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Introduction: Adventure tourism has become one of Malaysia's most attractive tourism demands, and mountain climbing is rapidly becoming a popular recreational sport. Exploring mountain adventures offers a dynamic experience, preserving this fascinating activity, yet the climbers are exposed to the risk of altitude sickness, such as Acute Mountain Sickness (AMS). This study aimed to evaluate the prevalence of AMS and investigate the effects of high-altitude sickness on the climber profile associated with climbing at Mount Kinabalu, Malaysia. Methods:. The Lake Louise acute mountain sickness LLS score questionnaire collected 95 climber's data at four different altitudes. SPO2 and Pulse rate was (PR) measured using a finger pulse oximeter. In a cohort study, AMS was measured on day one at 1866m (1st station), 3622m (2nd station), and day two at 3810m (3rd station), and 4095m (4th station). Results: At the altitude of 1866 (Timpohon Gate), the prevalence of AMS was 0%, 30% at 3622m (Laban Rata), 34.7% at 3810m (Sayat-Sayat), and 37.9% at 4095m (Low's Peak). The overall prevalence of AMS was 37.9% and the majority of AMS cases were moderate in severity and the LLS score is significant with Pulse Rate and peripheral capillary oxygen saturation (SPO2). Conclusion: Concisely, this finding has triggered a need for consideration from multi agencies to enhance mountaineering guidance, especially for beginners or inexperienced hikers, for a suitable package for climbing attempts to reduce the incidence of AMS among Mount Kinabalu climbers. [ABSTRACT FROM AUTHOR]

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Advances in understanding geographic patterns of life history variation depend on documentation of life history traits for species in poorly studied regions. In the tropics, most species have not had their life history traits described. We compared the reproductive biology of two closely related Muscicapids, the Bornean Whistling-Thrush (Myophonus borneensis) and the Bornean subspecies of the White-crowned Forktail (Enicurus leschenaulti borneensis), coexisting in Mount Kinabalu Park in Sabah, Malaysia. Both species specialize in riparian habitats, but whistling-thrushes are more adaptable to human presence and can be found nesting on and foraging around buildings, whereas forktails are more wary of humans. We located and monitored 77 forktail nests and 130 whistling-thrush nests from 2009 to 2020. Mean clutch size was 2.00 ± 0.04 for forktails and 1.89 ± 0.04 for whistling-thrushes. Mean egg mass at lay was 4.07 ± 0.04 g for forktails and 11.65 ± 0.12 g for whistling-thrushes. Forktail incubation period (17.0 ± 0.42 d) was slightly shorter than for whistling-thrush (18.6 ± 0.19 d), but both species had similar rates of incubation attentiveness. Nestling periods were much shorter for the forktail (15.89 ± 0.39 d) than the whistling-thrush (24.00 ± 0.20 d). The shorter nestling period was associated with faster growth and higher provisioning rates for forktails than whistling-thrushes. Whistling-thrushes are larger and better able to protect their nests from predation, yielding much lower daily nest predation rates (0.012 ± 0.002) than in forktails (0.042 ± 0.006). Indeed, whistling-thrushes were themselves predators of nestlings and eggs of other passerines, whereas forktails were not. The larger size and lower predation risk may explain the slower growth and development of whistling-thrushes. Both species are vulnerable to climate change and droughts because of their reliance on riparian habitats.

The genus Chassalia (Gentianales: Rubiaceae-Palicoureeae) in Borneo is revised based on a morphological survey of herbarium specimens using classical taxonomic methods. The tribal placement and probable paraphyly of Chassalia as currently delimited is reviewed. Previously, four described species of Chassalia were known from Borneo, with only one endemic species, Chassalia psychotriformis I.M.Turner nom. nov. (≡ Cephaelis psychotrioides Valeton). A key is given to the 18 species of the genus recognised from Borneo in this study. In total, 14 new species are described, all of them endemic to Borneo. These are: Chassalia atropurpurea T.Y.Yu sp. nov., Chassalia beamanii T.Y.Yu sp. nov., Chassalia calamus T.Y.Yu sp. nov., Chassalia chewii T.Y.Yu sp. nov., Chassalia involucrata T.Y.Yu sp. nov., Chassalia kinabaluensis T.Y.Yu sp. nov., Chassalia lancifolia T.Y.Yu sp. nov., Chassalia lancifolioides T.Y.Yu sp. nov., Chassalia longipes T.Y.Yu sp. nov., Chassalia macrocarpa T.Y.Yu sp. nov., Chassalia muluensis T.Y.Yu sp. nov., Chassalia muscicola T.Y.Yu sp. nov., Chassalia northiana T.Y.Yu sp. nov. and Chassalia ramosa T.Y.Yu sp. nov. Circumscriptions and discussions are given for all Bornean species recognised. A morphological glossary for Asian species of Chassalia is provided. Three separate species groups are recognised, the Chassalia curviflora and C. javanica groups, represented by a single species each in Borneo, and a new informal group, the ‘Involucrate group’, which is proposed and circumscribed to encompass the majority (16) of the Bornean species. Proposals for further work on Asian Chassalia are given.

Intra‐annual periodicity of canopy photosynthetic activity and leaf development has been documented in seasonal and weakly seasonal tropical forests in the Amazon and elsewhere. However, vegetative periodicity such as leaf flush and fall in apparently 'aseasonal' equatorial tropical forests has not been well documented. Moreover, causal drivers of the vegetative periodicity in those forests have not been identified largely because of the difficulty in performing manipulative experiments targeting whole forest ecosystem dynamics.Here we show a distinct annual seasonality in canopy dynamics using a Fourier analysis with a statistical significance test on the long‐term, fortnightly monitored dataset of leaf litterfall in nine evergreen tropical rain forests on Mount Kinabalu, Borneo. Statistically significant annual periodicity occurs across elevations and soil types in all years irrespective of the year‐to‐year climatic variability, suggesting that fluctuations in regional climate rather than local micro‐climatic, edaphic and/or biotic conditions cause the precise 1‐year periodicity.We examine climatic factors that have causative effects on the distinct 1‐year periodicity using the spectrum convergent cross mapping that we developed in the present study that can distinguish causal relationships from seasonality‐driven synchronization. According to the analysis, we find that mean daily air temperature is most strongly, causatively related to the 1‐year periodicity of leaf litterfall. However, knowledge on ecophysiolocial and molecular mechanisms underlying temperature‐control of tropical tree growth is limited and further studies are required to understand the detailed mechanisms.Synthesis. We suggest that intra‐annual temperature changes in association with the movement of the intertropical convergence zone cause the distinct annual vegetative periodicity. Because vegetative periodicity can be transmitted to the dynamics of higher trophic levels through a trophic cascade, interactions between vegetative periodicity and daily air temperature, not rainfall, would more strongly cause changes in the dynamics of equatorial tropical rain forests. Our results show that clear vegetative periodicity (i.e. annual seasonality) can be found in equatorial tropical rain forests under diverse local environments, and that air temperature is a more important factor than the other climate variables in the climate–forest ecosystem interactions. [ABSTRACT FROM AUTHOR]

Borneo has gone through dramatic changes in geology and topography from the early Eocene until the early Pliocene and experienced climatic cycling during the Pleistocene. However, how these changes have shaped the present-day patterns of high diversity and complex distribution are still poorly understood. In this study, we use integrative approaches by estimating phylogenetic relationships, divergence time, and current and past niche suitability for the Bornean endemic land snail genus Everettia to provide additional insight into the evolutionary history of this genus in northern Borneo in the light of the geological vicariance events and climatic fluctuations in the Pleistocene. Our results show that northern Borneo Everettia species belong to two deeply divergent lineages: one contains the species that inhabit high elevation at the central mountain range, while the other contains lowland species. Species diversification in these lineages has taken place before the Pliocene. Climate changes during the Pleistocene did not play a significant role in species diversification but could have shaped contemporary species distribution patterns. Our results also show that the species-rich highland habitats have acted as interglacial refugia for highland species. This study of a relatively sedentary invertebrate supports and enhances the growing understanding of the evolutionary history of Borneo. Species diversification in Everettia is caused by geological vicariance events between the early Miocene and the Pliocene, and the distribution patterns were subsequently determined by climatic fluctuations in the Pleistocene.

A new species, Asplenium alleniae, is described from high elevation habitats in Sabah (Malaysia) and Papua New Guinea. Previous phylogenetic analyses of chloroplast loci determined that A. alleniae was most closely related to A. pauperequitum from New Zealand. Asplenium alleniae differs from A. pauperequitum most obviously by the acuminate apices of its longer pinnae. The combination of pinnate fronds with few pairs of primary pinnae and dark red-brown axes distinguishes A. alleniae from superficially similar species of Asplenium in Malesia. Asplenium alleniae is provisionally assessed as Endangered. [ABSTRACT FROM AUTHOR]

Yang, Su Lan, Nor At'fina Ibrahim, Grazele Jenarun, and Houng Bang Liew. Incidence and determinants of acute mountain sickness in Mount Kinabalu, Malaysia. High Alt Med Biol. 21:265–272, 2020. Background: Acute mountain sickness (AMS) is the most common type of high-altitude sickness. The incidence of AMS varies by mountain location, trail characteristics, and study design. The lack of local epidemiology data has driven us to investigate the incidence and severity of AMS and its associated factors at Mount Kinabalu, Malaysia. Methods: A cohort study was conducted to collect data from climbers after days 1 (3272 m) and 2 (4095 m) of ascent. A self-administered questionnaire was used to explore climbers' demographic and climb characteristics, history of AMS, alcohol exposure, and AMS prevention measures. The Lake Louis score 2018 was used to assess the presence and severity of AMS (cutoff ≥3). Univariate and multivariable logistic regressions were performed to determine the factors associated with the development of AMS on day 2. Results: Data from 345 climbers were analyzed. The incidence of AMS was 23.9% (95% confidence interval [CI] 19.5%–28.7%) and 21.7% (95% CI 17.5%–26.3%) on days 1 and 2, respectively. The majority were mild cases. Experiencing AMS on day 1 (odds ratio [OR] = 12.88; 95% CI 6.71–24.75), alcohol consumption (OR = 3.73; 95% CI 1.66–8.39), receiving guide advice on day 1 (OR = 0.49; 95% CI 0.26–0.93), and age (OR = 0.96; 95% CI 0.93–0.99) were significant determinants of AMS at Mount Kinabalu. Gender, history of AMS, past exposure to high altitude, ascending time, water intake, acetazolamide use, physical fitness, pulse rate, and peripheral capillary oxygen saturation (SpO2) were not associated with AMS at Mount Kinabalu. Conclusion: Future analysis with age strata is required to ascertain the association of age with AMS. Our research has signposted a strong call for collaborative efforts to improve the provision of hiking advice and discourage alcohol sales to mitigate the risk of AMS among Mount Kinabalu climbers. [ABSTRACT FROM AUTHOR]

Psychological and physical conditions may influence the behaviour and satisfaction of mountaineers. This exploratory study aims to investigate the influence of spirituality and physical activity level on responsible behaviour and mountaineering satisfaction among mountaineers on Mount Kinabalu, Borneo. We surveyed all mountaineers at the base of Mount Kinabalu after the completion of their climb over a period of one month in 2013. A total of 916 mountaineers completed the questionnaires and we analysed the data using structural equation modelling. The findings indicated that spirituality positively influences both responsible mountaineering behaviour and satisfaction. A high physical activity level moderates both of these relationships. The study contributes to knowledge on the important roles of and physical activity level in influencing both responsible behaviour and satisfaction among mountaineers. It also provides theoretical, marketing and managerial contributions. [ABSTRACT FROM PUBLISHER]

On 5 June 2015, an earthquake of 6.0 magnitude rattled Malaysia's Sabah state. The epicentre was near Mount Kinabalu, and shockwaves spread across a wide area. Serious rockfalls on the mountain, one of Southeast Asia's highest peaks and a popular climbing spot, killed 18 climbers. A few days earlier, a group of Western male and female tourists had appeared on social media posing nude on the mountain. Local residents consider Mount Kinabalu sacred, and many of them believed the earthquake was caused by the actions of these tourists, who had angered the mountain's guardian spirits. In this article we examine the Monolibabou and Tumabur rituals conducted by the Lotud people, a Dusunic ethnic group living in Tuaran District, to appease the guardians of Mount Kinabalu. [ABSTRACT FROM AUTHOR]

Mount Kinabalu consists of granites at its core on the higher ground of the mountain, and is surrounded by sedimentary rocks of Trusmadi formations at its foot, with the occurrences of serpentinised ultrabasic rocks found between the granites and sedimentary rock at the elevation of 2000m to 2800m. The granite is sub-divided into hornblende granite, biotite granite and porphyritic granite. The porphyritic granite is found in a belt between serpentinite in the lower part and hornblende granite in the upper part of the mountain. A ground magnetic data acquisition was conducted in May 2013 along the tracks from Mesilau to the summit of Mount Kinabalu and from summit down at Timpohon gate. The processed magnetic data shows distinctive magnetic characteristics that correlate very well with three different rock formations of Mount Kinabalu. Large variations of total magnetic total field from 39400nT to 41700 nT (magnetic variation range of 2300nT) were observed within the serpentinised ultrabasic rocks. It is believed that this distinctive magnetic characteristic is due to occurrence of ferromagnetic minerals, which was formed as a result of serpentinisation of ultrabasic rock with the presence of water during deep seated hydrothermal activity. The total magnetic field within the granite zone decreased gradually from the edge of serpentinite to the hornblend granite near the summit with relatively smaller variations from 40900nT to 39990nT (magnetic variation range of 910nT), probably due to small percentage of magnetite in it. The Trusmadi sedimentary formation in lower altitudes was magnetically "stable", with the small magnetic variation from 40000nT to 40385 nT (magnetic variation range of 385nT). [ABSTRACT FROM AUTHOR]

We present reviews of the Sabah (Malaysia, on the island of Borneo) species of the following problematical genera of land snails (Mollusca, Gastropoda): Acmella and Anaglyphula (Caenogastropoda: Assimineidae); Ditropopsis (Caenogastropoda: Cyclophoridae); Microcystina (Pulmonata: Ariophantidae); Philalanka and Thysanota (Pulmonata: Endodontidae); Kaliella, Rahula, (Pulmonata: Euconulidae); Trochomorpha and Geotrochus (Pulmonata: Trochomorphidae). Next to this, we describe new species in previously revised genera, such as Diplommatina (Diplommatinidae); Georissa (Hydrocenidae); as well as some new species of genera not revised previously, such as Japonia (Cyclophoridae); Durgella and Dyakia (Ariophantidae); Amphidromus, and Trachia (Camaenidae); Paralaoma (Punctidae); Curvella (Subulinidae). All descriptions are based on the morphology of the shells. We distinguish the following 48 new species: Acmella cyrtoglyphe, A. umbilicata, A. ovoidea, A. nana, A. subcancellata, A. striata, and Anaglyphula sauroderma (Assimineidae); Ditropopsis davisoni, D. trachychilus, D. constricta, D. tyloacron, D. cincta, and Japonia anceps (Cyclophoridae); Diplommatina bidentata and D. tylocheilos (Diplommatinidae); Georissa leucococca and G. nephrostoma (Hydrocenidae); Durgella densestriata, Dyakia chlorosoma, Microcystina microrhynchus, M. callifera, M. striatula, M. planiuscula, and M. physotrochus (Ariophantidae); Amphidromus psephos and Trachia serpentinitica (Camaenidae); Philalanka tambunanensis, P. obscura, P. anomphala, P. rugulosa, and P. malimgunung (Endodontidae); Kaliella eurytrochus, K. sublaxa, K. phacomorpha, K. punctata, K. microsoma, Rahula delopleura, (Euconulidae); Paralaoma angusta (Punctidae); Curvella hadrotes (Subulinidae); Trochomorpha trachus, T. haptoderma, T. thelecoryphe, Geotrochus oedobasis, G. spilokeiria, G. scolops, G. kitteli, G. subscalaris, and G. meristorhachis (Trochomorphidae). [ABSTRACT FROM AUTHOR]

Tropical rain forests in SE Asia are well known for the occurrence of supra-annual synchronous reproductive events, masting. Answering the question how trees allocate carbon (C), nitrogen (N) and phosphorus (P) to such irregular but gregarious reproduction requires a long-term observation. We conducted a 10-year continuous monitoring of litterfall in eight tropical rain forests, which differ significantly in P (and N) availability on Mount Kinabalu, Borneo., Mean P concentration in reproductive organ litter decreased significantly with increasing P-use efficiency of net primary production (PUE), an index of P deficiency. Therefore, P in reproductive organ litter became diluted as the magnitude of P deficiency increased., Mean annual litterfall (kg ha−1 yr−1) of reproductive organs over the 10 years ranged from 128.5 to 730.9 across the eight forests. Long-term C allocation ratio to reproductive organs (i.e. C in reproductive organs per C in total litterfall) varied from 2.0% to 7.8% across the eight forests and did not relate with PUE, indicating that long-term C allocation ratio to reproduction was not controlled by the availability of the most critical soil nutrient., Long-term N allocation ratio to reproduction varied from 2.7% to 9.9% and significantly positively related with C allocation ratio. The quotient of N allocation ratio to C allocation ratio ranged from 1.1 to 1.4. Long-term P allocation ratio to reproduction varied from 9.8% to 16.4%. The quotient of P allocation ratio to C allocation ratio ranged from 1.6 to 5.0. Therefore, tropical trees allocated much greater proportion of P to reproduction than C and N over the 10 years. Moreover, trees disproportionately increased P allocation to reproduction with decreasing C allocation to reproduction. Trees adjusted P allocation relative to C allocation and maintained a narrow range of P allocation ratio to reproduction in the long run in each site., Synthesis. Reproduction in Bornean tropical rain forests costs more P than C and N. Our results suggest that reproductive events in these forests are regulated by P at the level of overall long-term mean. Understanding patterns and processes of reproductive events requires a long-term monitoring of nutrient dynamics. [ABSTRACT FROM AUTHOR]

Background and Aims Globally, conifer dominance is restricted to nutient-poor habitats in colder, drier or waterlogged environments, probably due to competition with angiosperms. Analysis of canopy structure is important for understanding the mechanism of plant coexistence in relation to competition for light. Most conifers are shade intolerant, and often have narrow, deep, conical crowns. In this study it is predicted that conifer-admixed forests have less distinct upper canopies and more undulating canopy surfaces than angiosperm-dominated forests. Methods By using a ground-based, portable light detection and ranging (LIDAR) system, canopy structure was quantified for old-growth evergreen rainforests with varying dominance of conifers along altitudinal gradients (200–3100 m a.s.l.) on tropical and sub-tropical mountains (Mount Kinabalu, Malaysian Borneo and Yakushima Island, Japan) that have different conifer floras. Key Results Conifers dominated at higher elevations on both mountains (Podocarpaceae and Araucariaceae on Kinabalu and Cupressaceae and Pinaceae on Yakushima), but conifer dominance also varied with soil/substrate conditions on Kinabalu. Conifer dominance was associated with the existence of large-diameter conifers. Forests with higher conifer dominance showed a canopy height profile (CHP) more skewed towards the understorey on both Kinabalu and Yakushima. In contrast, angiosperm-dominated forests had a CHP skewed towards upper canopy, except for lowland dipterocarp forests and a sub-alpine scrub dominated by small-leaved Leptospermum recurvum (Myrtaceae) on Kinabalu. Forests with a less dense upper canopy had more undulating outer canopy surfaces. Mixed conifer–angiosperm forests on Yakushima and dipterocarp forests on Kinabalu showed similar canopy structures. Conclusions The results generally supported the prediction, suggesting that lower growth of angiosperm trees (except L. recurvum on Kinabalu) in cold and nutrient-poor environments results in a sparser upper canopy, which allows shade-intolerant conifers to co-occur with angiosperm trees either as emergents or as codominants in the open canopy. [ABSTRACT FROM AUTHOR]

The species of the snail genus Everettia in the Malaysian state of Sabah are superficially similar and difficult to distinguish by their shells. This paper presents new data on the taxonomy and distribution of Everettia in Sabah that have accumulated since the revision by Godwin-Austen in 1891. By using morphological and molecular phylogenetic approaches, we reveal at least seventeen species of Everettia in Sabah, of which eleven are new to science, namely: Everettia layanglayang sp. nov., Everettia lapidini sp. nov., Everettia paulbasintali sp. nov., Everettia occidentalis sp. nov., Everettia jasilini sp. nov., Everettia safriei sp. nov., Everettia interior sp. nov., Everettia jucundior sp. nov., Everettia planispira sp. nov., Everettia monticola sp. nov., and Everettia dominiki sp. nov., and one new subspecies, namely, Everettia corrugata williamsi ssp. nov. Phylogenetic analysis of mitochondrial COI and 16S, and nuclear ITS-1 sequences demonstrates the monophyly of most of the morphologically well-defined species. Our results show that certain aspects of classical morphology-based taxonomy for Everettia species, especially with regard to the unique combination of shell surface sculptures, animal head colour, and mantle pigmentation, are solid. A dichotomous key to the Sabah species and subspecies of Everettia is provided. [ABSTRACT FROM AUTHOR]

We examined the basal area of two life forms (conifers vs. broadleaf trees) along elevational gradients on Yakushima Island, Japan and on two series of geological substrate on Mount Kinabalu, Borneo. On Yakushima, total stand basal area abruptly increased from 700 to 1,050 m in accordance with the high dominance of conifers, indicating the presence of additive basal area of conifers in conifer–broadleaf mixed forests at higher elevations (1,050–1,300 m). Along two substrate series on Kinabalu, some forests at higher elevations (1,860–3,080 m) showed relatively high dominance of conifers, but conifer basal area did not appear to be additive. Conifers were emergents above the canopy of broadleaf trees in mixed forests on Yakushima, but two life forms usually coexisted in the single-story canopy in mixed forests on Kinabalu. Litterfall rate as a surrogate of productivity decreased with decreasing temperature along elevation on both the sites, but the rate of decrease was slower on Yakushima, where mixed forests at higher elevations showed relatively high rates. Thus, we suggest that additive basal area of conifers was linked to their emergent status, and that it enhanced productivity by complementary use of light by two life forms that occupy different stories. On Yakushima, typhoons are a major disturbance, but do not severely limit the height growth of conifers, allowing the development of two-story mixed forests. On Kinabalu, a major disturbance is El Niño-driven drought, and hydraulic limitation to tree height may explain the non-additive and non-emergent nature of conifers. [ABSTRACT FROM AUTHOR]

The genus Menegazzia (Parmeliaceae, lichenized ascomycetes) in Malaysia and Indonesia is studied. Some specimens from Papua New Guinea are also included. The great majority of available specimens are from Kinabalu Park, State of Sabah, Malaysia. Three species are described as new to science, namely the two sorediate species M. capitata (from Sabah and Pahang in Malaysia) and M. sabahensis (from Sabah), and the fertile, primary species M. monospora (from Sabah and Papua New Guinea). M. asahinae, M. dissoluta, and M. efflorescens are reported for the first time from Malaysia, and M. subsimilis is reported for the first time from Malaysia and Indonesia. The subgenus Megamenegazzia is newly described to accommodate the large, broad-lobed species with numerous perforations on the lower surface. M. efflorescens is selected as the type species for the new subgenus. Notes are also provided on the type specimens of Hypogymnia pectinatula, a species originally considered as belonging to Menegazzia. [ABSTRACT FROM AUTHOR]

Aim We quantify the elevational patterns of species richness for all vascular plants and some functional and taxonomic groups on a regional scale on a tropical mountain and discuss some possible causes for the observed patterns. Location Mount Kinabalu, Sabah, Borneo. Methods A data base containing elevational information on more than 28,000 specimens was analysed for vascular plant distribution, taking into account sampling effort. The total species richness pattern was estimated per 300-m elevational interval by rarefaction analyses. The same methods were also applied to quantify species richness patterns of trees, epiphytes, and ferns. Results Total species richness has a humped relationship with elevation, and a maximum species richness in the interval between 900 and 1200 m. For ferns and epiphytes the maximum species richness is found at slightly higher elevations, whereas tree species did not have a statistically significant peak in richness above the lowest interval analysed. Main conclusions For the first time a rigorous estimate of an elevational pattern in species richness of the whole vascular plant flora of a tropical mountain has been quantified. The pattern observed depends on the group studied. We discuss the differences between the groups and compare the results with previous studies of elevational patterns of species richness from other tropical areas. We also discuss the methods used to quantify the richness pattern and conclude that rarefaction gives an appropriate estimate of the species richness pattern. [ABSTRACT FROM AUTHOR]

In situ photosynthetic nitrogen-use efficiency (PNUE, photosynthetic capacity per unit leaf nitrogen) was investigated in species that commonly distributed at different altitudes (600–3700 m above sea level) on Mount Kinabalu. Photosynthetic nitrogen-use efficiency was lower in species at higher altitudes, with a mean PNUE at 3700 m being one-third as large as that at 600 m. This difference in PNUE was larger than that explained by the biochemical response to lower air pressures only. Across altitudes a negative correlation between 13 C abundance (δ13 C) and PNUE was found. Species at higher altitudes tended to have higher δ13 C, suggesting that they had a lower conductance for CO2 diffusion from the air to chloroplasts. The lower conductance might be responsible for the lower PNUE in species at higher altitudes. Although leaf nitrogen content per unit area tended to be higher at higher altitudes, it did not seem to contribute to increasing photosynthetic rates. Thus, the idea that a higher nitrogen content at higher altitudes is a compensation for a lower PNUE was not supported. In contrast to the large difference in PNUE among altitudes, PNUE tended to converge within a narrow range among species growing at the same altitude. [ABSTRACT FROM AUTHOR]

Premise of the study: Nuclear microsatellite (simple sequence repeat [SSR]) markers were developed for the woody species Leptospermum recurvum found on Mount Kinabalu, Borneo, to facilitate investigation of the genetic structure and patterns of gene flow in relation to leaf phenotypic polymorphisms. Methods and Results: Eleven primer pairs were developed using the compound SSR marker technique. Ten of the 11 loci were polymorphic and their expected heterozygosity ranged from 0.04 to 0.83. Neither linkage disequilibrium nor departure from Hardy–Weinberg equilibrium were detected. All primer pairs also amplified the SSR loci of L. polygalifolium. Conclusions: These findings suggest the utility of these primers for investigating genetic structure and gene flow in L. recurvum and indicate their applicability to another species of Leptospermum.

Borneo has gone through dramatic changes in geology and topography from the early Eocene until the early Pliocene and experienced climatic cycling during the Pleistocene. However, how these changes have shaped the present-day patterns of high diversity and complex distribution are still poorly understood. In this study, we use integrative approaches by estimating phylogenetic relationships, divergence time, and current and past niche suitability for the Bornean endemic land snail genus Everettia to provide additional insight into the evolutionary history of this genus in northern Borneo in the light of the geological vicariance events and climatic fluctuations in the Pleistocene. Our results show that northern Borneo Everettia species belong to two deeply divergent lineages: one contains the species that inhabit high elevation at the central mountain range, while the other contains lowland species. Species diversification in these lineages has taken place before the Pliocene. Climate changes during the Pleistocene did not play a significant role in species diversification but could have shaped contemporary species distribution patterns. Our results also show that the species-rich highland habitats have acted as interglacial refugia for highland species. This study of a relatively sedentary invertebrate supports and enhances the growing understanding of the evolutionary history of Borneo. Species diversification in Everettia is caused by geological vicariance events between the early Miocene and the Pliocene, and the distribution patterns were subsequently determined by climatic fluctuations in the Pleistocene., Competing Interests: The authors declare that they have no competing interests. Jaap Jan Vermeulen is employed by JK Art and Science which is a science illustrator company., (© 2020 Liew et al.)