102 research outputs found
The potential impacts of climate change on the distribution of Nepenthes and dipterocarps of the Trus Madi Forest Reserve
Publisher PD
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
Polyalthia montis-silam
Polyalthia montis-silam is restricted to Mount Silam area and Madai Hill in Lahad Datu district. The estimated area of occupancy (AOO) and extent of occurrence are 16 km2 and 47 km2, respectively. Due to land-use changes there has been an estimated decline of 20% in AOO. Fire is a potential threat that could drive this species to Critically Endangered or Extinct in the near future. Hence, it is assessed as Vulnerable. Polyalthia-montis-silam is endemic to Sabah, Malaysia. It was recorded from Lahad Datu district
Polyscias havilandii
Polyscias havilandii is a tree known from Mount Kinabalu and vicinity. The estimated extent of occurrence (EOO) and area of occupancy (AOO) are both 8 km2. Due to land use changes, a decline of at least 60% is inferred due to reductions in EOO and AOO over the past three generations (90 years). The remaining known individuals are within protected area (Kinabalu Park). Thus, it is assessed as Endangered. Polyscias havilandii is endemic to Sabah, Malaysia. This species is restricted to Kinabalu Park (Totally Protected Area)
Polyalthia lasioclada
Polyalthia lasioclada is restricted to the montane area in Kinabalu Park and Mensalong Forest Reserve, Sabah. The estimated area of occupancy (AOO) and extent of occurrence (EOO) are 16 km2 and 29 km2, respectively. Due to land use change, estimated past loss of the species' AOO and EOO has been about 20% and 22%, respectively. Decline has now ceased as the species is protected in situ in at least two Totally Protected Areas. However, the species is at risk from potential threats such as climate change and forest fire which if they occur could drastically change its conservation status to Critically Endangered or Extinct. Hence, it is assessed as Vulnerable. Polyalthia lasioclada is endemic to Sabah, Malaysia. It is only known from Mount Kinabalu and vicinity. It is estimated that at least 20% of the species' area of occupancy (AOO) and 22% of its extent of occurrence (EOO) has been lost (based on GeoCAT reduction analysis). However as the remaining individuals are in protected areas decline is not continuing. The species has a small remaining AOO and EOO of 16 km2 and 29 km2, respectively
Schefflera serpentinicola
Schefflera serpentinicola is only known from Wuluh river, Kinabalu Park. The estimated area of occupancy (AOO) and extent of occurrence (EOO) are both 4 km2. The most plausible threat that could affect this species is climate change, in the form of temperature extremes and droughts. If this was to occur it could rapidly drive the species towards Critically Endangered or Extinct within a short space of time. Hence it is assessed as Vulnerable. Schefflera serpentinicola is endemic to Sabah, Malaysia. It is only known from Wuluh river, Kinabalu Park
Timonius tambuyukonensis
Timonius kinabaluensis is only known from Ranau district, Sabah. The estimated area of occupancy (AOO) and extent of occurrence (EOO) are both 8 km2. The species is threatened by forest fire (Bukit hampuan forest reserve) with recurring fires occurring especially in the dry season. If these were to occur it could drive the species towards Critically Endangered or Extinct in the near future. Hence, it is assessed as Vulnerable. Timonius kinabaluensis is endemic to Sabah, Malaysia. It is restricted to the western and southern part of Kinabalu Park
Timonius kinabaluensis
Timonius kinabaluensis is only known from Ranau district, Sabah. The estimated area of occupancy (AOO) and extent of occurrence (EOO) are both 8 km2. The species is threatened by forest fire (Bukit hampuan forest reserve) with recurring fires occurring especially in the dry season. If these were to occur it could drive the species towards Critically Endangered or Extinct in the near future. Hence, it is assessed as Vulnerable. Timonius kinabaluensis is endemic to Sabah, Malaysia. It is restricted to the western and southern part of Kinabalu Park
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