David Tng
The School for Field Studies, Center for Rainforest Studies, Department Member
- UFBA - Federal University of Bahia, IBIO Institute of Biology, Faculty Memberadd
- I am a plant ecologist and biologist and my professional goals are centered around the functional ecology and biodiversity of rain forests and related ecosystems. To test my research questions, I adopt a combination of macroecological, ecophysiological and anatomical approaches. My outreach involves publishing in peer-reviewed scientific journals and also in popular articles and various social media.edit
Background: Understanding patterns in traditional plant use knowledge is crucial for assisting policy making with regard to nature conservation, human nutrition, human health, as well as educational and participatory processes in... more
Background: Understanding patterns in traditional plant use knowledge is crucial for assisting policy making with regard to nature conservation, human nutrition, human health, as well as educational and participatory processes in traditional communities. We aim to document and describe local ethnobotanical knowledge and test the hypothesis that gender structures the knowledge of plant use possessed by artisanal fishers in a fishing community in northeast Bahia, Brazil.
Litsea Lam. is an ecological and economic important genus of the "core Lauraceae" group in the Lauraceae. The few studies to date on the comparative chloroplast genomics and phylogenomics of Litsea have been conducted as part of other... more
Litsea Lam. is an ecological and economic important genus of the "core Lauraceae" group in the Lauraceae. The few studies to date on the comparative chloroplast genomics and phylogenomics of Litsea have been conducted as part of other studies on the Lauraceae. Here, we sequenced the whole chloroplast genome sequence of Litsea auriculata, an endangered tree endemic to eastern China, and compared this with previously published chloroplast genome sequences of 11 other Litsea species. The chloroplast genomes of the 12 Litsea species ranged from 152,132 (L. szemaois) to 154,011 bp (L. garrettii) and exhibited a typical quadripartite structure with conserved genome arrangement and content, with length variations in the inverted repeat regions (IRs). No codon usage preferences were detected within the 30 codons used in the chloroplast genomes, indicating a conserved evolution model for the genus. Ten intergenic spacers (psbE-petL, trnH-psbA, petA-psbJ, ndhF-rpl32, ycf4-cemA, rpl32-trnL, ndhG-ndhI, psbC-trnS, trnE-trnT, and psbM-trnD) and five protein coding genes (ndhD, matK, ccsA, ycf1, and ndhF) were identified as divergence hotspot regions and DNA barcodes of Litsea species. In total, 876 chloroplast microsatellites were located within the 12 chloroplast genomes. Phylogenetic analyses conducted using the 51 additional complete chloroplast genomes of "core Lauraceae" species demonstrated that the 12 Litsea species grouped into four sub-clades within the Laurus-Neolitsea clade, and that Litsea is polyphyletic and closely related to the genera Lindera and Laurus. Our phylogeny strongly supported the monophyly of the following three clades (Laurus-Neolitsea, Cinnamomum-Ocotea, and Machilus-Persea) among the above investigated "core Lauraceae" species. Overall, our study highlighted the taxonomic utility of chloroplast genomes in Litsea, and the genetic markers identified here will facilitate future studies on the evolution, conservation, population genetics, and phylogeography of L. auriculata and other Litsea species.
Research Interests:
The genus Elaeocarpus is the largest genus in the family Elaeocarpaceae, comprising more than 350 species of trees and shrubs with a mainly Indo-Pacific distribution. Approximately 28 species in the genus, including nine species from... more
The genus Elaeocarpus is the largest genus in the family Elaeocarpaceae, comprising more than 350 species of trees and shrubs with a mainly Indo-Pacific distribution. Approximately 28 species in the genus, including nine species from Australia, are known to possess ruminate endosperm. To provide a basis for understanding fruit development and endosperm rumination in the genus and, therefore, its taxonomic and evolutionary significance, we studied the fruit anatomy of Elaeocarpus ruminatus F.Muell. at different developmental phases (petal-fall to maturity). We found lignin in pericarp and ovary wall tissues in the earliest stages of development. In contrast, endosperm rumination occurs only after fruits have fully expanded, and becomes more pronounced as fruits ripen. Its phylogenetic distribution suggests that ruminate endosperm is a derived, albeit homoplasious character in Elaeocarpus. Comparative studies on related species will be instructive in determining the utility of ruminate endosperm for informing infra-generic taxonomy of the genus, and gaining insight into its adaptive significance.
Research Interests:
Increased drought is forecasted for tropical regions, with severe implications for the health and function of forest ecosystems. How mature forest trees will respond to water deficit is poorly known. We investigated wood anatomy and leaf... more
Increased drought is forecasted for tropical regions, with severe implications for the health and function of forest ecosystems. How mature forest trees will respond to water deficit is poorly known. We investigated wood anatomy and leaf traits in lowland tropical forest trees after 24 months of experimental rainfall exclusion. Sampling sun‐exposed young canopy branches from target species, we found species‐specific systematic variation in hydraulic‐related wood anatomy and leaf traits in response to drought stress. Relative to controls, drought‐affected individuals of different tree species variously exhibited trait measures consistent with increasing hydraulic safety. These included narrower or less vessels, reduced vessel groupings, lower theoretical water conductivities, less water storage tissue and more abundant fiber in their wood, and more occluded vessels. Drought-affected individuals also had thinner leaves, and more negative pre‐dawn or mid‐day leaf water potentials. Future studies examining both wood and leaf hydraulic traits should improve the representation of plant hydraulics within terrestrial ecosystem and biosphere models, and help finetune predictions of how future climate changes will affect tropical forests globally.