Production and conservation of nutrient-rich small fish (SIS) in ponds and wetlands for nutrition security and livelihoods in South Asia: Proceedings of a World Bank/SAFANSI funded regional workshop on small fish and nutrition, Dhaka, Bangladesh, 1st - 2nd March 2014

Small indigenous fish species (SIS) are an important source of essential macro- and micronutrients that can play an important role in the elimination of malnutrition and micronutrient deficiencies in the populations of many South and Southeast Asian countries. Of the 260 freshwater fish species in Bangladesh, more than 140 are classified as SIS and are an integral part of the rural Bangladeshi diet. As many SIS are eaten whole, with organs and bones, they contain high amounts of vitamins and minerals, including calcium, and iron and zinc. Some SIS, such as mola, are also rich in vitamin A. SIS are often cooked with vegetables and a little oil, so they contribute to the food diversity of the rural poor.SIS are recognized as a major animal-source food group, contributing to improved food and nutrition security and livelihoods of the people of South and Southeast Asia. The purpose of this workshop is to bring together policy makers, extension agents, researchers, non-governmental and development organizations to share knowledge about small fish, their contribution to better nutrition, production technologies, and strategies for wider dissemination of pond culture and wetland based-production and conservation technologies. The workshop is expected to generate ideas for further research and development of sustainable technologies for production, management and conservation of SIS for the benefit of the people of Bangladesh as well as the South and Southeast Asian region.

Tree-ring records as indicators of air-sea interaction in the northeast Pacific sector

Climate conditions in land areas of the Pacific Northwest are strongly influenced by atmosphere/ocean variability, including fluctuations in the Aleutian Low, Pacific-North American (PNA) atmospheric circulation modes, and the El Niño-Southern Oscillation (ENSO). It thus seems likely that climatically sensitive tree-ring data from these coastal land areas would likewise reflect such climatic parameters. In this paper, tree-ring width and maximum lakewood density chronologies from northwestern Washington State and near Vancouver Island, British Columbia, are compared to surface air temperature and precipitation from nearby coastal and near-coastal land stations and to monthly sea surface temperature (SST) and sea level pressure (SLP) data from the northeast Pacific sector. Results show much promise for eventual reconstruction of these parameters, potentially extending available instrumental records for the northeastern Pacific by several hundred years or more.

Nutrient Enhanced Coastal Ocean Productivity (NECOP). Data report: CTD and hydrographic data, R/V Pelican cruise, April 3-11, 1993

The Nutrient Enhanced Coastal Ocean Productivity (NECOP) Program is a component of NOAA's Coastal Ocean Program. The central hypothesis of this research is: Anthropogenic nutrient inputs have enhanced coastal ocean productivity with subsequent impacts on coastal ocean water quality, living resource yields, and the global marine carbon cycle. The initial study area for this program is the Mississippi/Atchafalaya River Outflow and adjacent Louisiana shelf region.

寄生植物在入侵植物防治中的作用——以两种菟丝子为例

生物入侵在全世界广泛发生，目前已经受到全球关注。入侵生物对群落生物多样性和生态系统功能造成严重威胁，导致严重的环境问题和惨重的经济损失。薇甘菊(Mikania micrantha)、五爪金龙(Ipomoea cairica)和南美蟛蜞菊(Wedelia trilobata)是我国华南地区危害最严重的三种外来入侵种，其中以薇甘菊危害最严重，是世界十大有害杂草之一。从20世纪80年代发生以来，薇甘菊已在我国广东农林区域造成严重危害。 机械防治、化学防治和传统的生物防治等治理措施，未能有效治理外来入侵种的危害，直到使用本地种菟丝子(Cuscuta spp)的防治策略。与从原产地引进有害生物天敌的传统生物防治方法不同，本地种由于适应当地气候且与其他物种协同进化，因此，对生态环境潜在的负作用小。从2000年，被发现寄生和抑制薇甘菊之后，菟丝子被认为是防治薇甘菊的有效措施。 为了探讨菟丝子寄生对外来入侵种的治理，及对入侵群落的恢复，本研究在内伶仃岛的林地(入侵种群落被引入菟丝子寄生1-4年)，以及东莞、深圳和海丰的干扰样地(入侵种群落被菟丝子自然寄生5年以上)开展野外调查。在每个样地分别设立外来种入侵亚群和菟丝子治理亚群，通过测定群落结构与组成、土壤性质与养分含量，以及外来种和菟丝子的生长与养分含量等参数之后，本研究得出以下主要结论。 (1) 虽然，被寄生的外来入侵种薇甘菊、五爪金龙和南美蟛蜞菊通过调节资源分配以抵御南方菟丝子(Cuscuta australis)的寄生影响，但是，菟丝子寄生导致外来入侵种生物量降低、繁殖能力下降、养分含量降低。虽然，很多寄生植物都是广谱寄生，能同时寄生多种寄主植物，但是，在本研究的被入侵的群落中，菟丝子主要寄生外来入侵植物。尤其是寄生于南美蟛蜞菊和薇甘菊的菟丝子，生长旺盛、繁殖能力强，表现出高度的适应性。因此，菟丝子对外来入侵种(南美蟛蜞菊和薇甘菊)有寄生偏好性，并对本地种的负面影响小。 (2) 通过吸收寄主的养分，田野菟丝子(Cuscuta campestris)有效地抑制了薇甘菊的危害。由于入侵种的凋落物养分含量高且分解效率高，而且，菟丝子能够促进其它凋落物的分解，并使难以被植物吸收的养分转化成易于被吸收利用的状态。因此，菟丝子与薇甘菊的寄生作用导致土壤养分含量的升高。在薇甘菊被抑制之后，本地种利用丰富的土壤养分资源，提高生长适应性，增强抵抗入侵的能力，甚至抵制薇甘菊的再生。 (3) 菟丝子的寄生作用改变了外来寄主与本地非寄主的竞争平衡，促进本地植物的生长与重建。在外来种被抑制之后，本地种的丰度和群落的物种多样性逐渐增加。本地种如：野葛(Pueraria lobata)和芦苇(Phragmites australis)，取代了入侵群落中的入侵种，成了群落的优势种。而其它原先被薇甘菊抑制的本地草本、藤本和灌木，在引入菟丝子防治之后长势较好。群落稳定性与物种多样性密切相关，被治理群落本地种的增加有利于群落的演替与稳定。 (4) 被干扰的生态系统往往更容易被外来种入侵，而外来入侵种又常导致人工干扰生境的严重退化。在人工干扰样地的菟丝子对薇甘菊的抑制效果与在林地的效果一致，导致被寄生的薇甘菊生长衰退、养分竞争能力下降、入侵危害能力降低。而在薇甘菊被菟丝子治理之后，土壤养分资源增加，入侵群落的物种丰度和生物多样性提高。本 地种的重建与本地群落的恢复密切相关，利于本地被治理群落的稳定，促进被干扰植被的恢复。 菟丝子是一种治理外来入侵种危害的有效措施，适用于破碎的生境和被干扰的生态系统，尤其是在采用目前防治措施难以治理的情况下。本研究为本地种防治外来入侵种提供科学依据，且表明以入侵地的本地种治理外来入侵种有可能成为有效且可持续发展的生物防治策略。