Construction of a growth model to predict the individual stem volume of Tectona grandis L.f. (Teak) in Sri Lanka

Stem volume is one of the most important variables in commercial forestry since all the managementdecisions are taken on the volume production of trees. Also volume is the most difficult variable tomeasure and therefore it has to be predicted using a reliable method. Therefore, a growth model wasnewly constructed in this study to predict the individual stem volume of teak (Tectona grandis L.f.)planted as even-aged rnonocultures in Svi Lanka.In order to construct the model, data were collected from 11 plantations in dry zone (Anuradhapura,Harnbatota and Puttlam Forest Divsions) and intermediate zone (Kurunegala Forest Division). Theselected plantations vary in age from 27 to 44 years. Stratified random sampling was used to collectthe data with 0.02 ha circular sample plots. It was decided to use the Newton's formula for volumecalculations and for this reason, the standing tree stems were divided into 3-5 sections and enddiameters, mid diameter and length of each section were measured. The final section was assumedas a cone. The stem volume was then calculated by adding all the section volumes together. Inaddition to that, breast height diameter, total height and crown height were also measured. Usingthose data. tree volume, basal area and top height were calculated which were necessary for theanalysis.A theoretical model was developed to predict the individual tree volume using the relationship of treevolume with form factor, basal area and total height. Three site factors and four transformationswhich are biologically accepted were used to enhance the quality of the models. When tested for thesite differences using top height/age index, five classes were identified from the 1 J plantations. At thefirst stage of analysis, the data of ench site class were fitted separately to the basic model structures.As J result, eight cornmon models v-e-e i :1c'1tified for all five site classes with R2 over 91.0 and goodstandard residua' d.stributions. However, the regression parameters were different for different siteclasses evei (or the same model structure.In order to eliminate the difficulty of using different parameter sets for different site classes, datacollected from all plantations were fooled anc' fitted at the second stage to tile selected eight modelsand new parameter sets were estimated. Then the normal residuals were calculated separately forfiv , site classes using those models and tested using one way ANaYA. Only one model indicated thenon-significant residuals for all site types, i.e., V1/2= 0.5730 (basal area * total height')1/2+ 0.0235 [1/(top height / age)]. That model indicated negligible bias (-0.002) and very high modelling efficiency(0.91). When validated with the reserved data which were 110tused for model building, it indicated agood distribution of normal residuals. Finally it was conc!uded that the selected model proved itsability of predicting the unbiased volume of individual teak stems of all site classes in Sri Lanka andtherefore it is recommended to LIse in the field.(Financial support from the University of Sri Jayewardenepura is acknowledged.)

COMPARISON OF TOP HEIGHT AND DOMINANT HEIGHT WITH TREE VARIABLES AT THE EVEN AGED Pinus caribaea (MORELET) PLANTATION AT YAGIRALA

Top height and dominant heights are 'Confusedlyinterpret in many countries. The mainaim of this study was find the similarity of above two terms and to build some models topredict them.The study was carried out in Yagirala 25 year old even aged Pinus caribaea plantation.Top height and dominant heights were compared with other tree variables. Stratifiedrandom sampling without replacement was used to select the sampling unit. Circular plotsof 0,05 hectare with slope correction and boundary adjustment were used to obtain therequired tree measurementsDiameter at breast height, total height, lower and upper crownheight were measured andbasal area and crown depth were calculated. Top height and dominant height were alsoestimated.Results indicated that there is a significant difference between top and dominant heights.Also two separate equations to predict these two heights were developed. According to theresults initially ten equations were selected. Five equations described the relationshipbetween top and total height while the other five described the relationship betweendominant height and total height. Finally the best two equations were selected usingcoefficient of variation values and the distributions of standard residuals.

RELATIONSHIP BETWEEN STEM BIOMASS WITH HEIGHT AND DIAMETER OF Pinus caribaea IN THE YAGIRALA FOREST RESERVE

The biomass is an important measurement in commercial forestry maintained to producepulp, paper, chips, fuel wood products etc. The estimation of biomass of the tree is not aneasy task and a few studies were carried out so far on this problem.The present study was conducted in 25 years old pine plantation in Yagirala ForestReserve, situated in low country wet zone. According to the geographical differences ofthe plantation, stratified random sampling was carried out and two 0.05 ha circular plotswere established in each stratum. Altogether 6 plots were used for the data collection.The diameter at the breast height (dbh) and total height were measured for all the trees inthese plots.Biomass of the tree was estimated by extracting core samples at the breast height and midheight of the tree. The density of the core samples was estimated using oven dry weightand green volume of the core samples. When tested, there was no significant differenceof density along the stem. Therefore stem biomass was estimated using the density atbreast height. Also there was no significant density difference between three sites.The regression analysis was used with pooled data to find out the relationship betweenthe stem biomass with the tree diameter and height. Using variables of stem volume (W),total height (h), diameter at breast height (d) and their transformations, several modelswere developed. The best model was selected by testing for the R2 value, standardresidual distribution, modelling efficiency and bias. The best relationship for the stembiomass, total height and diameter at breast height was given by the following equation,which has R2 value of90.3.logW = -0.917 + 2.081ogd + O.0195h

Estimation of above ground biomass of forest trees using dbh as a single parameter

Forests in Sri Lanka contribute to the mitigation of climate change through sequestrating a net amountof carhon dioxide and also maintaining carbon stock as biomass. Total tree biomass comprised ofabove ground and below ground biomass of trees. This paper presents a methodology developed toestimate individual tre-e above ground biomass using allometric relationships. The advantage of thismethod is that the above ground biomass per unit area can be determined by estimating these valuesfor different species separately within that area. The present study was conducted in Yagirala Natural Forest Reserve situated in Kalutara District, low country wet zone of Sri Lanka. In this study, theabove ground biomass of different species available in that forest were predicted using the diameterat breast height (dbh).45 tree species were identified in the forest and models were separately developed for each species.For each species, 3 classes were established using the size, i.e., small, medium, and large. For class 1and 2 trees, the main stem and the average size branch were divided into sections and for eachsection end diameters and length were measured. The volume of each section was estimated usingSmal ian's formula. The total branch volume was estimated by multiplying the average branch volumeby number of branches. Then a volume and biomass relationship was estimated for each species bymeasuring the biomass of a known volume.The leaf biomass in the crown was estimated by measuring that in I m''of crown volume. Then it wasconverted to the entire crown via crown volume. Finally above ground tree biomass was calculatedby adding branch and crown biomass to stem biomass.Then allometric relationships were developed to predict the above ground biomass of each of 45species separately using dbh. A strong relationship was found between total tree biomass and dbh ofall species with R2 values over 95%. Tn order to test further improvement of the models, total heightwas added as the second explanatory variable. However, it did not improve the R~ and for mostspecies height became non-significant. Therefore the finally selected basic model structure was logbiomass = a + b log dbh. The model parameters however, indicated different values for a and b forthe different species, varying a from -1.71 (Mastixia tetranda) to - 0.73 (Xylopia parvifolia) and bfrom 2.01 (Putranjiva zeylanica) to 3.29 (Syzygium cordifolium). 

RELATIONSHIP BETWEEN STEM BIOMASS AND VOLUME OF Pinus caribaea IN THE YAGIRALA FOREST RESERVE

The biomass is an important measurement in commercial forestry maintained to producepulp, paper, chips, fuel wood products etc. The estimation of the biomass of the tree is notan easy task and few studies were carried out so far.The present study was conducted in the 25 years old Pinus caribaea plantation in YagiralaForest Reserve, which is in the low country wet zone. According to the geographicaldifferences in the plantation, i.e., valley, slopes and ridge, stratified random sampling wascarried out and two 0.05 ha circular plots were established in each stratum. Altogether 6plots were used for the data collection.The diameter at breast height (dbh), total height were measured for all the trees in theseplots and after dividing the tree stem into several sections, the length and end and middiameters of each section was measured using the Spiegel relaskop.The volume of the stem was estimated by calculating section volumes. Smalian's andNewton's formula were used to estimate the section volumes except for the final section atthe top, which was assumed as a cone. In order to save time, one plot was measured forNewton's formula and the rest was measured for Smalian's formula. Then a relationshipwas build to estimate Newton's volume (Ne) using Smalian's volume (Sm) as theexplanatory variable (equation I). The R2value was 99.9%.Ne = 0.976 * Sm (1)Biomass of the tree was estimated by extracting core samples at the breast height and midheight of the tree. The density of the core samples were estimated using oven dry weightand the green volume of the core samples. When tested, there was no significant differenceof the density along the stem. Therefore stem biomass was estimated using the density atthe breast height, and the total stem volume. Also there was no significant densitydifferences between three sites.The regression analysis was used with the pooled data to find out the relationship betweenthe stem biomass (W) and the volume (V). Using variable of stem volume and the biomassand its tranformations developed the several models. The best model was selected bychecking the R2 value, standard residual distribution, modelling efficiency and bias. Thebest rclationshin for the hiOI1l;]SS :l1lrl YOIIl"lr ,,·:1< lhr rnll:l1;nn ') whir]' h·w 02 .... 1.. " n

Santalum album L. (Indian sandalwood) oil content variation of Welimada region, Sri Lanka

Indian sandalwood (Santalum album) has a cultural and economic attraction mainly because of its fragrant oil, known as Santalol, produced in the heartwood. Due to its woody, sweet aroma and fixative properties, Santalol is widely employed in the fragrance industry; in highly priced perfumes and for incenses. The increasing demand and price therefore, have produced a very high market interest.Welimada-Badulla region of Sri Lanka is accepted as the best geographical location for best growth of sandalwood trees with higher oil yields. However, according to the literature, sandalwood oil quantity varies within the same area even for the same size of trees. The present study was therefore initiated to identify the oil quantity variation in Welimada region due to diameter at breast height (dbh) and height of the tree, as well as the percentage of heartwood available.Samples from four different locations of Welimada area were collected for the present study. Core samples were extracted from the selected trees. Oil from each tree was extracted by hydro- distillation method. The dbh, height and the sapwood heartwood percentages were measured for the sample trees. The variations of oil content were then tested with dbh, height and heartwood percentage. Twenty three trees were used for the present study and the oil content of them varied from 0.05% to 4.28%. According to the results, the oil quantity did not significantly vary with diameter at breast height and percentage of heartwood but showed a negative correlation with height. Therefore, it can be concluded that sandalwood oil quantity does not vary with dbh and heartwood percentage. However more samples need to be analyzed to test the relationship between oil content and height of sandalwood trees.

CONSTRUCTION OF A PRECISE GROWTH MODEL TO PREDICT THE NDIVIDUAL STEM VOLUME OF Alstonia macrophylla WALL. EX G. DON

In order to reduce the pressure on existing Natural Forests in Sri Lanka,Forest Department promoted growing timber species as plantations and inhome gardens. Among the suggested species Alstonia macrophylla(Hawarinuga) has recently become popular due to its fast growth rate, ease ofestablishment and timber value. There are about 1913 ha extent of Alstoniamacrophylla plantations at the end of the year 1998 maintained by the ForestDepartment of Sri Lanka. However, this figure must be higher than thatbecause many other private organizations are establishing Alstoniamacrophylla plantations in the wet zone in large scale. This species is alsogrown in home gardens, alleys and borders as non-blocks (non-plantations).However, at present there is no method at present for estimating the stemvolume of this species, which is considered as the most important variable incommercial forestry. Therefore a mathematical model was constructed in thisstudy to predict the individual stem volume of Alstonia macrophylla treesgrown in plantations.Since Alstonia macrophylla is widely found in wet zone of Sri Lanka, studysites were selected from Galle (two even-aged plantations from Pituwala andWattehena Beats) districts. The ages of these plantations were 19 and 16respectively. Ten 0.02 ha circular plots with slope correction were randomlylaid out for each plantation, in order to measure the necessary parametersfrom the individual trees. Diameter at breast height (dbh), total height andheight to the crown base of all the trees inside the plots were measured.Newton's formula was used in this research because it is the most accuratemethod. In order to calculate the volume using the Newton's formula, thestem of each tree was hypothetically divided into 4 -5 sections. Then thebottom, mid and top diameters and section lengths were measured usingSpeigal Relascope and Blume Leiss Altimeter respectively. The final sectionof the tree was assumed as a cone and only the bottom diameter and heightwere used in that particular section. The total volume of each section wasestimated by adding the section volumes calculated using Newton's formulato the volume of the final section.First a theoretical model structure was developed using the relationship ofform factor with volume, height and area at the base. Regression analysis wasused to fit the data into the model. Untransformed as well as transformedcombinations of all variables were tested. In this procedure the combinedvariable (basal area * tree height) was always kept as the first explanatoryvariable. After trying with many combinations of selected variables withvolume, final model was selected using its compatibility with the real world,R2 values, and residual distributions, model bias value and modelingefficiency. The selected models at the preliminary stage indicated very highperformance and insignificant bias. In order to select a final one, the abovemodels were validated with a new set of data. The final selected model in thisstudy to predict the individual stem volume with insignificant bias ofAlstonia macrophylla is; --.jv= 0.659 log BA *Ht + 0.00404 ...fer h

PREDICTION OF INDIVIDUAL TREE DIAMETERS OF Pinus nigra var. maritima (Ait.) Melville (CORSICAN PINE)

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Building local capacities in the operation and management of an integrated solid waste management programme; Experience of Ampara District, Eastern Sri Lanka

Open dumping and burning of wastes in the environmental sensitive areas were common practices in almost all the local authorities in Ampara district. It had become a big threat to public health, the beautiful natural environment and to the local economy. The Local Authorities of the District often faced severe difficulties in the management of solid waste in an environmentally, socially and economically feasible manner. The lack of technical and financial capacities to apply and practice the newly developed waste management guidelines and policies further aggravated this situation.Having identified the gravity  and the importance of this serious environmental issue, the Department of Assistant Commissioner of Local Government of Ampara District, with the financial assistance of the European Union and the technical assistance of the United Nations Office for Project Services (UNOPS), is currently implementing an Integrated Solid Waste Management Programme (ISWMP) in 12 local authorities of the District. This ISWMP is completely being operated with the full coordination of the District Office of the Central Environmental Authority, Ampara. The UNOPS, as part of its technical assistance, has constructed solid waste management facilities such as 7 engineered landfills, one Waste Transfer Station, 4 Recycling Centers, 5 compost yards, well developed collection systems  as well as provided with capability building/training assistance aiming to establish an effective and efficient solid waste management system for the District. These  facilities are now completed,  already in use and operational. With these facilities in place, and with the continued support from UNOPS in providing institutional and capacity building assistance to the LA officers and staff, haphazard dumping and littering of waste in certain areas of the LAs have now been stopped. Thus 45,000 urban households or 58% of the total urban population are benefitted under thisprogramme with a total collection of 137tonnes of wastes per day through this programme. Out of this 137tonnes of waste, 59 tonnes are collected from cluster systems involving five local authorities while the balance from the other non-clustered Local Authorities.The paper will also present the processes and methodologies to improve the landfill practices from the open dumping practices to controlled tipping and then to engineered landfills  among the implementing local authorities. It will also highlight interventions/strategies to ensure sustainability of the operation and their management through the introduction of a User Fee system/Service Charge which is currently being implemented in 04  Local Authorities. This collected User Fee covers about 80% of cost of collection of waste which would otherwise been spent through their normal budget.Key words: Integrated Solid Waste Management, Ampara, haphazard dumping, controlled tipping, engineered landfill

PREDICTION OF THE ERROR GENERATED BY SMALIAN'S AND HUBER'S FORMULAE IN VOLUME MEASUREMENTS OF Pinus caribaea (MORELET).

One of the common methods of volume estimation is the use of mathematical equations.Among such equations, Huber's, Smalian's and Newton's formulae are commonly usedand it is believed that Newton's formula which uses bottom, mid and top diameter of thelog and log length gives most precise volume estimations than Smalian's or Huber'sformulae. The latter two equations use only log length and end diameters and middiameter respectively. Usually for volume calculations Huber's formula is used due to theinvolvement of less measurements (mid diameter and log length)Present study was conducted in the 26 year old Pinus caribaea plantation in YagiralaForest Reserve situated in the low country wet zone of Sri Lanka. In order to representthe whole area of the forest, stratified random sampling method was used and one O.OShasample plot was laid in each stratum. Altogether 3 plots were selected.Each tree was divided into twelve one meter long sections using a ranging staff. Threediameters i.e., bottom, mid and top diameters of each section were measured using theSpiegel relascope. Other than section diameters, diameter at breast height (dbh) of thetree was measured using the diameter tape.Cumulative section volumes per each tree were calculated separately from Im to 12musing Huber's, Smalian's and Newton's formulae. other than the above method volumewas calculated using section lengths separately up to twelve meter long sections usingNewton's formula to test whether log length affect the Newton's volume. When testedthere was no significant difference between two volume types. However, for furtheranalysis Newton's volume calculated using the sectio•. length separately was used.For each cumulative volume (i.e., lm to 12m) calculated using different formulae werestatistically tested using one way ANOVA. According to the results 6m is the maximumlength for Huber's formula to predict the volume accurately. However it does not show asignificant difference between Smalian's and Newton's formulae up to twelve metersection length.Generally Huber's formula underestimates and Smalian's formula overestimates thevolume. Therefore it is recommended to use Huber's formula for volume calculations dueto it's ease of use, keeping the log length shorter than 6m.