Monitoring Growth Performance of Naturally Regenerated Woody Species in an Enriched Pine Stand, Sri Lanka

Monitoring growth performance of newly recruited plant species after applying several silvicultural treatments in monoculture plantations is important to evaluate the success of forest restoration. This study was conducted in 2015 to determine the growth performance of the naturally regenerated woody plant species in an unrestored (UP) and a restored (RP) Pinus caribaea Morelet plantation, in lower Hantana, Sri Lanka. In RP, partial thinning of pines followed by enrichment planting of four broad-leaved tree species in 2003 and total thinning of pines was initiated in 2009. In both sites fifteen plots (5x5m) and within each of them three subplots (1x1m) were demarcated randomly. The height of seedlings (SE, <50 cm in height) in subplots and height of saplings (SA1= 50-129 and SA2=130-300 cm in height) and trees (TR, >300 cm in height) and dbh of SA2 and TR in all the plots were recorded. Collectively, 417 individuals (RP=298, UP=119) representing 28 species (RP=24, UP=12) and 22 plant families (RP=18, UP=13) survived by the end of the six months. The mean monthly increment of height (MMIH)of survived species in RP was higher for all the life forms except for SE (SE=1.35, SA1=1.61, SA2= 1.38, TR= 4.45 cmmo-1) than in UP (SE=2.06, SA1= 0.17, SA2= 0.00, TR= 1.65 cmmo-1). The MMIH of trees was significantly higher in RP than UP. The mean monthly increment of dbh (MMID) of survived individuals in RP was higher for both SA2 (0.017 cm per mo-1) and TR (0.027 cm per mo-1) than in UP (SA2= 0.0007, TR= 0.024 cmmo-1). The MMID of SA2 was significantly higher in RP than UP Of the 24 species tested in all four life form categories in RP, 19 (SE=39%, SA1=56%, SA2=69%, TR=85% of the species)had MMIH exceeding 1 cm mo-1while eight (SA2=5%, TR=26%) had dbh increment exceeding 0.05 cm mo-1. In UP, only five species (SE=60%, SA1=100%, SA2=25%, TR=77%of the species) had MMIH exceeding 1cm while one species (Alstonia macrophylla)(SA2=25%, TR=22%) had MMID exceeding0.05 cm mo-1. As the growth performance of the naturally regenerated woody species in RP was higher than UP, we conclude that restoration of pine plantation in mountainous regions of Sri Lanka, using silvicultural techniques is successful in achieving restoration goals.Keywords: Growth performance, Natural regeneration, Pinus plantation, Restoratio

Ranking the importance of quality variables in determination of price for plantation grown Teak (Tectona grandis) timber

Tectona grandis is one of the major plantation species in Sri Lanka which was introduced in 17th century. Teak timber is preferably used for furniture, joinery, decorative and parquet industries as a super luxury timber. State Timber Corporation (STC) involves in marketing of state timber resources from Forest Department plantations. Among all other timbers, Teak round wood at STC depots shows the highest sales in every year. When buying timber, customers assess the quality by visual observation of surface characteristics such as log dimensions and visible defects. If the log is inferior in quality the buyer would bid and buy it at a lower price than the marked price at auctions. Hence, the buyers‟ preference is indirectly reflected by the achieved price (selling price). In the present study, an attempt was made to study the relationship between the achievable price and the quality attributes of Teak logs. Such studies are useful as there is a lack of information on the impact of timber quality on timber price in the case of high demanding species such as teak. This information is extremely important to improve financial return of Teak management through realistic timber management concepts.A set of randomly selected logs representing a total quantity of 116079 cubic decimeters (dm3) were used as the sample. The dimensions, surface defects and end defects (size and quality variables) of each graded Teak log were measured and recorded. Length, mid girth, diameter at top end, butt end and middle of the log, total number of knots, presence of hollows and their diameter, depth and position, bend fraction, shape of the log, heartwood percentage, presence of splits, felling damages, heart rot and region where the logs were produced were the independent variables used in the study. Achieved prices for the selected logs were taken from STC records. Based on multiple linear regressions, a price-quality model was derived to explain the buyers‟ preference by means of log size and quality variables.Among the seventeen independent variable classes, only the “mid girth”, the “length”, the “number of knots per meter”, the “average knot diameter”, the “hollow position”, the “bend fraction”, the “log shape” and the “heart rot” contributed significantly to explain the buyers‟ preference. Above variables were ranked according to their order of affiliation and the ranking showed that the “mid girth” is the most important timber quality variable, followed by “length”, “number of knots per meter”, “hollow at top end &/or middle”, “bend fraction greater than 1.0”, “irregular log shape”, “average knot diameter” and “heart rot”.

Ranking the importance of quality variables in determination of price for plantation grown Teak (Tectona grandis) timber

Tectona grandis is one of the major plantation species in Sri Lanka which was introduced in 17th century. Teak timber is preferably used for furniture, joinery, decorative and parquet industries as a super luxury timber. State Timber Corporation (STC) involves in marketing of state timber resources from Forest Department plantations. Among all other timbers, Teak round wood at STC depots shows the highest sales in every year. When buying timber, customers assess the quality by visual observation of surface characteristics such as log dimensions and visible defects. If the log is inferior in quality the buyer would bid and buy it at a lower price than the marked price at auctions. Hence, the buyers‟ preference is indirectly reflected by the achieved price (selling price). In the present study, an attempt was made to study the relationship between the achievable price and the quality attributes of Teak logs. Such studies are useful as there is a lack of information on the impact of timber quality on timber price in the case of high demanding species such as teak. This information is extremely important to improve financial return of Teak management through realistic timber management concepts.A set of randomly selected logs representing a total quantity of 116079 cubic decimeters (dm3) were used as the sample. The dimensions, surface defects and end defects (size and quality variables) of each graded Teak log were measured and recorded. Length, mid girth, diameter at top end, butt end and middle of the log, total number of knots, presence of hollows and their diameter, depth and position, bend fraction, shape of the log, heartwood percentage, presence of splits, felling damages, heart rot and region where the logs were produced were the independent variables used in the study. Achieved prices for the selected logs were taken from STC records. Based on multiple linear regressions, a price-quality model was derived to explain the buyers‟ preference by means of log size and quality variables.Among the seventeen independent variable classes, only the “mid girth”, the “length”, the “number of knots per meter”, the “average knot diameter”, the “hollow position”, the “bend fraction”, the “log shape” and the “heart rot” contributed significantly to explain the buyers‟ preference. Above variables were ranked according to their order of affiliation and the ranking showed that the “mid girth” is the most important timber quality variable, followed by “length”, “number of knots per meter”, “hollow at top end &/or middle”, “bend fraction greater than 1.0”, “irregular log shape”, “average knot diameter” and “heart rot”.

Propagation of three important medicinal plants in Aacanthaceae; <em>Andrographis paniculata</em>, <em>Barleria prionitis</em> and <em>Rhinacanthus polonnaruwensis</em>

High demand has increased the exploitation of medicinal plants from the wild. Insufficient information on germination and seedling development hinders the propagation of such plants. Thus, seed germination and seedling development of three medicinal species in the family Acanthaceae were studied. Seeds were collected during their peak dispersal period. Seed moisture content (SMC) was determined using the oven dry method. Seed germination and effect of 500 ppm GA treatment and dry storage on germination were studied. Seedlings were transferred to three potting media, viz, sand: coir dust: compost, sand: compost, sand: coir dust and sand: garden soil (in equal ratio) and raised until 45 days in a greenhouse. Number of leaves and height of plants were measured in 7-day intervals. Fresh weight, root, shoot and leaf dry weights were measured after 45 days. SMC of all the studied species was &lt; 15%, revealing that they are orthodox. Thus, no special conditions are needed to store them. Rhinacanthus polonnaruwensis seeds had a T50 &lt; 30 days, indicating that they have no dormancy. Barleria prionitis and Andrographis paniculata seeds were dormant as the T50 was &gt; 30days. Germination increased &gt; 80 % after GA3 treatment and dry storage. Therefore, seeds of B. prionitis and A. paniculata have non-deep physiological dormancy. Dry storage for 1 and 3 months could be recommended for these two species, respectively. Seedlings of all three-study species showed high growth performance in the sand: garden soil potting medium which could be recommended to grow these species. These information will be useful to germinate and grow these three species for large-scale commercial pursoses

Enhancement of total lipid production in vegetative tissues of alfalfa and sainfoin using chemical mutagenesis

Alfalfa (Medicago sativa L.) and sainfoin (Onobrychis viciifoila Scop.) are two key forage legumes for the western Canadian cattle industry. Despite the high protein content, drawbacks to their use exists, including inefficient protein digestibility and energy use efficiency in the ruminant system leading to economic losses and negative environmental impacts. Increasing the proportion of lipids in the diet of cattle is known to mitigate greenhouse gas emissions; however, the above two forage legumes possess only trace quantities of lipids in the shoot tissues used by the ruminants. In the current study, chemical mutagenesis was used as a conventional breeding approach to enhance lipid levels in the vegetative tissues of alfalfa and sainfoin. The mutagenesis procedures for these two forages need to be firmly established. We developed protocols for ethyl methanesulfonate (EMS)‐mediated mutagenesis by optimizing mutagen concentration and seed soaking duration. EMS‐treated populations were assessed for morphological variants and total shoot lipid content (TSLC). Fatty acid composition was examined in a subset of plants with increased TSLC. Within 24 months, the screening process identified mutagenized plants with significant increases in TSLC (3 ‐ 5% on a dry weight basis) and a subset of these also displayed alterations in fatty acid composition in both species. These genotypes provide a novel source of germplasm for the future improvement of these two forage species