Gaps play a key role in forest ecosystem development and result from either natural processes or targeted forest management activities. The aim of this study was to investigate the interrelationships of soil properties in each of three forest types and two treatments, and to identify factors that influence levels of soil mineral nitrogen forms. The relation between mineral nitrogen and factors of soil parameters and stand type (European beech, Norway spruce, mixed stand) categories were investigated. The spruce forest type stored significant nitrogen in both mineral forms of nitrogen. Moreover, there was a significant linear dependence between N–NO₃ ⁻ (nitrate anion) concentrations and cation exchange capacity (CEC) parameters such as base cation contents (S-CEC) and potential ureolytic activities (UreasePot), as well as between N–NH₄ ⁺ (ammonium cation) concentrations and both hydrolytic acidities (Ha-CEC) and ureolytic activities. The dependence of N–NO₃ ⁻ concentrations on S-CEC contents and UreasePot was negative, especially in adjacent stand. The dependence of N–NH₄ ⁺ concentrations on Ha-CEC and UreasePot was week in the beech and mixed forest types while it was significantly positive in the spruce forest type.

Although several studies have assessed the effects of thinning on water quality, including nitrogen (N) exports, few have examined N-saturated plantations. This study assessed the short-term effect of thinning on N exports from a N-saturated plantation forest in northern Kyushu, western Japan, that was thinned (43% of basal area) during January–March 2012. Water levels at the gauging station were continually measured, and stream-water baseflow and stormflow samples were collected before (2011) and after (2013) forest thinning. Annual precipitation before (2469 mm) and after (2418 mm) forest thinning differed little, and annual water discharge after thinning (1641 mm) was similar to that before thinning (1609 mm). However, direct flow during stormflow periods was higher after thinning (260 mm) than before (153 mm). The concentrations of major ions in stream water did not differ before and after thinning. As a result, the high annual dissolved inorganic N (DIN) exports differed little before (35.8 kg N ha⁻¹ a⁻¹) and after (36.5 kg N ha⁻¹ a⁻¹) forest thinning. DIN exports during stormflow periods were slightly higher after (12.2 kg N ha⁻¹ a⁻¹) than before thinning (10.5 kg N ha⁻¹ a⁻¹) and were proportional to the increased direct flow after thinning (561 mm after vs. 470 mm before thinning). We concluded that thinning does not affect annual N exports from the N-saturated plantation forest, but it can increase the proportion of N exported during stormflow periods in proportion to increased water volume of direct flow after thinning.

Stand structural complexity enhancement is an increasingly popular management objective, especially on public lands. Complex stand structures are hypothesized to support a relatively high degree of native forest diversity and be more resistant and resilient to disturbances. Complex structures are characterized by the presence of deadwood and heterogeneity of tree-size classes and tree architecture. Relatively little is known about how discrete disturbance events affect structural complexity and compositional diversity in Quercus-dominated stands at fine spatial scales (i.e. neighborhoods). We established 20 0.05 ha fixed-radius plots on the Sipsey Wilderness of William B. Bankhead National Forest in northern Alabama to quantify woody plant species composition and structure. Trees were mapped on each plot to quantify overstory structural complexity and compositional diversity. We extracted two cores from all canopy Quercus spp. ≥ 5 cm diameter at breast height to quantify age, recruitment pulses, and reconstruct canopy disturbance history. Shannon species diversity in the sampled area was 1.75 for trees, 2.08 for saplings, and 1.69 for seedlings. Quercus alba had the greatest basal area, and Ostrya virginiana had the highest density. The stand exhibited a reverse J-shaped distribution with a q-factor of 1.72. The oldest Quercus dated to 1795, and the largest recruitment pulse occurred in the 1870s. The mean return interval for intermediate-severity disturbance was 38 years. Although we documented no relationships between disturbance frequency and compositional diversity at the neighborhood scale (0.05 ha), less frequent disturbance was associated with higher structural complexity (r ² = 0.258, p = 0.026) at the neighborhood scale. We suggest that localized disturbance increases species diversity and structural complexity, but these processes are manifest at the stand level and not at the neighborhood scale. We conclude that the spatial variability (i.e. size, shape, orientation, microsite conditions) is likely more influential on diversity and complexity than the temporal variation (frequency) of these processes at the neighborhood scale.

The present study describes the floristic composition and dominance pattern of sal forests in Ranchi, Jharkhand, eastern India. Vegetation was studied in 47 belt transects (50 × 100 m) that had 137 plant species (110 identified and 27 unidentified) belonging to 51 families. The family Fabaceae with 17 species (8 spp. belonging to subfamily Faboideae, 6 spp. to Caesalpinioideae and 3 spp. to Mimosoidieae) contributed the most to diversity, followed by Rubiaceae (8 spp.) and Euphorbiaceae (6 spp.). Tree density in sal was inversely related to species richness. Total tree density (≥ 10 cm GBH) in the studied forests was 397 individuals ha⁻¹, with a basal cover of 262.50 m² ha⁻¹. Important plants of conservation concern are Pterocarpus marsupium Roxb, Andrographis paniculata (Burm.f.) Wall, Sterculiaurens Roxb., Tinospora cordifolia (Willd.) Miers, and Asparagus densiflorus (Kunth) Jessop. Phanerophytes had the highest percentage (71%, with percentage deviation from normal life form of + 25) followed by therophyte (15%, with percentage deviation + 2). Observed percentage deviation from normal life form was much lower (with + 2 percentage deviation) in both chamaephytes (8%) and therophytes (15%), suggesting that the studied sal forests are favorable for supporting various plants species. The forest management strategies should focus on the increasing demands for different timber and non-timber forest products to conserve the plant diversity of these natural forests.

This study focuses on age, growth rate and diameter distribution of pine forests in the Malam Jabba area, Swat District, Pakistan. Wood core samples were taken from twenty stands. Picea smithiana was the oldest at 234 years with a 112-cm diameter. Abies pindrow was 125 years with an 80-cm diameter while the oldest Pinus wallichiana was 122 years with 75-cm diameter. The fastest overall growth rate of 1.5 ± 0.1 year/cm was for P. wallichiana on a west-facing aspect, while the slowest 5.8 ± 2.6 year/cm growth was P. smithiana on an east-facing exposure. P. wallichiana and A. pindrow exhibited marked differences in growth rates over a 5-year period. The highest growth was by P. wallichiana from 1966 to 2006. A. pindrow showed less growth over the same years, such pattern simultaneously reverse from 1911 to 1965. The relationship between diameter and age, diameter and growth rate and age and growth rate were correlated. P. wallichiana and A. pindrow ages were correlated with diameter and growth rates. P. smithiana age was positive correlated with diameter. Generally, topographic and edaphic factors did not show significant correlations with growth rates, although some appreciable correlations were recorded. The growth of P. wallichiana was correlated with elevation while A. pindrow was correlated with maximum water retaining capacity. Diameter and age produced uneven size classes and many size gaps, which could be the result of anthropogenic disturbances.

Soil moisture is an important resource for plant growth on the arid and semi-arid Loess Plateau of China where the “Grain for Green” project was launched in 1999, but there has been no systematic evaluation of soil moisture from the effects of ecological restoration at a regional scale. We systematically assessed 63 published studies during 2000–2015, including 2050 observations at 68 sites on the Loess Plateau with the aim of determining soil moisture changes and the factors influencing those changes. We found that, after land use conversion, soil moisture decreased by 17% in the upper 100 cm soil layer and that tree plantations and shrub lands appeared to cause soil moisture depletion which became increasingly serious with soil depth. The decrease of soil moisture was significantly influenced by the planting species in all restoration types (tree plantations, shrub lands, and grasslands). We also found that tree plantations and grasslands converted from farmlands consumed more soil moisture than from wasteland (including bare land, abandoned land and wild grasslands). Artificial restoration led to significant soil moisture reduction, but natural restoration had little effect on soil moisture. Therefore, natural restoration should be an alternative restoration practice on the Loess Plateau. These results will provide helpful information for artificial afforestation and planning ecological restoration campaigns for policy makers on water-limited regions.

Information on forest structure is fundamentally important to track successional vegetation dynamics for efficient forest management. This study reports on vegetation characteristics, dominance patterns and species height growth in a northern mistbelt forest type in South Africa. Common alpha-diversity indices (species richness and Shannon–Weiner diversity), structural vegetation parameters (tree density and basal area), and species importance value index were used. Size class distribution and height–diameter allometry were further examined for the overall stand and most important species. Stem densities (472.0 ± 43.5 and 605.3 ± 28.1 trees ha⁻¹ for ≥ 5 cm to < 10 cm and ≥ 10 cm dbh (diameter at breast height) classes, respectively) and basal area values (1.99 ± 0.19 and 48.07 ± 3.46 m² ha⁻¹, respectively) are comparable to other Afromontane forests in East Africa. The overall stand showed an inverted-J shaped distribution pattern which is a typical feature of stand size class distribution in most natural forests. Most ecologically important species also exhibited an inverted-J shaped distribution pattern, suggesting good regeneration and recruitment potential. There were significant differences in species on height, reflecting species-specific height growth patterns, possibly a result of intrinsic growth potential and competitive interactions. The present study suggests that conservation and management policies, including protection of surrounding land uses against fire, contribute to maintaining a successful recovery of these forests. However, it should be noted that these forests may be experiencing relatively slow dynamic flux as a result of the over-mature state of some trees with several years under relatively strict protection.

The effect of tree age and climatic variables on stem radial growth of two hybrid clones of Eucalyptus was determined using longitudinal data from eastern South Africa. The stem radius of was measured weekly as the response variable. In addition to tree age, average weekly temperature, solar radiation, relative humidity and wind speed were simultaneously recorded with total rainfall at the site. An additive mixed effects model that incorporates a non-parametric smooth function was used. The results of the analysis indicate that the relationship between stem radius and each of the covariates can be explained by nonlinear functions. Models that account for the effect of clone and season together with their interaction in the parametric part of the additive mixed model were also fitted. The interaction between clone and season was not significant in all cases. For analyzing the joint effect all the covariates, additive mixed models that included two or more covariates were fitted. A significant effect of tree age was found in all cases. Although tree age was the key determinant of stem radial growth, weather variables also had a significant effect that was dependent on season.

This study addresses the increasing demand for large-diameter production timber, and considers the time and space variability of half-sib families of Pinus massoniana. Height, diameter at breast height (DBH) and timber volume of 440 open-pollinated half-sib progeny families were investigated in 14 progeny trials in different years and production regions. An evaluation of the genetic variation of all half-sib families was carried out during the sustainable rapid growth period and individual volumes were characterized as a major index. ANOVA analysis showed that there was considerable variance in the growth traits of most families in different years and on different sites. The variations caused by temporal and spatial changes of the mating system required three selection methods for analysis. The results show that there were differences among the heritabilities of different growth traits by different half-sib progenies. Average heritability values of height, DBH and volume were 0.33, 0.34 and 0.36, respectively. Forty-five superior families were selected in every progeny test, 12 were selected in progeny trials by different years and five in different habitat progeny trials. Three superior families (Gui GC553A, Gui GC414A and Gui GC431A) were selected, although in different years and production regions. The genetic gains of timber volume of these selected r families ranged from 1.20 to 47.00%, which could provide a foundation for superior wood property selection and serve as material for seed improvement and extension in surrounding areas.

Peach palm (Bactris gasipaes Kunth) has been micropropagated from pre-procambial cells that provide stem-like cell niches, (i.e., pre-procambial cells), multipotent, pluripotent and totipotent for direct vascularization, adventitious buds and somatic embryogenesis, respectively. The direct induction of adventitious buds and somatic embryogenesis reduces the frequency of mutations when compared to indirect morphogenesis. Long-term in vitro cultivation of perennial species such as peach palm cause the clones to age and deteriorate; however, the consequences for morphogenesis potential are not fully clear. The morphogenic potential of peach palm clones established and in vitro cultivated for 8 years (regeneration of adventitious buds without callus formation) was investigated in leaves, roots and stem bases using histological and histochemical analyses. Data from long-term cultures (8-years-old) was compared to data from short-term cultures (1-year-old). Morphogenic pathways monitoring for direct induction of somatic embryos and adventitious buds revealed a strong morphogenic reduction potential in the pre-procambial cells, parenchyma cells in the proximal region of stem bases, and external cells of leaf sheaths. Initial cells of shoot apical meristems and pre-procambial cells commit cell reprogramming to the undifferentiated state and subsequent acquisition of cellular competence. These results are applicable in the micropropagation of peach palm, with consideration to obtaining clones and their long-term in vitro culture.

Genetic transformation is becoming routine for engineering specific traits in important clones of recalcitrant species such as Eucalyptus; however, the efficiency is still low for most species, so many researchers still use seeds instead of clones as initial explants. This work aimed to develop a genetic transformation protocol, based on a highly efficient in vitro organogenesis protocol, for an Eucalyptus urophylla clone selected in our breeding program. Plant growth regulators were evaluated for indirect organogenesis and rooting. In a two-step protocol, the combination of callus induction media supplemented with 0.5 µM thidiazuron + 0.5 µM naphthaleneacetic acid (NAA) and shoot induction media supplemented with 5.0 µM benzylaminopurine + 1.0 µM NAA allowed up to 85.6% shoot formation with more shoots per explants when compared with other concentrations. Transgenic plants expressing the uidA gene were obtained using Agrobacterium tumefaciens and selected for kanamycin resistance. A RAPD analysis was used to check for somaclonal variation. In tests using 11 RAPD primers, we did not observe somaclonal variation in the in vitro stages evaluated.

Juniperus excelsa subsp. polycarpos, (Persian juniper), is found in northeast Iran. In this study, the relationship between ground cover and vegetation indices have been investigated using remote sensing data for a Persian juniper forest. Multispectral data were analyzed based on the Advanced Visible and Near Infrared Radiometer type 2 and panchromatic data obtained by the Panchromatic Remote-sensing Instrument for Stereo Mapping sensors, both on board the advanced land observing satellite (ALOS). The ground cover was calculated using field survey data from 25 sub-sample plots and the vegetation indices were derived with 5 × 5 maximum filtering algorithm from ALOS data. R ² values were calculated for the normalized difference vegetation index (NDVI) and various soil-adjusted vegetation indices (SAVI) with soil-brightness-dependent correction factors equal to 1 and 0.5, a modified SAVI (MSAVI) and an optimized SAVI (OSAVI). R ² values for the NDVI, MSAVI, OSAVI, SAVI (1), and SAVI (0.5) were 0.566, 0.545, 0.619, 0.603, and 0.607, respectively. Total ratio vegetation index for arid and semi-arid regions based on spectral wavelengths of ALOS data with an R ² value 0.633 was considered. Results of the current study will be useful for forest inventories in arid and semi-arid regions in addition to assisting decision-making for natural resource managers.

Remote sensing is an important tool for studying and modeling forest stands. Vegetation indices obtained from Landsat-8 remotely sensed data were used to estimate the forest parameters in the western mountains of Iran. Thirty-four sample points were selected on the map of Bayangan County, Kermanshah province, Iran. At each point, a cluster of five rectangular plots of 8100 m² and 200 m apart was established. Some clusters were primarily sampled to determine the variance of the forest parameters. The coefficient of variation was used as a criterion for sample allocation. Stand density, canopy cover and basal area per hectare were calculated for each plot. Vegetation indices were extracted from the Landsat-8 images for each plot. Simple linear and nonlinear regressions were conducted to develop the models. The models were validated using an independent data set. Stability of model parameters was statistically evaluated. The results showed that Normalized difference vegetation index (NDVI) and Transformed normalized difference vegetation index (TNDVI) followed by Simple ratio vegetation index (SRVI) were the best predictors, explaining up to 91% of the variations with high precision. For NDVI, Soil adjusted vegetation index 2 (SAVI2) and SRVI, the cubic model was more appropriate than the linear model for predicting the forest parameters. For this model, the R-square value increased while NRMSE decreased significantly. For Infrared percentage vegetation index (IPVI), the quadratic model was better, but, for other vegetation indices, nonlinear models were not superior to linear ones. Finally, it can be concluded that Landsat-8 imagery is suitable for predicting forest parameters in the oak forests of western Iran. Of course, large plots must be selected, and pre-classification is necessary to gain accurate and precise estimations.

In the summer of 2015, hundreds of forest fires burned across the state of Alaska. Several uncontrolled wildfires near the town of Tanana on the Yukon River were responsible for the largest portion of the area burned statewide. In July 2017, field measurements were carried out in both unburned and burned forested areas nearly adjacent to one another, all within 15 miles of the village of Tanana. These surveys were used to first visually verify locations of different burn severity classes, (low, moderate, or high), estimated in 2016 from Landsat images (collected before and after the 2015 Tanana-area wildfires). Surface and soil profile measurements to 30-cm depth at these same locations were collected for evidence of moss layer and forest biomass burning. Soil temperature and moisture content were measured to 30-cm depth, and depth to permafrost was estimated by excavation wherever necessary. Digital thermal infra-red images of the soil profiles were taken at each site location, and root-zone organic layer samples were extracted for further chemical analysis. Results supported the hypothesis that the loss of surface organic layers is a major factor determining post-fire soil water and temperature changes and the depth of permafrost thawing. In the most severely burned forest sites, complete consumption of the living moss organic layer was strongly associated with both warming at the surface layer and increases in soil water content, relative to unburned forest sites. Soil temperatures at both 10-cm and 30-cm depths at burned forest sites were higher by 8–10 °C compared to unburned sites. Below 15 cm, temperatures of unburned sites dropped gradually to frozen levels by 30 cm, while soil temperatures at burned sites remained above 5 °C to 30-cm depth. The water content measured at 3 cm at burned sites was commonly in excess of 30% by volume, compared to unburned sites. The strong correlation between burn index values and depth to permafrost measured across all sites sampled in July 2017 showed that the new ice-free profile in severely burned forest areas was commonly 50-cm deeper than in unburned soils.

A comparative study of Frequency Ratio (FR) and Analytic Hierarchy Process (AHP) models are performed for forest fire risk (FFR) mapping in Melghat Tiger Reserve forest, central India. Identification of FFR depends on various hydrometeorological parameters (altitude, slope, aspect, topographic position index, normalized differential vegetation index, rainfall, air temperature, land surface temperature, wind speed, distance to settlements, and distance by road are integrated using a GIS platform. The results from FR and AHP show similar trends. The FR model was significantly higher accurate (overall accuracy of 81.3%, kappa statistic 0.78) than the AHP model (overall accuracy 79.3%, kappa statistic 0.75). The FR model total forest fire risk areas were classified into five classes: very low (7.1%), low (22.2%), moderate (32.3%), high (26.9%), and very high (11.5%). The AHP fire risk classes were very low (6.7%), low (21.7%), moderate (34.0%), high (26.7%), and very high (10.9%). Sensitivity analyses were performed for AHP and FR models. The results of the two different models are compared and justified concerning the forest fire sample points (Forest Survey of India) and burn images (2010–2016). These results help in designing more effective fire management plans to improve the allocation of resources across a landscape framework.

In light of concerns over climate change and increasing levels of CO₂ in the atmosphere, it is of importance to investigate soil organic matter in Mediterranean forests at a profile scale. In-depth studies of the organic fraction are also of interest to improve understanding of carbon balance and to facilitate modelling of carbon fixation in forest soils. This research evaluates the relationships between diverse parameters such as colour, content, and form of soil organic matter (SOM). Two Quercus pyrenica ecosystems with soils classified as inceptisols with a xeric or dry moisture regime, and developed under a Mediterranean climate in Spain, were used to characterize SOM through the complete sequence of layers of the soil profile. The differentiating factor between the two ecosystems was slope gradient. Characterization was done using characteristics of humic substances (HS) as indicators of SOM turnover in inceptisols. Infrared analysis was used to further characterize the humic acids. As soil colour measurements are a tool for soil type classification and soil organic carbon prediction, the relation between HS colour measured by reflection and by transmission was determined in order to establish a relationship between measurement techniques. Infrared analysis and colour provided evidence of a different level of stabilization of HS from both soils, and between the different horizons. Oxidation of humic acids was found to be greater in deeper horizons than in the surface layers. An inverse relationship between HS colour measured by reflection and by transmission was revealed. Both soils showed a clear trend in which horizons presenting lower absorbance numbers showed higher figures of hue and value. A more marked accumulation of humified compounds was found in pedons, (the smallest unit or volume of soil that contains all the soil types), in the less steep slope. This might be explained in terms of the physiographic position affecting infiltration behavior and exposure to runoff.

The expansion of fast-growing tree plantations is a worldwide process, with consequences on soil fertility and soil carbon storage. Disparate results were found on the effects of afforestation with Eucalyptus on soil carbon and other nutrient contents. These discrepancies are usually caused by differences in climate, land use history, soil texture as well as by management related factors such as plantation age, number of rotations, method of establishment (plantation or coppice), harvest residue management and soil preparation. We studied the effect of plantation age, number of rotations, and method of establishment on soils and plant nutrient concentrations in Eucalyptus grandis plantations in NE Argentina on different textured soils. We also determined if yields changed with nutrient variations in soils, and compared soils under plantations to soils under grasslands they replaced. Thirty-one E. grandis stands of different ages, number of rotations and method of establishment were evaluated as well as eight grassland sites. Levels of carbon, nitrogen, phosphorus, potassium, calcium and magnesium were determined for soils and plants. Soil carbon and nitrogen decreased over the number of rotations and were more pronounced in soils with 50–60% sand than soils with > 75% sand. Coppice stands showed higher soil carbon and nitrogen levels than plantations, suggesting a negative effect of site preparation before planting on soil nutrient conservation, especially in fine-textured soils. Foliar nutrient concentrations did not follow the trends observed for soil nutrients nor did they reflect nutrient limitations. There was no evidence of decreased yields over successive rotations. Soil carbon and nitrogen contents decrease when grasslands are replaced by E. grandis plantations, and therefore a yield limitation may occur in a medium to long-term frame, especially in stands re-established for short-rotation management. Harvest residue management and site preparation must be specifically designed for improving soil nutrient management.

Decaying mangrove detritus plays a significant role in nutrient cycling and fueling in both the forests and aquatic habitats where the detritus stems from estuarine and coastal food webs. Detrital decay rates partly depend on the type of detritus, but most studies have thus far focused on leaf litter decay and decomposition, whereas other detrital sources (except for roots) have largely been ignored. We compare the decay rates of Rhizophora apiculata and Xylocarpus granatum non-leafy detritus (flowers, propagules, stipules, and twigs) with mangrove leaf litter in field studies, using litter bags during the dry and the wet seasons in the tropical mangrove forest of Sibuti, Sarawak, Malaysia. We observed higher microbial decay rates of stipules, flowers, propagules, and twigs for both the R. apiculata and X. granatumduring the wet months. By contrast, leaf decay rates were higher during the dry months. Decay rates depended on the lignin content of the detrital sources of both species, both during dry and wet months. Accordingly, the half-life (T _0.5) and 95% lifespan (T _0.95) of non-leaf materials (flowers, propagules, stipules and twigs) for both species were remarkably longer than those of leaf litter. Slowly decaying non-leafy detritus may play a significant role in nutrient and carbon cycling over longer time, when leaf litter is either being decomposing rapidly and/or being washed away by tidal flush and river runoff. Hence, non-leafy (flowers, propagules, stipules and twigs) detritus should be taken into account when budgeting organic matter turnover in mangroves.

Plantation establishment using invasive alien plants is common in South Africa, but the effects of these plants on soil physical properties in the Vhembe biosphere is unknown. In this comparative study, soils underneath Pinus elliottii and Eucalyptus cloeziana were assessed for differences in physical properties compared to soils underneath adjacent natural sites in the Entabeni plantation in the Vhembe biosphere in Limpopo Province, South Africa. Soils were collected from topsoil over 3 months and quantified for gravimetric soil moisture, penetration resistance, soil infiltration, hydraulic conductivity and soil water repellency. For all 3 months, soils from both P. elliottii and E. cloeziana plantations were compact and had low penetration resistance compared to soils from adjacent natural sites. Soil infiltration and hydraulic conductivity were significantly (p < 0.05) lower in soils from plantations compared to soils from adjacent natural sites, and more so from the E. cloeziana plantation than from P. elliottii. Soil water repellency was observed in soils from E. cloeziana only in May and June. Soils from the invasive alien tree plantation have decreased soil moisture, infiltration rate, hydraulic conductivity and are compact as well as repellent (only E. cloeziana), all poor soil physical properties. However, this decline in soil physical properties was not uniform between the two invasive alien plantation species; hence we cannot generalize about the effects of invasive alien plantation species on soil physical properties, and further research is required across different ecological regions.

The consequence of land-use change from forest to agriculture and other uses has become one of the world’s greatest concerns. The soil, one of the most important components of forests and containing all the required plant nutrients as soluble ions, is highly impacted by these changes. Because vast areas of the Zagros forests in western Iran have changed in use during the last few decades, the present study investigated the effects of land-use changes of forest area to agriculture, orchard, and agroforestry on soil chemical and physical properties. Soil was sampled at four land-use areas: less-disturbed forest areas (control) and agricultural, orchard, and agroforestry areas. Among each of the two forest-use areas (agroforestry and orchard), we selected five trees with similar-sized crowns and sampled under each tree crown at 0–15 and > 15–30 cm depths. Five soil samples also were taken in agriculture area at each depth. The findings indicated that during land-use changes, soil sand particles decreased, and clay and silt particles of soil increased, resulting in a fine soil texture. Moreover, the amount of nitrogen (N), phosphorus (P), organic carbon (OC), and electrical conductivity (EC) of soil decreased at both depths due to the decrease in organic matter. Soil pH and magnesium (Mg) level rose during land-use change at both depths except at agricultural sites. Soil potassium (K) content decreased during agricultural use due to the elimination of tree cover. The level of K decreased only at the depth of 0–15 cm because of K dependency on parent materials. Generally, most soil nutrients were affected by plant removal in the conversion. Forest and agricultural soil are distinguishable by their properties, while land-uses such as agroforestry-orchard separated from the others. Soil nutrients were severely affected by the decrease and elimination of tree cover, plowing, and continuous harvesting, resulting in a decline in soil quality and fertility.

Accurate and reliable predictions of pest species distributions in forest ecosystems are urgently needed by forest managers to develop management plans and monitor new areas of potential establishment. Presence-only species distribution models are commonly used in these evaluations. The maximum entropy algorithm (MaxEnt) has gained popularity for modelling species distribution. Here, MaxEnt was used to model the spatial distribution of the Mexican pine bark beetle (Dendroctonus mexicanus) in a daily fashion by using forecast data from the Weather Research and Forecasting model. This study aimed to exploit freely available geographic and environmental data and software and thus provide a pathway to overcome the lack of costly data and technical guidance that are a challenge to implementing national monitoring and management strategies in developing countries. Our results showed overall agreement values between 60 and 87%. The results of this research can be used for D. mexicanus monitoring and management and may aid as a model to monitor similar species.

Characterizing the mechanical properties of wood cell walls will lead to better understanding and optimization of modifications made to wood infected by the blue-stain fungi. In this study, in situ nanoindentation was used to characterize the mechanical properties of the cell walls of Pinus massoniana infected by blue-stain fungi at the cellular level. The results show that in situ nanoindentation is an effective method for this purpose and that blue-stain fungi penetrate wood structures and degrade wood cell walls, significantly reducing the mechanical properties of the cell walls. The method can also be used to evaluate and improve the properties of other wood species infected by blue-stain fungi.

To elucidate the development of heartwood, bark, sapwood, pith and specific gravity of wood in fast-growing teak (Tectona grandis) plantations in Costa Rica, we sampled three trees in each of 55 plantations and modelled each variable with age, site and different tree heights. Age and stand density of plantations were significant correlated with stem diameter at breast height and total height of the tree. Formation of heartwood was initiated at the age of 4-year-old and increased in direct proportion with age. The age of plantation had a significant relationship with stem diameter at breast height, heartwood percentage, sapwood thickness, sapwood percentage, percentage of bark, pith diameter and percentage, and specify gravity. The model for these tree parameters was model with these parameters as dependent variable and in relation to age as independent variable.