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Shorea leprosula and Shorea johorensis do not live alone, but are associated with other plant species within a forest ecosystem. The relationships or associations of plants in the forest can be positive and negative. Positive association occurs when a plant species is present together with other plant species, while negative association occurs when a plant species is not present together with other plant species. The purpose of this study was to determine the distribution pattern of tree species, the Important Value Index (IVI), the association between species, and the kinship value of S. leprosula and S. johorensis in the IUPHHK (Timber Forest Product Utilization Business Permit) area of PT. Kemakmuran Berkah Timber, West Kutai Regency, East Kalimantan Province. The results showed that S. leprosula had an IVI (Important Value Index) of 15.89% - 42.02% and S. johorensis had an IVI of 28.56%. Based on the association of kinship values, there was a significant negative association between S. leprosula and Myristica sp. and Cinnamomum sp., with negative coefficients of 7.28% and 8.83%, respectively. As for the S. johorensis species, it was only found in plot 1, with one significant combination with the Palaquium sp. species with a positive coefficient of 5.63%. S. johorensis plays a significant role in plot 1, while S. leprosula shows complex interactions with significant negative species combinations in several plots. [ABSTRACT FROM AUTHOR]

Shorea leprosula belongs to the Dipterocarpaceae family and grows in Indonesia's tropical forests which have an economic and ecological role. They are a plant in tropical forests that is known as a producer of fruit and tengkawang oil. The presence of S. leprosula trees in the habitat naturally at this time was very hard to find and began to decrease in population. This study aims to determine the potential and distribution pattern of S. leprosula found around KHDTK Aek Nauli. The research method uses the plot path method measuring 20 m × 20 m, the total number of plots is 150 plots. The research results show that the potency of S. leprosula is 63.17 m3 ha-1. The highest important value index of S. leprosula at the tree level was 25.45%. The distribution pattern of S. leprosula at the sapling, pole, and tree levels was clustered, while the distribution pattern at the seedling level was random. The importance of information about the potential and pattern of S. leprosula to be known as an indicator of the current status of its population at KHDTK Aek Nauli and as an information basis for managing management S. leprosula for support preservation in the forest. [ABSTRACT FROM AUTHOR]

Shorea leprosula belongs to the Dipterocarpaceae family and grows in Indonesia's tropical forests which have an economic and ecological role. They are a plant in tropical forests that is known as a producer of fruit and tengkawang oil. The presence of S. leprosula trees in the habitat naturally at this time was very hard to find and began to decrease in population. This study aims to determine the potential and distribution pattern of S. leprosula found around KHDTK Aek Nauli. The research method uses the plot path method measuring 20 m × 20 m, the total number of plots is 150 plots. The research results show that the potency of S. leprosula is 63.17 m3 ha-1. The highest important value index of S. leprosula at the tree level was 25.45%. The distribution pattern of S. leprosula at the sapling, pole, and tree levels was clustered, while the distribution pattern at the seedling level was random. The importance of information about the potential and pattern of S. leprosula to be known as an indicator of the current status of its population at KHDTK Aek Nauli and as an information basis for managing management S. leprosula for support preservation in the forest.

Shorea leprosula Miq. and Shorea selanica (Lam.) Blume are fastgrowing plants, and can be used as a rehabilitation plant. Plant adaptability can be seen from the growth in diameter. Furthermore, rehabilitation plants have the potential to store carbon stocks which can support Indonesia's Forestry And Other Land Use (FOLU) Net Sink 2030 program. This study aims to analyze diameter growth and estimate carbon stocks stored in 8-yearold S. leprosula and S. selanica species in unproductive forest area KHDTK Haurbentes, Bogor. Furthermore, the data collection of diameter was conducted by census, while carbon stock estimation used allometric equations. The diameter distribution of S. leprosula and S. selanica was normally distributed. The normal diameter distribution is defined as the highest number of frequencies around the mean value. The results of the normality test of S. leprosula and S. selanica have normal diameter distribution data, which indicate that these species have good adaptability in unproductive forest areas. Moreover, the incremental growth of S. leprosula diameter is 1,38 cm, while the diameter increment of S. selanica is 1,19 cm. The carbon stock of S. leprosula is 4,72 tons/ha while S. selanica is 8,32 tons/ha. S. leprosula and S. selanica have good adaptability. Thus, they can be used as plants to rehabilitate unproductive forests and store potential carbon stocks. [ABSTRACT FROM AUTHOR]

Shorea leprosula is one of the tree species within Dipterocarpaceae Family, which is a major source of timber production. The species has been planted massively in Gunung Dahu Research Forest (GDRF) in Leuwiliang, Bogor. Gunung Dahu Research Forest is a manmade dipterocarp forest that has varying slope classes, topography, and canopy cover. Furthermore, natural regeneration is an important ecological factor in assessing the ability of forest regeneration, including in a plantation forest. Therefore, it is necessary to know the effect of slope and canopy cover on the regeneration of S. leprosula in order to characterize what factors support and constrain the naturally regenerating forest of Gunung Dahu Research Forest. Regeneration capacity of the species was observed in purposive plots which have been recorded for their flowering events. Seedlings were grouped into seedlings and saplings. It was measured by census method on every slopes. Meanwhile, variable observed included number of available seedlings at each slope category slope with its canopy cover, height and diameter of seedlings, and litter thickness. The results show that a flat slope with shady canopy cover has the highest capacity of seedlings and the best growth. The uneven distribution of height and diameter indicates the need for silviculture action, such as, maintenance. [ABSTRACT FROM AUTHOR]

Shorea leprosula Miq is a Dipterocarps forest plantation that has the prospect of being developed because it is a fast-growing species with high economic value. Given its commercial importance, this study was conducted to analyze the effect of slope class and slope direction on growth. Data were collected using the census method on S.leprosula stands with a spacing of 2m x 2m and 4m x 8m. The direction of the slope is determined based on the configuration of the slope according to the cardinal directions, while the slope of the land is determined based on the classification of the slope class of the land. The results showed that the slope class, slope direction, and the interaction between factors had a significant effect on the growth of S.leprosula. The interaction between the slope class and the direction of the slope produces the highest average annual increment of diameter in the flat slope class with the direction of the slope facing north, which is 1.79 m / year while the highest annual increment of the total average height is in the very steep slope class with to the slope facing to the north at 0.82 m / year.

Natural regeneration of Dipterocarpaceae depends on the availability of the mother trees, flowering cycle, and favorable site conditions. Potential seed of Shorea leprosula in Haurbentes Forest Research, Jasinga District, Bogor, should be supported with sufficient regeneration ability. This research aims to identify the condition of regeneration of Shorea leprosula, environmental conditions and soil conditions that support for the sustainability of the S. leprosula regeneration in Haurbentes Forest Research, Jasinga, Bogor district. The results of the vegetation analysis showed that condition of the forest regeneration S. leprosula in KHDTK Haurbentes quite sufficient for seedling which are found quite a lot and dominating on every block of observations. However, seedlings are experiencing obstacles in resuming its growth to the level of sapling and poles. This can be seen by the existence of another species that dominates at the level of the sapling and the least amount of poles found. The existence of competition with other species and lack of space grows to regeneration due to the dominance of mature trees suspected that caused the regeneration S. leprosula on blocks of thisplant disturbed. Environmental conditions and soil conditions sufficiently support growth of S. leprosula. However, the lack of light intensity that goes into the stands is suspected to be one of the barriers to regeneration of S. leprosula.

Although cutting is a useful method for vegetative propagation and tree breeding, there is a difference in rooting ability between tree species and even between node positions within a species. A large number of F1 hybrids of Shorea (Shorea curtisii × S. leprosula) (Dipterocarpaceae) have recently been found in Singapore. Given that some of the hybrid traits appear to have higher physiological performances than those of their parent species, understanding the rooting ability of the leafy-stem cuttings of F1 hybrids may contribute to performance improvement in dipterocarp trees. In this study, we compared the rooting abilities of cuttings taken from seedlings of F1 hybrids and their parent species at different node positions. The cuttings of F1 hybrids showed rooting ability with small internode differences, and the rooting rate (32.2%) was almost intermediate between those of S. curtisii (42.0%) and S. leprosula (21.0%). The rooting rates of hybrids and parents fell into the middle range of previously reported values for 21 closely related Shorea species. Overall, the rooting ability of F1 hybrids is comparable with that of their parent species and/or other Shorea species in the red meranti group. Thus, F1 hybrids could be mass propagated through cuttings. [ABSTRACT FROM AUTHOR]

• We tested ecophysiological traits in tropical dipterocarp trees and their hybrids. • Parent species traits were passed to their hybrids through introgression. • Drought tolerance was enhanced via crossing with more tolerant species. • Hybridization may enable adaptation to drought induced by climate change. Gene transfer through interspecific hybridization can enhance functions such as growth performance, although its role in the ecophysiological functions of tropical tree species remains unclear. Hybrid seedlings of genus Shorea (Dipterocarpaceae), which dominates the canopy layer, are found in fragmented tropical rainforests in Southeast Asia. To elucidate changes in dipterocarp environmental adaptability due to hybridization, we studied the ecophysiological traits of dipterocarp seedlings including leaf morphology, photosynthesis, and drought tolerance in two parent species (Shorea curtisii and Shorea leprosula) and their hybrids, including F 1 and backcross hybrids. Then, we induced drought stress to investigate drought tolerance in these seedlings. Photosynthetic ability was higher in S. leprosula than in S. curtisii , with the F 1 and backcross hybrids showing intermediate characteristics. By contrast, drought tolerance, as indicated by stem hydraulic safety, cuticle thickness, and leaf mass per area, was higher in S. curtisii , lower in S. leprosula , and intermediate in their hybrids. The leaf turgor loss point decreased in S. curtisii due to osmotic adjustment under drought conditions, which led to lower predawn leaf water potential and higher water absorption ability from drier soil. By contrast, these changes were smaller and drought tolerance was weaker in S. leprosula. The hybrids including backcrosses had higher drought tolerance than S. leprosula , suggesting that gene transfer through introgression may facilitate the acquisition of drought tolerance. Although increased drought stress due to climate change and forest degradation are likely to limit seedling regeneration in S. leprosula , drought-tolerant genes obtained through hybridization with S. curtisii may contribute to its survival. [ABSTRACT FROM AUTHOR]

Wood quality of five year-old of cultivated Red Meranti (Shorea leprosula Miq.) was studied in order to assure its proper utilization. The evaluation was conducted based on fiber dimension and physical properties of wood. Fiber dimension was measured through maceration specimen, while green moisture content, wood density, and specific gravity were measured following the modification of BS 373.75. Result shows that quality of Red Meranti wood studied was similar to that of naturally grown, except for its fibers which were shorter and thinner than those of naturally grown. It was found that wood quality of each tree was homogenous and even. Result also shows that average values of fiber length, cell wall thickness, moisture content in green condition, wood density and SG are 968.12 µm, 2.72 µm, 104.57%, 0.81 g/cm3, and 0.50, respectively. The wood is categorized as strength class of III, therefore, this Shorea leprosula wood is potential as raw material for plywood and furniture manufacturing, as well as for the 3-rd class of structural and other purposes. The trees unfortunately have not produce the mature wood yet, and the wood produced is not suitable for the highest quality of pulp and paper manufacturing.

Abstract: In a unique phenomenon restricted to the ever wet forests of Southeast Asia, hundreds of species from dozens of plant families reproduce synchronously at irregular, multi‐year intervals. The proximate environmental cues that synchronize these general flowering events have not been evaluated systematically because there have been no long‐term, high temporal resolution, species‐level records from the region. We present 13 years of weekly flowering records for five Shorea species as well as daily temperature and rainfall records from the Pasoh Forest Reserve, Peninsular Malaysia. We constructed models to evaluate hypothesized relationships between flowering and cool temperature, drought, and additive and synergistic effects of cool temperature and drought for each species. Model parameters include periods of time for floral cue accumulation and flower development and temperature and/or rainfall thresholds required for floral initiation. Parameters estimated using flowering observations from 2001 to 2011 were used to forecast flowering for 2011–2014. We show that drought and cool temperatures acting synergistically best explain the timing of flowering events for all Shorea species in the section Mutica and forecast the largest general flowering event accurately. Periods estimated for signal accumulation ranged from 54 to 90 days among species. Periods estimated for flowers to develop ranged between 43 and 96 days and closely followed the interspecific sequence of flowering in the Shorea species. Drought and temperature thresholds also varied among species, with Shorea maxwelliana requiring the most severe drought and Shorea leprosula the lowest temperatures. Synthesis. Our results indicate that cool temperatures and low rainfall occurring on seasonal time‐scales of about 2–3 months rather than brief cold snaps or brief droughts best explain general flowering in Shorea species at the Pasoh Forest Reserve. Low rainfall is equally likely in winter (December–February) and summer (July–August) and cool temperatures are most likely in winter at Pasoh, which explains why general flowering events are restricted to spring and fall, with more frequent and stronger flowering in spring. In addition, species‐specific sensitivity to environmental cues suggests that future climate change will have differential impacts on the frequency of reproduction, with potential consequences for regeneration of these dominant species of lowland tropical forests. [ABSTRACT FROM AUTHOR]

This research aimed to study the ectomycorrhiza formed by basidiospores attached to the outer surface of Shorea leprosula (Dipterocarpaceae) seed collected from a lowland tropical dipterocarp forest. Two groups of seeds were collected: control seeds collected from plastic net hanging 2 m above the ground and forest floor seeds collected on the forest floor. Before planting, 15 seeds from each group were observed for basidiospores attached to the seed. Ten of the 3-week-old S. leprosula seedlings of each group were individually grown in 1.5 kg of sterile zeolite for 8 months in a greenhouse. Pots were fertilized with MMN solution containing half the strength of phosphate. Fungal identity, ectomycorrhizal root tip colonization and anatomy, plant growth, and phosphate uptake were measured. The control seeds did not have basidiospores attached, whereas the forest floor seeds had 2 × 10 basidiospores of Tomentella. Bioassay test results indicate that the seedlings from the control seeds did not form ectomycorrhiza, whereas those seedlings from the forest floor seeds formed 3 morphotypes of ectomycorrhizae. Based on ITS1, 5.8S, and ITS2 rDNA region analyses, the 3 morphotypes belonged to Tomentella sp. HBT2, Tomentella sp. HBT4, and Scleroderma sp. HBS3. Root colonization percentage was above 70% for all three morphotypes. Root colonization in general increased plant growth and phosphate uptake. This is the first report of Tomentella basidiospores attached on the seed surface as a functional inoculum and of Tomentella ectomycorrhiza from dipterocarps lowland tropical forest. [ABSTRACT FROM AUTHOR]

Selective Cutting and Line Planting (SCLP) silvicultural system can be applied in the logged over forest and low potential forest to improve their productivity . The research was aimed to create the growth modelling of Shorea plantations in the line planting system. The research was conducted at research plots of SCLP in logged over forest of PT Gunung Meranti, Central Kalimantan Province. The research plots were divided into three plots of Shorea leprosula plantation that planted in 1994 as plot 1, year 1999 as plot 2 and year 2008 in which consisted of 200 samples of trees, respectively. Data of Shorea leprosula growth were evaluated by Stella 9.0.2 and SPSS 13, and predicted using table of volume, exponential and polynomial equations. The research result showed that exponential equation was y= 1,0269.e0,012X (R2= 96,02%) and estimated cutting cycle at 37 year old, average polynomial equation was y=0,0297x2 + 0,8208x + 0,3728 (R2= 86,89%) and estimated cutting cycle at 30 year old and group polynomial equations (R2> 95%) estimated cutting cycle at 32 years old. The best model was group polynomial equations that represented exponential equation and average polynomial equation in the yield of volume

The development of sequence characterized amplified region (SCAR) markers derived from amplified fragment length polymorphisms (AFLPs) is described for Shorea leprosula. An AFLP fragment that showed nearly complete differentiation between Borneo and Sumatra was gel-extracted, sequenced, and converted into a SCAR marker using the inverse polymerase chain reaction (PCR) technique. The single nucleotide polymorphism (SNP) that originally caused the AFLP was found in the MseI restriction site. Differentiation between islands was detected either as size variation of the codominant SCAR marker or after digestion of the PCR products with the restriction enzyme MseI (PCR-RFLP). Size variation was due to insertions/deletions found within the sequenced region that flanked the original AFLP fragment. After genotyping 151 samples of S. leprosula from 14 populations in Sumatra and Borneo, all but one sample from Sumatra were homozygous for one size variant (427 bp), while S. leprosula populations from Borneo showed different genotypes than Sumatra populations and variation not only among populations but also within populations. Complete differentiation and fixation on alternative variants was found for the geographic regions of Sumatra and Borneo by the PCR-RFLP method. The SCAR marker did not amplify in Shorea parvifolia and thus can also be used to distinguish between S. leprosula and S. parvifolia. The marker was successfully amplified from wood DNA extracts suggesting its applicability to track the geographic origin of timber. [ABSTRACT FROM AUTHOR]

Background: The impact of logging and restoration on species diversity has been well studied in tropical forests. However, little is known about their effects on genetic diversity within species. Aims: We assess the degree of genetic diversity among dipterocarp seedlings used for enrichment planting of selectively logged forests in Sabah, Malaysia, and compare it with diversity in naturally regenerating seedlings. Methods: We sampled young leaf tissues from seedlings ofShorea leprosulaandParashorea malaanonanfor DNA genotyping, using microsatellite markers. Results: The levels of genetic diversity (expected heterozygosity and rarefied allelic richness) of naturally regenerating seedlings were statistically indistinguishable among unlogged, once logged and repeatedly logged forest areas. Enrichment-planted seedlings ofP. malaanonanexhibited similar levels of genetic diversity to naturally regenerating seedlings whereas those ofS. leprosulahad significantly lower genetic diversity than natural seedlings. Interestingly, reduction of genetic variation was consistently observed in single-species plots relative to mixed-species plots among enrichment-planted seedlings. Conclusions: There was no reduction of genetic variation in naturally regenerating dipterocarp seedlings in areas of selective logging. However, genetic variation of enrichment-planted seedlings was lower in single-species plots relative to mixed-species plots. This suggests that enrichment-planting strategies should adopt diverse mixtures that should promote levels of both species richness and genetic diversity within species. [ABSTRACT FROM PUBLISHER]

Background:Although natural hybridisation between dipterocarp trees is considered rare, putative dipterocarp hybrids (Shoreaspp.) are found in a forest fragment in Singapore. Understanding the performance of hybrids is critical to inform conservation efforts and has implications for the demographic and genetic viability of these small populations. Aims:First, is there a difference in the frequency of hybrids between the mature and seedling stages, and second, do parent and hybrid seedlings have different ecological traits? Methods:We analysed seedling survival and growth rates in relation to environmental variables forShorea curtisii, S. leprosulaand hybrids of the two species. We monitored the height and diameter of seedlings for 4 years, as well as light conditions and soil moisture. Results:The proportion of hybrids at the seedling stage was 41% forS. leprosulaand 17% forS. curtisii, respectively. Hybrids were more frequent at the seedling stage than at the mature stage. Hybrid individuals had growth and survival rates comparable to their parent species, with the exception of slower growth rates thanS. leprosula. Conclusions:Hybrid seedlings lacked obvious heterosis, and might therefore have similar fitness to that of parent species in the present forest environment. [ABSTRACT FROM PUBLISHER]

Abstract: Shorea leprosula is one of the valuable species in the tropical rain forest and it has distributed widely in the lowland tropical rain forest with altitude up to 700 m above sea level. Due to decreasingthe number of forest area, it will affect the sustainability of S. leprosula in the tropical rain forest. Ex situ conservation through establishment of S.leprosula progeny test was one of the best way to evaluate the best genotypes of mother trees (family) in order toset up the breeding program and produce the improved planting stock materials for forest rehabilitation.The research was conducted in Balik Papan Forest Industries (BFI), a Forestry Company in East Kalimantan, Indonesia. A total of 60 open pollinated plus trees have been selected and used for the genetic materials of the study. The progeny test wasplanted in 2009and laid out in randomized completely block design (RCBD), 4-tree line plots/family with 3 replications and at a spacing6 x 3 meter. The result of research showed significant in both high and DBH variable at tα Family5%. The biggest and lowest of DBH growth were the family no. 51018 (2.78cm.year-1 of mean annual increment/MAI) and family no. 51052 (1.66cm.year-1 of MAI). Moreover, the highest and the lowest of height growth were family 51030 (2.6 m.year-1 of mean annual increment/MAI) and 51003 (1.5 m.year-1 of MAI) respectively. Families selected in this research could be used to produce the improved planting stock material for rehabilitation insecondary tropical rain forest [Copyright &y& Elsevier]

We developed microsatellite markers from newly isolated expressed sequence tags of an endangered tropical tree species, Shorea leprosula (Dipterocarpaceae). Twenty-four loci exhibited clear, polymorphic amplification patterns among 52 individuals from a population in Indonesia, with two to 16 alleles per locus. No locus showed significant departure from Hardy-Weinberg equilibrium, and no significant genotypic disequilibrium was detected for any pair of loci after sequential Bonferroni correction. [ABSTRACT FROM AUTHOR]

Abstract: Soil carbon (C) stocks in forest ecosystems have been widely estimated to a fixed soil depth (i.e., 0–30cm) to clarify temporal changes in the C pool. However, surface elevations change as a result of compaction or expansion of the soil under forest management and land use. On the other hand, the calculation of soil C stocks based on “equivalent soil mass” is not affected by compaction or expansion of forest soil. To contribute to the development of a forest C accounting methodology, we compared changes in soil C stocks over 4years between depth- and mass-based approaches using original soil data collected at 0–30cm depths in young plantations and secondary forests in West Java, Indonesia. Our methodology expanded on the mass-based approach; rather than using one representative value for the mass-based calculation of soil C stocks, we adjusted individual values, maintaining the coefficient of variance in soil mass. We also considered the effect of an increase or decrease in soil organic matter on equivalent soil mass. Both increasing and decreasing trends in soil C stocks became clearer when the mass-based approach was used rather than the depth-based approach. The trends in soil C stocks based on equivalent soil mass were particularly evident in the surface soil layers (0–5cm) and in plantation sites, compared with those for soil profiles including subsurface soil layers (0–30cm) and in secondary forests. These trends in soil C stocks corresponded with temporal trends in litter stocks. We suggest that equivalent mass-basis soil C stock for the upper 30cm of soil be calculated based on multiple soil layers to reduce estimation errors. Changes in soil organic matter mass had little effect on the estimation of soil C stock on an equivalent mass basis. For the development of a forest C accounting system, the mass-based approach should be used to characterize temporal trends in soil C stocks and to improve C cycle models, rather than simpler methods of calculating soil C stocks. These improvements will help to increase the tier level of country-specific forest C accounting systems. [Copyright &y& Elsevier]

Shorea (Dipterocarpaceae) is a large genus in which many closely related species often grow together in Southeast Asian lowland tropical rain forests. Many Shorea species share common pollinators, and earlier studies suggested occurrence of interspecific hybridization and introgression. Here, we show morphological and molecular evidence of hybridization between Shorea species. In the census of all the trees of Shorea curtisii, Shorea leprosula, and Shorea parvifolia (>30 cm dbh) within the 164-ha area of Bukit Timah Nature Reserve in Singapore, we found 21 morphologically recognizable hybrid individuals. All of the putative hybrids could be distinguished obviously from the parental species on the basis of vegetative characters. Population genetic analysis of DNA sequences of two nuclear ( GapC and PgiC) and chloroplast ( trnL- trnF) regions demonstrated that each of the three species had several species-specific mutations. The nuclear sequences of the putative hybrids were heterozygote at all the species-specific sites between two parental species. Hybrid between S. curtisii and S. leprosula was found most, while S. curtisii × S. parvifolia and S. leprosula × S. parvifolia hybrids were also found. Almost no shared polymorphism between populations of the parental species suggests rarity of introgression. The study indicated that natural hybridization between sympatric Shorea species should not be uncommon, but all of the hybrid individuals were F, and the post-F hybrids were considerably rare. [ABSTRACT FROM AUTHOR]

Background and Aims: Knowledge of pollen dispersal patterns and variation of fecundity is essential to understanding plant evolutionary processes and to formulating strategies to conserve forest genetic resources. Nevertheless, the pollen dispersal pattern of dipterocarp, main canopy tree species in palaeo-tropical forest remains unclear, and flowering intensity variation in the field suggests heterogeneity of fecundity. [ABSTRACT FROM PUBLISHER]

Abstract: The impact of selective logging on genetic diversity of two tropical tree species with contrasting breeding systems was examined using direct comparison and simulation methods. Shorea leprosula is a diploid and predominantly outcrossed species, whereas Shorea ovalis ssp. sericea is an autotetraploid species with apomictic mode of reproduction. Direct comparison of adjacent natural and logged-over stands showed reduction of genetic diversity of S. leprosula, but not of S. ovalis ssp. sericea. These results clearly demonstrated that a single logging event would cause the genetic erosion of S. leprosula. However, the apomictic mechanisms and the effects of tetrasomic inheritance of S. ovalis ssp. sericea might be a way of maintaining the level of genetic diversity. These results clearly implied that outcrossing species might be more susceptible to the negative impact of logging on genetic diversity than apomictic species. Simulation studies were conducted using three approaches: (1) simulated-removal of individuals based on diameter size classes; (2) simulated-removal of individuals at random; and (3) simulated-removal of individuals in clump. The simulation study based on the first approach showed that the loss of genetic diversity was higher for the Malayan Uniform System (MUS) compared with the Selective Management System (SMS). This might suggest that SMS is more orientated towards the conservation of genetic diversity. In addition, the simulation study showed that to conserve 100% of the total number of alleles, the tolerable cutting limits of S. leprosula in the 50-ha plot of Pasoh FR should be >85cm diameter at breast height (dbh). Comparison of simulation studies based on the second and third approaches showed that the loss of genetic diversity was more rigorous if logging activities were anticipated through extraction of trees in clump rather than to extract trees at random. Implications of the studies for conserving and managing the tropical forests are discussed. [Copyright &y& Elsevier]

Simple sequence repeats (SSRs) derived from expressed sequence tags (ESTs) are valuable markers because they represent transcribed regions and often transferable to related taxa. Here, we report the development and characterization of EST–SSRs from Shorea leprosula. Fifty-four sequences containing SSRs were identified in 2003 unigenes assembled from 3159 ESTs. Twenty-four EST–SSRs were developed, of which four gave multiple amplifications, five were found to be monomorphic and 15 showed polymorphism, with allele numbers ranging from two to 17 in a single Pasoh Forest Reserve population of 24 individuals. The observed and expected heterozygosities ranged from 0.05 to 0.91 and from 0.16 to 0.93, respectively. Cross-species transferability of the 15 loci to 36 species within Dipterocarpaceae revealed between four and 14 loci that gave positive amplification and 10 loci were found to be transferable to more than 15 species. [ABSTRACT FROM AUTHOR]

Phosphorus concentrations in many south-east Asian tropical rain forest soils are very low. To determine the growth responses of seedlings of a light-demanding ( Shorea leprosula) and a more shade-tolerant ( Hopea nervosa) dipterocarp species to increasing P, we carried out a nursery fertilisation experiment. Responses of symbiotic ectomycorrhizal (EcM) fungi to the treatments were also determined. Seedlings were grown under high light (13 mol m−2 d−1) or moderate light (4 mol m−2 d−1) in shade-chambers and were fertilised with a solution containing 0, 1, 10 or 100 mg L−1 P. The growth of Hopea and Shorea showed different responses to the light and P fertilisation treatments with Hopea having greater growth under moderate light conditions and Shorea having greater growth under high light conditions. Shorea responded to P fertilisation by increasing its foliar P concentrations and growth rates, whereas Hopea did not take up additional P and did not improve its growth rates. There was no effect of either light or P fertilisation on total EcM colonisation or EcM diversity, but around half of the EcM morphotypes observed were affected by one of these two abiotic perturbations, most notably for Riessiella sp. which increased with P fertilisation suggesting it may not be a mutualistic fungus. These results show how niche partitioning in both dipterocarp seedlings and EcM fungi can be divided along contrasting axes. [ABSTRACT FROM AUTHOR]

The genetic diversity within and among populations of Shorea leprosula and Shorea parvifolia from Indonesia was investigated using amplified fragment length polymorphisms (AFLPs). The results indicated that S. leprosula is genetically more variable than S. parvifolia. At the population level, a higher level of genetic diversity was revealed for S. leprosula with a percentage of polymorphic loci (PPLp) of 53.32% and an expected heterozygosity ( H ep) of 0.16 in comparison with S. parvifolia showing PPLp of 51.79% and H ep of 0.14. At the species level, S. leprosula showed PPLs of 92.86% and H es of 0.21, while S. parvifolia showed PPLs of 85.71% and H es of 0.21. Genetic differentiation ( G st) indicated that 25 and 31% of total genetic diversity in S. leprosula and S. parvifolia, respectively, were attributed to the differences among populations. An analysis of molecular variance (AMOVA) at two hierarchical levels exhibited that most genetic variation resided within populations with proportion of 70.2% for S. leprosula and 66.2% for S. parvifolia. The AMOVA at three hierarchical levels performed for S. leprosula and S. parvifolia together revealed that the genetic difference between the two species was remarkably higher with a proportion of 44.1% than the differences within and among populations (38.1 and 17.8%, respectively). The genetic differentiation between islands was significant for S. leprosula but not for S. parvifolia. The observed genetic diversity agreed with the life history traits of Shorea species. Highly differentiating individual AFLP markers were found for each species, which will serve as diagnostic markers for the identification of wood of different species, from different islands and regions. [ABSTRACT FROM AUTHOR]