This study presents the utility of remote sensing (RS), GIS and field observation data to estimate above ground biomass (AGB) and stem volume over tropical forest environment. Application of those data for the modeling of forest properties is site specific and highly uncertain, thus further study is encouraged. In this study we used 1460 sampling plots collected in 16 transects measuring tree diameter (DBH) and other forest properties which were useful for the biomass assessment. The study was carried out in tropical forest region in East Kalimantan, Indonesia. The AGB density was estimated applying an existing DBH — biomass equation. The estimate was superimposed over the modified GIS map of the study area, and the biomass density of each land cover was calculated. The RS approach was performed using a subset of sample data to develop the AGB and stem volume linear equation models. Pearson correlation statistics test was conducted using ETM bands reflectance, vegetation indices, image transform layers, Principal Component Analysis (PCA) bands, Tasseled Cap (TC), Grey Level Co-Occurrence Matrix (GLCM) texture features and DEM data as the predictors. Two linear models were generated from the significant RS data. To analyze total biomass and stem volume of each land cover, Landsat ETM images from 2000 and 2003 were preprocessed, classified using maximum likelihood method, and filtered with the majority analysis. We found 158±16 m³·ha⁻¹ of stem volume and 168±15 t·ha⁻¹ of AGB estimated from RS approach, whereas the field measurement and GIS estimated 157±92 m³·ha⁻¹ and 167±94 t·ha⁻¹ of stem volume and AGB, respectively. The dynamics of biomass abundance from 2000 to 2003 were assessed from multi temporal ETM data and we found a slightly declining trend of total biomass over these periods. Remote sensing approach estimated lower biomass abundance than did the GIS and field measurement data. The earlier approach predicted 10.5 Gt and 10.3 Gt of total biomasses in 2000 and 2003, while the later estimated 11.9 Gt and 11.6 Gt of total biomasses, respectively. We found that GLCM mean texture features showed markedly strong correlations with stem volume and biomass.

This paper presents equations for estimating limiting stand density for T. undulata plantations grown in hot desert areas of Rajasthan State in India. Five different stand level basal area projection models, belonging to the path invariant algebraic difference form of a non-linear growth function, were also tested and compared. These models can be used to predict future basal area as a function of stand variables like dominant height and stem number per hectare and are necessary for reviewing different silvicultural treatment options. Data from 22 sample plots were used for modelling. An all possible growth intervals data structure was used. Both, qualitative and quantitative criteria were used to compare alternative models. The Akaike’s information criteria difference statistic was used to analyze the predictive ability of the models. Results show that the model proposed by Hui and Gadow performed best and hence this model is recommended for use in predicting basal area development in T. undulata plantations in the study area. The data used were not from thinned stands, and hence the models may be less accurate when used for predictions when natural mortality is very significant.

Ten multipurpose tree species, Terminalia arjuna, Azadirechta indica, Prosopis juliflora, Pongamia pinnata, Casuarina equisetifolia, Prosopis alba, Acacia nilotica, Eucalyptus tereticornis, Pithecellobium dulce and Cassia siamea, were raised in a monoculture tree cropping system on the sodic soil of Gangetic alluvium in north India (26° 47′ N: 80°46′ E) for 10 years to evaluate the biomass and bio-energy production. The soil was compact, sodic and impervious to water associated with nutrient deficiency or toxicity. Maximum plant height was recorded with E. tereticornis followed by C.equisetifolia and P. juliflora. A. nilotica performed better than the other species in terms of diameter at breast height (DBH) with a basal area of 13.04 m²·ha⁻¹, followed by P. juliflora and C. equisetifolia. P. juliflora and A. nilotica produced nearly similar biomass of 56.50 and 50.75 Mg·ha⁻¹, respectively, at 10 years; whereas, A. indica, P. pinnata, C. siamea and P. alba did not perform well. P. juliflora scored maximum in net biomass production and nutrient demand. Nutrient (N, P, K, Ca, and Mg) concentrations were higher in leaf component of P. juliflora. However, in woody components, there was little variation between the species. N removal for production of one ton of wood was lowest in Acacia nilotica, P in T. arjuna, K in P. dulce and Ca and Mg in P. juliflora. P. juliflora gave the highest energy production of 1267.75 GJ·ha⁻¹ followed by A. nilotica with 1206 GJ·ha⁻¹ and the lowest of A. indica (520.66 GJ·ha⁻¹).

Disturbance is often touted as a management tool, as moderate disturbance is believed to enhance diversity; thus an understanding of frequent and fluctuating disturbance regimes in forests and their effects on stand structure, dominance and diversity is very crucial. Here, the effects of different disturbance regimes, along a gradient, on diversity and dominance of five Shorea robusta Gaertn. f.-dominated forests were investigated in 25 one-ha plots in Nepal. A total of 67 tree species were recorded; of which 41 species were encountered in least disturbed and 10 species in heavily disturbed forest. Significant variations among forests were observed for all measures of alpha diversity. Alpha diversity measures declined linearly along a disturbance gradient while dominance increased linearly. Relative basal area of S. robusta increased as the level of disturbance increased, which in turn produced more than two-fold higher important value index in heavily disturbed forest than the least disturbed forest. All alpha diversity measures declined in an order of three with increasing relative basal area of S. robusta. The similarity in species composition between each pair of disturbed forests was generally low (Jaccard’s similarity index < 57%), suggesting a higher Beta diversity. It can be concluded that diversity of Sal forests declines with increasing magnitude of disturbance, which in turn favors a higher dominance of S. robusta. Controlling the population of the dominant species, mainly S. robusta, is recommended to enhance diversity and to achieve multiple-use forest management objectives.

The Litter nutrient concentrations of N, P, Ca, Mg, K and Na in mature leaves, twigs and reproductive parts and their relationship between senescent and young leaves were investigated in five forest species: Acacia nilotica, Acacia leucophloea. Tectona grandis, Miliusa tomentosa and Butea monosperma in Indian tropical dry deciduous forest in Western India.. Total dry matter of plant species was recorded and analyzed for N, P, Ca, Mg, K and Na. A. nilotica had the highest concentrations of N in leaf, while A. leucophloea had the highest concentrations of Ca and Mg in leaf. The highest concentrations of P in leaf were found in A. nilotica, A. leucophloea and B. monosperma where as lowest in T. grandis and M. tomentosa. No significant differences in K and Na were registered among the species. A marked seasonal variability was observed in the concentrations of N, P and K, except for Ca and Mg. Potassium is the single element that undergoes leaching and mobilization in all species. Resorped N and P can be used for the production of fresh leaf in the following annual cycle. Nutrient resorption and retranslocation from senescent leaves and litter supports the production of new foliage and increase the fertility of soil.

Conversions from rural to urban land uses have the potential to greatly modify soil phosphorus (P) levels. Soils in shrubs, Masson pine forest, conifer and broadleaf mixed forest, evergreen broadleaved forest and bamboo forest in the mid-subtropical region along an urban-rural gradient in Nanchang City, southern China, were analyzed for total P and P fractions using the modified Hedley P sequential fractionation method. Results show that the topsoil total P and total exactable P concentrations were significantly higher in the urban area (0.71 g·kg⁻¹ and 378.50 mg·kg⁻¹, respectively) than in the suburban (0.30 g·kg⁻¹ and 150.74 mg·kg⁻¹, respectively) and rural areas (0.31 g·kg⁻¹ and 147.38 mg·kg⁻¹, respectively) (p<0.05). Among the five P fractions of resin-P, NaHCO₃-P, NaOH-P, Sonication-P and HCl-P, the relative abundance of HCl-P in urban forest soils (36%) was the highest and also significantly higher than in suburban (8%) and rural soils (6%), while NaOH-P was the dominant form in suburban (41%) and rural soils (50%). Phosphorus accumulation in the urban soils could affect the cycle of P in urban forest systems, particularly the HCl-P fraction that might rapidly enrich aquatic systems in urban areas.

Thirty-six medicinal plant species belonging to 25 families were surveyed to study Arbuscular mycorrhizal (AM) fungal diversity from different localities of North and South Goa of Western Ghats, Goa region, India. A total of 30 medicinal plant species were found to be mycorrhizal and six plant species showed absence of AM fungal colonization. Forty two AM fungal species belonging to five genera viz., Glomus, Acaulospora, Scutellospora, Gigaspora and Ambispora were recovered from the rhizosphere soil. Glomus was found to be the most dominant genera in the study sites, and Glomus fasciculatum the most dominant AM fungal species. Negative significant correlation was observed between percent colonization and spore density. Simpson’s and Shannon Weiner diversity index studies carried out in North and South Goa exhibited less variation in both the sites, indicating a stable and a diverse plant community.

The coconut palm tree leaf sheath fibers were analyzed by FTIR spectral analysis, Chemical, X-ray and thermo gravimetric methods to assess their suitability as reinforcements in the preparation of green composites. The morphology of the untreated and alkali treated fibers was studied by scanning electron microscopic method. The FTIR and chemical analyses indicated lowering of hemi-cellulose content by alkali treatment of the fibers. The X-ray diffraction revealed an increase in crystallinity of the fibers on alkali treatment. The thermal stability of the fibers was found to increase slightly by alkali treatment. The tensile properties of these fibers increased on alkali treatment. The mechanical and other physical properties indicated that these fibers were suitable as reinforcements for making the green composites.

Four kinds of iron oxide pigments were added into wood-fiber/high-density-polyethylene composites (WF/HDPE) at three different concentrations, to determine the effects of pigments on the changes in the color and mechanical properties of the composites before and after UV accelerated weathering. HDPE, wood fibers, pigments and other processing additives were dry-mixed in a high-speed mixer. The mixtures were extruded by two-step extrusion process with a self-designed twin-screw/single-screw extruder system. Color of the samples was determined according to CIE 1976 L*a*b* system by a spectrophotometer and the bending properties were tested to evaluate the mechanical properties before and after accelerated UV weathering. The result shows that the modulus of elasticity of WF/HDPE did not obviously changed after incorporating with the pigments, but the bending strength increased. After accelerated aging for 2000 h, both color and mechanical properties significantly changed. Iron oxide red and black performed better than the other two pigments, and the pigments dosage of 2.28% in the composites is favourable.

The study was undertaken to investigate the properties of cassava starch and gum arabic bonded briquettes from the sawdust of Azadirachta indica. The briquettes were produced using a Jack press at an average pressure of 10.7 kg·cm⁻². The sawdust and binders were mixed at ratios of 100:15, 100:25, 100:35 and 100:45 in weight, respectively. The briquettes produced were subjected to physical and combustion tests. Both the physical and combustion properties of the briquettes vary with binder types and binder levels (p < 0.05). The result shows that briquettes bonded with starch gave better performance based on density of 0.546 g·cm⁻³, durability rating of 95.93%, heating value of 33.09 MJ·kg⁻¹, percentage of fixed carbon of 84.70% and low ash and volatile matter of 3.35% and 11.95%, respectively, while briquette bonded with gum arabic has density of 0.425 g·cm⁻³, durability rating of 94.85%, heating value of 32.76 MJ·kg⁻¹, percentage of fixed carbon of 87.30% and low ash and volatile matter of 4.45% and 8.75, respectively. Since the aim of briquetting is to produce briquette that will serve as a good source of fuel and support combustion, the best briquette was produced when the sawdust-starch ratio and sawdust-gum arabic ratio was 100:25 and 100:35, respectively.

The effectiveness of pilodyn was tested in evaluating wood basic density, outer wood density, heartwood density, and modulus of elasticity (MoE) at 22 four-year-old eucalyptus clones in Guangxi, China. Results indicated that the mean value ranged from 9.44 to 15.41 mm for Pilodyn penetration, 0.3514 to 0.4913 g·cm⁻³ for wood basic density, and 3.94 to 7.53 Giga Pascal (GPa) for MoE, respectively. There were significant differences (1% level) in pilodyn penetration between different treatments, different directions and among the clones. Generally strongly negative correlations were found between pilodyn penetration and wood properties, and the coefficients ranged from −0.433 to −0.755. Our results, together with other studies, suggest that the use of pilodyn for assessing wood density and MoE was confirmed as a possibility.

Leaf area is an important parameter for modeling tree growth and physiological processes of trees. The single young and mature leaf area estimation models of eucalyptus were developed based on leaf fresh weight. In total, leaf area and leaf weight were measured from 455 fresh leaves of 25 trees of eucalyptus in southern China. The majority of the data (80%) were used for model calibration, and the remaining data (20%) were used for model validation. The linear, compound and power models were tested. Based on goodness of fit, prediction ability and residual performance, we found that linear and power models could best describe the relationship between leaf area and weight for young leaf and mature leaf, respectively. The study provides a simple and reliable method for estimating single-leaf area, which has a good potential in the functional-structural model of eucalyptus.

Seven extracting temperatures (25, 35, 45, 55, 65, 75, 85°C) and extracting time (30, 40, 50, 60, 70, 80, 90 min) were designed for selecting the optimal extracting time and extracting temperature for ultrasonic extraction of T. amurensis flowers. Polysaccharides from T. amurensis flowers were isolated and determined by spectrophotometry. Results show that the optimal ultrasonic temperature was 75°C and extracting time 52 min. The content of polysaccharides in T. amurensis flowers measured by anthrone—H₂SO₄ colorimetry under 580 nm, was 9.74% with 0.47% of relative standard deviation (RSD, n=3). This study demonstrated that ultrasonic extraction method was simple, and the color of the treated samples was stable in 4 h. The average recovery value for the polysaccharides measured was 99.48%±1.01%, with 0.112% of RSD (n=3).

The efficacies of some indigenous herbal dyes for use in staining plant materials were examined to obtain non-toxic, eco-friendly and cheap stains for use in plant histology. Dye extracts from Bixa orellana, Curcuma domestica, Lonchocarpus cyanescens and Pterocarpus osun were used to stain wood sections using the existing standard staining procedures with little modification. All the extracts had affinity for the fibre and vessel elements except the extract from L. cyanescens. The extracts from C. domestica and B. orellana had higher selectivity than those of P. osun for fibre. From the results of the absorbance curves, each of the dye extracts from all speciese had minimum of two peaks, indicating that they had two or more colour imparting chromophores except dye extract from C. domestica. All the dye extracts were acidic with pH range of 3.77 to 6.77. Therefore, this study shows that dye extracts from B. orellana, C. domestica and P. osun could be solitarily or in combination with artificial dyes for plant histological staining.

An ethno-medicinal investigation was conducted to understand the traditional knowledge of medicinal plants being used by the Manipuri tribe in Bangladesh. The present study was done through structured questionnaires in consultations with the tribal practitioners. A total 32 plant species belonging to 26 families and 29 genera were found to use for curing 37 ailments. Results show that the use of aboveground plant parts was higher (86%) than the underground plant parts (14%). Leaf was used in the majority of cases for medicinal preparation (17 species) followed by bark, fruit, root/rhizome, whole plant, seed and flower. Among the 32 plant species, they were mainly used to treat dysentery (10 species), followed by fever and rheumatism (5 species each); asthma, constipation, wounds and skin diseases (4 species each); cold ailments, cough and diarrhea (3 species each). The study revealed that 72% plant species investigated were used to cure more than one ailment. About 75% medicinal plants were taken orally followed by externally (9%) and both orally and externally (16%). The study thus underscores the potentials of the ethno-botanical research and the need for the documentation of indigenous healthcare knowledge pertaining to the medicinal plant utilization for the greater benefit of mankind.

Soil nematode communities were investigated in the Changbai Mountain in Broad-leaved Korean Pine forest, Korean Pine and spruce-fix mixed forest, Dark Coniferous forest, Erman’s birch forest and Alpine tundra along different altitude gradients from 762 m to 2 200 m a.s.l. Soil animal samples were collected from the litter layer and the soil depth of 0–5 cm, 5–10 cm and 10–20 cm at each site in the spring of 2001 and 2002. In total 27 nematode families and 60 genera were observed. The dominant genera were Plectus Bastian and Tylenchus Bastian and most of them live in litter layer. The total number of soil nematode was significantly correlated with soil moisture (r=0.357; p<0.01). Nematodes were classified in bacterivores, fungivores, plant parasites, omnivores-predators, and omnivores according to known feeding habitats or stoma and esophageal morphology. Species richness of fungivorous nematode was higher than others in different vegetation communities and soil depths. The total number of soil nematode and trophic groups varied significantly (p<0.05) in response to different soil depths. The fungivore/bacterivore ratio (F/B) and the ratio of (fungivores + bacterivores)/plant-parasites (WI) also changed significantly (p<0.05) in different soil depths. In conclusion, soil moisture is proved to be one of the most important variables affecting nematode density and trophic composition, and the altitude gradient does not significantly affect the ecological indices of soil nematode such as trophic diversity (TD) and the Shannon index (H′).

Using the 3-year observational data from ChinaFlux (Chinese Terrestrial Ecosystem Flux Research Network), we studied the gas regulation flux dynamics and cumulative process of gas regulation value in Qianyanzhou middle subtropical plantation (QYF) and Changbai Mountain temperate mixed forest (CBF). The gas regulation service was differentiated into vegetation gas regulation service and net ecosystem gas regulation service. Carbon tax approach, reforestation cost approach and industrial oxygen approach were employed to calculate gas regulation value. Results show that there was significant seasonal variation in vegetation gas regulation flux. Daily CO₂ uptake fluxes averaged 82.00 kg·ha⁻¹·d⁻¹ and 59.37 kg·ha⁻¹·d⁻¹ and the corresponding O₂ emission fluxes were 59.65 kg·ha⁻¹·d⁻¹ and 43.19 kg·ha⁻¹·d⁻¹ for QYF and CBF, respectively. The cumulative curves of vegetation gas regulation value always followed a sigmoid shape, and the annual gas regulation value produced by vegetation was RMB 14 342.69 yuan·ha⁻¹ and RMB 10 384.18 yuan·ha⁻¹ for both QYF and CBF, respectively. In terms of monthly net ecosystem gas regulation service, QYF appeared as a CO₂ sink and O₂ source for the whole year, while CBF appeared to be a CO₂ sink and O₂ source mainly in the period between May and September. The cumulative curves of net ecosystem gas regulation value presented a sigmoid (“S”) shape for QYF, while a unimodal type curve for CBF. The annual net ecosystem gas regulation value was 8470.52 yuan·ha⁻¹ and 5091.98 yuan·ha⁻¹ for QYF and CBF, respectively. The economic value of both the vegetation gas regulation service and net ecosystem gas regulation service were mainly produced between May and October.

A study was conducted in central Ethiopian highland in 2008 to investigate the consumption of house construction wood, the tree species preference for construction wood and the forthcoming conditions of this forest product and possible strategies for future availability. Twenty-four iron-roofed houses and twenty-eight thatch-roofed houses belonging to thirty-six farm households were investigated for types, volumes and sources of construction wood used. It was found that an average farmhouse with a floor space of 57 m² consumed about 13.7 m³ of wood. Both floor space and wood consumptions vary with house types. An average iron-roofed house with floor space of 51.9 m² consumed 16.8 m³ of wood and an average thatch-roofed house with mean floor space of 28.6 m³ consumed 3.2 m³ of wood. Family size and floor space were the major factors influencing construction wood consumption. An average living house was composed of woods of 39.3% Juniperus procera, 5.6% Cupressus lusitanica, 29.2% Eucalyptus globulus and 26% Eucalyptus camaldulensis. The wood volume from the first two species and half that of the third species were obtained from state forest which is currently banned from any construction wood extraction and hence there is a shortage of around 59.5% of woods. We suggest the promotion of various tree planting approaches to increase the wood supply and the use of alternative local materials like soil bricks for house construction.

A total of 19 protected areas (PAs) have been established in Bangladesh representing all the four forest types of the country. Apart from being the repository of biological diversity, these PAs serve as the source of subsistence livelihoods to the local communities. While all the PAs are managed by the state Forest Department (FD), with a view to ensure sustainability, a recent approach of co-management has been initiated in five PAs as a pilot project with an aid of development partners incorporating stakeholders’ participation. Along with demonstrating a number of upbeat impacts, the initiatives exert some constraints which need to be addressed properly to ensure the success of participatory approach and enhance the ongoing conservation scheme. This paper reviews the published works, government and project documents to analyze the present status of PAs and suggest recommendations accordingly.