1977 British Crop Protection Conference —Pests and Diseases,Brighton, November 1977

Abstract

The golden apple snail, Pomacea canaliculata (Lamarck, 1822) (Mesogastropoda: Pilidae), has recently been introduced to several Asian countries where it has unexpectedly developed into a pest of rice. Reasons for the introduction as well as the economic and ecological impact of the snail are described. Most farmers have resorted to chemical control, with implications for human health and the environment. Integrated snail management practices are summarized including the use of the snail as a valuable aquatic resource. It is concluded that research on control strategies is urgently needed but requires sound knowledge of the ecology of the snail in its natural habitat.     

东亚北风异常对西北东部春季降水的影响

利用1961-2008年NCEP/NCAR(2．5°×2．5°)再分析逐月500 hPa高度场资料和1961-2008年西北地区东部陕、甘、宁、青4省170个气象观测站的月降水量资料,计算春季东亚北风指数,分析研究区春季降水的历史演变规律、东亚北风指数的年代际变化及其与西北春季降水的关联。结果表明:50 a来降水演变特点是以黄河为界,黄河以西降水呈增多趋势,黄河以东降水呈减少趋势,降水减少的幅度明显大于增加的幅度;特别是近20 a,黄河以东广大区域降水减少的幅度越来越大,干旱化趋势明显,而青海南部、河西走廊则降水呈增加趋势。在此期间,春季东亚北风逐渐增强,特别是20世纪90年代中期以后明显增强。进一步分析表明,当春季东亚北风偏强（弱）时,除青海南部外,西北地区东部大部分地方降水偏少（多）,即春季东亚北风异常增强,可引起西北地区东部黄河以东干旱少雨,导致干旱化加剧。     

从水土资源匹配关系看中亚地区水问题

中亚地区是世界上水土资源开发利用引起生态问题最突出的地区之一。运用基尼系数法和单位面积耕地所拥有的水资源量法,对中亚地区水土资源空间匹配关系进行定量分析。结果表明：中亚作为一个整体,水土资源匹配状况良好,通过调配可以达到水土资源均衡。但中亚五国间差异较大,表现为上游国家匹配状况优于下游国家。此外,通过对水土资源匹配状况的定量分析,得出中亚水问题不仅仅是量的问题,核心所在是国家间、尤其是上下游国家间对跨界河流水资源的利用与分配问题。     

青藏高原与西南亚地区野生二棱大麦性状的比较研究

比较研究了青藏高原和西南亚地区野生二棱大麦的生活型、形态性状、变种性状、特性性状、经济性状。结果表明 :在生活型、碎穗、三联小穗颖型、小穗轴毛长、侧小穗柄、护颖、芒型和芒性等性状上 ,它们基本相同。结合他人有关染色体和核型等有关报道 ,认为它们可能起源于共同祖先 ,即有真正野生群落的原始野生二棱大麦。然而 ,两个地区生态环境迥然有异 ,导致它们在植物学特征和生物学特性的 12个性状上 ,存在着明显的生态型或变种间的差异。研究结果对研究大麦的起源与进化、遗传与育种以及野生大麦遗传资源的保护与可持续利用等都有重要意义     

亚洲发展中地区推广农村户用沼气池的SWOT-PEST分析

过去几十年,亚洲发展中地区的户用沼气池建设取得了很大发展.文章运用SWOT-PEST相融合的分析法,对亚洲发展中地区推广户用沼气池的内部优势和劣势与外部环境的机会和威胁四个方面进行了详细的分析,从政策、经济、社会、技术等方面总结了目前亚洲发展中地区推广户用沼气池的问题,并提出了相应的发展策略.     

基于MODIS数据的中亚地区旱情监测及影响因素分析

在全球变暖的背景下，及时准确地进行干旱监测对保障区域生态安全、对"新丝绸之路经济带"沿线各国的经济发展以及农业生产具有重要的指导意义。近年来，世界各地自然灾害频繁发生，中亚地区的干旱问题已成为全球生态环境变化中最显著的问题之一，阻碍了中亚及周边国家社会经济的长期、稳定发展。该研究基于2001-2020年的MODIS地表温度（Land Surface Temperature，LST）和归一化植被指数（Normalized Difference Vegetation Index，NDVI）数据建立了温度植被干旱指数（Temperature Vegetation Dryness Index，TVDI）模型，利用趋势分析、MK趋势检验、地理探测器等方法揭示了中亚地区近20 a的干旱时空变化及特征、干旱演变规律并探讨了不同因素（气温、年均降雨量、土地利用类型、人口密度、高程、坡度、坡向）对TVDI的影响。结果表明：1）中亚干旱区TVDI空间分布具有明显的区域特征，呈现出自西南向东北递减趋势，其中66%面积呈干旱显著加剧趋势（P<0.05），34%的面积呈干旱显著减弱趋势（P<0.05），呈现"北部变干、南部变湿"空间变化趋势。其中，哈萨克斯坦的西北部一带旱情加剧显著；2）从旱情年际变化趋势可知，近20 a中亚地区生长季干旱程度略呈加剧趋势，2012年为干旱最严重的年份。TVDI空间分布差异显著，整体呈季节性变化，其干旱等级表现为：夏季>春季>秋季；3）单因子探测结果显示，气温和高程是驱动研究区干旱化形成的主要影响因素，多因子交互作用下，气温和高程、气温和坡度、气温和土地利用、气温与降雨量这4对组合贡献最大。随着全球气候变化、人类活动（植被破环、城市化建设、开垦耕地、过度放牧、工业污染等）持续加剧，近20 a来中亚地区气温逐渐上升，降雨量的减少，导致植被退化，进而导致生态环境恶化、干旱化趋势加剧。该研究可为当地政府及相关部门的旱灾防控提供参考和提升中国应对中亚生态风险及地缘安全影响的能力具有重要意义。     

Forest conversion adversely affects native Macrobrachium shrimp assemblages in tropical Malaysian streams

1. Commodity-driven forest conversion represents one of the most severe threats to freshwater biodiversity in Southeast Asia, notably causing population declines and the extinction of freshwater fish species.
2. Although a variety of freshwater taxa are likely to be adversely affected by forest conversion, little is known about the impact on ecologically and economically important invertebrates such as decapod crustaceans.
3. This study evaluated the impact of forest conversion and land-use change on freshwater Macrobrachium shrimp species, using species richness, abundance, and environmental data collected from 20 streams across southern Peninsular Malaysia. Streams were located in three types of landscape: forest; oil palm plantation; and mixed land use, comprising young secondary forest, small-scale plantations, patches of open and sparsely vegetated areas, and agricultural fields and clearings.
4. Generalized linear models showed that even incomplete change from forest habitats to mixed land use and oil palm plantation resulted in significantly lower Macrobrachium native species richness and higher non-native species abundance. Native species richness was positively correlated with canopy cover, leaf litter, substrate size, and dissolved oxygen, and was negatively correlated with water temperature and conductivity. Native species richness was also negatively correlated with non-native species abundance, with non-native species abundance increasing along the human disturbance gradient.
5. These results highlight the need for riparian habitat protection to conserve native Macrobrachium and limit the spread of non-native species. A management priority should be to maintain or restore optimum instream habitat conditions for shrimps, which would also benefit fish and other benthic macroinvertebrates. Suitable riparian management requires substantial support and funding from multiple stakeholders, but it can be aligned with other catchment-based strategies to optimize the use of limited resources available for freshwater biodiversity conservation.