New records of florivory on dipterocarp flowers

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The morphology and exine ornamentation of fresh pollen from four dipterocarp species in Sabah

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The potential impacts of climate change on the distribution of Nepenthes and dipterocarps of the Trus Madi Forest Reserve

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Are patterns of fine-scale spatial genetic structure consistent between sites within tropical tree species?

JRS was funded by the Swiss National Science Foundation (SNF) (http://www.snf.ch/en/Pages/default.aspx) grant number PDFMP3_132479 / 1 awarded to JG. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Genetic diversity affects seedling survival but not growth or seed germination in the Bornean endemic dipterocarp Parashorea tomentella

Background: Logging and habitat fragmentation of tropical rain forests may disrupt patterns of gene flow and genetic diversity. Consequently, inbreeding in tree populations may reduce fitness and increase extinction risks, especially among species that are predominantly outcrossing, dependent on biotic pollination and/or display limited seed dispersal such as species of the Dipterocarpaceae. Aims: To test the hypothesis that heterozygosity of individual progeny affects their likelihood of germination and the growth and survival of seedlings. Methods: Standardised measure of multilocus heterozygosity (sMLH) was estimated from seven microsatellite loci for individual progeny collected from 18 mother trees of the large dipterocarp Parashorea tomentella. The relationships among sMLH, germination and seedling growth and survival were determined for the progeny. Results: Seedling survival over 18 months increased with greater sMLH and fresh fruit weight. This result was expressed under all experimentally controlled combinations of light and nutrient availability in the nursery and in the shaded understorey of primary forest where survival overall was much lower than in the nursery. sMLH did not affect the probability of germination or seedling growth rate in any experimental treatment. Conclusions: These results provide evidence that reduced heterozygosity is associated with reduced seedling survival in a tropical forest tree species

Impacts of an extreme precipitation event on dipterocarp mortality and habitat filtering in a Bornean tropical rainforest

The frequency of extreme precipitation events is predicted to increase in some tropical regions in response to global climate change, but the impacts of this form of disturbance on the structure and dynamics of tropical tree communities across heterogeneous landscapes remain understudied. We determined the effects of an extreme precipitation event (EPE) in July 2006 on mortality of dipterocarps on a 68 ha permanent inventory plot in Sepilok Forest Reserve, Sabah. For stems ≥30 cm dbh, 12 of the 15 species of Dipterocarpaceae on this plot have significant positive and/or negative associations to habitats defined by topography and soil type. Short-term mortality induced by the EPE was much greater for individuals growing on the alluvial floodplain (13.7%) than in the mudstone (1.4%) or sandstone (0.0%) habitats, but mortality of dipterocarps did not differ among these habitats in the subsequent 5-yr interval. The likelihood of mortality in response to the EPE was highest for a small group of fast growing dipterocarps that possess low wood density and a strong association to the alluvial forest habitat. This group of species represents a high percentage of dipterocarp individuals but a low proportion of dipterocarp diversity in this habitat. We conclude that disturbance induced by high rainfall events contributes to the episodic nature of tropical forest dynamics, and that increases in the frequency of these events would disproportionately impact low-lying alluvial forest environments and some of the species growing in them

Conservation assessment and spatial distribution of endemic orchids in Sabah, Borneo

Orchids are among the most threatened plants due to habitat loss and illegal harvesting for horticultural demands. Sabah is a centre of orchid diversity, with approximately 1300 species of which 250 orchid taxa are endemic to Sabah. In this study, we conducted an IUCN Red List assessment on 136 endemic species and used Maximum Entropy (MaxEnt) to develop species distribution models for 47 species. The species distribution models were developed using presence-only data and six environmental predictors. The accuracy of the models were assessed using the area under the curve (AUC) and models with an AUC of higher than 0.8 stacked together to produce a species richness heatmap. We found that 83% of the researched species were threatened, of which 14 species were assessed to be Critically Endangered, eight species as Endangered and 93 species as Vulnerable. The heatmap shows that all of the species occurred within the Totally Protected Area (TPA) network in western Sabah. The heatmap highlighted the mid-altitude areas adjacent to the Kinabalu and Crocker Range parks and Ulu Sipitang regions as areas with a high species richness that were outside the TPA network. These areas are also important for the conservation of the majority of the species assessed as Critically Endangered and Endangered. Urgent conservation actions are needed to protect these species from extinction. The results from this work will be used as part of an intensive conservation action plan for threatened endemic orchids of Sabah and used to identify important plant areas currently not within the existing TPA networ

Incorporating connectivity into conservation planning for the optimal representation of multiple species and ecosystem services

Funding was provided by the Rainforest Trust foundation. Support was also provided by the Sabah Forest Department, Forest Research Centre, the South East Asia Rainforest Research Partnership, the U.N. Development Programme, the Universiti Malaysia Sabah (FRGS0414-STWN-1/2015), PACOS Trust, BC Initiative, the Natural Environment Research Council UK (grant NE/R009597/1), and the Universities of Aberdeen, Montana, and York. We are grateful to the numerous researchers that collected the data used in our analyses, as well as the local communities and government staff who manage forested areas across Sabah.Peer reviewedPostprin

Ecological implications of a flower size/number trade-off in tropical forest trees

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