model has high predictive accuracy (the cross-validation variance explained was 96.2%, 99.7%, and 98.6%; and the prediction root mean square distance was 0.704 m, 19.1 trees ha−1, and 1.03 m2ha−1 for dominant height (DH), trees per hectare (N), and basal area (BA), respectively), and can be used to project the current stand attributes following combinations of MRSP and with different thinning intensities. Simulations across southern physiographic regions allow us to conclude that the most overall ranking of MRSP after thinning is fertilization + competitive vegetation control (Fert + CVC) > fertilization only (Fert) > competitive vegetation control only (CVC), and Fert + CVC show less than additive effect. Because of the model structure, the response to treatment changes with location, age of application, and dominant height growth as indicators of site quality. Therefore, the proposed model adequately represents regional growth conditions.

Production and carbon allocation in clonal Eucalyptus plantations under different planting spacings

Wood productivity in plantation forests depends on successful choices of genetic materials and silvicultural practices. Wisely defining the intitial tree spacing according to edaphoclimatic conditions is important as spacing influences the amount of water, nutrients and light available for each tree. Resource availability, in turn, influences some important processes controlling wood production such as tree survival, CO2 uptake, and partitioning of photosynthates to stem wood and other tree compartments. Different genotypes may respond differently to tree spacing, due to possible differences in their canopy structure, physiology, and strategies for soil ressources acquisitions and carbon allocations. Our objective in this study was to investigate the interactive effects of genotype and tree spacing on wood production of fast-growing clonal eucalypt plantations in Southeastern Brazil. Tree growth, gross primary production (GPP) and partitioning of GPP to total belowground carbon flux (TBCF), wood and leaf production, and aboveground respiration were assessed in an experimental trial involving three commercial E. urophylla clones (AEC 0144, AEC 224 and COP 1404) planted at two spacings (3 m × 2 m; 3 m × 4 m). We hypotetized that (1) the most productive genotypes are those with both the highest GPP and the highest carbon partitioning to stem wood production; and (2) at closer spacing, leaf area index (LAI) and GPP are higher, but the partitioning to wood production is lower, and the belowground partitioning is higher, due to reduced soil water and nutrients availability per tree. Biomass and LAI were measured at ages 40 months (mid-rotation) and 52 months, and GPP, TBCF, wood production and leaf production were estimated between these two stand ages. Stem biomass and LAI were higher, for all clones, at the closer spacing (3 m × 2 m), as we could have expected since this spacing (corresponding to a stocking of 1667 tree ha−1) is the most commonly chosen in industrial eucalypt plantations in this region. Consistently with clonal ranking established in other studies, at spacing 3 m × 2 m clones were ranked as AEC 0144 > AEC 224 > COP 1404 for their wood production, but this ranking almost vanished at wide spacing. Our first hypothesis was supported by data: at spacing 3 m × 2 m the most productive clones (AEC 0144 > AEC 224 > COP 1404) were those with both the highest GPP (6.14 > 4.63 > 4.57 kg C m−2 year−1) and the highest carbon partitioning to wood production (0.33 > 0.29 > 0.26), although the differences between COP 1404 and AEC 224 were not significant (at P = 0.05). Our second hypothesis was only partially supported by data: wood biomass at age 40 months was higher at the closer spacing, but this positive effect of tight spacing seemed to decrease with stand age, as wood production and GPP measured between ages 40 and 52 months remained higher at the closer spacing only for clone AEC 0144. There was no consistent difference in the partitioning of GPP to wood production between the two spacings. The age-related decrease of the positive effect of high stockings may result from a faster depletion of deep soil water reserves in dense stands.

Forest Management as a Component of Ungulate Management to Avoid Game Damage

Forest management system as a component of ungulate pest management. Wild ungulates are an important site factor in forests and landscapes. Impacts of ungulates on forest vegetation and the effect of hunting systems are often investigated and discussed. In contrast, the impact of silvicultural systems on forest damage by ungulates is much less conscious. Therefore, in a long-term research program in Central Europe since the 1990ies two questions were investigated additionally, (i) in which way can forest management systems and landscape structures influence the interactions between ungulates and forest vegetation, and (ii) how can silvicultural practices modify the susceptibility of forests to damage by ungulates. The results showed a strong impact of these factors on the emergence of game damage to forests. Factors that are often underestimated in practice. Recommendations for a coordinated management of different land users to avoid ungulate damage to forest vegetation and to preserve biodiversity were made.

Farmers' preferences for water-saving strategies in Brazilian eucalypt plantations

In a climate change context, changing temperature and precipitation patterns are expected to have strong impacts on Brazilian eucalypt plantations. Implementing adaptive water-efficient management practices is thus becoming necessary to maintain high levels of productivity while preserving the water resources. This paper investigates the ability of eucalypt farmers to modify their current silvicultural practices in order to adapt to drought in the near future. We ran a choice experiment in the state of Minas Gerais, among 80 eucalypt tree farmers, who were asked to choose from several management options associated with various financial supports. The results show that adaptation by reducing the length of the eucalypt rotation proves to be by far the preferred option, despite the associated costs. On the contrary, reducing density appears to be the least chosen option by the respondents, which may suggest that they underestimate the benefits of this strategy. We moreover find a clear and relevant segmentation of farmers' choice behavior, the general preference for reducing the length of the eucalypt rotation being driven by the most vulnerable farmers of the sample.

Near infrared spectroscopy of Eucalyptus pellita for foliar nutrients and the potential for real-time monitoring of trees in fertiliser trial plots

Eucalyptus pellita F. Muell. has become an important tree species in the forest plantations of SE Asia, and in Malaysian Borneo in particular, to replace thousands of hectares of Acacia mangium Willd. which has suffered significant loss caused by Ceratocystis manginecans infection in Sabah, Malaysia. Since its first introduction at a commercial scale in 2012, E. pellita has been planted in many areas in the region. The species replacement requires new silvicultural practices to induce the adaptability of E. pellita to grow in the region and this includes relevant research to optimise such regimes as planting distance, pruning, weeding practices and nutrition regimes. In this present study, the nutritional status of the foliage was investigated with the aim to develop near infrared spectroscopic calibrations that can be used to monitor and quantify nutrient status, particularly total foliar nitrogen (N) and phosphorus (P) in the field. Spectra acquired on fresh foliage in situ on the tree could be used to predict N and P with accuracy suitable for operational decision-making regards fertiliser application. If greater accuracy is required, spectra acquired on dry, milled foliage could be used to predict N and P within a relative error of 10% (R2c, r2CV, RMSEP, RPD = 0.77, 0.71, 0.02 g 100 g-1, 1.9 for foliar P and = 0.90, 0.88, 0.21 g 100 g-1, 3.0 for foliar N on dry, milled foliage). The ultimate application of this is in situ nutrient monitoring, particularly to aid longitudinal studies in fertiliser trial plots and forest operations, as the non-destructive nature of NIR spectroscopy would enable regular monitoring of individual leaves over time without the need to destructively sample them. This would aid the temporal and spatial analysis of field data.

Does the type of silvicultural practice influence spruce budworm defoliation of seedlings?

AbstractSpruce budworm (Choristoneura fumiferana (Clem)) is the main defoliator in the boreal forest of North America, and its outbreaks have major ecological and economic consequences and represent a challenge for forest management. Numerous studies have addressed the effects of this defoliator on mature trees, whereas the effects of spruce budworm on regeneration remain elusive. Furthermore, intensive exploitation practices during the last decades have left a large area of the Canadian boreal forest in an early development stage. In this context, it becomes vital to understand those factors affecting the severity of spruce budworm‐related defoliation on regeneration. Here, we determine the defoliation severity of black spruce and balsam fir seedlings in both mature pure black spruce and black spruce–balsam fir stands subjected to two different silvicultural treatments (clear‐cutting and partial cutting). Defoliation intensity varied between stand types, silvicultural treatments, species, and height classes. Seedlings in black spruce–balsam fir stands experienced twice the defoliation of those in pure black spruce stands (black spruce seedlings 10% vs. 23%; balsam fir seedlings 29% vs. 47%, respectively). Harvesting methods also influenced seedling defoliation. Under clear‐cutting, black spruce seedlings (24%) were three times as defoliated as black spruce seedlings in partial cutting stands (8%), whereas balsam fir seedlings in clear‐cutting plots experienced twice the defoliation (42%) of balsam fir seedlings in partial cutting plots (20%). The level of defoliation also increased with seedling height. This study will help silvicultural strategies adapt to the effects of natural disturbance regimes. As the intensity and severity of defoliator outbreaks are expected to increase under climate change, these results will help guide forest management strategies to select harvesting methods that will limit the effects of defoliation on conifer regeneration.

Positive impact of traditional coppicing restoration on biodiversity of ground-dwelling spiders in a protected lowland forest

Lowland forests of Central Europe had been managed by diverse traditional practices for millennia. Such management helped to maintain heterogeneous habitat conditions suitable for a wide variety of arthropod species. Modern approaches to conservation, however, with their strategies of nonintervention, unintentionally caused an overall habitat homogenization within protected areas in many ecosystem types during the20thcentury. As a result, the diversity of organisms, including several large groups of arthropods, has gradually declined. Active interventions that would diversify homogenized lowland forest reserves are increasingly being reintroduced. A question remains as to whether the traditional management restoration at various intensities will maintain conditions suitable for high diversity of functionally important groups of arthropods. Here,we studied the effect of canopy thinning, aimed at coppice restoration, on ground-dwelling spider assemblages. Sampling was based on experimental plots distributed equally in an abandoned coppice-with-standards among three canopy thinning intensities: strong thinning, moderate thinning, and nonintervention as a control. We recorded 116 species of spiders, including a high proportion of Red-listed and threatened species. The species richness and presence of rare and threatened species increased with the intensity of canopy thinning. The abundance of spiders was greater in plots with moderate thinning than in control plots. Functional richness was greatest in open habitats with strong canopy thinning, however functional traits were equally distributed across allhabitats. Although ordination analyses revealed that species of conservation concern tended to be associated with open habitats, some conservation-valuable species had affinities alsofor nonintervention plots. Overall, our results indicated that the best silviculture practice for biodiversity conservation is a combination of various management intensities that would support functional groups ranging from open habitat specialists to species typical for dense and more humid forest patches. We demonstrated that returning to active coppicing management can be a successful strategy for biodiversity restoration in lowland forests.

Intraspecific Growth Response to Drought of Abies alba in the Southeastern Carpathians

The intensity and frequency of drought have increased considerably during the last decades in southeastern Europe, and projected scenarios suggest that southern and central Europe will be affected by more drought events by the end of the 21st century. In this context, assessing the intraspecific genetic variation of forest tree species and identifying populations expected to be best adapted to future climate conditions is essential for increasing forest productivity and adaptability. Using a tree-ring database from 60 populations of 38-year-old silver fir (Abies alba) in five trial sites established across Romania, we studied the variation of growth and wood characteristics, provenance-specific response to drought, and climate-growth relationships during the period 1997–2018. The drought response of provenances was determined by four drought parameters: resistance, recovery, resilience, and relative resilience. Based on the standardized precipitation index, ten years with extreme and severe drought were identified for all trial sites. Considerable differences in radial growth, wood characteristics, and drought response parameters among silver fir provenances have been found. The provenances’ ranking by resistance, recovery, and resilience revealed that a number of provenances from Bulgaria, Italy, Romania, and Czech Republic placed in the top ranks in almost all sites. Additionally, there are provenances that combine high productivity and drought tolerance. The correlations between drought parameters and wood characters are positive, the most significant correlations being obtained between radial growth and resilience. Correlations between drought parameters and wood density were non-significant, indicating that wood density cannot be used as indicator of drought sensitivity. The negative correlations between radial growth and temperature during the growing season and the positive correlations with precipitation suggest that warming and water deficit could have a negative impact on silver fir growth in climatic marginal sites. Silvicultural practices and adaptive management should rely on selection and planting of forest reproductive material with high drought resilience in current and future reforestation programs.

Hybrid height growth and survival model for juvenile Eucalyptus globoidea (Blakely) and E. bosistoana (F. Muell) in New Zealand

Juvenile plantation forest dynamics are complex but understanding and predicting early growth and survival enables effective management. Information provided by traditional growth and yield models is an essential input in decision-making processes for managing planted forests. They are generally fitted using permanent sample plot data, thus they are robust and simple. However, the introduction of explanatory factors affecting tree development (e.g. wetness index, morphometric protection index etc.) not only to improve the quality of predictions but also to add useful information underpinning forest management decisions (e.g. species choice, silvicultural practice etc.). In this study, three different hybrid growth and yield approaches for modelling height growth and survival were tested, culminating in models being developed for Eucalyptus globoidea and E. bosistoana by integrating climatic, edaphic and topographic factors. Permanent sample plot data (n = 84) were used to develop these models. The results showed that inclusion of topographic and climatic factors alongside potentially usable light sum (PULS) slightly improved both height and survival prediction of both species compared to time-based models (TA). The ranking and alignment of coefficient of determination for height models were PULS = 0.79 > 0.77 > TA = 0.75 and survival models were PULS = −0.47 > TA = −0.45, respectively. Both of the species were site-sensitive, especially to soil moisture and wind speed. This sensitivity also indicated the optimal requirements for height growth and survival for these species. All three modelling approaches can be applied for juvenile Eucalyptus plantations in any given site-specific case, based on available information and management demands. The models developed in this study can help forest managers make better decisions for new plantation establishment and management.

A systematic evaluation of gap size and within-gap position effects on seedling regeneration in a temperate secondary forest, Northeast China

Forest gaps play an important role in tree regeneration and forest restoration in modern silviculture. Many previous studies examined gap effects on seedling survival, growth, or both but lacked a systemic assessment incorporating morphological and physiological responses to varying environmental gradients along gap size and within-gap position, which limits foresters to understand the general gap impacts on the early stage of regeneration. Here, we systemically evaluated gap impacts on over 20 regeneration-related variables from two dominant tree species (Manchurian walnut [Juglans mandshurica Maxim.] and Korean spruce [Picea koraiensis Nakai]) planted along the gap-understory gradients based on our previous studies of survival and growth of these two species. The factor analysis of mixed data indicated that seedling specific leaf area, biomass allocation, chlorophyll content, and NSC content in gaps were largely determined by interspecific differences, but seedling survival, growth, and biomass accumulation were mainly related to gap size and within-gap position. Specifically, the net photosynthetic rates of Manchurian walnut were higher in large and medium gaps (or gap centers and transitions) than those in small gaps and forest understory (or gap edges). The root starch content of seedlings in gaps was almost twice as much as that in the forest understory, which also reflected species divergence in gaps. By contrast, Korean spruce exhibited less variation in net photosynthesis and root starch content and fewer differences for most other examined variables, which indicated that it had broad ecological niches and a relatively small gap would promote its regeneration during the seedling stage. Our findings provide evidence of gap partitioning on explaining regeneration patterns of light-demanding species. Therefore, gap size and within-gap position can compensate for each other during gap-based silviculture practices. Timely selective logging can extend an existing gap in a specific direction to change the relative position of target tree species for better light conditions. Appropriate selection and match of tree species to gap size and within-gap position during enrichment planting can improve gap space utilization.

Impact of silvicultural system on natural regeneration in Western Himalayan moist temperate forests of Pakistan

Site conditions (topography, aspect, moisture availability, humus thickness, light exposure, and grazing activities) play a vital role in the germination and regeneration process. The research was conducted in the Himalayan moist temperate forest. The research site was divided based on the silvicultural system (group selection system and single-tree selection system) into 148 plots and 150 plots, respectively. The group selection system was examined on the site of 2 ha which was clear-felled under a project in the 1980's. The present study examined the impact of silvicultural systems on regeneration. The frequency table was used, and relative frequency was calculated for the species and silvicultural system, density per m2 was also calculated. Diversity indices were calculated through taxa, dominance, Simpson’s index, Shannon index, evenness, equitability, and fisher alpha. Ten taxa were found in both silvicultural systems, with individual repetition of 17 and 15 taxa, respectively. Group selection is more compact visibly as compared to the single-tree selection system. The single-tree selection system is more diversified in species composition, stand structure, moisture availability, and less humus availability. The study also highlights future predictions for the conservation of these forests, which are highly sensitive and a hotspot for wildlife and climate change phenomena. Silvicultural practices such as silvicultural system, cleaning, weeding, thinning operations are regularly practiced, which can reduce the negative impact on these productive forests.

Selective logging reduces body size in omnivorous and frugivorous tropical forest birds

Selective logging is the main anthropogenic disturbance in tropical forests, driving shifts in species abundances. Body size and body condition are important metrics of fitness that may be affected by habitat degradation. We conducted a four-year study to investigate how selective logging impacted the body size and body condition index (BCI) of 55 Bornean bird species and whether changes in body metrics were associated with shifts in relative population abundance. Frugivorous and omnivorous birds had reduced body size in selectively logged versus unlogged forest, but we found no evidence for selective removal of individuals driven by sex differences or post-fledging body size, indicating different developmental conditions for frugivores and omnivores in logged forest. Change in body size between forest types showed no clear patterns for insectivorous birds, and did not differ between IUCN categories. BCI of birds was affected by study year, suggesting an effect of climatic conditions on food availability, but not by logging. At the community level, post-logging change in population abundance was not associated with reduced body size, although between species variation suggests that adverse environmental conditions and different coping strategies underlie body size reductions in logged forest. Our study suggests that body size is a valuable metric to assess how logging impacts forest birds, pointing towards potential functional consequences related to seed dispersal within logged forests and need for improved silvicultural practices.

A review of modeling, and simulation for sustainable replanting eucalyptus

The growth process of eucalyptus plants in the form of log volume is influenced by abiotic, and biotic factors, which then have a relationship with climate, genotype, soil conditions, both physical, and chemical, silvicultural practices, and forest management. Therefore, to improve forest resilience, and productivity, identification of eucalyptus plants is needed. The most promising tool available to help government, and companies is to use eucalyptus-based models. This model is useful for getting the right planning, assessing the variables that affect climate, and determining long-term direction, and for seeing changes in the forest sector. Individual growth models with trees, and st, anding levels are needed to estimate future forest structures. The purpose of this study is to provide information about the models, and simulations used in the process of replanting eucalyptus plants that have benefits in various sectors of life.

Intra-household gender relations and women participation in non-industrial private forestry in the Southern Highlands of Tanzania

This paper draws on a study conducted in the selected districts of Iringa and Njombe regions in the Southern Highlands of Tanzania where over the past decade Non-industrial Private Forestry (NIPF) has emerged involving village-based domestic investors. Data for the study were largely collected using focus group discussions (FGDs) of men and women tree growers. Data were analysed using content analysis focusing on the emerging themes, subthemes, and patterns. The paper shows that gender division of labour characterizes silvicultural practices in private forestry. Men play a key and dominant role in decision making on the allocation of labour and marketing of timber. We argue that, given this arrangement, as long as men continue to dominate the market sphere, mere ownership of woodlots by women is not a feasible pathway to having control over income obtained from the sales of timber from their woodlots. To address this, the paper comes up with some recommendations.