This review seeks to examine the extreme response of isolated somatic plant cells of apical meristematic tissues of mature conifer trees towards specific stress conditions in vitro resulting in somatic embryogenesis. Signal molecules regulating embryo development have been described in angiosperms, but very little is known about somatic rejuvenation in conifers. Recent studies on cloning of mature conifers provide new perspectives on signal molecules on cellular dedifferentiation into the embryogenic pathway. Our recent studies show that signal molecules such as butenolide, calcium ions, salicylic acid, antioxidants, amino acids, triacontanol and 24-epibrassinolide all play an important role in the conversion of somatic cells into an embryogenic pathway in many recalcitrant pines. This constitutes a major breakthrough in forest biotechnology with many practical applications in clonal forestry.

Forest managers and policy makers increasingly demand to have access to estimates of forest fragmentation, human accessibility to forest areas and levels of anthropogenic pressure on the remaining forests to integrate them into monitoring systems, management and conservation plans. Forest fragmentation is defined as the breaking up of a forest unit, where the number of patches and the amount of expose edge increase while the amount of core area decreases. Forest fragmentation studies in Mexico have been limited to local or regional levels and have concentrated only on specific forest types. This paper presents an assessment of the fragmentation of all forest types at the national level, their effective proximity to anthropogenic influences, and the development of an indicator of anthropogenic pressure on the forests areas. Broadleaf forests, tropical evergreen forests and tropical dry deciduous forests show the greatest fragmentation. Almost half (47%) of the tropical forests are in close effective proximity to anthropogenic influences and only 12% of their area can be considered isolated from anthropogenic influences. The values for the temperate forests are 23% and 29% respectively. Anthropogenic pressure in the immediate vicinity of anthropogenic activities is much higher in the tropical forests (75 in a scale 0–100) than in the temperate forests (30). When considering these results jointly, the tropical forests, and more specifically, the tropical evergreen forests and tropical dry deciduous forests are under the greatest pressure and risks of degradation.

Large scale harvest of Korean pine (Pinus koraiensis) seeds as a food product in the mixed Korean pine-hardwood forest of northeastern China poses a serious threat to the sustainability and restoration of this endangered regional ecosystem. Seed collection over past decades greatly reduced the seed bank and subsequent seedling and sapling recruitment, and impacting a wide array of granivorous animals that rely on the pine seeds. We surveyed Korean pine seeds, including solid seeds (SS), insect consumed seeds (ICS) and other (animal) consumed (OCS) kernels, of the seed bank (forest floor and the top 10 cm of mineral soil), the seedlings and saplings from 1 m² sample plots in five forest types in Liangshui Nature Reserve (LNR) of the southern Xiao Xing’an Mountains in northeastern China to provide accurate information for assessing the Korean pine regeneration potential. The average number of pine seeds in the seed bank were 11.2 seeds/m², 9.1 seeds/m², 4.6 seeds/m², 1.1 seeds/m², and 0.2 seeds/m2 in Korean pine-basswood forest, mixed Korean pine-hardwood forest, mixed conifer-hardwood forest, white birch forests, and oak forests, respectively. In the first three forest types, percentages of SS (potentially viable seeds) were 11.2%, 3.5% and 27.8%, respectively. The percentages of ICS (not viable seeds) were consistent at around 35%. The higher but variable percentages of OCS (not viable seeds) indicated high seed predation in these forests. Compared with other studies, we recorded higher percentages of seed damage, probably due to our survey approach and the increased depth of seed bank sampled in our study. Depletion of pine seeds in the seed bank greatly reduced seedling and sapling recruitment. Densities of pine seedlings varied from about 180 trees/ha in the mixed Korean pine-hardwood forest to about 5,400 trees/ha in the mixed conifer-hardwood forests and showed a high degree of spatial variation. Saplings were rare in the mixed Korean pine-hardwood forest, but ranged in the thousands in other forests. Large scale pine seed harvest has seriously threatened the sustainability of the mixed Korean pine-hardwood forest ecosystem. Scaling down the seed harvest or supplemental planting of pine saplings are urgently needed to maintain the health of the existing Korean pine forests and to restore this endangered ecosystem.

Tree species diversity and population structure at different community types were described and analyzed for primary and secondary lowland moist deciduous forests in Tripura. Overall 10,957 individual trees belonging to 46 family, 103 genera and 144 species were counted at ≥30 cm DBH (diameter at breast height) using 28 permanent belt transects with a size of 1 ha (10 m × 1000 m). Four different tree communities were identified. The primary forests was dominated by Shorea robusta (mean density 464.77 trees·ha⁻¹, 105 species) and Schima wallichii (336.25 trees·ha⁻¹, 82 species), while the secondary forests was dominated by Tectona grandis (333.88 trees·ha⁻¹, 105 species) and Hevea brasiliensis (299.67 trees·ha⁻¹, 82 species). Overall mean basal area in this study was 18.01m²·ha⁻¹; the maximum value was recorded in primary Shorea forest (26.21 m²·ha⁻¹). Mean density and diversity indices were differed significantly within four different communities. No significant differences were observed in number of species, genera, family and tree basal cover area. Significant relationships were found between the species richness and different tree population groups across the communities. Results revealed that species diversity and density were increased in those forests due to past disturbances which resulted in slow accumulation of native oligarchic small tree species. Seventeen species were recorded with <2 individuals of which Saraca asoka (Roxb.) de Wilde and Entada phaseoloides (L.) Merr. etc. extensively used in local ethno-medicinal formulations. The present S. robusta Gaertn dominated forest was recorded richer (105 species) than other reported studies. Moraceae was found more speciose family instead of Papilionaceae and Euphorbiaceae than other Indian moist deciduous forests. Seasonal phenological gap in such moist deciduous forests influenced the population of Trachypithecus pileatus and capped langur. The analysis of FIV suggested a slow trend of shifting the population of Lamiaceae group by Moraceae species in secondary T. grandis L. dominated community.

We studied seedling survival and growth of Aquilaria malaccensis in three different environmental conditions (homegardens, green house and in different canopy conditions) of northeast India. Results show that mean seasonal survival was highest in green house (95.53%±2.33), followed by homegardens (89.3%±1.89) and different canopy conditions (77.62%±6.73); the highest values were found during February to April for both the homegardens (96%±1.68) and green house (98% ± 0.88) and lowest during November to January (78%±2.99) in homegardens and May to July (90%±4.53) in green house. In case of transplanted seedlings in different canopy conditions, mean seasonal survival was highest during May to July (98%±1.92) and lowest during August to October (66%±12.81). However, mean seasonal growth of collar diameter was highest in different canopy conditions (23.99%±1.76 compared to green house (21.52%±2.70) and homegardens (12.44%±1.33) and it was highest during rainy season (May to July) and lowest during dry winter (November to January) in all the three experimental sites. These variations may be due to the different microclimatic conditions as well as nutrient status of the soil in all the three experimental sites. Although, seedling quality plays a great role in their survival and growth, based on the result of green house experiment, it can be concluded that maintenance of seedlings in green house conditions during their early growth period may improve both the survival and growth for large scale plantation of the species. Thus, the species can be reintroduced in its natural forest range to compensate the loss of natural population of this precious species in northeast India.

Fine root turnover plays a key role in carbon (C) budgets and nutrients cycles in forest ecosystems. However, the difference between branch-order-based and diameter-based approaches in estimating fine root turnover is still unclear. We studied root biomass turnover based on multiplying root standing biomass by turnover rate (inverse of median root longevity) in two Chinese temperate tree species, Fraxinus mandshurica Rupr. and Larix gmelinii Rupr. The minirhizotron (MR) technique was used to estimate longevities for first and second order roots, and total roots (R _total) apparent on the MR tube surface. The corresponding biomass for each root group was estimated by soil monolith. The difference in biomass turnover between R _total and the sum of the first and second order roots was used to represent the discrepancy between diameter- and order-based approaches. First order roots had shorter life spans and higher biomass turnover rates than the second order roots in both species. Biomass turnover estimated by the order-based method for F. mandshurica and L. gmelinii were 155.4 g·m⁻²·a⁻¹ and 158.9 g·m⁻²·a⁻¹, respectively, in comparison with 99.5 g·m⁻²·a⁻¹ and 117.7 g·m⁻²·a⁻¹ estimated by the diameter-based method, indicating that the diameter-based approach underestimated biomass turnover. The most probable reason was that the order-based method enhanced separation of the heterogeneous root population into relatively homogenous root groups with varying turnover rates. We conclude that separating fine root pool into different branch orders can improve the accuracy of estimates for fine root turnover, as well as the understanding of the belowground C allocation and nutrient cycling at ecosystem level.

Eucalyptus benthamii is a forest species of economic interest that has difficulty with seed production and also is considered to have difficulty with adventitious rooting using propagation techniques, such as cutting or mini-cutting. We aimed to assess the adventitious rooting percentage under different storage times in low temperatures and at various IBA (indole-3-butyric acid) concentrations to determine the optimal time of permanence for rooting Eucalyptus benthamii minicuttings in a greenhouse. Shoots collected from mini-stumps cultivated in a semi-hydroponic system were used to obtain the mini-cuttings. For the first experiment, the mini-cuttings were stored at 4°C for 0 (immediate planting), 24, 48, 72, 96 and 120 h. The second experiment evaluated the rooting dynamic to determine the optimal time of permanence for minicuttings in a greenhouse. The basal region of the mini-cutting was treated with various IBA solutions: 0 (free of IBA), 1,000, 2,000, 3,000 and 4,000 mg·L⁻¹. Every seven days (0 (immediate planting), 7, 14, 21 and 28 days), destructive sampling of the mini-cuttings was performed to evaluate the histology of the adventitious rooting. Eucalyptus benthamii minicuttings should be rooted immediately after the collection of the shoots. The 2,000 mg·L⁻¹ IBA concentration induced a greater speed and percentage of adventitious rooting, and an interval of 35 to 42 days was indicated for permanence of the mini-cuttings in the greenhouse. Exposure to low temperature induced adventitious root formation with diffuse vascular connections.

Because of global climate change, it is necessary to add forest biomass estimation to national forest resource monitoring. The biomass equations developed for forest biomass estimation should be compatible with volume equations. Based on the tree volume and aboveground biomass data of Masson pine (Pinus massoniana Lamb.) in southern China, we constructed one-, two- and three-variable aboveground biomass equations and biomass conversion functions compatible with tree volume equations by using error-in-variable simultaneous equations. The prediction precision of aboveground biomass estimates from one variable equation exceeded 95%. The regressions of aboveground biomass equations were improved slightly when tree height and crown width were used together with diameter on breast height, although the contributions to regressions were statistically insignificant. For the biomass conversion function on one variable, the conversion factor decreased with increasing diameter, but for the conversion function on two variables, the conversion factor increased with increasing diameter but decreased with increasing tree height.

We documented the status of fern diversity, biomass and carbon accumulation at Chilapatta Reserve Forest in Cooch Behar Wildlife Division, West Bengal. Stratified random nested quadrat sampling was adopted for analyzing the qualitative and quantitative characters. Nineteen fern species were recorded, of which two are yet to be identified. Identified species were of eight families and nine genera. Highest and lowest frequency recorded were 25.44 and 0.19 while relative frequency varied from 3.16 to 12.25. Fern density ranged from 93 to 13,403 individuals ·ha⁻¹. Most of the species were widely distributed. IVI values ranged from 7.54 to 37.45. The above ground portion of ferns accumulated the major portion of biomass and carbon.

Plants in the alpine zone mainly depend on the reserved food materials stored in their rhizomes for the next growing season. We investigated the effect of mixed cropping (Phaseolus vulgaris L. var. Pinto) with four rhizomatous medicinal plants, i.e., Angelica glauca, Arnebia benthamii, Rheum emodi and Pleurospermum angelicoides as well as three levels of water stress treatment under two conditions (shade net and open field) on macronutrients (NPK) and biochemicals (carbohydrates and protein). The experiment was conducted by completely randomized design (CDR). The data were analyzed with ANOVA as well as CDR. The experimental results show that in all the species shade conditions with sever water stress (SSWS) increased the level of macronutrients (NPK). However, (N) concentration was highest under shade with mixed cropping (SMIX). Under SMIX, carbohydrate content was highest than open field control conditions (CONT). This investigation results demonstrate that mixed cropping of medicinal plants with Phaseolus vulgaris could be a good livelihood option in the mountainous regions of Indian Central Himalaya. And the water-stress conditions along with mixed cropping could improve the biochemical constituents in the rhizome of these species.

We report the effects of shifting cultivation on water quality in 16 creeks investigated once in 2007 and twice in 2008 in 16 apparently similar small neighboring watersheds, each of 3 to 5 ha, at four locations around Barkal sub-district under Rangamati District of Chittagong Hill Tracts in Bangladesh. Concentrations of SO₄ ²⁻ and K⁺, and pH in creek water were lower, and NO₃-N and Na⁺ concentrations were higher in shifting-cultivation land compared to land with either plantation or natural forest or a combination of these cover types. Shifting cultivation effects on some water quality parameters were not significant due to change in land cover of the watershed between two sampling periods either through introduction of planted tree species or naturally regenerated vegetation. Conductivity and concentrations of HCO₃ ⁻, PO₄ ³⁻, Ca²⁺ and Mg²⁺ in creek water showed no definite trend between shifting cultivation and the other land cover types. At one area near the Forest Range Office of Barkal, creek water pH was 5.8 under land cover with a combination of shifting cultivation and plantation. At this area Na⁺ concentration in shifting-cultivation land ranged from 32.33 to 33.00 mg·L⁻¹ and in vegetated area from 25.00 to 30.50 mg·L⁻¹ in 2007. At another area, Chaliatali Chara, SO₄ ²⁻ concentration in a shifting-cultivation watershed ranged from 4.46 to 10.51 mg·L⁻¹, lower than in a vegetated watershed that ranged from 11.69 to 19.98 mg·L⁻¹ in 2007. SO₄ ²⁻ concentration in this shifting-cultivation area ranged from 1.28 to 1.37 mg·L⁻¹ and in the vegetated area from 1.37 to 3.50 mg·L⁻¹ in 2008.

We assessed soil fungal diversity in the dry deciduous forest of a Bhadra Wildlife Sanctuary of the Western Ghats (210.31 m a.s.l.; N 13°44′ and E75°37′). Soil samples were collected by random mixed sampling during winter (November, 2008), summer (March, 2009) and monsoon (August, 2009) seasons, and physico-chemical parameters were recorded. During winter, summer, and monsoon seasons, 49, 45 and 49 of fungal species belongs to 20, 18 and 19 of genera were isolated, respectively. Isolated soil fungi were mainly of the Mitosporic fungi, followed by Zygomycotina, Ascomycotina, Oomycotina and Coelomycetes. Indices of diversity, dominance and fisher alpha during winter, summer and monsoon seasons were 3.756, 3.638 and 3.738 (H′), 0.9737, 0.9694 and 0.9726 (1-D) and 18.84, 29.83 and 19.46 (α), respectively. Spearman’s (r) correlation coefficient of fungal population with physico-chemical parameters of soils showed significantly positive and negative correlations (p<0.01) during winter, summer and monsoon seasons. Physico-chemical soil parameters played an important role in the occurrence, diversity, distribution, and relative abundance of fungal species in the tropical dry deciduous forest soil.

A survey of 35 tree species (belonging to 28 genera in 19 families) in Aliyar, South India was carried out to ascertain their arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) fungal status. All the tree species examined had AM association. AM and DSE colonization is reported for the first time in 20 and 14 species respectively. Cooccurrence of AM and DSE was observed in 14 (40%) tree species. The extent of DSE colonization was inversely related to the extent of AM fungal colonization. Six tree species had Arum-type, 18 had intermediatetype and 11 had typical Paris-type AM morphology. AM fungal spore morphotypes belonging to 11 species in two genera were isolated from the rhizosphere soil. AM fungal spore numbers were not related to the extent of AM colonization and Glomus dominated spore diversity. AM association individually and along with DSE were found respectively in the 63% and 44% of the economically important tree species. The occurrence of AM and DSE fungal association in economically important indigenous tree species indicates the possibility of exploiting this association in future conservation programmes of these species.

Developing appropriate control measures for the Mahogany shoot borer, Hypsipyla robusta Moore has become increasingly important due to the severe damaging effect of the pest on the establishment of the saplings of Swietenia mahagoni Jacq (Sapindales: Meliaceae). Existing management methods are largely limited to silvicultural practices and spraying of chemical insecticides. To identify a potential fungal biocontrol agent, we compared the virulence of six native and two standard ARSEF isolates of Metarhizium anisopliae Metsch. against this pest. The average survival time and conidial yield of IWST-Ma7 was higher (6.2 to 7.3 days and 4.9 to 4.7×10⁵ conidia/ml) than the standards. Significant difference in sporulation on the cadavers between isolates, doses and incubation periods were substantiated for the selection of potential strain. The mycotoxic effects of crude soluble protein extract when incorporated in the artificial diet, the ARSEF 2596 and ARSEF 3603 showed LD⁵⁰ value of 3.7% and 5.6%. However, IWST-Ma7 was highly lethal with significant lowest LD⁵⁰ value of 2.6%. The enzyme activity of IWST-Ma7 was highest for chitinase, CDA, protease and lipase viz., 1.90 U/mg, 1.80 U/mg, 0.98 U/mg and 0.80 U/mg respectively. However the enzyme activity of chitinase and Chitin deacetylase assay for all the isolates was significantly higher than protease and lipase activity. The ITS regions (5.8S rDNA and 28S rDNA) of seven isolates of M. anisopliae were amplified using the ITS1 and ITS4 primers which was a unique fragment of approximately 550 bp. Based on ITS regions, phylogenetic tree have been constructed and the isolates have been grouped in to 5 clades. The virulence and mycotoxic effects of different isolates could rationally be used to employ them for the management of the mahogany borer.

Zhalong National Nature Reserve (Zhalong) is an important stopover for migratory birds. In recent decades, Zhalong has become the focus of researchers and public discussion in relation to irrigation. We studied relationships between birds and habitats at different water levels to guide development of more effective habitat management measures. We used line transects to survey bird numbers and distribution during April-May from 2005–2009 at Zhalong, and used cluster analysis and Chi-Square tests to analyze data. We recorded 139 bird species of 39 families and 13 orders during spring migration, including Anseriformes, Charadriiformes, Ciconiiformes, Columbiformes, Coraciiformes, Cuculiformes, Falconiformes, Galliformes, Gruiformes, Passeriformes, Piciformes, Podicipediformes, Strigiformes. Dominant vegetation and geographic region were the main influence factors of avian distribution. Different ecological groups preferred different water levels (p<0.01) and different habitat types (p<0.01). Grallatores, Natatores and Passeres were the main ecological groups in different wetland habitats, and reed marsh and lake are the main habitats for management. Grallatores preferred reed marsh and lake with water levels >30 cm and 5–15 cm. Natatores preferred lakes with deep water (>30 cm). Passeres preferred open forest and reed marsh with no surface water. Different avian ecological groups occupied specific habitats depending on water level and we recorded some overlaps in bird distribution.

This study aims at exploring the technical efficiency of lumber industry in northwestern Ontario, Canada using data envelopment analysis (DEA). The DEA model analyzes relative technical efficiency of lumber mills with disproportionate inputs and outputs by dividing the 10-year time series data, for inputs and outputs of 24 lumber mills, over two periods (1999–2003 and 2004–2008). Four inputs, namely, material (log volume), labour (man-hours), two types of energy (hog-fuel and electricity), and one output (lumber volume) are used in this study. The trend analysis shows an annual reduction of 10%, 13% and 13% for lumber output, log consumption (input) and number of employees, respectively, during the period 1999–2008. The results from DEA with two scenarios with energy inputs and without energy inputs, for the two periods are found to be mixed and interesting. While some mills have improved their performance in terms of best use of available scarce inputs in the second period, some have shown negative per cent change in efficiency. In the with energy input and the without energy input scenario, some of the mills show a reduction in efficiency in the second period from the first period, with the highest estimated reductions of −13.9% and −47.6%, respectively. A possible explanation for these negative performances of mills in the latter period is the decline in production in the second period compared to the first period, where these mills were not able to adjust their inputs (mostly labour) as proportional lay-offs might not have been possible. These results provide policy makers and industry stakeholders with an improved understanding of the trends of efficiency and employment as well as reallocation opportunities of future inputs in order to increase benefits from this sector.

We investigated procurement of raw materials for particleboard to minimize costs and develop an efficient optimization model for product mix. In a multiple-vendor market, vendors must be evaluated based on specified criteria. Assuming sourcing from the highest-scoring vendors, annual purchase quantities are then planned. To meet procurement needs, we first propose a model to describe the problem. Then, an appropriate multi-criteria decision making (MCDM) technique is selected to solve it. We ran the model using commercial software such as LINGO® and then compared the model results to a real case involving one of the largest particleboard manufacturers in the region. The model run based real data yielded a procurement program that is more efficient and lower in cost than the program currently in use. Use of this procurement modelling approach would yield considerable financial returns.

The performance of the skidder Timber jack 450 C was presented in timber skidding of non-coniferous trees in hilly and mountainous conditions. An empirical time study was conducted to evaluate the current skidding system in Hyrcanian forest in northern Iran for improving production rate of skidding and finding out the production cost for planning. Based on the identified elements of skidding work phase and 130 recorded cycles, we calculated the models for effective time consumption, total productivity, and unit cost. The validity of the model was tested at 95% confidence interval. The average load volume per cycle was 2.82 m³, average one way skidding distance was 450 m, and the average slope was 18%. The average travel speed of unloaded skidder was 5.8 km·h⁻¹, and the average speed of loaded skidder was 0.1 km·h⁻¹ higher than the speed of the unloaded ones. The travel speed was predominantly affected by longitudinal slopes and types of strip roads. The average speed of pulling the cable was 1.16 km·h⁻¹, and that of load winching was 0.74 km·h⁻¹. The average outputs in skidding was 10.6 m³·h⁻¹ and the unit cost was 12.1 US$ per hour. The time consumption and productivity of skidding depends on distances and slope, number of logs per cycle, volume, log length, etc. However, the influence of variables is not the same.

Time and motion studies were conducted to evaluate the impact of selective cutting type on Chainsaw productivity in Caspian forests, the selective cutting performed as single and group selection cutting in the region. The selective cutting was performed on a 42-ha tract with an average slope of 30%. The results indicate that felling time for per tree is most affected by diameter at breast height, the distance among harvested trees in single-tree selection method and diameter at breast height in group selection method. The production rate in single and group selection cutting were 21.2 m³·h⁻¹ and 28.4 m³·h⁻¹ for one person, respectively. Considering the gross and net production rate in single and group selection cutting, the unit cost was 1.11 USD·m⁻³ and 0.88 USD·m⁻³, respectively. The results indicate that group selection cutting can be more profitable than single-tree selection method.

We studied effect of desiccation on Knema attenuata seeds in the laboratory conditions (28 ± 2°C) for 8 days. We also monitored biochemical changes during germination by following standard procedures. Seeds lost their viability in 8 days by decreasing to 18% of moisture content from its original value of 31%. The total sugar, protein and lipid contents decreased during seed ageing. An increase was noticed in the protease activity during desiccation. The phenolic content in seed exudates was increased during ageing. The result confirms the degradation of stored biomolecules in seeds during ageing. Desiccation sensitivity and biochemical changes during dehydration confirm its recalcitrant nature.

Mooseer (Allium hirtifolium Boiss.) is bulbous perennial herb widely used in pharmaceutical and food industry in Iran. We studied germination of mooseer seeds in two separate experiments. In the first experiment, we evaluated four treatments: sulfuric acid scarification, sandpaper scarification, cold stratification, and gibberellic acid (GA₃) application. In the second experiment, we evaluated combinations of these treatments. All treatments in the first experiment had no effect on seed germination, suggesting that mooseer seeds have physical and physiological dormancy. In the second experiment, the highest germination percentage (86.6%) was observed after five minutes scarification with sulfuric acid (75% v/v), followed by 60 days of cold stratification. Duration of sulfuric acid scarification (5, 10, and 20 min) did not affect germination rates, but increasing duration of cold stratification (from 15 to 60 days), increased germination from 28.3% to 86.6%. Our study showed that mooseer seeds have both physical and physiological dormancy.