Comparison of cavity modification and community involvement as strategies for hornbill conservation in Thailand

We monitored breeding success of hornbills in Thailand for four sympatric species at Khao Yai National Park during 1981-2002 and six species at Budo-Sungai Padi National Park during 1994-2002. Within a 60 km² study area at Khao Yai, the well protected area, use of available cavities ranged from 94% in 1984 to 50% in 1993. Competition for nesting cavities was 40% of cavities available indicating the shortage of suitable cavity. We monitored the cavity condition and modified 48 cavities and, between 1996 and 2000, these contributed annually 23-45% of nestings that were successfully fledged (n = 352). Within the 90 km² at Budo Mountain, with heavy human disturbance, use of available cavities for nesting decreased from 81% in 1997 to 30% by 2001 and of successful fledging from 96% in 1997 to 55% in 1999, but both increased once our involvement with local communities had eradicated poaching and reduced disturbance. Competition for nesting cavities here was 26% of cavities available indicating the effect of poaching. Both strategies were successful in the short term but long-term management of cavities in large forest trees is required at Khao Yai and of forest disturbance at Budo.     

Role of soil redox in growth and fertilizer nitrogen uptake by rice in Thailand paddy soils

Abstract. In a laboratory study, ¹⁵N ammonium fertilizer uptake and rice growth was determined in a non-acid sulphate marine soil (Typic Tropaquept) and an acid sulphate soil (Sulfic Tropaquept). Acid sulphate sensitive (IR 26) and acid sulphate tolerant (IR 46) rice varieties were grown in soil suspensions incubated at four Eh levels (+500, +250, +50, and -150 mV) in microcosms for three weeks. The results showed that rice grown in non-acid sulphate marine soils gave slightly better dry matter weight of 1.8g/pot, greater ¹⁵N uptake of 12.8 mg N/pot, and higher total N uptake of 38.4 mg N/pot than under acid sulphate soil conditions indicating the non-acid marine soil is more favourable to rice culture. Growth as measured by weight of dry matter was significantly reduced from 2.1g/pot under oxidized condition (+500 mV) to 0.8g/pot under highly reduced condition (-150 mV). N uptake by rice was significantly reduced from 16.9 mg/pot at + 500 mV to 4.5 mg N/pot at -150 mV Total N uptake also decreased with decreasing Eh. Growth, ¹⁵N uptake and total N uptake by acid sulphate tolerant rice, IR 46 were significantly higher than the acid sulphate sensitive rice variety, IR 26. Under highly reduced soil conditions (-150 mV), growing rice in acid sulphate soil would require additions of lime, intermittent irrigation and/or mid season drainage in order to increase soil redox potential and remove toxic substances.     

泰国龙眼品种的引进与研究

中国和泰国是世界上最重要的龙眼主产地.1981-2002年,福建省农业科学院果树研究所先后从泰国引进了苗翘、施冲蒲、潘通、依登和依多等龙眼品种在福州试种,长期试验观察结果表明,其耐寒力和嫁接亲和力与中国龙眼品种无明显差异.这些品种在福州虽均能开花结果,且多表现投产快、抽穗率高、晚熟,以及果核小、肉厚、高糖、质脆和香气浓郁等优良性状;但由于气候的差异和枝梢生长季节的缩短,在福州容易出现过度抽穗开花、新梢萌生不足、树势衰弱、坐果率低、果变小和不丰产等问题,难以直接在生产上大面积推广应用.除了要注意选择在与泰北气候较接近的地区种植,避免过早采收,以及做好疏折花穗,秋季灌溉,促进夏、秋梢萌生良好等工作外,最好能通过与我国的良种杂交,从中培育出既具有国内外先进水平的果实品质,又适宜中国栽培的鲜食龙眼新品种.     

Floristic regeneration in five types of teak plantations in Thailand

Teak is the most important timber species in northern Thailand, and as such, large areas of teak forest have been disturbed or become highly degraded. Teak plantations have been established on this highly degraded land, where the rate of natural recovery is relatively slow. At the study site, five mixed or pure teak plantation types have been established to ameliorate limiting soil properties in order that long-term productivity is maintained. Observations within these plantations in northern Thailand have suggested that native species become established naturally under the shade of a “nurse” plantation, one that shades out early successional species. The objective of this study was to investigate the influence of the number of species in nurse plantations on the diversity and number of seedlings representative of mature native forests that become established within the plantations. Five types of plantations were investigated: (1) Tectona grandis L.f. (T); (2) T.grandis and Tamarindus indica L. (TT); (3) T.grandis and Gmelina arborea Roxb. (TG); (4) T.grandis, T. indica and G. arborea (TTG); (5) T.grandis, T.indica and Anacardium occidentale L. (TTA). These plantations were established primarily for the production of T.grandis (teak), with the other species introduced as economic trees. The plantations were surrounded by native stands of species representative of late successional and mature teak forests. In each of the plantations studies measurements were made on species density, species diversity, and evenness of plants regenerating in the understorey. Results showed that plantations consisting of several species in the overstorey had a higher diversity of native forest species in the understorey than the single-species plantation. Mixed plantation types were also found to reduce the density of the grass Imperata cylindrica (L.) P. Beauv. Consideration of the establishment of woody species found that TG and TTA had high densities of trees and shrubs. This suggested that if the goal of management was to regenerate forest with a high diversity of tree species similar to that found in native mature forests, multiple-species plantations, especially TG and TTA, would be more effective nurse communities than the single-species plantation in providing an environment into which seeds of native species could disperse and germinate. In addition, several climax species, such as Xylia xylocarpa (Roxb.) Taub. var. kerrii (Craib & Hutch) I.C. Nielsen, Pterocarpus macrocarpus Kurz, Largerstroemia sp., Afzelia xylocarpa (Kurz) Craib, Lannea coromandelica (Houtt) Merr., Spondias pinnata (L.f.) Kurz, Garuya pinnata Roxb., Terminalia mucronata Craib & Hutchison, Diospyoros mollis Griff., Irvingia malayana Oliv. ex Benn., Milletia leucantha Kurz, Dalbergia oliviri Gamble ex Prain, Chukrasia tabularis A. Juss and Schleichera oleosa (Lour.) Oken, were found in the early stages of succession, thus indicating that some may be suitable for planting in future restoration processes in order to accelerate natural succession and provide economic returns to managers.     

Forest villages: an agroforestry approach to rehabilitating forest land degraded by shifting cultivation in Thailand

The Forest village scheme was introduced by the Forest Industries Organisation (FIO) of Thailand in 1967 as an attempt to stop further spread of the fast increasing shifting cultivation and deforestation in the country. The underlying princple of the scheme is to relate reforestation with social welfare of the people involved. It is essentially a modification of the traditional taungya method of plantation establishment.The salient aspect of the scheme is to induce the shifting cultivators to settle down in villages where each family is given tenure over a plot of land to construct a house and develop a homegarden around it. The farmers are required to help establish and maintain forest plantations, in which they are permitted to raise agricultural crops during the first three years of its establishment. The farmers are also given free medical and educational facilities, and technical advice on crop and livestock husbandry. They can also earn cash rewards for successful plantation establishment.Although the scheme has not achieved its full target in terms of area covered and number of families settled, it is proving to be a successful method of luring people away from destructive shifting cultivation. The approach is applicable to other countries and regions with similar land-use problems and socio-cultural background.The paper also examines the constraints to the effective working of the scheme, provides some simple suggestions for improving its functioning and identies some of the issues that can easily be tackled by research.     

Comparative Phenotypic and Genotypic Analyses of Salmonella Rissen that Originated from Food Animals in Thailand and United States

Salmonella enterica serovar Rissen has been recognized as one of the most common serovar among humans and pork production systems in different parts of the world, especially Asia. In the United States, this serovar caused outbreaks but its epidemiologic significance remains unknown. The objectives of this study were to compare the phenotypic (antimicrobial susceptibility) and genotypic attributes of Salmonella Rissen isolated in Thailand (Thai) and the United States (US). All the Thai isolates (n = 30) were recovered from swine faecal samples. The US isolates (n = 35) were recovered from swine faecal samples (n = 29), cattle (n = 2), chicken (n = 2), dog (n = 1) and a ready‐to‐eat product (n = 1). The antimicrobial susceptibility of isolates was determined using the Kirby‐Bauer disk diffusion method with a panel of 12 antimicrobials. Pulse‐field gel electrophoresis (PFGE) was used to determine the genotypic diversity of isolates. All Thai isolates showed multidrug resistance (MDR) with the most frequent antibiotic resistance shown against ampicillin (100%), sulfisoxazole (96.7%), tetracycline (93.3%), streptomycin (90%) and chloramphenicol (30%). About half of the isolates of USA origin were pan‐susceptible and roughly 30% were resistant to only tetracycline (R‐type: Te). Salmonella Rissen isolated from Thailand and the USA in this study were found to be clonally unrelated. Genotypic analyses indicated that isolates were clustered primarily based on the geographic origin implying the limited clonality among the strains. Clonal relatedness among different host species within the same geography (USA) was found. We found genotypic similarity in Thai and US isolates in few instances but with no epidemiological link. Further studies to assess propensity for increased inter‐regional transmission and dissemination is warranted.     

Occurrence and characterization of livestock-associated methicillin-resistant Staphylococcus aureus in pig industries of northern Thailand

This study was conducted to determine the prevalence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in pigs, farm workers, and the environment in northern Thailand, and to assess LA-MRSA isolate phenotypic characteristics. One hundred and four pig farms were randomly selected from the 21,152 in Chiang Mai and Lamphun provinces in 2012. Nasal and skin swab samples were collected from pigs and farm workers. Environmental swabs (pig stable floor, faucet, and feeder) were also collected. MRSA was identified by conventional bacterial culture technique, with results confirmed by multiplex PCR and multi locus sequence typing (MLST). Herd prevalence of MRSA was 9.61% (10 of 104 farms). Among pigs, workers, and farm environments, prevalence was 0.68% (two of 292 samples), 2.53% (seven of 276 samples), and 1.28% (four of 312 samples), respectively. Thirteen MRSA isolates (seven from workers, four from environmental samples, and two from pigs) were identified as Staphylococcal chromosomal cassette mec IV sequences type 9. Antimicrobial sensitivity tests found 100% of the MRSA isolates resistant to clindamycin, oxytetracycline, and tetracycline, while 100% were susceptible to cloxacillin and vancomycin. All possessed a multidrug-resistant phenotype. This is the first evidence of an LA-MRSA interrelationship among pigs, workers, and the farm environment in Thailand.     

Effects of mangrove deforestation on fish assemblage at Pak Phanang Bay,southern Thailand

Daytime sampling using a seine net was conducted at Pak Phanang Bay (Nakhon Si Thammarat Province, Thailand) in February and July 2006, to determine differences in fish assemblage structures between a mangrove site and an adjacent site completely cleared of mangroves. The overall numbers of fish species and individuals were significantly higher at the mangrove site than the cleared site in both months. Although benthic crustacean feeders showed more species and individual numbers at the mangrove site in both months, the opposite was found for zooplankton feeders. A cluster analysis, based on the abundance of each species, demonstrated that the fish assemblage structures were distinctly different between the two sites. In addition, significant differences in length frequency distributions for each of the four most abundant species were found between the sites in February and/or July. Small individuals of Scatophagus argus, Ambassis nalua, and Tetraodon nigroviridis were more common at the mangrove site, and of Chelon subviridis at the cleared site. These results suggest that mangrove deforestation exerts marked effects on fish assemblages.     

Incentive for shifts in water management systems by shrimp culturists in southern Thailand

ABSTRACT:   Water management systems and other business situations of shrimp culturists were surveyed in two districts in southern Thailand. There were three types of water management systems in southern Thailand, namely closed, semiclosed and open systems, categorized by the frequency of exchange of pond water. Shrimp culturists in those districts tended to shift their system from the open system to the closed system of their own accord, and the average net income ratio decreased due to the change of water management system in a district from more than 2 to less than 1. The reason for this shift, in spite of the decrease in the profit rate, was prevention of infectious disease caused by water exchange. In conclusion, it was proven that independent shrimp culturists, such as medium and small scale shrimp pond owners in southern Thailand, would accept short-term decreases in profit rate in order to stabilize production.