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A phytochemical investigation of three species of Malaysian Dipterocarpus contributed to the isolation of 22 compounds which consist of 15 oligostilbenoids, 2 terpenes, 2 coumarins, and 3 flavonoids. The isolation of flavonoids in the Dipterocarpaceae family is very limited. Moreover, 4-methoxepigallocatechin-3-O-O-(3-methyl) gallate (20) was isolated for the first time in the plant. The occurrence of 4-O-methylgallocatechin (18) and its stereoisomer; 4-O’-methylepigallocatechin (19) was first reported in the Dipterocarpaceae family. This study also reported the existence of several types of oligostilbenoids such as davidiol A (8), stenophyllol B (9), isohopeaphenol (11), resveratrol (1), and ampelopsin E (10) which are the first occurrence in Dipterocarpus genus and suggested a significant chemotaxonomic relationship between Dipterocarpus, more closely to Vatica which is classified under Dipterocarpeae tribe.

IntroductionParashorea chinensis Wang Hsie (Pc) is an endangered tree species endemic to tropical and subtropical China. However, the acidic red soil areas where it is distributed generally face nutrient limitation. The study of the effects of mixed planting on soil biogeochemical processes contributes to the sustainable management and conservation of Pc.MethodsWe selected pure and mixed stands of Pc and collected its rhizosphere and bulk soil samples to clarify the effect of mixed planting on the soil microbial community and the nutrient status.ResultsThe results showed that (1) All stands were strongly acidic phosphorus-deficient soils (pH

Abstract Tropical and subtropical trees provide key ecosystem services but are facing global population decline due to logging, habitat degradation, land conversion, and climate change. Vatica guangxiensis used to be a characteristic timber species of China's tropical forests but is now terminally endangered (280 individuals) and fragmented into three relictual populations in southwest China. Generating genome‐wide DNA for ∼82% of all living tree individuals of this species complex, we found evidence for a late Pliocene division into two species‐level lineages that have not had gene flow for approximately 3 million years. All three relictual populations exhibited a loss of genetic diversity and recent bottlenecks. In addition, forward simulations indicated a likely population collapse in all three populations within the next century. Our study generates a model framework for the integration of genomic evidence—including evolutionary history, current genetic variation, and future projections—into conservation planning.

In tropical Southeast Asia, Shorea is the most economically important tree and the largest genus in the Dipterocarpaceae family. It comprises about 150–200 species, of which majority are distributed in Malaysia, with others found in Sumatra and Borneo (Kalimantan) in Indonesia. Research on the chemical constituents of Shorea plants has been ongoing for many years. To date, a total of 113 different compounds, including 83 stilbenes and their resveratrol oligomers, 18 triterpenes/terpenoids, 7 coumarins 3 flavonoids and 2 steroids have been isolated and successfully elucidated from 26 different species of this genus. The diversity of the stilbene resveratrol oligomers in the Shorea genus is primarily due to the difference in the amount of resveratrol constituent units, which include dimers, trimers and tetramers. In addition to the species’ traditional usage in the treatment of illnesses, such as diarrhea, toothaches, skin diseases, ear troubles and wounds, the extracts and secondary metabolite compounds isolated from various parts of the plant species are known to have a very potent antioxidant, antimicrobial, anticancer, anti-diabetic, anti-obesity, antiulcer, hepatoprotective and nephroprotective activities. This review aims to summarize the most recent research made from 1999 to date on the secondary metabolite compounds isolated from different species of genus Shorea, as well as the bioactivity (in vitro and in vivo) of the crude extracts and the isolated secondary metabolite compounds.

Climatic factors have commonly been attributed as the trigger of general flowering, a unique community-level mass flowering phenomenon involving most dipterocarp species that forms the foundation of Southeast Asian tropical rainforests. This intriguing flowering event is often succeeded by mast fruiting, which provides a temporary yet substantial burst of food resources for animals, particularly frugivores. However, the physiological mechanism that triggers general flowering, particularly in dipterocarp species, is not well understood largely due to its irregular and unpredictable occurrences in the tall and dense forests. To shed light on this mechanism, we employed ecological transcriptomic analyses on an RNA-seq dataset of a general flowering species, Shorea curtisii (Dipterocarpaceae), sequenced from leaves and buds collected at multiple vegetative and flowering phenological stages. We assembled 64,219 unigenes from the transcriptome of which 1,730 and 3,559 were differentially expressed in the leaf and the bud, respectively. Differentially expressed unigene clusters were found to be enriched with homologs of Arabidopsis thaliana genes associated with response to biotic and abiotic stresses, nutrient level, and hormonal treatments. When combined with rainfall data, our transcriptome data reveals that the trees were responding to a brief period of drought prior to the elevated expression of key floral promoters and followed by differential expression of unigenes that indicates physiological changes associated with the transition from vegetative to reproductive stages. Our study is timely for a representative general flowering dipterocarp species that occurs in forests that are under the constant threat of deforestation and climate change as it pinpoints important climate sensitive and flowering-related homologs and offers a glimpse into the cascade of gene expression before and after the onset of floral initiation.

IntroductionShorea macrophylla is a commercially important tropical tree species grown for timber and oil. It is amenable to plantation forestry due to its fast initial growth. Genomic selection (GS) has been used in tree breeding studies to shorten long breeding cycles but has not previously been applied to S. macrophylla.MethodsTo build genomic prediction models for GS, leaves and growth trait data were collected from a half-sib progeny population of S. macrophylla in Sari Bumi Kusuma forest concession, central Kalimantan, Indonesia. 18037 SNP markers were identified in two ddRAD-seq libraries. Genomic prediction models based on these SNPs were then generated for diameter at breast height and total height in the 7th year from planting (D7 and H7).Results and discussionThese traits were chosen because of their relatively high narrow-sense genomic heritability and because seven years was considered long enough to assess initial growth. Genomic prediction models were built using 6 methods and their derivatives with the full set of identified SNPs and subsets of 48, 96, and 192 SNPs selected based on the results of a genome-wide association study (GWAS). The GBLUP and RKHS methods gave the highest predictive ability for D7 and H7 with the sets of selected SNPs and showed that D7 has an additive genetic architecture while H7 has an epistatic genetic architecture. LightGBM and CNN1D also achieved high predictive abilities for D7 with 48 and 96 selected SNPs, and for H7 with 96 and 192 selected SNPs, showing that gradient boosting decision trees and deep learning can be useful in genomic prediction. Predictive abilities were higher in H7 when smaller number of SNP subsets selected by GWAS p-value was used, However, D7 showed the contrary tendency, which might have originated from the difference in genetic architecture between primary and secondary growth of the species. This study suggests that GS with GWAS-based SNP selection can be used in breeding for non-cultivated tree species to improve initial growth and reduce genotyping costs for next-generation seedlings.

Shorea macrophylla belongs to the Shorea genus under the Dipterocarpaceae family. It is a woody tree that grows in the rainforest in Southeast Asia. The complete chloroplast (cp) genome sequence of S. macrophylla is reported here. The genomic size of S. macrophylla is 150,778 bp and it possesses a circular structure with conserved constitute regions of large single copy (LSC, 83,681 bp) and small single copy (SSC, 19,813 bp) regions, as well as a pair of inverted repeats with a length of 23,642 bp. It has 112 unique genes, including 78 protein-coding genes, 30 tRNA genes, and four rRNA genes. The genome exhibits a similar GC content, gene order, structure, and codon usage when compared to previously reported chloroplast genomes from other plant species. The chloroplast genome of S. macrophylla contained 262 SSRs, the most prevalent of which was A/T, followed by AAT/ATT. Furthermore, the sequences contain 43 long repeat sequences, practically most of them are forward or palindrome type long repeats. The genome structure of S. macrophylla was compared to the genomic structures of closely related species from the same family, and eight mutational hotspots were discovered. The phylogenetic analysis demonstrated a close relationship between Shorea and Parashorea species, indicating that Shorea is not monophyletic. The complete chloroplast genome sequence analysis of S. macrophylla reported in this paper will contribute to further studies in molecular identification, genetic diversity, and phylogenetic research.

Many companies are making ambitious pledges to achieve positive impacts for climate and nature by financing restoration of carbon- and biodiversity- rich natural habitats. However, companies cannot make evidence-based choices that will deliver successful restoration if the scientific information required to guide investment has not been synthesised in a way that they can use, or there are knowledge gaps. To explore this issue, share information, and identify knowledge gaps and research priorities, we bring together researchers, a conservation NGO and a multinational consumer goods company (Unilever), focusing on Southeast Asian rainforests. These habitats offer significant restoration opportunities for carbon and biodiversity in areas that have been degraded by commercial logging and agriculture. We find that procedures for carbon restoration are much better developed than those for biodiversity, and that new research is urgently needed to deliver evidence-based biodiversity restoration. Companies need to be confident that their actions are fit-for-purpose to meet their environmental pledges. Achieving successful restoration outcomes will require co-designed projects with the potential to deliver positive co-benefits for carbon, biodiversity and local livelihoods.

Dipterocarpus cornutus Dyer is commonly known as ‘keruing’. It belongs to the family of Dipterocarpaceae, an important timber family in South East Asia. D. cornutus is listed as critically endangered on IUCN Red List. Since no comprehensive study has been documented on the chemical constituents of D. cornutus, there is an urgent need to study this plant comprehensively. Phytochemical study of the stem bark of D. cornutus afforded a new flavonoid (1) and nine known compounds, which consist of flavonoids (2, 3), oligostilbenoids (4, 5, 7, 8, 9, 10), and coumarin (6). The finding of the study contributes to the chemotaxonomic differentiation in the plants of the tribe Dipterocarpae.

Leaf litter is an essential functional aspect of forest ecosystems, acting as a source of organic matter, a protective layer in forest soils, and a nurturing habitat for micro- and macro-organisms. Through their successional occurrence, litter-inhabiting microfungi play a key role in litter decomposition and nutrient recycling. Despite their importance in terrestrial ecosystems and their abundance and diversity, information on the taxonomy, diversity, and host preference of these decomposer taxa is scarce. This study aims to clarify the taxonomy and phylogeny of four saprobic fungal taxa inhabiting Dipterocarpus alatus leaf litter. Leaf litter samples were collected from Doi Inthanon National Park in Chiang Mai, northern Thailand. Fungal isolates were characterized based on morphology and molecular phylogeny of the nuclear ribosomal DNA (ITS, LSU) and protein-coding genes (tub2, tef1-α, rpb2). One novel saprobic species, Ciliochorella dipterocarpi, and two new host records, Pestalotiopsis dracontomelon and Robillarda australiana, are introduced. The newly described taxa are compared with similar species, and comprehensive descriptions, micrographs, and phylogenetic trees are provided.

Abstract While reforestation is gaining momentum to moderate climate change via carbon sequestration, there is also an opportunity to use tree planting to confront declining global biodiversity. Where tree species vary in support of diversity, selecting appropriate species for planting could increase conservation effectiveness. We used a common garden experiment in Borneo using 24 native tree species to examine how variation among tree species in their support of beetle diversity is predicted by plant traits associated with “acquisitive” and “conservative” resource acquisition strategies. We evaluate three hypotheses: (1) beetle communities show fidelity to host identity as indicated by variation in abundance and diversity among tree species, (2) the leaf economic spectrum partially explains this variation as shown by beetle preferences for plant species that are predicted by plant traits, and (3) a small number of selected tree species can capture higher beetle species richness than a random tree species community. We found high variation among tree species in supporting three highly intercorrelated metrics of beetle communities: abundance, richness, and Shannon diversity. Variation in support of beetle communities was predicted by plant traits and varied by plant functional groups; within the dipterocarp family, high beetle diversity was predicted by conservative traits such as high wood density and slow growth, and in non‐dipterocarps by the acquisitive traits of high foliar K and rapid growth. Using species accumulation curves and extrapolation to twice the original sample size, we show that 48 tree species were not enough to reach asymptote levels of beetle richness. Nevertheless, species accumulation curves of the six tree species with the highest richness had steeper slopes and supported 33% higher richness than a random community of tree species. Reforestation projects concerned about conservation can benefit by identifying tree species with a disproportional capacity to support biodiversity based on plant traits.

Abstract Microsatellite markers were isolated and characterized for Hopea hainanensis Merrill & Chun, an endangered tree species with scattered distribution in Hainan Island and northern Vietnam. Twenty‐six microsatellite markers were developed based on next‐generation sequencing data and were genotyped by capillary electrophoresis on an ABI 3730xl DNA Analyzer. Twelve markers were found to be polymorphic in H. hainanensis. GENODIVE analyses indicated that the number of alleles ranged from 2 to 6 per locus, and the observed and expected heterozygosity varied from 0 to 0.755 and from 0.259 to 0.779, respectively. Primer transferability was tested with Hopea chinensis Hand.‐Mazz. and Hopea reticulata Tardieu, in which 3 and 7 microsatellite markers were found to be polymorphic, separately. The results showed that H. reticulata and H. hainanensis had similar levels of genetic diversity. A neighbor joining dendrogram clustered all individuals into two major groups, one of which was exclusively constituted by H. hainanensis, while the other consisted of two subgroups, corresponding to H. reticulata and H. chinensis, respectively. The 12 polymorphic microsatellite markers could be applied to study genetic diversity, population differentiation, mating system, and fine‐scale spatial genetic structures of H. hainanensis as well as its close relatives, facilitating the conservation and restoration of these endangered but valuable Hopea species.

The Malay Archipelago is one of the most biodiverse regions on Earth, but it suffers high extinction risks due to severe anthropogenic pressures. Paleobotanical knowledge provides baselines for the conservation of living analogs and improved understanding of vegetation, biogeography, and paleoenvironments through time. The Malesian bioregion is well studied palynologically, but there have been very few investigations of Cenozoic paleobotany (plant macrofossils) in a century or more. We report the first paleobotanical survey of Brunei Darussalam, a sultanate on the north coast of Borneo that still preserves the majority of its extraordinarily diverse, old-growth tropical rainforests. We discovered abundant compression floras dominated by angiosperm leaves at two sites of probable Pliocene age: Berakas Beach, in the Liang Formation, and Kampong Lugu, in an undescribed stratigraphic unit. Both sites also yielded rich palynofloral assemblages from the macrofossil-bearing beds, indicating lowland fern-dominated swamp (Berakas Beach) and mangrove swamp (Kampong Lugu) depositional environments. Fern spores from at least nine families dominate both palynological assemblages, along with abundant fungal and freshwater algal remains, rare marine microplankton, at least four mangrove genera, and a diverse rainforest tree and liana contribution (at least 19 families) with scarce pollen of Dipterocarpaceae, today’s dominant regional life form. Compressed leaves and rare reproductive material represent influx to the depocenters from the adjacent coastal rainforests. Although only about 40% of specimens preserve informative details, we can distinguish 23 leaf and two reproductive morphotypes among the two sites. Dipterocarps are by far the most abundant group in both compression assemblages, providing rare, localized evidence for dipterocarp-dominated lowland rainforests in the Malay Archipelago before the Pleistocene. The dipterocarp fossils include winged Shorea fruits, at least two species of plicate Dipterocarpus leaves, and very common Dryobalanops leaves. We attribute additional leaf taxa to Rhamnaceae (Ziziphus), Melastomataceae, and Araceae (Rhaphidophora), all rare or new fossil records for the region. The dipterocarp leaf dominance contrasts sharply with the family’s

Abstract Liana dynamics may influence tree dynamics and vice versa. Only long‐term studies can perhaps disentangle them. In two permanent plots of lowland dipterocarp forest at Danum, a liana census in 1988 was repeated in 2018. The primary forest was still in a late stage of recovery from an inferred large and natural disturbance in the past. Mean number of lianas per tree decreased by 22% and 34% in plots 1 and 2, and in different ways. By 2018, there were relatively more trees with few lianas and relatively fewer trees with many lianas than in 1988. The redistribution was strongest for overstory trees of the Dipterocarpaceae (more with no lianas by 2018) and understory trees of the Euphorbiaceae (many losing high loads in especially plot 2). Proportion of trees with lianas increased overall by 3.5%. The number of lianas per tree showed a quadratic relationship with tree size: maximal for large trees, and fewer for smaller and very large trees. Tree survival and stem growth rate were significantly negatively related to the number of lianas after accounting for spatial autocorrelation. Monte Carlo random subsampling of trees in 1988 and 2018, to achieve statistical independence, established significance of change. Dipterocarps and euphorbs clearly differed in their liana dynamics between plots. Regression models had different forms for the two plots, which reflected a complicated structural–spatial variability in host–liana dynamics. Analysis of the abundant tree species individually highlighted a group of emergent dipterocarps with low liana counts decreasing with time. Building on an earlier hypothesis for this forest type and site, these very large trees appear to have been losing their lianas by branch shedding, as they moved into and out of the main canopy. They were evidently escaping from the parasite. The process may in part explain the characteristically very uneven forest canopy at Danum. Change in liana density was therefore contingent on both forest history and site succession, and plot‐level structure and tree dynamics. Liana promotion in the intermittent ENSO dry periods was seemingly being offset by closing of the forest and dominance by dipterocarps in late seral stages.

Dipterocarpus tempehes is an endangered tropical timber tree species endemic to Borneo. In this study, the plastome of D. tempehes was assembled. The whole chloroplast genome was 145,323 bp in length, with a large single-copy (LSC) region of 80,375 bp and small single-copy (SSC) region of 20,394 bp, separated by two inverted repeats (IRs) regions of 22,277 bp. It contained 145 genes, including 102 coding genes, 35 tRNA genes, and 8 rRNA genes. A phylogenomic analysis confirmed that Malvaceae s.l., Thymelaeaceae, and Dipterocarpaceae formed its respective monophyletic clade, with D. tempehes forming a sister clade with species from the Shoraeae tribe within the family.

In this study, we investigated the effects of the highly prized ectomycorrhizal (ECM) mushroom, Astraeus odoratus, on the growth of Dipterocarpus tuberculatus Roxb. and Shorea roxburghii G. Don seedlings. The two seedling species were inoculated using two methods: 1) spore suspension of 25 mL/seedling; and 2) hyphal suspension of 25 mL/seedling. On harvesting, it was found that 30-60% of the roots formed by the inoculated seedlings were ectomycorrhizal roots. Seedling development was influenced by the inoculation method and the host plant species. A higher growth response was observed in the S. roxburghii seedlings inoculated with A. odoratus compared to D. tuberculatus seedlings. Moreover, the non-inoculated S. roxburghii seedlings had a lower growth response than D. tuberculatus seedlings, but their growth response was significantly higher than D. tuberculatus seedlings inoculated with a spore or hyphal suspension of A. odoratus. However, there was no difference between the effects of the spore and hyphal suspension treatments. Therefore, both the inoculation methods can be used to enhance the growth of seedlings, especially that of S. roxburghii.

Hopea glabra Wight & Arn. and Hopea utilis (Bedd.) Bole are two little-known highly threatened endemic dipterocarps distributed in evergreen forests of the Western Ghats. Although literature surveys and herbarium records show occurrence of these species in different forest areas of Kerala, the present study could locate Hopea glabra from the Silent Valley National Park and Hopea utilis from Shankili forests in Kulathupuza range, enabling the portrayal of current distribution, basic ecology covering phenology, species association, regeneration and conservation status along with taxonomic notes.

The loss of forests is a major environmental, social, and economic problem. The disappearance has been occurring to an extreme degree in many parts of Southeast Asia, including Thailand. Logging and clearing of forests for agriculture, cash crops, and food production has destroyed much of the tropical forests in Thailand. Floristic inventory could provide essential information for forest conservation but species identification as a part of inventory creating could be challenging in some cases. Barcode DNA coupled with High Resolution Melting analysis (Bar-HRM) was used here in aiding species identification of plant in Dipterocarpaceae (Dipterocarpus alatus, D. costatu, D. intricatus, D. obtusifolius, Hopea ferrea, H. odorata, Shorea guiso, S. obtuse, S. roxburghii, and S. siamensis) and Fagaceae (Castanopsis echinocarpa, C. inermis, Lithocarpus wallichianus, Quercus aliena and Q. oidocarpa) families. Two main experiments were conducted including: (1) a comparing method for primer design and (2) testing the robustness of the Bar-HRM by trying to identify tree samples that did not have sequences in the GenBank. In experiment 1, the manual design primer pair was found to be the best fit for the work. Of key importance is finding the primers which give the most nucleotide variations within the generated amplicon; this is a parameter that cannot be set in any web-based tools. Next, in experiment 2, Bar-HRM using primers of ITS1 and ITS2 regions were able to discriminate all 10 tested tree species without any problem, even when there were no sequences of the samples to be analysed before performing the HRM. Here, Bar-HRM poses potential to be a game-changer in tropical forest conservation, as it will be useful for species identification.

Dua puluh lima jenis kayu Dipterocarpaceae diuji sifat keawetannya terhadap serangan penggerek kayu di laut. Masing-masing jenis kayu dibuat contoh uji berukuran 2,5 cm x 5 cm x 30 cm, direnteng dengan tali plastik, kemudian dipasang di perairan pulau Rambut dan diamati setelah 6 bulan. Tujuan penelitian ini adalah untuk mendapatkan informasi tentang keawetan 25 jenis kayu Dipterocarpaceae terhadap penggerek kayu di laut. Hasil penelitian menunjukkan bahwa setelah 6 bulan, sebagian besar contoh uji mendapat serangan berat oleh famili Pholadidae dan Teredinidae. Lima dari 25 jenis kayu atau 20% tahan terhadap penggerek di laut. Giam durian (Cotylelobium flavum Pierre) dan balau laut (Shorea falcifera Dyer) termasuk dalam katagori sangat tahan, sedangkan giam tembaga (Cotylelobium melanoxylon Pierre), balau laut batu (Shorea elliptica Burck.), dan resak ayer (Vatica teysmanniana Burck.) termasuk dalam katagori tahan terhadap penggerek di laut. Kelima jenis kayu tersebut cocok untuk bangunan kelautan.

Hopea reticulata Tardieu is a critically endangered tree species distributed in limited regions in Thailand, Vietnam and Hainan Island of China. In this study, we reported the complete chloroplast genome sequence of H. reticulata assembled from pair-end reads generated by Illumina sequencing. The circular chloroplast genome is 151,407 bp in length and comprises a large single copy region of 84,352 bp, a small single copy region of 19,733 bp, and a pair of inverted repeats of 23,661 bp each. The complete genome encodes 129 functional genes, including 83 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. The overall GC content of the chloroplast genome was 37.4%. Phylogenetic analysis showed that H. reticulata is sister to H. hainanensis with strong bootstrap support.

Vatica guangxiensis S.L. Mo is an evergreen large tree of Dipterocarpaceae. Herein, we assembled the complete chloroplast genome of Vatica guangxiensis by next-generation sequencing technologies. The complete chloroplast genome sequence of Vatica guangxiensis is 151,010 base pairs (bp) in length, including a pair of inverted repeat regions (IRs, 23,827 bp), one large single-copy region (LSC, 83,353 bp), one small single-copy region (SSC, 20,003 bp). Besides, the complete chloroplast genome contains 123 genes in total, including 83 protein-coding genes, 36 tRNA genes, and 8 rRNA genes. Phylogenetic analysis showed that Vatica guangxiensis has the closest relationship with Vatica mangachapoi. Our study lay a foundation for further research of Vatica mangachapoi.

Temperature, rainfall and extreme weather have been indicated to affect the phenological patterns and forest productivity by shifting flowering and fruiting seasons and patterns, as well as crop production. Dipterocarpaceae are high value trees for both timber and non-timber forest products. This study aims to determine the response of phenological patterns of flowering and fruiting of Dipterocarps to climate variables. The study was conducted at Way Canguk PHKA/WCSIP Research Station of the Bukit Barisan Selatan National Park (BBSNP), Lampung during May-November 2012 by analyzing 14 years (1998-2012) of phenological data of Dipterocarps. The phenology surveys were carried out on monthly basis by estimating the percentage of flowering, fruiting (divided into 0-4 scoring) and the crop production. The results indicated that the phenological patterns of Dipterocarps in the area depicted major and minor patterns without mass-flowering time, different from what have been reported for Kalimantan or North Sumatra. Minor peak flowering season showed regular flowering, particularly during March to July every year. However, there were major flowering seasons in November 2002 (20.2%), September 2006 (21%), and October-November 2011 (20.3%). Average monthly fruit production showed a peak at the end of the dry season. Major flowering season seemed to coincide with the period of major El Nino events in November 2002 and September 2006, while others associated with La Nina. This study suggest that phenology and climate change may have implications in designing strategies for collection of seed materials to support the conservation and plantation programs of the Dipterocarps.

Dryobalanops rappa Becc. and Shorea albida Sym. are Bornean endemics of high conservation value and increasingly threatened by anthropogenic disturbances. In-situ study of seedling abundance and growth performance of these Dipterocarp species was conducted in two selected peat swamp forests of Brunei Darussalam, following a mast fruiting event in March–May 2014. Within six 6 x 6 m plots at each forest site, D. rappa seedlings at the Anduki peat swamp forest and S. albida seedlings at the Badas peat swamp forest were measured for abundance at the initial census in September 2014, as well as survival and relative growth rates (RGR) after a period of 5 months, with the final census in February 2015. We found significantly higher seedling abundance for D. rappa (1885 ± 208) than S. albida (160 ± 71). Significantly higher percentage survival was recorded for D. rappa seedlings (90.8 ± 2.2%) in comparison to S. albida seedlings (81.7 ± 2.2%). S. albida seedlings (0.24 ± 0.02 mm mm-1 month-1) showed significantly greater RGR in stem diameter than D. rappa seedlings (0.18 ± 0.02 mm mm-1 month-1), however, there were no significant differences in the RGRs based on seedling height, leaf number and biomass between D. rappa and S. albida seedlings. In terms of seedling abundance and percentage survival, D. rappa seedlings appeared to be more successful in regeneration and may potentially be used for rehabilitation of degraded tropical peat swamps and other forest types. Our results suggested that greater conservation efforts of peat swamps must be made to protect the Bornean endemic plant species, in particular S. albida.

The role that mycorrhizal fungal associations play in the assembly of long-lived tree communities is poorly understood, especially in tropical forests, which have the highest tree diversity of any ecosystem. The lowland tropical rain forests of Southeast Asia are characterized by high levels of species richness within the family Dipterocarpaceae, the entirety of which has been shown to form obligate ectomycorrhizal (ECM) fungal associations. Differences in ECM assembly between co-occurring species of dipterocarp have been suggested, but never tested in adult trees, as a mechanism for maintaining the coexistence of closely related tree species in this family. Testing this hypothesis has proven difficult because the assembly of both dipterocarps and their ECM associates co-varies with the same edaphic variables. In this study, we used high-throughput DNA sequencing of soils and Sanger sequencing of root tips to evaluate how ECM fungi were structured within and across a clay–sand soil nutrient ecotone in a mixed-dipterocarp rain forest in Malaysian Borneo. We compared assembly patterns of ECM fungi in bulk soil to ECM root tips collected from three ecologically distinct species of dipterocarp. This design allowed us to test whether ECM fungi are more strongly structured by soil type or host specificity. As with previous studies of ECM fungi on this plot, we observed that clay vs. sand soil type strongly structured both the bulk soil and root tip ECM fungal communities. However, we also observed significantly different ECM communities associated with two of the three dipterocarp species evaluated on this plot. These results suggest that ECM fungal assembly on these species is shaped by a combination of biotic and abiotic factors, and that the soil edaphic niche occupied by different dipterocarp species may be mediated by distinct ECM fungal assemblages.

Vatica mangachapoi is a tree up to 20 m tall with white resinous. It is distributed in China (Hainan province), Indonesia, Malaysia (N Borneo), Philippines, Thailand, and Vietnam. It grows in forests on hills and mountain slopes below 700 metres. Its durable wood is used for making boats and building bridges and houses. It has been ranked as a VU (Vulnerable) species in China. Here we report and characterize the complete plastid genome sequence of V. mangachapoi in an effort to provide genomic resources useful for promoting its conservation and phylogenetic research. The complete plastome is 151,538 bp in length and contains the typical structure and gene content of angiosperm plastome, including two Inverted Repeat (IR) regions of 23,921 bp, a Large Single-Copy (LSC) region of 83,587 bp and a Small Single-Copy (SSC) region of 20,109 bp. The plastome contains 114 genes, consisting of 80 unique protein-coding genes, 30 unique tRNA gene, and 4 unique rRNA genes. The overall A/T content in the plastome of V. mangachapoi is 62.80%. The phylogenetic analysis indicated that V. mangachapoi and V. odorata is closely related and as an independent branch in Malvales in our study. The complete plastome sequence of V. mangachapoi will provide a useful resource for the conservation genetics of this species and for the phylogenetic studies for Vatica.

Unambiguous insertion-deletion events were previously identified in trnL intron of 110 species of subfamily Dipterocarpoideae (Dipterocarpaceae). These indels are associated with the formation of four stem loop structures and featuring characteristic for generic/infra-generic level depended upon which taxonomic classifications are followed. Phylogenetic analyses were performed by including and excluding these structures to examine the robustness of resulted topologies. Results indicated that inclusion of such structures yielded more resoved topologies, and that none of the stemloop structures were homoplasious. Results of this present study was also in agreement with the previous molecular phylogenetic studies that using several genes of cp genomes in that tribe Dipterocarpae was polyphyletic by the placement of all members of the genus Dipterocarpus within tribe Shoreae, and that tribe Shoreae was a potential monophyletic group. The phylogenetic relationships between variable genera of Hopea and Shorea was also in accordance to earlier studies that suggested a potential monophyly of the two with inclusion of Parashorea and Neobalanocapus heimii. Genera that were recived strong branch support (Dipterocarpus, Dryobalanops, Vatica, and Stemonoporus) possessed certains indels exclusive to each and this may contributed to the monophyletic nature of these genera.

Unambiguous insertion-deletion events were previously identified in trnL intron of 110 species of subfamily Dipterocarpoideae (Dipterocarpaceae). These indels are associated with the formation of four stem loop structures and featuring characteristic for generic/infra-generic level depended upon which taxonomic classifications are followed. Phylogenetic analyses were performed by including and excluding these structures to examine the robustness of resulted topologies. Results indicated that inclusion of such structures yielded more resoved topologies, and that none of the stemloop structures were homoplasious. Results of this present study was also in agreement with the previous molecular phylogenetic studies that using several genes of cp genomes in that tribe Dipterocarpae was polyphyletic by the placement of all members of the genus Dipterocarpus within tribe Shoreae, and that tribe Shoreae was a potential monophyletic group. The phylogenetic relationships between variable genera of Hopea and Shorea was also in accordance to earlier studies that suggested a potential monophyly of the two with inclusion of Parashorea and Neobalanocapus heimii. Genera that were recived strong branch support (Dipterocarpus, Dryobalanops, Vatica, and Stemonoporus) possessed certains indels exclusive to each and this may contributed to the monophyletic nature of these genera.

A new resveratrol dimer, acuminatol (1), was isolated along with five known compounds from the acetone extract of the stem bark of Shorea acuminata. Their structures and stereochemistry were determined by spectroscopic methods, which included the extensive use of 2D NMR techniques. All isolated compounds were evaluated for their antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (RSA) and the β-carotene-linoleic acid (BCLA) assays, and compared with those of the standards of ascorbic acid (AscA) and butylated hydroxytoluene (BHT). All compounds tested exhibited good to moderate antioxidant activity in the DPPH assay (IC50s 0.84 to 10.06 mM) and displayed strong inhibition of β-carotene oxidation (IC50s 0.10 to 0.22 mM). The isolated compounds were evaluated on the Vero cell line and were found to be non-cytotoxic with LC50 values between 161 to 830 µM.

Dipterocarpaceae are one of the economically most important native tree families for timber production in tropical Asia. We report the complete chloroplast genome of Vatica odorata (Griff.) Symington, the first in the family Dipterocarpaceae. The chloroplast genome was 151,465 bp in length, with a large single-copy (LSC) region of 83,538 bp and a small single-copy (SSC) region of 20,095 bp, separated by two inverted repeat (IRs) regions of 23,916 bp. It contained 126 genes, including 90 coding genes, 30 tRNA genes, and 8 rRNA genes. The overall GC content was 37.2%, and 43.1%, 35.2%, and 33.3% in the IRs, LSC and SSC regions, respectively. A phylogenetic tree showed Vatica accumulated more variation when compared with Tilia, and that internal relationships in Malvales need to be reassessed.

Tropical rain forests (TRF) are the most diverse terrestrial biome on Earth, but the diversification dynamics of their constituent growth forms remain largely unexplored. Climbing plants contribute significantly to species diversity and ecosystem processes in TRF. We investigate the broad-scale patterns and drivers of species richness as well as the diversification history of climbing and non-climbing palms (Arecaceae). We quantify to what extent macroecological diversity patterns are related to contemporary climate, forest canopy height and paleoclimatic changes. We test whether diversification rates are higher for climbing than non-climbing palms and estimate the origin of the climbing habit. Climbers account for 22% of global palm species diversity mostly concentrated in Southeast Asia. Global variation in climbing palm species richness can be partly explained by past and present-day climate and rain forest canopy height, but regional differences in residual species richness after accounting for current and past differences in environment suggest a strong role of historical contingencies in climbing palm diversification. Climbing palms show a higher net diversification rate than non-climbers. Diversification analysis of palms detected a diversification rate increase along the branches leading to the most species-rich clade of climbers. Ancestral character reconstructions revealed that the climbing habit originated between early Eocene and Miocene. These results imply that changes from non-climbing to climbing habit may have played an important role in palm diversification, resulting in the origin of one fifth of all palm species. We suggest that, in addition to current climate and paleoclimatic changes after the late Neogene, present-day diversity of climbing palms can be explained by morpho-anatomical innovations, the biogeographic history of Southeast Asia, and/or ecological opportunities due to the diversification of high-stature dipterocarps in Asian TRFs.

Deciduous dipterocarp forests across mainland Southeast Asia are dominated by two families: the Dipterocarpaceae and Fabaceae. Monsoon conditions produce strong seasonal climates with a hot dry season of 5–7 months extending from late November or early December through April or early May. Seasonal measurements of stomatal conductance and plant water potential found important differences between members of the two families. Despite their long dry season, Shorea siamensis and S. obtusa (Dipterocarpaceae) showed little significant patterns of seasonal change in xylem water potentials, with midday potentials never dropping below −1.3 MPa. These species present a classic example of isohydric strategies of adaptation where stomatal regulation maintains a relatively stable minimum water potential over the course of the year. However, maximum rates of stomatal conductance dropped sharply in the late dry season as the leaves heated in full sun without significant transpirational cooling, reaching as high as 44–45 °C, making them potentially sensitive to global increases in extreme temperature. The woody legumes Xylia kerrii and Dalbergia oliveri present different patterns of seasonal water relations and leaf response to high temperatures. The legumes exhibit anisohydric behavior where water potential decreases over the dry season as evaporative demand increases. Dry season midday water potentials dropped from high wet season levels to −2.4 to −3.2 MPa, moderately lowering maximum stomatal conductance. The relatively small leaflets of these legumes responded to the high temperatures of the late dry season by temporarily wilting, reducing their exposure to solar radiation and taking advantage of convective cooling. Large leaf size of dipterocarps in this community may not be an adaptive trait but rather an ancestral condition compensated for with ecophysiological adaptations.

The aim of the present study is to provide a basic knowledge in view of a better understanding of the global structure of threetropical forests at the Sakaerat Environmental Research Station (Pak Tong Chai district, Northeastern Thailand): a drydipterocarp forest (DDF), a dry evergreen forest (DEF) and an intermediate stage (DDFwf), characterized by the absence offire since 29 years in a pyro-climax. These forest ecosystems were contrasted by the composition and floristic structure, thebasal area and the tree density. The species richness increases with the passage from the DDF, the most open environment, to the DDFwf, the most densely wooded. By these tree density and basal area, the DDF (602 trees/ha at DBH ³ 5 cm, 14.2 m2/ha) and the DEF (992 trees/ha at DBH ³ 5 cm, 29.0 m2/ha) studied belong to the typical tropical ecosytems of southeast Asia. The man-made fires and anarchic forest exploitations are a danger for the stability of these different ecosystems.