Studies on the volcanic ash soils in the environs of Mt. Daisen

The environs of Mt. Daisen, Tottori Prefecture, are generally mountainous or hilly, and apart rom small areas of alluvial and coastal flats there is little level ground. The volcanic ash soils derived from the quartz biotite hornblende andesitic ejecta occur on the gently undulating foot-hill and on the level ground with exception of alluvial flats. Considering the fact that these soils were formed from not only volcanic ash but the coarser materials, they may be properly called volcanogenous soils. The volcanic ejecta have been deposited on the soils from diluvial series, andesite, basalt, granite, and tertiary sedimentary rocks. It was recognized that in an eruption the large ejecta, such as fine porous pumiceous lapiili descended first, then the smaller Particles such as sands, and finally the smallest, as ashes. All of these deposits have been highly weathered, but the quartz and hornblende remain in a fresh state¹⁾. The author has studied some characteristics of these volcanic ash soils.     

Calculation and mapping of critical loads of s,n and acidity on ecosystems of the Northern Asia

On the basis of modified simple steady state mass-balance equations, the critical loads for nutrient and acidifying nitrogen as well as for sulphur and acidity have been calculated for various ecosystems of northern Asia using simplified expert-modelling GIS and grid cells 150×150 km. The minimal values of critical loads of nitrogen, CL(N), (<50eq a/yr)=" were=" shown=" for=" arctic=" and=" subarctic=" ecosystems=" and=" the=" maximal=" ones=" (=">300eq/ha/yr) for ecosystems of chernozemic and chernozem-like soils in southern Siberia and the Far East. The minimal values of critical loads of sulphur, CL(S), as well as acidity were shown predominantly in the northern part of east Siberia and in the Kamchatka peninsula and the maximal ones for ecosystems having neutral and alcaline soils. The corresponding exceedances were indicated for many regions of the northern part of Asia with maximal values for regions of Ural mountains, frontery of Kazakhstan, Altai, lower Yenisei river flow, Far East, Sakhalin and South-Kurilean islands.     

Degradation and development of peatlands in Peninsular Malaysia and in the islands of Sumatra and Borneo since 1990

In this study, we investigated the extent of peatland degradation and development in Peninsular Malaysia and in the islands of Sumatra and Borneo, in the western part of insular Southeast Asia, since 1990. Furthermore, carbon emissions caused by these land cover changes were estimated in order to evaluate their contribution to global climate change. High resolution Landsat (30 m spatial resolution) and Satellite Pour l'Observation de la Terre (SPOT; 10–20 m) satellite images were used to derive information on land cover in 1990 and 2008. Analysis of land cover changes since 1990 revealed remarkable reduction and degradation of peatswamp forest ecosystems. In less than 20 years, 5·1 Mha of the total 15·5 Mha of peatland had been deforested (11·6 Mha → 6·5 Mha; 75 per cent → 42 per cent) and the great majority of the remaining forests had been selectively logged. Simultaneously, area covered by unmanaged secondary growth ecosystems had doubled to nearly a quarter of all peatlands and industrial plantations had expanded dramatically (0·3 Mha → 2·3 Mha; 2 per cent → 15 per cent). It was conservatively estimated that these changes have caused minimum of 1·5 Gt carbon emissions into the atmosphere since 1990. Currently, peatlands of the study area emit at least 81 Mt of carbon (equivalent to 300 Mt of carbon dioxide) on annual basis due to mere peat decomposition. Thereby, it was concluded that peatland degradation and development in insular Southeast Asia during the past two decades have not only put the existence of Southeast Asian peatswamp forest ecosystems in danger but it has also caused globally significant carbon emissions and created a constant source of carbon dioxide. Copyright © 2010 John Wiley & Sons, Ltd.     

Modeling studies on sulfur deposition and transport in East Asia

A three dimensional regional Eulerian model of sulfur deposition and tranport has been developed. It includes emission, transport, diffusion, gas-phase and aqeous-phase chemical process, dry depostion, rainout and washout process. A looking up table method is provided to deal with the gas-phase chemical process including sulfur transfer. Calculated values have reasonable agreement with observations. Distribution of sulfur deposition and transport in East Asia are also analyzed in the paper. Simulation shows that sulfate (SO ₄ ^2– ) is the main substance to transport in long range transport. Some amount of sulfur emission of different countries transport across boundaries, but the main origin of sulfur deposition in each country in East Asia is from herself. Furthermore, some transport paths on different layers and outlet or inlet zones are found.     

Importance of reservoirs for the conservation of freshwater molluscs in a tropical urban landscape

Freshwater species and ecosystems are gravely imperiled, particularly within urban landscapes of tropical Asia. In one of the region’s most urbanized landscapes (i.e., Singapore), we determined: (1) the importance of six different habitats (i.e., catchment reservoirs, estuarine reservoirs, forest streams, rural streams, ponds and monsoon canals) for conserving the diversity of freshwater molluscs; (2) key environmental factors (e.g., pH) affecting molluscan distribution; (3) important biogeographical determinants (e.g., area) of molluscan richness within each habitat; and (4) the habitat affinities of introduced species. High sampling saturation was achieved at most study habitats with minimal sampling effort, suggesting that the utilization of molluscs as bioindicators can expedite freshwater conservation initiatives. Estuarine reservoirs (6.0 ± 2.0) had the highest molluscan richness, vis-à-vis catchment reservoirs, forest streams, rural streams, ponds and monsoon canals (3.0 ± 1.5; 0; 3.3 ± 2.0; 1.8 ± 0.5 and 3.5 ± 0.5 respectively). Both reservoir types possessed species compositions distinct from other habitats and contained majority (76%) of the sampled species. Reservoirs therefore serve to conserve the bulk of local freshwater malacofauna, especially if they are maintained at near-neutral pH levels (i.e., ∼7.3) and contain large substrates (i.e., rocks). Area was the best predictor of molluscan richness across all habitats, implying that larger freshwater habitats require higher conservation priorities than smaller ones. Introduced (non-native) species (e.g., Pomacea canaliculata) had high affinities for reservoirs, which are in need of monitoring to curb population expansions. The interminable growth of human settlements urgently requires a reconciliatory approach, which includes the ecologically-sound design and management of modified habitats to complement reserves in sustaining native freshwater species.     

A note on the variation of phaseolin among common bean landraces collected in Eastern Asia

Summary Phaseolin seed protein was used as a marker to reveal the origin, Mesoamerican or Andean, of common bean (Phaseolus vulgaris) accessions cultivated in some countries (Korea, China, and Japan) of eastern Asia. Andean cultivars (T and C phaseolin patterns) are predominant in this geographical area. Introductions from Middle America, represented by cultivars with S phaseolin type, also occurred at lower rate. In all cases, genotypes with larger seeds have been favoured.     

Lowland rainforest avifauna and human disturbance: persistence of primary forest birds in selectively logged forests and mixed-rural habitats of southern Peninsular Malaysia

We compared the composition and structure of primary forest avifauna among primary forests, selectively logged forests and mixed-rural areas (e.g. villages and agricultural areas) of Peninsular Malaysia. We found that forests that were selectively logged at least 30 years ago contained only 73-75% of the 159 species of extant primary forest birds, with an increased proportion of dominant species. We estimated that only 28-32% of the primary forest species utilized the mixed-rural habitat, and that the number of species that bred in the agricultural landscapes might be even lower. The microhabitat of different species most affected their vulnerability to disturbance. Most small, arboreal frugivores and omnivores, and insectivores that fed from tree trunks, showed greater persistence in the mixed-rural habitat than ground dwelling bird species, which were affected most by disturbance. Resource abundance and variables that were closely related to forest disturbance such as the density of large trees, density of dead trees, canopy cover density and shrub volume influenced the distribution of the primary forest birds. Large primary forest reserves and a revision of short-cycle logging regimes (ca. 30 years) are needed if we are to conserve the lowland rainforest avifauna of Peninsular Malaysia and other parts of Southeast Asia.     

Nitrogen Fertilizer Affects Growth,Yield, and N Recovery in Cassava (Manihot esculenta L. Crantz)

Cassava is a very important tuber crop in Asia. As fertilizer application, especially nitrogen (N), is important to sustain yields, the impact of different rates of N fertilizer and their time of application on growth, yield, and N-recovery efficiency was evaluated over two major seasons in Asia. Applying N at planting increased leaf area index (LAI), especially at greater rates. Split application of 90 kg N at planting and 45 days later induced growth of more tubers, resulting in good yields, when compared to single or three split applications at 45 and 90 days after planting. Split application on two occasions also developed the greatest N-recovery efficiency by both shoots and roots. The correlations between N efficiency and yield parameters were significant and negative (P = 0.05). The importance of two split applications of moderate rates of fertilizer to cassava is presented.     

Identification of powdery mildew and leaf rust resistance genes in common wheat (Triticum aestivum L.). Wheat varieties from the Caucasus, Central and Inner Asia

225 wheat varieties from Kazakhstan, Mongolia and Russia were analysed for their resistance to powdery mildew and leaf rust diseases. A set of 11 different Blumeria graminis f. sp. tritici isolates was used to test for powdery mildew resistance and a set of 10 different Puccinia triticina isolates for leaf rust. 115 cultivars/lines were susceptible to powdery mildew and 32 cultivars/lines showed an intermediate resistance response. 21 cultivars/lines revealed the response pattern of individual resistance genes Pm1, Pm2, Pm3, pm5, Pm6, Pm8, Pm9, Pm17 and Pm22, respectively, therefrom three line showed a combination of two resistance genes and two varieties a combination of three genes. 50 cultivars/lines showed resistance to some specific isolates but an assignment to known resistance genes or gene combinations was not possible, whereas seven lines were completely resistant to all used isolates. The leaf rust test showed that 83 cultivars/lines were susceptible and 11 lines revealed intermediate resistance response. 62 cultivars/lines could be assumed to possess major resistance genes Lr1, Lr3, Lr10, Lr23 and Lr26, respectively, therefrom seven cultivars possessed a combination of two resistance genes. Lr3 was the most widespread resistance gene, occurring in 42 cultivars/lines. 13 lines were completely resistant to all used isolates, however, the response patterns of 56 cultivars/lines did not match to any known gene or gene combination. In 13 varieties the T1BL·1RS wheat-rye translocation could be identified, in five cultivars resistance gene Pm8 was suppressed.     

中亚农业水资源脆弱性及其变化特征分析

农业用水是链接自然环境和社会经济发展的重要环节,研究农业水资源脆弱性的时空变化对揭示水资源的可持续开发利用、保障水资源安全、应对洪旱灾害具有重要意义。为研究中亚地区农业水资源脆弱性变化特征,本文以中亚五国为研究区,基于气象、土地覆盖、地形和社会经济数据,依据脆弱性概念框架,从暴露度、敏感度和适应度3个方面选取18个指标,建立了农业水资源脆弱性评价指标体系,采用等权重法和主成分分析法确定指标权重,对1992-2017年中亚农业水资源脆弱性进行了评价及特征分析。结果表明:1)中亚农业水资源脆弱性空间分布表现为"南高北低"的特征,5国中土库曼斯坦农业水资源脆弱性最强,其次为乌兹别克斯坦、塔吉克斯坦和吉尔吉斯斯坦,而哈萨克斯坦农业水资源脆弱性最弱;研究时段内农业水资源脆弱性空间分布格局变化较小。2)中亚农业水资源脆弱性随时间变化表现为"前期升高,中期降低,后期稳定"的态势,整个研究期内研究区农业水资源脆弱性变化类型以相对稳定为主。不同地区农业水资源脆弱性随时间的变化存在差异,吉尔吉斯斯坦西部和土库曼斯坦的农业水资源脆弱性升高,乌兹别克斯坦、塔吉克斯坦以及咸海地区水资源脆弱性降低,其他地区相对稳定。3)不同地区农业水资源脆弱性对各指标的敏感性不同,北部农业水资源脆弱性动态变化对农田灌溉定额和灌溉指数以负敏感为主,对其他指标以正敏感为主,而南部对各指标的敏感性正负均有;相关性分析表明,森林覆盖率、农业用水比例、农田灌溉定额、水分胁迫指数、灌溉指数和农业水分生产率是导致中亚农业水资源脆弱性空间差异的重要因素。4)为降低农业水资源脆弱性,中亚地区需发展集约型农业,调整作物种植结构,推广耐旱品种农作物,进行节水灌溉。研究结果可为中亚农业水资源规划管理、农业生产布局调整以及农业可持续发展提供参考依据。     

Peat swamp forest avifauna of Central Kalimantan, Indonesia: Effects of habitat loss and degradation

Peat swamp forest is a unique wetland ecosystem covering extensive areas in Southeast Asia that has received relatively little scientific attention and is now being lost at a rapid pace. This study examines the effects of anthropogenic degradation on bird communities in disturbed peat swamp forest habitats – namely, intact logged forest, a degraded forest fragment, and non-forest regrowth – in Central Kalimantan, Indonesia. Results show that species richness was significantly higher and species composition significantly different in intact logged forest in comparison to the degraded forest fragment and non-forested area. Nectarivore and tree foliage-gleaning insectivore abundance declined outside the intact forest, while the regrowth was dominated by the yellow vented bulbul, an open country insectivore–frugivore. Surveys reveal that large intact tracts of logged peat swamp forest can harbour threatened and near threatened bird species (36% of records) and thus play a role in their conservation, especially for a few habitat specialists. Given the extent of unmanaged degraded peatlands and continuing pressure to development them, urgent conservation actions are needed to rehabilitate and protect this ecosystem.     

Microbiological studies on the Humification Process (Part 1) Effect of Microbes on the Transformation

It is well known that soil humus becomes a definite type under a definite environmental condition. When the soil condition is changed, the humus is brought into transformation, and after a period of time it is adjusted to an equilibrium state depending on the newly established condition. Previously K. Kobo 1) showed that the soil humus of newly ploughed up volcanic ash soil was transformed, increasing the degree of humification, under cultivation. In relation to this work, we studied the effect of several microorganism on the transformation of humus for the purpose of elarifying the humification process.     

东亚和邻近地区受盐影响土壤的性质及盐化危险

Asia is the largest distribution area of salt-affected soils in the world,Very few countries in Asia could escape from hazard of salinization.This paper deals with various salt-affected soils spreading in East Asia and its neighboring regions (including China,Japan,Kampuchea,Democratic Peolpe‘s Republic of Kores,Republic of Korea,Laos,Mongolia,Burma,Thailand and Vietnam),Principles of occurrence of salinization,and features of salt-affected soils in these regions have been studied in the present paper,Based on studies on types,features and distribution patterns of salt-affected soils.a salt-affected soil map of East Asia and its neighboring regions has been complied.Mechanism and manifestation of the salinization hazard on the regional agriculture and ecological environment,measures of preventing salinization hazard and exploiting salt-affected soils in these regions are also discussed.     

Evaluating the effectiveness of Protected Areas for conserving tropical forest butterflies of Thailand

In many cases, the designation of Protected Areas (PAs) is not based on biological information, particularly in tropical regions where such information is generally lacking. Thus it is unclear whether tropical PAs are well-placed for conserving biodiversity currently, or under future climate change. We used reserve-design software (‘Zonation’) to investigate current and future conservation value of PAs of Thailand (N = 187 PAs, covering ∼20% of Thailand) in relation to forest-cover and butterfly diversity. Currently, PAs are about 2 °C cooler than non-PAs because PAs tend to occur at higher elevation (66% of land above 1000 m is protected compared with only 6% below 250 m). Temperature is predicted to increase in Thailand in future, but PAs are predicted to remain ∼2 °C cooler than non-PAs in future. We obtained modelled distribution data for 161 butterfly species (∼12% of national butterfly fauna), and used Zonation to rank areas (∼1 km² grid resolution) based on species richness, complementarity, and forest cover. The conservation value of PAs was approximately twice that of non-PA areas, although many highly-ranked areas are not currently protected. The species richness of PAs was projected to decline by ∼30% in future, but the relative conservation rankings of individual PAs were projected to change very little. The preponderance of PAs in montane regions makes them well-placed to support forest species shifting from areas at lower elevation that become climatically unsuitable in future. By contrast, the conservation value of low-elevation PAs may decline in future if climate conditions become unsuitable for species.     

云南雨季开始期的时空变化特征及其与季风的关系

利用197l-2007年云南124站逐日降水资料计算雨季开始期,采用EOF(经验正交函数)分解和最大熵谱分析方法,研究云南雨季开始期的空间分布、时间演变及周期变化特征,并初步分析云南雨季开始期不同分布型与季风的关系,以期为指导春季农业生产提供依据。结果表明,全省雨季开始期一致偏早或偏晚为云南雨季开始期的最主要空间分布特征,其次为滇中及以东地区与滇西北及滇西南地区雨季开始期反向变化的空间分布型;雨季开始期全省一致分布型存在3～5a的显著周期变化,滇中及以东地区与滇西北及滇西南地区雨季开始期反向变化的空间分布型存在3～4a的显著周期变化;云南雨季开始期与同年5月孟加拉湾地区和南海地区OLR有显著的相关关系(P<0.05);南亚季风与南海季风强度指数对云南雨季开始期有重要的指示性意义。     

入世过渡期中国与东南亚的农业合作机遇

东南亚农业具有资源丰富、创汇力强、市场潜力大、与中国等世界农业大国合作基础良好等特点。结合数量分析，认为从《中美农业合作协议》生效到2004年这一段中国农业的入世过渡期间，中国与东南亚的农业合作机遇有4种：政策推动、市场拉动、制度创新驱动、科技进步促动。着重分析了双方政府近期频密签署的合作协议的政策推动，东南亚地区经济一体化和经济复苏及中国西部大开发等方面产生的巨大市场拉动，中国加入WTO，享受世贸协议、乌拉圭回合《农业协议》所带来的制度创新驱动。并提出了抓住机遇的若干对策。     

Effects of anthropogenic land use on forest birds and butterflies in Subic Bay, Philippines

Despite the loss of 83% of native forests in the Philippines, little is known on the effects of this massive habitat loss and degradation on its forest biotas. This is a cause for concern because of the threat posed to the country’s large number of endemic taxa. To investigate the impacts of anthropogenic disturbance, forest birds and butterflies were surveyed in closed and open canopy forests, as well as suburban, rural and urban areas within the Subic Bay Watershed Reserve and Olongapo City in western Luzon. Measures of forest species richness and population densities for both taxa were similar in the two forest types, but showed different patterns in the other habitats. Indirect gradient analysis showed that forest bird species were positively correlated with vegetation variables (i.e., canopy cover, tree density, height to inversion and ground cover), while forest butterflies were not strongly correlated to any of the measured habitat variables. Community composition of birds in forests was distinct from those in modified habitats, while butterfly communities were more similar. A simulation showed that canopy cover of 60% or higher was required by 24 of the 26 bird species that were sensitive to canopy loss. Endemicity and nesting strata were the significant predictors of vulnerability to habitat disturbance for birds, while endemicity and larval hostplant specificity were significant for butterflies. Both taxa were negatively affected by anthropogenic disturbance but may respond to different components in the habitat (i.e., structure and resources), and thus cannot be used as surrogates of each other. Conservation of forests with contiguous canopy cover should be prioritized, and more ecological research is needed to improve the knowledge on the effects of disturbance on Philippine biodiversity.     

Allium vavilovii M. Popov et Vved. and a new Iranian species are the closest among the known relatives of the common onion A. cepa L. (Alliaceae)

A wild onion species from Karaj valley east of Tehran istaxonomically described as Allium asarense R. M.Fritsch et Matin. Sharing the bubble-like inflated lower scapewith A. vavilovii, the newspecies differs by semi-cylindrical leaves and small flowerswith translucent greenish-yellow tepals from all other knownspecies of Allium sect.Cepa. Molecular data suggest a closerelationship to A. cepa(but to a lesser degree than A.vavilovii) and indicate a still weakerphylogenetic connection of A.oschaninii to the common onion. The questionabout the possible wild ancestor of A.cepa is discussed against this background, and akey for determination of the Oschaninii-alliance of sect.Cepa is presented.     

Dynamic modelling for linear erosion initiation and development under climate and land-use changes in northern Laos

Linear erosion (LE) induced either by piping or overland flow is one of the most active factors in the evolution of soils. During single storm events LE may remove enormous amounts of soil material from the uplands to the bottomlands and has thus become a broad challenge for food supply, food security, and human health. Recent and rapid changes in land-use and climate patterns in the sloping lands of tropical areas may dramatically increase LE. Our main objective was to investigate to what extent one could use direct flow velocity estimations from dynamic models for predicting LE initiation and development at the event level. The second objective was to estimate the impact of expected land-use and climate changes on LE. The study was conducted in the 0.62 km² watershed of northern Laos presented inChaplot et al. (2005). Field observations of the formation and the development of LE features throughout 2001 were compared to flow velocity estimations from an existing surface water routing algorithm developed at Utrecht University ([De Roo, A.P.J., Wesseling, C.G. and Ritsema, C.J. 1996. LISEM: a single event physically based hydrologic and soil erosion model for drainage basins. I: theory, input and output. hydrological processes 10 (8): 1107–1117.]). In 2001, two main rainfall events were responsible for the formation or development of 14 linear features with a total length of 972 m and an erosion rate of 3.5 Mg ha^{− 1}. The water routing algorithm was calibrated using the water and the sediment hydrographs observed at the watershed outlet during the first rainfall event. Assuming realistic estimations of flow velocity in hillslopes, a threshold of 0.062 m s^{− 1} for linear erosion estimated over 10-m cells was defined. This threshold, validated using the remaining rainfall event, accurately predicted the length (mean error of estimate of less than 15%) and location of LE features. Using this simulation tool, an increase of the percentage of land under cultivation from 9% to 100% resulted in 600% increase in linear erosion. The tested scenarios of climate changes had less impact on linear erosion.     

Land use and conservation value for forest birds in Central Sulawesi (Indonesia)

Unprecedented deforestation is currently underway in Southeast Asia. Since this trend is likely to continue, it is critical to determine the value of human-modified habitats (e.g., mixed-rural habitat) for conserving the regional native forest avifauna. The impacts of ongoing deforestation on the highly endemic avifauna (33%) of Sulawesi (Indonesia) are poorly understood. We sampled birds in primary and secondary forests in the Lore Lindu National Park in central Sulawesi, as well as the surrounding plantation and mixed-rural habitats. Species richness, species density and population density of forest birds showed a consistent decreasing trend in the following order: primary forests > secondary forests > mixed-rural habitat > plantations. Although primary forests contained the highest proportion (85%) of a total of 34 forest species recorded from our point count surveys, 40-yr old secondary forests and the mixed-rural habitat showed high conservation potential, containing 82% and 76% of the forest species, respectively. Plantations recorded only 32% of the forest bird species. Fifteen forest species had the highest abundance in primary forests, while two species had higher abundance outside primary forests. Our simulations revealed that all forest birds that were sensitive to native tree cover could be found in areas with at least 20% continuous native tree cover. Our study shows that although primary forests have the highest conservation value for forest avifauna, the potential of degraded habitats, such as secondary forests and the mixed-rural habitat, for conserving forest species can be enhanced with appropriate land use and management decisions.