Plant‐frugivore interactions in an intact tropical forest in north‐east Thailand

Fleshy‐fruited plants in tropical forests largely rely on vertebrate frugivores to disperse their seeds. Although this plant–animal interaction is typically considered a diffuse mutualism, it is fundamental as it provides the template on which tropical forest communities are structured. We applied a mutualistic network approach to investigate the relationship between small‐fruited fleshy plant species and the fruit‐eating bird community in an intact evergreen forest in northeast Thailand. A minimum of 53 bird species consumed fruits of 136 plant species. Plant‐avian frugivore networks were highly asymmetrical, with observed networks filling 30% of all potential links. Whereas some of the missing links in the present study might be due to undersampling, forbidden links can be attributed to size constraints, accessibility and phenological uncoupling, and although the majority of missing links were unknown (58.2%), many were probably due to a given bird species being either rare or only a very occasional fruit eater. The most common frugivores were bulbuls, barbets and fairy‐bluebirds, which were responsible for the majority of fruit removal from small fleshy fruited species in our system. Migratory birds seemed to be a minor component of the plant‐frugivore networks, accounting for only 3% of feeding visits to fruiting trees; they filled 2% of the overall potential networks. The majority of interactions were generalized unspecific; however, Saurauia roxburghii Wall. appeared to be dependent on flowerpeckers for dispersal, while Thick‐billed Pigeons were only seen to eat figs.     

Effect of dose and type of fertilizer on flowering and fruiting of vanilla plants

Nutritional status affects the processes of flowering and fruiting of plants. This study was conducted to determine the effects of fertilizer application on flowering, fruiting, and leaf nutrient content of Vanilla planifolia (Jacks. ex Andr). Treatments consisted of the application of grade 10-20-20 nitrogen, phosphorus, and potassium (NPK) fertilizer to the substratum in annual doses of 20, 50, and 100 g/plant plus a monthly application of foliar fertilizer. Two more treatments were foliar fertilization and no fertilization (control). Treatments increased the number of inflorescences and flower buds per plant, as well as the number and weight of fruits per plant, and decreased the abortion of flowers and immature fruits. These effects depended on the type of fertilizer, the amount applied, and the time of evaluation. The best results were obtained with the 100 g/plant/year treatment with an annual production of 1.5 kg of fruits per plant in the second year. Unfertilized plants produced 0.55 kg/plant/year. Differences were also found in foliar content of N, P, K, and copper (Cu) between vegetative and reproductive branches. Application of fertilizer to the substratum appears to improve reproductive parameters of vanilla plants and the production of beans, while foliar fertilization alone was ineffective in increasing crop productivity. Nutrients also seem to translocate from mature leaves to fruit racemes.     

Short- and long-term effects of the endogeic earthworm Millsonia anomala (Omodeo) (Megascolecidæ, Oligochæta) of tropical savannas,on soil organic matter

Summary This study aimed to establish the effects of Millsonia anomala, a tropical geophagous earthworm common in the humid savannas of Lamto (Ivory Coast), on soil organic matter dynamics over different time scales under laboratory conditions. The texture of casts produced by the worms fed on a shrub savanna soil was not significantly different from that of the soil, which showed that M. anomala ingested soil particles without selection. Physical fractionation of soil organic matter showed that the coarse organic fraction (250–2000 m) was depleted by 25–30% in fresh casts compared to the control noningested soil; this was mainly due to a fragmentation of coarse organic debris. Incubation of casts and a 2-mm sieved control soil under laboratory conditions for more than 1 year showed that the C mineralisation rate was almost four times lower in the casts (3% year^-1) than in the control soil (11% year^-1). We therefore concluded that on a long time scale M. anomala populations may significantly reduce the decomposition rate of soil organic matter in Lamto savannas.     

氢化物发生—原子荧光光谱法热带水果中的锡

用氢化物发生－原子荧光光谱法测定热带水果中锡。经过正交试验选取测定条件，用SAS处理试验结果的数据，对影响测定灵敏度的一些实验参数进行了优化。方法检出限为0．004mg/kg，相关系数0．9999，线性范围0－200μg/L，回收率89．6％－106．6％，相对误差为0．5％－0．8％。     

The life history of Tenualosa macrura in Sarawak, further notes on protandry in the genus and management strategies

Abstract  The contraction of Tenualosa macrura (Bleeker) to the Sarawak coast and a small part of Sumatra, and the decline in its fishery mirror what has happened to three other species in the genus. Little was known of this species in its last stronghold in Sarawak where it is important for management and conservation reasons to understand its biology and life history. It forms part of a multispecies fishery where effort is uniform, but catches follow a lunar cycle. Tenualosa macrura is protandrous, but low numbers of small females suggest diandry. In Sumatra Tenualosa macrura spawn throughout the year, but in Sarawak have a seasonal peak in the NE monsoon (December). This has management implications because the Sarawak fishery ceases at this time because of adverse weather, hence reducing fishing pressure on spawning T. macrura . Management measures introduced in Sarawak for Tenualosa toli (Valenciennes) may therefore not be required for T. macrura .     

加强琼台农业合作 促进海南经济发展

本文概要地分析了海南和台湾农业生产的互补性与可行性 ,指出二者合作前景广阔 ,并结合当前琼台农业合作现状 ,进一步提出琼台农业合作的发展对策。     

早熟玉米品种主要农艺性状与产量相关研究

运用相关及回归分析方法，研究了20个早熟玉米品种主要农艺性状与产量之间的关系，并利用回归方程估测备性状值的变化对产量的影响。结果表明，行粒数与产量关系最为密切，其次是株高、穗长。穗粗、穗位高、穗行数、千粒重对单产的提高效果不大。     

几内亚热带气候对海波罗肉用仔鸡长期耗料量及料肉比影响的研究

分4批从孵出的海波罗鸡雏中选出888只公母混合雏，每批222只，研究几内亚热带气候对海波罗肉仔鸡生长期耗料量的影响。结果表明，4批鸡的整个试验中的累计耗料量分别为4745.58g/只、4507.44g/只、4682.73g/只和4545.77g/只。第Ⅱ、Ⅲ和Ⅳ批鸡的累计耗料量比第Ⅰ批鸡分别少5.28%、1.13%和4.40%，第Ⅱ和第Ⅳ批累计耗料量比第Ⅲ批分别少4.11%和3.23%，第Ⅱ批累计耗料量比第Ⅳ批的少0.5%，比第Ⅰ、Ⅲ和Ⅳ批偏少。4批鸡4周龄料肉比分别为1.23、2.03、1.90和1.67，饲料报酬都高，7周龄分别为3.78、2.97、2.56和2.52，除第Ⅰ批外，各批7周龄饲料报酬较高。在整个试验期，4批鸡1－7周龄的平均累计耗料量为4622.88g/只，其平均累计料肉比为2.28g，累计耗料量比海波罗的标准少217.12g，即4.70%。由于几内亚热带气候影响，本试验鸡采食量少，料肉比较低。     

Factors Affecting Fertility According to the Postpartum Period in Crossbred Dual-Purpose Suckling Cows in the Tropics

To determine the relationship between first service conception rate (FSC) and the postpartum period (PP), 6160 calvings from 2250 crossbred dual-purpose cows were analysed. The effects of breed predominance (BT: Bos taurus and BI: Bos indicus), season of service (dry, intermediate and humid), parity (1 or 2 and more), agroecological region (Sub-humid and Dry Tropical Forest) and milk production were studied. The postpartum period was grouped according to the calving–first service interval as G1 ≤ 60 days (n = 1889); G2 > 60 ≤ 90 days (n = 1436); G3 > 90 ≤ 120 days (n = 1030); and G4 > 120 days (n = 1805). Data were analysed by chi-squared test. The overall mean for FSC was 58.2% and was lower in G1 (p < 0.01). All PP showed a breed effect on FSC, with mean values of 61.6% and 53.3% for BI and BT, respectively. Season of service also affected FSC, which was significantly lower during the humid period: 51.2% versus 57.4% and 61.5% for the intermediate and dry periods (p < 0.01), respectively. Parity and environmental effects were not observed on FSC. Levels of milk yield did influence the FSC, which decreased from 66.7% and 61.0% for milk yields of < 1500 kg and between 1501 and 2000 kg to 46.0% in milk yields > 2000 kg (p < 0.01).     

基质在热带兰栽培过程中的养分释放研究

采用PT法探究几种常见热带兰栽培基质有效氮、磷、钾释放及pH变化情况。结果表明:整个试验阶段所有处理基质pH变化在5.24～6.88,适合大多数花卉生长,水苔受外界环境影响最大,有着较大的pH变化,不适宜热带兰长期栽培。各基质的养分释放并不是按一定规律来进行,混合基质养分释放量低于纯基质,混合基质可以避免纯基质养分释放量大的弊端。NH4+-N的释放遵循类似"U"型曲线变化,火山石与松树皮混合有利于NO3--N的释放。前60d内,A与B处理磷的释放变化较大,60d后磷含量表现为下降变化,直至趋于平缓,不过混合基质整体磷含量水平较低。A与B处理的钾释放量分别在第15和45天降至平缓释放水平,以后一直维持在该平缓水平上释放钾。