Genetic Variation and Genetic Structure of Two Closely Related Dipterocarp Species, Dryobalanops aromatica C.F. Gaertn. and D. beccarii Dyer

Large-scale genetic structure revealed in tree populations in SE Asia, as well as in many temperate forests, has been shaped by climatic fluctuation in the late Pleistocene, most importantly by that in the last glacial period. In a comparative study of the phylogeographic patterns of two closely related dipterocarp species, Dryobalanops aromatica C.F.Gaertn. and D. beccarii Dyer, we investigated how changes in land area associated with changes in climate affected large-scale genetic structure. We examined the genetic variation of D. aromatica, collected from nine populations throughout the Sundaic region, and of D. beccarii, collected from 16 populations mainly in Borneo, using seven polymorphic microsatellite markers. The two species were clearly distinguishable in the STRUCTURE analysis, although hybridisation probably occurred in sympatric populations and also in several other populations. The D. aromatica populations were divided into two main groups by the STRUCTURE analysis: Malay–Sumatra and Borneo. Mixing of the Sumatra and Borneo clusters occurred on the Malay Peninsula, supporting the hypothesis that tropical rainforests expanded over a dried Sunda Shelf during the last glacial period. The two main genetic clusters might have been formed by repeated cycles of fluctuation in land area. The D. beccarii populations in Borneo were divided into four geographically distinct groups: western Sarawak, central inland Sarawak, central coastal Sarawak and Sabah. The population on the Malay Peninsula (Gunung Panti) was an admixture of the four Bornean clusters. This suggests that this population is a relic of the recent range expansion of D. beccarii during the last glacial period

Population Genetic Diversity in The Genus Dryobalanops Gaertn. f. (Dipterocarpaceae) Based on Nuclear Microsatellite Markers

Abstract The genus Dryobalanops Gaertn. f. is a small but important genus that contains seven species and is found in the Southeast Asian tropical rain forests. Seven polymorphic nuclear microsatellite markers were analyzed in 46 natural populations of six extant Dryobalanops species (N = 700 individuals) covering the distribution range in Western Malesia. The mean gene diversity at the species level ranged from 0.392 in D. rappa to 0.635 in D. aromatica. The F ST value ranged from 0.156 in D. keithii to 0.283 in D. beccarii and all F ST values were highly significantly greater than zero. These results suggest that gene flow between populations has been limited and intensive genetic drift has occurred in all of the species. Plants with narrowly distributed species such as D. keithii and D. rappa, which are endemic to Borneo, tend to have lower levels of genetic diversity compared with widespread species such as D. aromatica. STRUCTURE analysis revealed that at least two of the six species could be effectively discriminated each other. The results of this study will be helpful for building effective conservation schemes as well as for providing basic data for future provenance trials of Dryobalanops species

New and little-known myrmecophytic associations from Bornean rain forests

The woody climber Millettia niuewenhuisii (Fabaceae) and the shrub Myrmeconauclea strigosa (Rubiaceae) in Sabah, Borneo are associated with ants. The hollow stems of Millettia nieuwenhuisii are regularly inhabited by an aggressive Cladomyrma sp., which keeps pseudococcids inside the stem. On Myrmeconauclea strigosa the ants live in hollow internodal swellings near the end of the branches. In this plant many different ant species use the nesting space in an opportunistic manner

Treating acute hypertensive cardiogenic pulmonary edema with high-dose nitroglycerin

Acute pulmonary edema due to sympathetic surge and increased peripheral vascular resistance often present to the emergency department (ED) with markedly elevated blood pressure, severe dyspnea, and desaturation. This condition is known as “SCAPE” (sympathetic crashing acute pulmonary edema). We present three SCAPE patients who were successfully treated with high-dose nitroglycerin (NTG) and bilevel positive airway pressure (BiPAP) ventilation. All three patients presented with respiratory failure on arrival but rapidly improved after treatment and did not require endotracheal intubation or admission to the intensive care unit (ICU). SCAPE patients usually present to the ED with extreme respiratory distress associated with diaphoresis, restlessness, and high blood pressure. Emergency physicians must know how to manage SCAPE with high-dose nitrates and NIPPV (noninvasive positive pressure ventilation) because, when treated promptly, one will not only save a life but also obviate the need for endotracheal intubation and ICU admission. Keywords: Pulmonary edema, Nitroglycerin, Emergency departmen

Co-benefits of sustainable forest management in biodiversity conservation and carbon sequestration.

BACKGROUND: Sustainable forest management (SFM), which has been recently introduced to tropical natural production forests, is beneficial in maintaining timber resources, but information about the co-benefits for biodiversity conservation and carbon sequestration is currently lacking. METHODOLOGY/PRINCIPAL FINDINGS: We estimated the diversity of medium to large-bodied forest-dwelling vertebrates using a heat-sensor camera trapping system and the amount of above-ground, fine-roots, and soil organic carbon by a combination of ground surveys and aerial-imagery interpretations. This research was undertaken both in SFM applied as well as conventionally logged production forests in Sabah, Malaysian Borneo. Our carbon estimation revealed that the application of SFM resulted in a net gain of 54 Mg C ha(-1) on a landscape scale. Overall vertebrate diversity was greater in the SFM applied forest than in the conventionally logged forest. Specifically, several vertebrate species (6 out of recorded 36 species) showed higher frequency in the SFM applied forest than in the conventionally logged forest. CONCLUSIONS/SIGNIFICANCE: The application of SFM to degraded natural production forests could result in greater diversity and abundance of vertebrate species as well as increasing carbon storage in the tropical rain forest ecosystems