66 research outputs found
Prediction of Stem Volume, Biomass and Carbon Using Age for Eucalyptus grandis in Nuwara Eliya and Badulla Districts
No full textForest trees act as carbon sinks and the main stem of the trees contribute most to the carbonstorage. Since Eucalyptus grandis has been extensively planted by both government andprivate sectors in the upcountry wet zone of Sri Lanka, this study attempted to predict thevolume, biomass and carbon content of the main stem of this species with age. In order toobtain a wider geographical coverage in data collection, 30 even-aged Eucalyptus grandismonoculture plantations were selected from Nuwara Eliya and Badulla Forest Divisions. Ageof those plantations varied from 7 to 40 years. Radom sampling of 0.02 ha plot size was usedfor data collection. Diameter at breast height and total height were measured from thesampled trees and a core sample was obtained from the stem for the determination of biomassand carbon amounts. Stem volume was estimated by using the model v = 0.3648(g * h) builtby Subasinghe in 2001 for the same species. Stem biomass and carbon amounts of the stemwere estimated by converting biomass and carbon contents of the extracted core samples ofknown volumes. Walkley-Black method was used for carbon content determination and thetree age was obtained from the plantation records available in the Sri Lanka ForestDepartment. Non-linear regression models were then built by using GENSTAT software topredict the selected variables using tree age. Both exponential and logistic curves were fittedto the data and model evaluation was done by the R2 values and the fitted line plots.According to the results, the stem biomass of the average tree varied from 110.8 kg at age 7to 1,095.4 at age 40. Stem carbon content varied from 68.7 kg at age 7 to 679.4 kg at age 40.When compared with the exponential models, logistic models showed poor performances andthe finally selected models for predicting dbh, height and stem volume with age weredbh = 17.83×1.028age, h = 20.09×1.019age, v = 0.264×1.066age. The R2 values for the selectedmodels were 79.1%, 84.0% and 80.1% respectively. The selected stem biomass and stemcarbon prediction models were BMstem = 108.3×1.059age, Cstem = 69.9×1.059age and those twomodels had R2 of 78.7% and 82.1% respectively. The fitted line plots too indicate very goodfits of all the selected models.
Agarwood Production in Gyrinops walla (Walla patta) Myths and Reality
No full textGyrinops walla is recorded only in the wet and intermediate zones of Sri Lanka and veryrarely in southwest India. Recently G. walla became famous in Sri Lanka due to smugglingefforts to extract a valuable resinous product known as Agarwood which is produced as aself-defence mechanism of certain species of family Thymalaeaceae. Most of the species ofAquilaria and a few species of Gyrinops, Aetoxylon and Gonystylus of the above family arecapable of producing agarwood.The process of Agarwood oleo-resin production is the tree’s response to injury of its first lineof defence, formation of phloem callus tissue, is inhibited from forming over the injury. TheAgarwood resin is highly sought after for religious, medical, ceremonial and domesticactivities by Asian Buddhists and Moslems. A large demand is also seen in Southeast Asia,Middle East, United States and Europe for perfume manufacturing.Several sesquiterpenes, chromone derivatives, sesquiterpene furanoids, tetradecanoic acidand pentadecanoic acid are contained in Agarwood resins and the sweet aroma of the woodcomes from sesquiterpene compounds. The research conducted so far revealed a strongsimilarity of the above compounds between G. walla and that of the commercially Agarwoodproducing Aquilaria species.According to the recent information, G. walla smuggling has been conducted in Sri Lanka fora long time. The highest single amount which was made ready to export was 13,489 kgrecorded in May 2013. Although agarwood production quantities using G. walla in Sri Lankahas not been properly recorded in the past, according to the data obtained from Sri Lankapolice and customs, over 17,500 kg have been harvested in the last 12 months.However, most of the illegally felled trees had not produce Agarwood resins as the formationhas to be artificially induced. Even the Agarwood has formed due to injuries, it would havebeen in minute scale because artificial resin induction was never practised in Sri Lanka.Unfortunately, the officials who valued the smuggled G. walla timber gave an unacceptablyhigh value and therefore people disastrously felled the trees growing in the wild andhomegardens expecting high incomes. Finally a massacre of trees was started and it did notprovide expected incomes.It should be known that G. walla trees do not produce Agarwood under natural conditions.Therefore until the current researches are completed to identify the best methods to formAgarwood in this species, unnecessary harvesting should be stopped. Awareness programmeswith the Government assistance is highly useful in this task. Otherwise no trees will be leftwhen the resin formation methods are identified.
Sandalwood Research: A Global Perspective
No full textSandalwood is a commercially and culturally important plant species belonging to the familySantalaceae and the genus Santalum. Sandalwood oil extracted from the heartwood has been used forperfumery, medicinal, religious and cultural purposes over centuries of years. In addition to oil, the woodand its powder are used for religious, cultural and medicinal purposes especially in the Asian and Arabregions. There are around 18 sandalwood species belonging to the genus Santalum which are; S.freycinetianum, S. haleakalae, S. ellipticum, S. peniculatum, S. pyrularium, S. involutum, S. boninese, S.insulare, S. austrocaledonicum, S. yasi, S. macgregorii, S. accuminatum, S. murrayanum, S. obtusifolium,S. lanceolatum, S. fernandezianum, S. salicifolium and S. spicatum. All the sandalwood species areidentified as obligate wood hemi-parasites which means they absorb certain nutrients such as phosphatesand nitrates from the host trees via root connections called haustoria
PREDICTION OF STEM VOLUME OF ALSTONIA MACROPHYLLA GROWING AS EVEN-AGED MONOCULTURES USING DIAMETER AT BREAST HEIGHT AND TOTAL HEIGHT
No full textA growth model to predict the stem volume of Alstonia macrophylla was constructed in this study using data collected from 23 plantations from Galle, Matara, Ratnapura and Kalutara districts. Trees own variables were mainly used as explanatory variables in this study and in addition, site quality indices were also tested. At the preliminary analysis, two different site quality types were identified for the selected plantations. Therefore, first, each site quality data set was separately fitted to the theoretical models developed in this study. The selected models indicated a high modelling efficiency and a negligible bias. Although the possibility of using a common model for both site types was tested, results proved that it was not possible. Therefore it was decided to recommend two models (same structure with different sets of statistical parameters) for two site types for the field use with the help of a given guideline to identify the plantations grown in two site types
Growth Performance of Teak Plantations Managed Under Different Treatments
No full textTectona grandis, commonly known as Teak, is an exotic species and is one of the mostdemanding and valuable timber species grown in Sri Lanka. Main factors that affect thegrowth of teak are site quality, planting material and silvicultural treatment applied whenmanaging the trees as plantations. Teak plantations have been established mainly in the dryand intermediate zones of the low country. The present study was conducted with theobjective of comparing the growth performance across the growth stages of young teakplantations managed under different treatment regimes.Nine teak plantations in the intermediate zone of the low country were selected for thepresent study. Three different management regimes were used for the selected plantationswhich can be categorized as, less intensive management (LM) and two intensive managementregimes (IM). Dbh and height of trees of the sample plots located at random were measuredusing standard methods. The tree growth records in those plantations in the past wereobtained by the available data records. Timber volumes of measured trees were calculatedusing the allometric equation developed by Subasinghe in 2004 for Teak. One way ANOVAtestwas used to compare the differences ofdbh, height and timber volume values of differentplantations considered in this study.Results indicate that dbh, height and timber volume of the IM plantation in Monaragala aresignificantly higher than those of other plantations across the growth stages. There are nosignificant differences in growth parameters and volume between state-owned plantations.There are also no significant differences between dbh, height and volume between LM andstate-owned plantations.
Construction of growth models for <i>Pinus nigra</i> var. <i>maritima</i> (Ait.) Melville (Corsican pine) in Great Britain
No full textPrediction of Stem Volume, Biomass and Carbon Using Age for Eucalyptus grandis in Nuwara Eliya and Badulla Districts
No full textData Dissemination in Forestry Sector: Need, Constraints and Trends
No full textOne of the main constraints involved with research and situation analysis in forestry sector is the lack of re-measured data over a long period of time. Since the forest dynamics and tree growth takes such a long time to provide valuable insight, the data gathered in a short time period is mostly not useful. Further long-term data measured at regular intervals to detect such changes is not feasible without an intervention of a dedicate institute or group of institutes so that they can implement a formal system to collect required data and disseminate in effective manner in a selected platform. Due to the rapid change of technology, data disseminated via printed form become less popular at present. Further, raw data cannot be provided in bulk via those methods. Therefore web-based data dissemination systems, especially web portals became very much popular among the present generations. In addition to the ease of data storage, there are many advantages of having portals such as data upload, data filtering etc. However, if the portals are poorly maintained or if those do not successfully cater the user requirements, the popularity will decline. This paper discusses about the different users of forestry sector data, characteristics of good data dissemination systems, problems faced by the users in data availability and different methods of data dissemination. In addition, advantages and disadvantages of web-based data dissemination systems, especially web portals are also discussed in detail.Keywords: web portal, public access to data, stakeholder coordination, improved communicatio
Santalum album as a Specialty Seed Oil Source: A Preliminary Study
No full textSandalwood is a commercially and culturally important plant species belongs to Family Santalaceae. Genus Santalum consists of 16 species where eight of them are commercially used as sources of valuable stem oil. In recent times sandalwood has been cultivated as an agroforesty crop to provide a sustainable solution to global sandalwood demand.Apart from stem oil, Western Australian scientists and industry identified sandalwood seed oil as a potential income for the plantation sector during the long crop cycle. Seed oils are increasingly used for cosmetic, nutritional and medicinal product, thus creating a niche for specialty oils. Further, an early study revealed that seeds of certain sandalwood species contain a rare acetylenic fatty acid in its lipid content, known as ximenynic acid. Further studies into Santalum spicatum (Australian sandalwood) found that the ximenynic acid has anti-inflammatory and vasodilator effects. This fatty acid is also reported in S. album, but a systematic study to evaluate its lipid content and fatty acid profile has not been reported.Therefore this study is a preliminary attempt to identify and quantify the seed parameters, lipid content and the fatty acid profile of S. album grown in plantations and home gardens of Sri Lanka. Trees growing in two different vegetations, i.e., a 4-year old plantation at Beragala (BG) and mature trees naturally growing in homegardens at Welimada (WM) were selected for this purpose. 100 seeds were collected from May to June 2015 and coats were removed and the oil of the kernel was collected by solvent extraction. The key constituents were detected using GC-MS methods.According to the results, the average seed diameter (5.57±0.05 mm) was smaller in WM trees of homegardens than the seeds of BG (6.26±0.03 mm) though the seed oil content was much higher (40.34±5.27%) than BG (27.5±6.85%). The ximenynic acid content of BG and WM were 94.67±1.03% and 91.17±0.65% respectively and those were not statistically significant. There were no significant differences of palmitic acid (BG=0.31%; WM=0.36%), palmitolenic acid (BG=0.10%; WM=0.13%); stearic acid (BG=0.42%; WM=0.35%); linoleic acid (BG=0.38%; WM=0.26%) and linolenic acid (BG=0.13%; WM=0.12%). However, significant differences were found for oleic acid (BG=2.96%; WM=6.29%) and steroic acid (BG=0.56%; WM=1.05%).Further studies are currently under way to identify the variations of the above parameters covering wider geographical areas and different plantation types. Based on these results Sri Lankan sandalwood growers could be benefitted by providing sandalwood seeds as a source of specialty seed oil.Keywords: Santalum album, Seed oil, Ximenynic acid, Acetylenic fatty aci
Analysis of mangrove vegetation cover and the present status of aquaculture
No full textMangrove forests are complex ecosystems that occur along intertidal accretive shores in the tropics. Mangroves play a significant role in both ecology and economy. In Sri Lanka many estuaries and lagoons are fringed with vastly diverse mangrove forests. The northwestern coastline represent all three major climatic zones in Sri Lanka. It also has the largest mangrove forest patch which is located in Puttlam – Kalpitiya lagoon. From the recent past the mangrove forest cover in Puttalam District is experiencing severe pressures from the adjoining settlements, the fishery industry, aquaculture and other activities in the catchment. An abrupt decline in the forest cover is evident due to being converted into industrial shrimp farms.An attempt was made in the present study to analyse the spatial pattern of mangrove destruction related to shrimp farm development and to analyse the distribution of mangrove species. For this purpose, shrimp farms of 2008 were mapped using IRS – LISS III image (2008) to identify the operational and abandoned shrimp farms. The results were verified by using Google Earth. In order to study the mangrove species distribution, a total of 40 sampling sites were selected to cover the whole study area. Data collection was done at each sampling point by a 10 m traverse established from the water level to the edge of the mangrove vegetation at the landside. Species and the number of individuals in each traverse were recorded during this survey. According to the findings of the study in 2008 there is a total of 5355 ha of land is used for shrimp farms but only 3872 ha is in operation and others are abandoned. These barren lands could be cultivated with mangroves if suitable restoration programme is implemented while natural regeneration is also evident in some areas. It was evident that Chilaw lagoon area is the richest when it comes to mangrove diversity. Rhizophore mucronata, Avicennia marina and Lumnitzera racemosa were the most dominant species in the study area. The most significant finding was the recording of Scyphiphora hydrophyllacea Gaertn. f. from Udappwa (854883.4 N 366900.8 E) which has now become very rare species in Sri Lanka. Only a few trees were previously recorded to be restricted to one locality on the Kalpitiya Peninsula in Puttalam lagoon
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