Important Timber Species Research Articles

Aboveground biomass and carbon stock assessment in forest stands of Gmelinaarborea Roxb. in Mizoram, North-East India

Aboveground biomass and carbon stock in tropical forest play an important role in global carbon cycle. Assessment of biomass and carbon pool in different forest stands may provide information in making decisions about the carbon management within the forest. Gmelina arborea , a fast growing species that is widely distributed and an important timber species of Mizoram has been chosen to assess its biomass and carbon stock. The present study was carried out to estimate the aboveground biomass and carbon stock in G. arborea in different forest stands of Mamit District, Mizoram, north-east India. The result shows that the total aboveground biomass ranged between 66-108 Mg ha -1 and carbon stock (30.00-53.20 mg C ha -1 ). The aboveground biomass and carbon stock was maximum in forest stands (site-III) with highest tree density and diameter class of 30-40cm and 40-50cm indicating the forest site was mature and undisturbed. The result demonstrates that G. arborea contribute in carbon sequestration and helps in mitigating global warming. Further, the aboveground biomass and carbon sequestration potential was greatly affected by the tree composition, population pressure and anthropogenic activities. Keywords: Aboveground biomass, carbon stock, diameter class,Gmelina arborea, tropical forest.

Regeneration of Cryptomeria japonica seedlings on pine logs in a forest damaged by pine wilt disease: effects of wood decomposer fungi on seedling survival and growth

ABSTRACTEvaluating the environmental factors that affect seedling regeneration on deadwood is important for predicting the forest recovery process after dieback events. Pine wilt disease (PWD) has killed many adult trees of Pinus densiflora in recent decades and consequently created a huge accumulation of deadwood in lowland forests in Japan. These deadwoods are now providing nice seedbeds for variety of tree species including Cryptomeria japonica, which is the most important timber species in Japan. In the present study, we tested the effects of various factors on Cryptomeria seedlings growing on decayed Pinus logs in Japan. In total, 126 individuals of Cryptomeria seedlings (height <50 cm) colonizing on 22 pine logs were investigated. During a 5-month research period from May to October 2015, the survival rate of the seedlings was 87.3%, and the maximum height growth was 32.0 cm. Analysis using generalized linear mixed models revealed that delignified white-rot wood in the sapwood of the logs negatively affected seedling survival and growth. These results suggest that type of wood decay, reflecting fungal wood decomposer activity, would strongly affect survival and growth of Cryptomeria seedlings, although logs were important microsites for their establishment after pine wilt disease.

Phylogeographic pattern suggests a general northeastward dispersal in the distribution of Machilus pauhoi in South China.

Machilus pauhoi Kanehira is an important timber species in China. A provenance trial was recently set up to evaluate the growth performance of trees from different localities, with the aim of designing seed transfer guidelines. Here, we tested twelve nuclear microsatellite markers derived from other species of the Lauraceae family and investigated population genetic structure in M. pauhoi. Both the number of observed alleles per locus (Na) and the polymorphic information content (PIC) significantly decreased against the latitude, but showed an insignificant decrease against the longitude. Heterozygosity (Ho) and gene diversity (h) exhibited a weak correlation with geographic location. Private alleles were present in multiple populations, and a moderate level of population genetic differentiation was detected (Gst = 0.1691). The joint pattern of genetic diversity (Na, PIC, Ho, and h) suggests that general northeastward dispersal led to the current distribution of M. pauhoi. Significant but weak effects of isolation-by-distance (IBD) occurred, implicating the mountain ranges as the major barrier to gene flow. Both STRUCTURE and hierarchical clustering analyses showed three distinct groups of populations related to the physical connectivity among mountain ranges. A priority in designing genetic conservation should be given to the populations at the southwest side of the species’ distribution. This conservation strategy can also be combined with the pattern of adaptive genetic variation from the provenance trial for comprehensive genetic resource management of native M. pauhoi.

Extensive seed and pollen dispersal and assortative mating in the rain forest tree Entandrophragma cylindricum (Meliaceae) inferred from indirect and direct analyses.

Pollen and seed dispersal are key processes affecting the demographic and evolutionary dynamics of plant species and are also important considerations for the sustainable management of timber trees. Through direct and indirect genetic analyses, we studied the mating system and the extent of pollen and seed dispersal in an economically important timber species, Entandrophragma cylindricum (Meliaceae). We genotyped adult trees, seeds and saplings from a 400-ha study plot in a natural forest from East Cameroon using eight nuclear microsatellite markers. The species is mainly outcrossed (t=0.92), but seeds from the same fruit are often pollinated by the same father (correlated paternity, rp =0.77). An average of 4.76 effective pollen donors (Nep ) per seed tree contributes to the pollination. Seed dispersal was as extensive as pollen dispersal, with a mean dispersal distance in the study plot approaching 600m, and immigration rates from outside the plot to the central part of the plot reaching 40% for both pollen and seeds. Extensive pollen- and seed-mediated gene flow is further supported by the weak, fine-scale spatial genetic structure (Sp statistic=0.0058), corresponding to historical gene dispersal distances (σg ) reaching approximately 1,500m. Using an original approach, we showed that the relatedness between mating individuals (Fij =0.06) was higher than expected by chance, given the extent of pollen dispersal distances (expected Fij =0.02 according to simulations). This remarkable pattern of assortative mating could be a phenomenon of potentially consequential evolutionary and management significance that deserves to be studied in other plant populations.

Variation in early growth in a second-generation whitewood (Endospermum medullosum) progeny trial in Vanuatu

ABSTRACTEndospermum medullosum (whitewood) is a commercially important plantation and agroforestry timber species in Vanuatu, used locally and for export. Commercial development depends on both increased productivity and genetic resource conservation. A second-generation progeny trial on Espiritu Santo Island was measured at ages 2 and 3 years. Growth traits were of low-to-moderate heritability, varying from 0.13 for height at 2 years, to 0.30 for diameter at breast height (DBH) at 3 years. Genetic correlations between growth and form traits were generally encouraging, with form at 3 years moderately-positively correlated (0.49 to 0.56) with the growth measures at ages 2 and 3 years, and no adverse correlations evident. Families of Espiritu Santo origins were consistently amongst the highest ranked for both growth and form traits, while families of Malekula and Pentecost Island performed poorly. These results are supportive of the recurrent selection and breeding strategy being implemented to deliver economic gains in growth traits. With natural populations severely depleted or extinct, the breeding population constitutes a repository for genetic variation already lost from wild sources. The long-term sustainability of the breeding program will therefore depend on provisions made for both improvement (narrowing of variation) and conservation (broadening of variation) of genetic resources.

Effects of Experimental Soil Warming and Water Addition on the Transpiration of Mature Sugar Maple

Sugar maple (Acer saccharum), an economically important timber and syrup species, is not expected to flourish under projected future climates. The objectives of our study were to (1) tease apart the effects of warming and soil moisture availability on transpiration rates of mature sugar maple trees with a full-factorial soil warming × water addition experiment and (2) determine the primary environmental driver(s) of sugar maple transpiration in the upper Midwestern United States. Over three growing seasons, we monitored sap flux of 33 trees in eight 100-m2 plots, two replicates each of four treatments: (1) heat (soil warmed +4°C), (2) water (1.3 × ambient growing season precipitation, (3) heat + water, and (4) control. As expected, sugar maple transpiration decreased under the heat treatments in all years and increased in water treatments in years 1 and 2, all mediated primarily by soil moisture. However, under the heat + water treatment, supplemental water compensated for the warming-induced soil evaporation only in year 1 (2011), which was the driest year. Despite clear evidence of a soil moisture-mediated treatment effect, light was the dominant driver of seasonal variation in sap flux in this sugar maple-dominated ecosystem with relatively short growing seasons. However, sap flux was reduced with decreases in soil moisture, and therefore, net C gain likely was as well. Overall, our results suggest that even though this northern temperate species is primarily limited by light, sugar maple productivity may be reduced by a warming climate on drier sites within its current range, if warming is not accompanied by a sufficient increase in precipitation.

A first-approximation simple dynamic growth model for forest teak plantations in Gujarat state of India

Tectona grandis (teak) is one of the most important tropical timber species occurring naturally in India. In India, teak is the single most important commercial timber species. Scientifically sound growth models, based on advanced modelling techniques, are often not available, although they are necessary for the successful management of teak stands in the country. Long-term forest planning requires mathematical models. In this paper, an attempt is made to develop a dynamic growth model based on the limited data, consisting of three annual measurements, collected from 15 teak sample plots in Gujarat state of India. A biologically consistent whole-stand growth model is presented, which uses the state-space approach for modelling rates of change of dominant height, stand density and stand basal area. A simple model containing few free parameters performed well and is particularly well suited to situations where available data are scarce.

Evaluation of municipal garbage as a component of potting media for economically important timber species seedlings for afforestation in tropics

Evaluation of municipal garbage as a component of potting media for economically important timber species seedlings for afforestation in tropics

ЭГЭЛ НАРСАН ОЙН ҮРИЙН ТАЛБАЙН ХӨРСНИЙ ШИНЖ ЧАНАРЫН СУДАЛГАА

Scots pine (Pinus sylvestris L.) is the one of the most important economic timber species even their distribution is very limited in Mongolia compared with Larix sibirica. P. sylvestris stand cover only 5% of total forest cover of Mongolia and distributes in subtaiga elevational zone. Forest resources in Mongolia have been continuously degraded over the past few years due to improper exploitation for timber and fuel wood (both permitted and illegal), forest and steppe fires [18], insects/pests and diseases, mining, uncontrolled grazing, and inadequate management. Hence, conservation of Scots pine forests which have very limited distribution is very important for this region. The study sites are located in Tujiin nars area, Altanbulag soum, Selenge province in the transitional zone where the mountainous zone around Lake Baikal changes to the Northern Mongolian highlands and are parts of the northern mountain range.Analysis of soil physical and chemical properties shown that seed stands with site index II has more humus accumulation (1.32%) than that of seed stands with sites index III (0.73%) and IV (0.65%), respectively, which suggests that site index or growth condition of forest stands which subjected as seed collection stands should be classified as site index II or III, accordingly.

Forest diversity promotes individual tree growth in central European forest stands

Summary Most experimental evidence on the relationship between biodiversity and ecosystem functioning comes from ecosystems with fast‐growing plants, such as grasslands. Although forests provide essential ecological services, they have been less well investigated. We used dendrochronology to compare the tree radial growth rates of four important timber species in replicated, spatially mapped stands that differed in tree composition and diversity within a central European managed forest. Growth rates differed among species but were largely unaffected by the density of neighbouring trees. Increasing stand diversity enhanced individual growth rates, after accounting for the effects of tree density and size. These increases were statistically indistinguishable among the four species. In contrast, the effects of stand and neighbourhood species composition on growth rates were non‐significant. Policy implications. Our study of long‐established central European forest stands revealed levels of tree diversity can be increased in managed forests, with the potential for modest increases in tree growth rates. These results suggest that in addition to the biodiversity and risk mitigation benefits associated with shifting practices away from monoculture management, increased carbon sequestration and yields in mature forests are likely to be realized. Our results suggest that it is possible to increase forest diversity with little or no costs to production and even with the potential for modest increases in tree growth rates.

Population dynamic and management of Pinus oocarpa and Tabebuia rosea within silvopastoral systems in Central America

Silvopastoral systems—the management of trees within pastures from natural regeneration or planting—are a strategy to promote sustainable livestock systems and ecosystems services. Timber is one of the products from these systems with potential to increase family revenues. The management of natural regeneration and population dynamics of trees is a feasible way to harvest timber and maintain environmental services. In this research, we modeled the population dynamics of Pinus oocarpa and Tabebuia rosea, two important timber species of silvopastoral systems in Central America. The results showed that farmers manage a significant density of different tree species from natural regeneration. However, only the species with well-known uses or desired services are allowed to remain. The natural regeneration is more impressive in silvopastoral systems with natural grass than those with exotic grass. Farming practices, for instance use of fire for weed control, are the main reasons for low rates of natural regeneration in pastures with exotic grass. The models of population dynamics for both species showed that the sustainable timber harvest plans are a viable activity in pasturelands under natural-regeneration management plans. Innovative farmers are willing to adopt silvicultural practices and management of population dynamics to increase timber revenues and sustainability if forestry regulations for sustainable use of trees in farms are simplified.

Transcriptional regulation of vascular cambium activity during the transition from juvenile to mature stages in Cunninghamia lanceolata

Cunninghamia lanceolata (Lamb.) Hook., an evergreen conifer distributed in southern China, has been recognized as the most commercially important timber species due to its rapid growth. However, the molecular mechanisms underlying growth alternation due to vascular cambium activity are poorly understood. Here, we used cryosectioning to isolate the vascular cambium tissue of C. lanceolata at three stages, namely, juvenile, transition and mature (3-, 13-, and 35-year-old trees respectively) for transcriptome-wide analysis. Through assembling and annotation of transcripts, 108,767 unigenes and some potential growth-regulated genes were identified. A total of 5213, 4873 and 2541 differentially expressed genes (DEGs) were identified in the three stages. DEGs related to cambial activity, cell division and cell wall modification were detected at various developmental stages of the vascular cambium. In addition, some putative genes involved in plant hormone biosynthesis were also differentially regulated. These results indicate that various cambium-related molecular activities result in alterations in the growth of C. lanceolata, particularly during the transition from juvenile to mature stages. The findings of the present study improve our understanding of cambium development and may aid in studies of the molecular mechanisms of wood production and provide fundamental insights into the establishment of the optimal rotation period for silvicultural trees.

Antioxidative and Biochemical Responses in Dalbergia sissoo Roxb. Seedlings Growing Under Cobalt and Lead Stress

Dalbergia sissoo Roxb. is one of the most important timber species of India. It is used for high quality furniture, cabinets making and has pesticidal property. It is commonly planted tree species in urban and suburban areas, roadsides and industrial areas where the soil may be polluted with heavy metals such as Co or Pb. Lead (Pb) and Cobalt (Co) are one of the non essential and toxic heavy metals which can cause oxidative stress in plants. The concentrations of these heavy metals in the environment are currently increasing, due mainly to anthropogenic activities. The effect of these heavy metals on biochemical parameters and antioxidant activity were studied in leaves of Dalbergia sissoo Roxb. grown under control laboratory conditions in pot culture and four levels of heavy metal stress (10, 20, 30 and 40ppm Pb2+, Co2+). Six months exposure of Dalbergia sissoo Roxb. plantlets to different concentration of Co or Pb in normal soil conditions elicited an antioxidative response, measured in terms of ascorbic acid, proline accumulation and biochemical responses in terms of protein and free amino acids. The results indicate that the proline, ascorbic acid contents increased with increase in Co and Pb amount in soil whereas the protein and total chlorophyll contents showed opposite trend.

Cloning of three genes involved in the flavonoid metabolic pathway and their expression during insect resistance in Pinus massoniana Lamb.

Pinus massoniana Lamb. is an important timber and turpentine-producing tree species in China. Dendrolimus punctatus and Dasychira axutha are leaf-eating pests that have harmful effects on P. massoniana production. Few studies have focused on the molecular mechanisms underlying pest resistance in P. massoniana. Based on sequencing analysis of the transcriptomes of insect-resistant P. massoniana, three key genes involved in the flavonoid metabolic pathway were identified in the present study (PmF3H, PmF3'5'H, and PmC4H). Structural domain analysis showed that the PmF3H gene contains typical binding sites for the 2OG-Fe (II) oxygenase superfamily, while PmF3'5'H and PmC4H both contain the cytochrome P450 structural domain, which is specific for P450 enzymes. Phylogenetic analysis showed that each of the three P. massoniana genes, and the homologous genes in gymnosperms, clustered into a group. Expression of these three genes was highest in the stems, and was higher in the insect-resistant P. massoniana varieties than in the controls. The extent of the increased expression in the insect-resistant P. massoniana varieties indicated that these three genes are involved in defense mechanisms against pests in this species. In the insect-resistant varieties, rapid induction of PmF3H increased the levels of PmF3'5'H and PmC4H expression. The enhanced anti-pest capability of the insect-resistant varieties could be related to temperature and humidity. In addition, these results suggest that these three genes maycontribute to the change in flower color during female cone development.

Microsatellite DNA Loci Reveal Successful Cross-Genus Amplification in a Critically Endangered Parashorea malaanonan

Parashorea malaanonan, of the family Dipterocarpaceae, is one of the most economically and ecologically important timber species in the Philippines. Presently, genetic resource of this species is highly threatened and its long-term survival is critically endangered. Hence, genetic investigation for the species is very essential. In this study, 23 microsatellite DNA loci developed for Shorea leprosula and S. curtisii were cross-amplified to P. malaanonan. This results a high transferability rate of 74%. The findings provided additional evidence for the potential cross-amplification of Shorea SSRs across genera within Dipterocarpaceae. The five polymorphic microsatellites are useful for further genetic studies of the remaining P. malaanonan populations.

Estimation of Stem Carbon Stock of Selected Eucalyptus grandis Plantations in Up Country Sri Lanka

Plantation forestry plays an important role in mitigating global warming and climate change by sequestering carbon dioxide in their biomass. Eucalyptus grandis is an important timber species in plantation forestry in Sri Lanka. The objectives of the present study were to estimate the stem carbon stock, the total amount of atmospheric carbon dioxide sequestered in stems and the monetary value of carbon sequestered in stems of selected E. grandis plantations in upcountry Sri Lanka. Four study sites were selected from Kandapola, Bogawanthalawa, Haputhale and Pinnawala to represent upcountry, intermediate zone and wet zone where E. grandis is confined to. Each plantation was divided into three strata and 0.05 ha circular sample plot was laid out in each stratum. Each individual in the plot was measured for total tree height and diameter at breast height (dbh). The carbon content of each E. grandis stem of individuals in the plantations was calculated using a constructed model to predict stem carbon of E. grandis, in which the explanatory variables are total tree height and dbh. Thereby total stem carbon stock of each plantation was estimated. Total amount of atmospheric carbon dioxide sequestered in all the E. grandis stems of each plantation and monetary value of carbon sequestered in each stem were thereby calculated for each plantation. The lowest value of estimated amount of carbon sequestered in E. grandis stems per hectare was observed in Kandapola plantation (28.176 t/ha) while the highest value was observed in Pinnawala plantation (504.095 t/ha). The highest value of estimated total stem carbon stock of a plantation was observed in Bogawanthalawa plantation (17,390.669 t). For estimated amount of atmospheric carbon dioxide sequestered in E. grandis stems, the lowest value was observed in Kandapola plantation (103.405 t/ha) while the highest value was observed in Pinnawala plantation (1,850.027 t/ha). The highest value of estimated total amount of atmospheric carbon dioxide sequestered in the stems of a plantation was observed in Bogawanthalawa plantation (63,823.757 t). When considering the monetary value of carbon stock in E. grandis stems, the lowest estimated value was observed in Kandapola plantation (3,803.72 Rs./ha) while the highest value was observed in Pinnawala plantation (68,052.76 Rs./ha). When considering plantation wise carbon stock, the highest value of estimated monetary value was observed in Bogawanthalawa plantation (Rs. 2,347,740.37). These estimates shall be presented to assess the carbon dynamics in E. grandis plantations in upcountry Sri Lanka. Keywords: Eucalyptus grandis, Carbon sequestration, Climate change, Carbon stock

Use of depth-first search and direct search methods to optimize even-aged stand management: a case study involving maritime pine in Asturias (northwest Spain)

Maritime pine (Pinus pinaster Ait.) is one of the most important timber species in Asturias and more generally in northwest Spain. A dynamic growth model has recently been developed for this species and region, allowing computation of the merchantable volume by two alternative methods: a disaggregation system and a stand volume ratio function. The model enables optimization of the management schedule for the species by modifying the rotation age and the number, intensity, and timing of thinning operations. The two methods of volume estimation were compared in optimization by using the depth-first search (DFS) method, and both were found to provide similar results. Because the stand volume ratio function is computationally much more efficient, it was used in the next step, in which five direct search methods were tested: Hooke and Jeeves method (HJ); differential evolution (DE); particle swarm optimization (PS); evolution strategy (ES); Nelder and Mead method (NM); the last four are population-based methods. The HJ and DE methods yielded the highest values of the objective function, slightly outperforming the results of DFS in most cases, which proved to be about 100 times slower than HJ and 30 times slower than DE. DE was more stable than HJ (standard deviation was €30.6·ha−1for HJ and €8.8·ha−1for DE) and was therefore used for subsequent evaluation of the effects of site quality, stem density, and discount rate on the optimal management schedule. Rotation age and timing of thinnings both decreased as site quality and discount rate increased. The optimal management schedules often included three heavy thinning operations. The pseudo-code of the optimization methods tested is provided in an Appendix.

Rainfall and temperature variability in Bolivia derived from the tree-ring width of Amburana cearensis (Fr. Allem.) A.C. Smith

Amburana cearensis is an important timber species in tropical lowland dry forests in Bolivia. We used dendrochronological methods to evaluate its climatic sensitivity and to identify its potential for the reconstruction of climate. For that, we collected eleven wood discs from randomly-selected mature trees. Despite the eccentricity of the discs and existence of false and wedging rings, all samples were successfully cross-dated. The average radial growth was 0.58cmyr−1. Significant correlation was found between the A. cearensis samples (0.34). Tree-ring width was positively correlated with monthly rainfall and negatively correlated with maximum temperatures during the 6-month rainy season (November–April). A. cearensis exhibits a potential for reconstructing climate in the Bolivian Chiquitania region.

Caracterização silvicultural da canafístula (Peltophorum dubium (Sprengel) Taubert)

This study aimed to systematize the information on forestry canafistula (Peltophorum dubium (Sprengel) Taubert), one of the most important timber species native to Brazil. The canafistula is found from Bahia to Rio Grande do Sul, has widespread use and acceptance of its products and by-products, depending on the wood quality, moderately heavy, hard, durable, high commercial value and potential in the Brazilian timber market. Can be used on furniture, leather tanneries, construction, paper industry, urban forest reclamation, fuel wood and energy. For this reason, it is important to know the behavior of the species as the silvicultural techniques that should be applied in the production of seedlings, establishment and management of the forest, management of plantations, pest control, among others, so that we can maximize production and provide information able to expand the plantations of the species.

Stem Volume Equations for Valuable Timber Species in Mozambique

Development of stem volume for umbrella-shaped crown trees remains a big challenge for efficient use of forest resources in Mozambique. In this study, species-specific stem volume equations were developed for the first time for three of the most important timber species in Mozambique: Afzelia quanzensis Welw. (Chanfuta), Millettia stuhlmannii Taub. (Jambire), and Pterocarpus angolensis D.C. (Umbila). The study was carried out at three locations in Mozambique: Inhaminga, Mavume, and Tome covering 58 trees from which, 24 of Chanfuta, 15 of Jambire, and 19 of Umbila. The volume of the sampled stem sections (logs) was calculated using Smalian’s formula, where stem volume total was obtained through the sum of the respective defined sections. Using a nonlinear procedure, different volume models were tested for each tree species independently. The coefficient of the determination of the tested equations in the tree species ranged from .90 to .95, making the equations potential candidate models for the stem volume equations object of the study. Based on statistical parameters analysis, the best fit nonliner power equation was Equation 2 with the lowest AICc and lowest average absolute bias. The stem volume for the studied species is better explained by models including both diameter and height as explanatory variables.