Papers by Yongyut Trisurat
HortScience: a publication of the American Society for Horticultural Science
... Trisurat. Department of Forest Biology, Kasetsart University, 50 Pahonyothin Road, Bangkok 10... more ... Trisurat. Department of Forest Biology, Kasetsart University, 50 Pahonyothin Road, Bangkok 10900, Thailand. Ladawan Puangchit. Department of Silviculture, Kasetsart University, 50 Pahonyothin Road, Bangkok 10900, Thailand. ...
Journal of Geological Resource and Engineering, 2015
The Raffles bulletin of zoology
The rufous-necked hornbill, Aceros nipalensis (Hodgson, 1829), is listed as vulnerable and is fou... more The rufous-necked hornbill, Aceros nipalensis (Hodgson, 1829), is listed as vulnerable and is found only in the Western Forest Complex. The objectives of this research were: 1) to estimate the geographical distribution for the rufous-necked hornbill at the Thung Yai-Huai Kha Khaeng World Heritage Site in both the breeding and non-breeding seasons; and 2) to determine seasonal changes in its habitat use. We collated the occurrence records of the rufous-necked hornbill from long-term monitoring data and conducted additional surveys during 2004–2008. In addition, spatial layers for potential environmental variables that might affect hornbill distribution were developed and Maximum Entropy (MaxEnt) modelling technique was used to generate potential distributions. The results indicated that MaxEnt models performed very well and the overall accuracies of the predicted maps in breeding and non-breeding seasons derived from the contingency matrix were 81% and 85% respectively. In addition, ...
Wildlife Research, 2014
Context. Tropical ecosystems are widely recognised for their high species richness and outstandin... more Context. Tropical ecosystems are widely recognised for their high species richness and outstanding concentrations of rare and endemic species. Previous studies either focussed on the effects of deforestation or climate change, whereas studies on the combined effects of these two major threats are limited.
Perspectives and Applications, 2011
Wildlife Research, 2010
... including tiger (Panthera tigris), Asian elephant (Elephas maximus), gaur (Bos gaurus), bante... more ... including tiger (Panthera tigris), Asian elephant (Elephas maximus), gaur (Bos gaurus), banteng (Bos javanicus), tapir (Tapirus indicus), great hornbill (Buceros ... According to Lekakul and McNeely (1977), tiger is found across a wide range of habitat types and occupies a large ...
Perspectives and Applications, 2011
... Land Use and Biodiversity in Northern Thailand (pages 199-218). Yongyut Trisurat (Kasetsart U... more ... Land Use and Biodiversity in Northern Thailand (pages 199-218). Yongyut Trisurat (Kasetsart University, Thailand), Rob Alkemade (PBL ... N. Raes (Leiden University, The Netherlands), JAN Parnell (Trinity College Dublin, Ireland), DA Simpson (Royal Botanical Gardens, UK), C ...
Perspectives and Applications, 2011
... Land Use and Biodiversity in Northern Thailand (pages 199-218). Yongyut Trisurat (Kasetsart U... more ... Land Use and Biodiversity in Northern Thailand (pages 199-218). Yongyut Trisurat (Kasetsart University, Thailand), Rob Alkemade (PBL ... N. Raes (Leiden University, The Netherlands), JAN Parnell (Trinity College Dublin, Ireland), DA Simpson (Royal Botanical Gardens, UK), C ...
Journal of Ecology
The objectives of this research were to predict land-use/land-cover change at the Sakaerat Enviro... more The objectives of this research were to predict land-use/land-cover change at the Sakaerat Environmental Research Station (SERS) and to analyze its consequences on the distribution for Black-crested Bulbul (Pycnonotus melanicterus), which is a popular species for bird-watching activity. The Dyna-CLUE model was used to determine land-use allocation between 2008 and 2020 under two scenarios. Trend scenario was a continuation of recent land-use change (2002)(2003)(2004)(2005)(2006)(2007)(2008), while the integrated land-use management scenario aimed to protect 45% of study area under intact forest, rehabilitated forest and reforestation for renewable energy. The maximum entropy model (Maxent), Geographic Information System (GIS) and FRAGSTATS package were used to predict bird occurrence and assess landscape fragmentation indices, respectively. The results revealed that parts of secondary growth, agriculture areas and dry dipterocarp forest close to road networks would be converted to other land use classes, especially eucalyptus plantation. Distance to dry evergreen forest, distance to secondary growth and distance to road were important factors for Black-crested Bulbul distribution because this species prefers to inhabit ecotones between dense forest and open woodland. The predicted for occurrence of Black-crested Bulbul in 2008 covers an area of 3,802 ha and relatively reduces to 3,342 ha in 2020 for trend scenario and to 3,627 ha for integrated-land use management scenario. However, intact habitats would be severely fragmented, which can be noticed by total habitat area, largest patch index and total core area indices, especially under the trend scenario. These consequences are likely to diminish the recreation and education values of the SERS to the public.
Climate change is a global threat to biodiversity because it has the potential to cause significa... more Climate change is a global threat to biodiversity because it has the potential to cause significant impacts on the distribution of species and the composition of habitats. The objective of this research is to evaluate the consequence of climate change in distribution of forest tree species, both deciduous and evergreen species. We extracted the HadCM3 A2 climate change scenario (regionally-oriented economic development) for the year 2050 in northern Thailand. A machine learning algorithm based on maximum entropy theory (MAXENT) was employed to generate ecological niche models of forest plants. Six evergreen species and 16 deciduous species were selected using the criteria developed by the Asia Pacific Forest Genetic Resources Programme (APFORGEN) for genetic resources conservation and management. Species occurrences were obtained from the Department of National Park, Wildlife and Plant Conservation. The accuracy of each ecological niche model was assessed using the area under curve of a receiver operating characteristic (ROC) curve. The results show that the total extent of occurrence of all selected plant species is not substantially different between current and predicted climate change conditions. However, their spatial configuration and turnover rate are high, especially evergreen tree species. Ten plant species will loss their ecological niches (suitable locations) ranging from 2 -13%, while the remaining 12 species will gain substantial suitable habitats. The assemblages of evergreen species or species richness are likely to shift toward the north where low temperature is anticipated for year 2050. In contrast, the deciduous species will expand their distribution ranges. Based on the IUCN Red List criteria, 10 plant species will be categorized as near threatened (NT) and 12 species will be listed as concerned status. An important point is that species distribution models were found to depend significantly on extreme climate variables such as minimum temperature of coldest months, and precipitation of driest and coldest quarters.
Oryx, 2013
Many hornbill species in Thailand are categorized as Endangered or Critically Endangered on the I... more Many hornbill species in Thailand are categorized as Endangered or Critically Endangered on the IUCN Red List. The objectives of this research were to predict hornbill distributions in Thailand and to assess the national conservation status of the species using extent of occurrence. We employed maximum entropy modelling, using 10 environmental variables that were believed to directly or indirectly influence hornbill distributions across Thailand, to predict the habitats potentially suitable for 10 of the country's 13 hornbill species. Data on the presence of hornbills were gathered from the Thailand Hornbill Project and additional field surveys in protected area complexes during 2004-2006. The results indicated that patch size is the most important factor affecting distribution, followed by latitude, ecoregion and distance to villages. All hornbill species were predicted to occur primarily in intact protected area complexes. The total extent of all hornbill habitats covers 9.3% of the country's land area. Seven of the 10 modelled species are at risk and the current distribution pattern is expected to reflect stochastic extinctions because of small population size. We recommend that the conservation status of Austen's brown hornbill Anorrhinus austeni and Tickell's brown hornbill Anorrhinus tickelli should be changed from Vulnerable to Endangered. The model identified five protected area complexes as hornbill hotspots in Thailand. These findings will help guide conservation management.
Journal for Nature Conservation, 2012
ABSTRACT
Environmental Management, 2010
Rapid deforestation has occurred in northern Thailand over the last few decades and it is expecte... more Rapid deforestation has occurred in northern Thailand over the last few decades and it is expected to continue. The government has implemented conservation policies aimed at maintaining forest cover of 50% or more and promoting agribusiness, forestry, and tourism development in the region. The goal of this paper was to analyze the likely effects of various directions of development on the region. Specific objectives were (1) to forecast land-use change and land-use patterns across the region based on three scenarios, (2) to analyze the consequences for biodiversity, and (3) to identify areas most susceptible to future deforestation and high biodiversity loss. The study combined a dynamic land-use change model (Dyna-CLUE) with a model for biodiversity assessment (GLOBIO3). The Dyna-CLUE model was used to determine the spatial patterns of land-use change for the three scenarios. The methodology developed for the Global Biodiversity Assessment Model framework (GLOBIO 3) was used to estimate biodiversity intactness expressed as the remaining relative mean species abundance (MSA) of the original species relative to their abundance in the primary vegetation. The results revealed that forest cover in 2050 would mainly persist in the west and upper north of the region, which is rugged and not easily accessible. In contrast, the highest deforestation was expected to occur in the lower north. MSA values decreased from 0.52 in 2002 to 0.45, 0.46, and 0.48, respectively, for the three scenarios in 2050. In addition, the estimated area with a high threat to biodiversity (an MSA decrease [0.5) derived from the simulated land-use maps in 2050 was approximately 2.8% of the region for the trend scenario. In contrast, the high-threat areas covered 1.6 and 0.3% of the region for the integratedmanagement and conservation-oriented scenarios, respectively. Based on the model outcomes, conservation measures were recommended to minimize the impacts of deforestation on biodiversity. The model results indicated that only establishing a fixed percentage of forest was not efficient in conserving biodiversity. Measures aimed at the conservation of locations with high biodiversity values, limited fragmentation, and careful consideration of road expansion in pristine forest areas may be more efficient to achieve biodiversity conservation.
Applied Geography, 2011
The objective of this research study was to evaluate the consequences of climate change on shifts... more The objective of this research study was to evaluate the consequences of climate change on shifts in distributions of plant species and the vulnerability of the species in Peninsular Thailand. A sub-scene of the predicted climate in the year 2100, under the B2a scenario of the Hadley Centre Coupled Model, version 3 (HadCM3), was extracted and calibrated with topographic variables. A machine learning algorithm based on the maximum entropy theory (Maxent) was employed to generate ecological niche models of 66 forest plant species from 22 families. The results of the study showed that altitude was a significant factor for calibrating all 19 bioclimatic variables. According to the global climate data, the temperature in Peninsular Thailand will increase from 26.6 C in 2008 to 28.7 C in 2100, while the annual precipitation will decrease from 2253 mm to 2075 mm during the same period. Currently, nine species have suitable distribution ranges in more than 15% of the region, 20 species have suitable ecological niches in less than 10% while the ecological niches of many Dipterocarpus species cover less than 1% of the region. The number of trees gaining or losing climatically suitable areas is quite similar. However, 10 species have a turnover rate greater than 30% of the current distribution range and the status of several species will in 2100 be listed as threatened. Species hotspots are mainly located in large, intact protected forest complexes. However, several landscape indices indicated that the integrity of species hotspots in 2100 will deteriorate significantly due to the predicted climate change.
tropicalforest.ch
... Paul PK Chai *1, Tonny Soehartono*2, Penguang Manggil*3 ... At the government level, protecti... more ... Paul PK Chai *1, Tonny Soehartono*2, Penguang Manggil*3 ... At the government level, protection of the TBCA as a joint watershed and catchment area can form another common bond to ensure that the populations in both countries will continue to enjoy good quality of life and ...
Extension and research interests: Integrating three aspects of the human dimensions of natural re... more Extension and research interests: Integrating three aspects of the human dimensions of natural resources sustainability: Sustainable living education to help individuals and families make intelligent, thoughtful quality of life and consumer choices about natural resources; Public engagement to better understand the public's natural resource values and beliefs systems; and Collaborative public processes that move people from conflict and promote direct and meaningful natural resources decision-making. http://www. forestry. oregonstate ...
Biological Conservation, 2011
Shorebirds are declining worldwide due to loss and degradation of critical breeding and wintering... more Shorebirds are declining worldwide due to loss and degradation of critical breeding and wintering habitats. Some human-modified habitats, particularly salt-pans which are used by shorebirds in many regions of the world, may help substitute for natural habitats lost for a wide range of species during migration. We studied the influence of landscape characteristics on species richness, abundance, and diversity of shorebirds at 20 sites covering most of the Inner Gulf of Thailand, a landscape with a long history of salt farming. Sites with salt-pans present held significantly higher species richness, abundance and diversity of shorebirds. Areas with larger proportions given over to aquaculture tended to have lower species richness, abundance and diversity. Generalized additive models indicated that landscapes with a larger proportion of tidal flats in conjunction with salt-pans were the best predictors of sites with higher species richness, abundance and diversity. Landscape configurations with higher richness, abundance and diversity of shorebirds also tended to be less fragmented and contained slightly larger patches. Shorebirds appeared to use ponds with exposed mud in salt-pans as both roosting sites and supplementary feeding grounds during high tide. Traditional salt-pans therefore proved to contribute significantly to maintenance of overwintering shorebird populations in this landscape and should be investigated elsewhere in Asian coastal zones. Collaboration between researchers, salt farmers and planning authorities as to how best to maintain salt-pans as potential shorebird roost sites such as in the Inner Gulf of Thailand is urgently needed in order to maintain habitat for shorebird populations in critical wintering and staging areas of this flyway.
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Papers by Yongyut Trisurat