Determining underlying factors that foster deforestation and delineating forest areas by levels of susceptibility are of the main challenges when defining policies for forest management and planning at regional scale. The susceptibility to deforestation of remaining forest ecosystems (shrubland, temperate forest and rainforest) was conducted in the state of San Luis Potosi, located in north central Mexico. Spatial analysis techniques were used to detect the deforested areas in the study area during 1993–2007. Logistic regression was used to relate explanatory variables (such as social, investment, forest production, biophysical and proximity factors) with susceptibility to deforestation to construct predictive models with two focuses: general and by biogeographical zone. In all models, deforestation has positive correlation with distance to rainfed agriculture, and negative correlation with slope, distance to roads and distance to towns. Other variables were significant in some cases, but in others they had dual relationships, which varied in each biogeographical zone. The results show that the remaining rainforest of Huasteca region is highly susceptible to deforestation. Both approaches show that more than 70% of the current rainforest area has high and very high levels of susceptibility to deforestation. The values represent a serious concern with global warming whether tree carbon is released to atmosphere. However, after some considerations, encouraging forest environmental services appears to be the best alternative to achieve sustainable forest management.

Soil aggregation varies according to climatic and management factors, and is difficult to measure because of irregular shapes and sizes of soil aggregates. We applied fractal theory to assess soil aggregation as affected by (1) land use change from forest to savanna, (2) nutrient additions in forest, ecotone, and savanna ecosystems, and (3) tillage practice and residue treatments in an agro-ecosystem. We used fractal dimensions nonlinear (D _non-lin) and linear (D _lin) based on number of aggregates (N) and mass of aggregates (M) (the range of values were 2.6–2.89 and 2.69–3.41, respectively) to capture the variations in the sizes of soil aggregates due to land use and treatments/management in these ecosystems. The variation in the values of non-linear fractal dimension based on mass (D _Mnon-lin) was smaller in forest and savanna ecosystems with and without nutrient additions, while the variation was wider in agro-ecosystems with different management practices. Linear fractal dimensions based on number (D _Nlin) and mass (D _Mlin) of aggregates varied marginally in these ecosystems and did not capture the variations in soil aggregates well. The variations in non-linear fractal dimension indicate that continued nitrogen loading in forest accelerates the formation of macro-aggregates, whereas in savanna the situation was reversed. The values of non-linear fractal dimensions did not show significant change after 6 years of nutrient additions in the ecotone; reflecting a buffering mechanism of this system in soil aggregate formation. On the basis of non-linear fractal dimension values, we conclude that residue retention and minimum tillage are appropriate for proper maintenance of soil aggregate stability for sustained crop production in the Indian dry land agro-ecosystems.

No attempt has been made to date to model growth in girth of rubber tree (Hevea brasiliansis). We evaluated the few widely used growth functions to identify the most parsimonious and biologically reasonable model for describing the girth growth of young rubber trees based on an incomplete set of young age measurements. Monthly data for girth of immature trees (age 2 to 12 years) from two locations were subjected to modelling. Re-parameterized, unconstrained and constrained growth functions of Richards (RM), Gompertz (GM) and the monomolecular model (MM) were fitted to data. Duration of growth was the constraint introduced. In the first stage, we attempted a population average (PA) model to capture the trend in growth. The best PA model was fitted as a subject specific (SS) model. We used appropriate error variance-covariance structure to account for correlation due to repeated measurements over time. Unconstrained functions underestimated the asymptotic maximum that did not reflect the carrying capacity of the locations. Underestimations were attributed to the partial set of measurements made during the early growth phase of the trees. MM proved superior to RM and GM. In the random coefficient models, both Gf and G0 appeared to be influenced by tree level effects. Inclusion of diagonal definite positive matrix removed the correlation between random effects. The results were similar at both locations. In the overall assessment MM appeared as the candidate model for studying the girth-age relationships in Hevea trees. Based on the fitted model we conclude that, in Hevea trees, growth rate is maintained at maximum value at t0, then decreases until the final state at dG/dt ≥0, resulting in yield curve with no period of accelerating growth. One physiological explanation is that photosynthetic activity in Hevea trees decreases as girth increases and constructive metabolism is larger than destructive metabolism.

The United Nations Framework Convention on Climate Change (UNFCCC) requires reporting net carbon stock changes and anthropogenic greenhouse gas emissions, including those related to forests. This paper describes the status of carbon stocks in sub tropical forests of Pakistan. There are two major sub types in subtropical forests of Pakistan viz a viz Subtropical Chir Pine and Subtropical broadleaved forests. A network of sample plots was laid out in four selected site. Two sites were selected from sub tropical Chir Pine (Pinus roxburghii) forests and two from Subtropical broadleaved forests. Measurement and data acquisition protocols were developed specifically for the inventory carried out from 2005 to 2010. In total 261 plots (each of 1ha.) were established. Estimation of diameter, basal area, height, volume and biomass was carried out to estimate carbon stocks in each of the four carbon pools of above- and below-ground live biomass. Soil carbon stocks were also determined by doing soil sampling. In mature (∼100 years old) pine forest stand at Ghoragali and Lehterar sites, a mean basal area of 30.38 and 26.11 m²·ha⁻¹ represented mean volume of 243 and 197 m³·ha⁻¹, respectively. The average biomass (t·ha⁻¹) was 237 in Ghoragali site and 186 t·ha⁻¹in Lehterar site, which is equal to 128 and 100 t C ha⁻¹ including soil C. However, on average basis both the forests have 114.5± 2.26 t·ha⁻¹ of carbon stock which comprises of 92% in tree biomass and only 8% in the top soils. In mixed broadleaved evergreen forests a mean basal area (m²·ha⁻¹) was 3.06 at Kherimurat with stem volume of 12.86 and 2.65 at Sohawa with stem volume of 11.40 m³·ha⁻¹. The average upper and under storey biomass (t·ha⁻¹) was 50.93 in Kherimurat site and 40.43 t·ha⁻¹in Sohawa site, which is equal to 31.18 and 24.36 t C ha⁻¹ including soil C stocks. This study provides a protocol and valuable baseline data for monitoring biomass and carbon stocks in Pakistan’s managed and unmanaged sub-tropical forests.

We investigated the floristic composition, phytosociological and regeneration status of Sarkot Van Panchyat (community forest) in Chamoli district of Garhwal Himalaya. A total of 52 plant species of 46 genera and 26 families were recorded, which included 12 trees, 18 shrubs and 22 herb species. Quercus leucotrichophora was dominant tree species in sapling and seedling layers, followed by Lyonia ovalifolia and Rhododendron arboreum. Out of 12 tree species, 7 species in seedling stage and 8 species in sapling stage were recorded in the study area. The 44.41% species in the study area showed good regeneration status, 16.66% species were fairly regenerating, and 8.33% species showed poor regeneration status, while 33% species were not regenerating. Number of individuals from lower girth classes (0–10 cm and 10–30 cm) showed decreasing trend with the increase in size of girth class. Shannon index (H) for trees, shrubs and herbs was recorded as 1.82, 2.24 and 2.41 respectively. Simpsons index (C _D) was recorded as 0.21, 0.12 and 0.12 for trees, shrubs and herbs respectively. The forest should be divided into compartments for better management purpose and each compartment should be closed for five years to assist regeneration and enrichment planting may also be carried out for sustainable management.

Determination of site quality is a basic tool for proper selection of locations and species, in management of forest plantations. Throughout the Caribbean studies of site quality are few and are hampered by statistical limitations, inappropriate growth models, and limited data. We fitted growth curves for dominant height to evaluate and classify site quality of teak (Tectona grandis) plantations by using data from 44 permanent sample plots established since 1990 in 3–22 years old teak plantations in the Colombian Caribbean region. We used Korf’s and von Bertalanffy’s models to fit curves as non-linear effects models. Both models, with a single random parameter, were considered as adequate for dominant height growth modelling, but Korf’s model was superior. The resulting curves were anamorphic and closely reflected high variability in site quality. Five site classes were clarified: at a base age of 12 years old, teak reached a mean dominant height of 24.8 m on the best sites, 9.8 m in the worst sites, and in the averages sites, 15.8–18.8 m. Using this model, we identified the best and the worst sites for teak plantations in the Caribbean region. This model proved a useful tool, not only for site quality evaluation, but also for improved teak plantation planning and management.

We compared the dead wood (DW) conditions of Cheshmeh-sar forest and Sardab forest with different management history, including reserve forest and harvested forest. The First forest took 100% inventory from all the available DW. Also dead trees were compared in terms of species, shape, location and quality of fracture in both forests. Volumes of dead wood in Cheshmeh-sar and Sardab forests were 207.47 and 142.74 m³, respectively. Due to this significant difference, impact on the management level was determined. In Cheshmeh-sar forest, 42% of dead trees were standing and 58% were fallen type while in Sardab forest 38.6% were standing and 61.4% fallen. But the difference was not statistically significant between them (p = 0.0587). In terms of quality, dead trees of hard, soft and hollow had the highest frequency, respectively. However, 71.5% of DW was seen as hard dead in Cheshmeh-sar forest while hard dead trees in Sardab forests were 54.2%. Soft quality degree of dead trees which formed in Cheshmeh-sar and Sardab forest were calculated as 26.6% and 43.4% respectively. Also 30% of the dead trees of Sardab forest were eradicated while in Cheshmeh-sar this amount was reduced to 12%. Due to this significant difference ((P=0/018), it is concluded that the type of management and human interference are affecting the quality of dead trees and makes us to think the human interferences could effect on the ecosystem of touched forests.

We studied the impact of forest vegetation on soil erosion, surface runoff, and sediment generation by using field simulated rainfall apparatus. We measured runoff and sediment generation of five 4.5 × 2.1 m runoff plots (a bare soil as a control; two Pinus tabulaeformis forest plots and two Platycladus orientalis forest with row spacing of 1 m × 1 m and 1.5 m × 1.5 m, respectively) in Beijing Jiu Feng National Forest Park under three rainfall intensities (0.42, 0.83, 1.26 mm per minute). Forest vegetation significantly reduced soil erosion and sediment yield. Mean total runoff volume in the four tree stand plots was 93% of that in the control plot, demonstrating the limited effectiveness of forest vegetation in runoff control. With increasing rainfall intensity, runoff reduction in forest plots declined from 28.32% to 2.1%. Similar trends in runoff coefficient and the relationship between runoff volume and rainfall duration was observed. Mean total sediment yield and mean sediment yield reduction rate under different treatments was 55.05% and 43.17% of those in the bare soil control plot, respectively. Rainfall intensity played an important role in runoff and sediment generation processes, and had a greater impact on runoff than on soil erosion and sediment generation. When considering several factors in runoff and sediment transport processes, the P. tabulaeform plot with row spacing at 1 × 1 m had a greater effect on soil and water conservation than did other forested plots.

DNA methylation plays a crucial role in regulating plant development and tissue differentiation. In this study, we compared the methylation levels in leaf, root, and stem in Chamaedorea elegans by using the technique of methylation-sensitive amplified fragment length polymorphism AFLP. Over 19% (42/220) bases were uniformly methylated in these tissues. The percentages of polymorphism resulting from varied methylation in mature leaf (L1), young leaf (L2), baby leaf (L3), stem (S), young root (R1) and lignified root (R2) were 29.5%, 29.0%, 27.1%, 30.7%, 63.0% and 28.3%, respectively. The numbers of polymorphic loci detected in the leaves of three developmental stages were similar, ranging from 20 to 30. In contrast, roots at the two developmental stages differed greatly, with 145 polymorphic loci detected in R1 and 27 in R2. Our results suggest that the methylation level in leaves slightly increases with aging, while that in roots decreases dramatically with aging.

We evaluated the effects of planting densities (500, 1,000, 1,500 and 2,000 trees·ha⁻¹) on tree growth performance (diameter at base, diameter at breast height, and clear bole height) of two clones (RRIM 2020 and RRIM 2025) of nine years old plantations of rubber tree (Hevea brasiliensis Muell. Arg) in Malaysia. For the four planting densities of the two clones, basal area and diameter at breast height declined with increasing planting density. Clear bole heights were greatest at 1,500 trees·ha⁻¹ and lowest at 500 trees·ha⁻¹ for the clone RRIM 2020, and at 2,000 trees·ha⁻¹ and 500 trees·ha⁻¹ for clone RRIM 2025. We conclude that the ideal planting density is 2,000 trees·ha⁻¹ for obtaining high volume of wood production and 500 trees·ha⁻¹ for high wood quality.

We analyzed the relationship between internode number and internode length for one of the largest bamboo, Phyllostachys pubescens Mazel ex Houz. For 50 sample culms with various sizes felled in a pure stand of P. pubescens, the internode number was assigned from base to tip and the length for each internode was directly measured. The result indicated that the internode length should be cumulated from base to tip, and then the cumulated internode length should be relativized by the total culm length. It was inappropriate to relativize the internode length by the maximum intenode length. In addition, the relationship between the relative internode number (the internode number relativized by the total number of internodes) and the relative cumulated internode length should be described not by a power function but by a sigmoid function such as the third-order function. The determined function enabled us to estimate the actual internode length, with the root mean squared error being 4 cm. In conclusion, the mathematical expression presented here, i.e., the relativization of the cumulated internode length by the total culm length and the application of the sigmoid function, will be useful in describing the relationship between internode number and internode length for P. pubescens.

We evaluated ten poplar clones (G-3, G-48, L-50/88, L-154/84, L-156/89, S7C8, S7C15, WSL-22, WSL-29 and Uday) for ovipositional preference and larval performance of Clostera restitura. Female moths did not show any preference with respect to clones for oviposition. Significant differences were observed for number of eggs laid on different plant parts. C. restitura laid eggs in clusters, preferably on upper surface of leaf and size of the egg cluster varied from 15 to 167 eggs. Clones varied for their relative resistance and susceptibility to C. restitura. L-50/88; L-156/89 were identified as most resistant clone based on minimum leaf consumption, whereas S7C15 was found to be most susceptible clone to C. restitura. In multiple choice experiments, no feeding preference by C. restitura larvae was detected amongst different poplar clones. After initial settlement of larvae on a particular clone, the larvae remained confined to that clone and negligible inter-clonal movement was noticed subsequently. The fresh pupal weight was correlated negatively (r = −0.37) with percentage surface leaf area eaten and positively (r = 0.47) with length of larval period, measured on different clones. Relationship between percentage leaf area eaten and length of larval period was negative (r = −0.23). Owing to relative resistance of L-50/88 and L-156/89 against C. restitura, these clones can be recommended for plantation in defoliator prone areas in north-western India.

We used standard isolation protocols to explore the endophytic fungal communities in three tissue types of two dominant orchids (Bulbophyllum neilgherrense and Vanda testacea) of the Kaiga forest of the Western Ghats. We surface sterilized and assessed 90 segments of each orchid for the occurrence and diversity of endophytic fungal taxa. The 118 fungal isolates were obtained from root, bulb and leaves of B. neilgherrense, consisting of 17 anamorphic taxa (range, 10–15 taxa) with 1.3 fungal taxa per segment (range, 1.2–1.4 taxa). Four taxa (Aspergillus flavus, A. niger, Penicillium sp. and morpho sp. 1) belonged to the core group (11.1%–32.2%). The relative abundance of A. flavus and morpho sp. 1 was more than 10%. A total of 130 fungal isolates from roots, stems and leaves of V. testacea yielded 20 anamorphic taxa (range, 11–15 taxa) with 1.4 fungal taxa per segment (range, 1.4–1.5 taxa). Aspergillus flavus, A. niger, A. ochraceus, Gliocladium viride, Penicillium sp. and morpho sp. 1 belonged to the core group. Relative abundance exceeded 10% for A. flavus, A. niger, and morpho sp. 1. The Simpson and Shannon diversity indices were higher in leaf than root or bulb/stem of both orchids. Jaccard’s similarity coefficient was higher between root and leaf in both orchids (56.3%-60%) than between other pairs. Our study revealed that the endophytic fungal assemblage and diversity of B. neilgherrense and V. testacea of Kaiga forest of the Western Ghats were relatively similar between orchids and their tissues.

We describe patterns of buttress formation and development in eleven tree species at Lawachara National Park, Bangladesh. Forty-five percent of trees of these 11 species had buttresses. Artocarpus chaplasha Roxb. showed maximum (87%) buttress formation, whereas Alstonia scholaris (L.) R. Br. did not show any buttress. Buttresses were recorded in 20%–40% of trees of six species and 40%–60% of trees in three species. Mean length and height of buttress varied among the species and ranged from 0.37–1.37 m and 0.71–2.13 m, respectively. Buttress height, mean buttress length, total buttress length, and total length plus length of secondaries increased with DBH (diameter at breast height) and tree height. Buttress number did not increase with DBH or tree height. Under-storey and mid-canopy trees produced less developed buttresses than did emergent trees (p<0.01). Wood density showed moderate effects on buttress characters (p<0.05), while the slope of the land did not. Canopy category was a primary regulating factor for tree buttressing, suggesting that buttresses are mechanical adaptations of trees to counter physical stresses.

We assessed growth traits and wood properties of DH32-29, a clone of Eucalyptus urophylla × E. grandis, at age of two to six years in Guangdong in China. Analysis of variance of studied traits showed that there were significant differences (1% level) on all studied traits among ages except for wood basic density. Analysis of age trends of growth traits and wood properties revealed that rotation length of DH32-29 should be more than six years or longer. Phenotypic correlations among traits at individual ages indicated that correlations between growth traits were strongly positive. There was significant change in relationship between growth and wood basic density with increasing age, ranging from −0.03 to −0.54 at 2 and 5 year and 0.003 to 0.3 at 3, 4 and 6 year. Correlations between Pilodyn pin penetration and basic density measured on increment cores showed that Pilodyn could rank or group genotypes or sites into density classes, but failure to predict individual tree and individual clone.

We investigated wood anatomical changes due to uptake and accumulation of cadmium and lead from contaminated soils in Acer velutinum Boiss seedlings. Two-year old seedlings were exposed for 180 days to soil concentrations with varying cadmium and lead concentrations. We measured three wood anatomical traits, average vessel area (μm²), vessel number per square millimetre, and vessel lumen area percentage (%). For assessing the cadmium and lead accumulation, we measured the concentrations in the soil, leaf, stem, and root. Average vessel area and vessel lumen area percentage were similar (p>0.05) in control and treated seedlings. Vessel number per square millimetre showed a decreasing trend from pith to bark in control and treated seedlings, and the trend was more pronounced in treated seedlings. We conclude that vessel number per square millimetre in A. velutinum is influenced by soil contamination. A. velutinum Boiss is not a suitable species for remediation of soils contaminated by cadmium and lead but it can be used as an indicator of the soil lead contamination, because lead concentrations in seedlings increased with increasing amount of lead in the soil.

We determined the effects of the penetration depth and spline material and composite material type as well as joining method on bending moment resistance under diagonal compression and tension in common wood panel structures. Composite materials were laminated medium density fiberboard (MDF) and particleboard. Joining methods were butt and miter types. Spline materials were high density fiberboard (HDF). The penetration depths of plywood, wood (Carpinus betolus) and spline were 8, 11 and 14 mm. The results showed that in both diagonal compression and tension, MDF joints are stronger than particleboard joints, and the bending moment resistance under compression is higher compared with that in tension. The highest bending moment resistance under tension was shown in MDF, butt joined using plywood spline with 8 mm penetration depth, whereas under compression bending moment resistance was seen in MDF, miter joined with the HDF spline of 14 mm penetration depth.

We studied radial and inter-progeny variations in the dimensions of the wood elements and specific gravity of 21 half sib progenies of Populus deltoides Bartr. ex Marsh. The female parents of half sib progenies were G48 and S7C13 clones. Variance ratio (F) test indicated that inter-progeny variations in the dimensions of wood elements and specific gravity were significant for all wood traits while variations were significant for radial location for specific gravity only. Hierarchical cluster analysis was done by Squared Euclidean Distance for all of 21 progenies considering six wood traits. 21 progenies were grouped into 4 clusters. Cluster 1 was the largest cluster with 11 progenies, whereas cluster 3 had only one progeny. Selected progenies in clusters 3 (progeny 155, male) and 4 (progeny 108, 196, both female) were highly divergent from the other progenies so they were used in combinations as parents of hybrids to develop new clones with desired characters. Progeny 155 showed higher growth, fiber dimensions, and specific gravity, thus, should be used for the development of new clones.

For manufacturing low-formaldehyde emission particleboard from wheat straw and urea-formaldehyde (UF) resins using urea treatment for indoor environments, we investigated the influence of urea treatment on the formaldehyde emission, physical and mechanical properties of the manufactured particleboard. Wheat straws were treated at three levels of urea concentration (5%, 10%, 15%) and 95°C as holding temperature. Wheat straw particleboards were manufactured using hot press at 180°C and 3 MPa with two types of UF adhesive (UF-45, UF-91). Then the formaldehyde emission values, physical properties and mechanical properties were considered. The results show that the formaldehyde emission value was decreased by increasing urea concentration. Furthermore, the results indicate that the specimens under urea treatment have better mechanical and physical properties compared with control specimens. Also specimens under urea treatment at 10% concentration and UF-91 type adhesive have the most optimum physical and mechanical strength.