Ecological functioning of free-living marine nematodes in coastal wetlands: an overview

Nematodes are small multicellular, thread-like organisms, inhabiting almost all conceivable environments; among these, some 25 % are free-living marine forms with a population density of （1-12） × 10^6 inds m^-2 in seabed sediment, reaching maximum values in muddy estuaries and salt marshes. A large quantity of carbon from the salt marsh plants enters the ecosystem via the detritus pathway, in which nematodes play an important role through their feeding and bioturbation activities. Vegetation influences the sedimentary environment and modifies the distribution pattern of nematode communities in coastal wetlands. Nematodes are coupled closely with bacteria/detritus in microbial food webs, stimulating bacterial growth and subsequent nutrient remineralization; they provide food sources for higher trophic levels and serve as a linkage between micro- and macro-fauna. Furthermore, nematodes have a potential to provide proxies that can be used in diagnosing environmental quality. In China, only a limited number of nematode data sets are available for the coastal wetlands across several different climatic zones. It is necessary to carry out additional investigations into the biology and ecology of nematodes in order to delineate their ecological functioning in coastal wetlands. On such a basis, the contribution made by nematodes to material cycling and the ecological functioning in coastal wetlands can be quantified. The assessment of their biological diversity should be a focus, which is fundamental in the study of wetland ecosystem dynamic mechanisms. In addition to laboratory and mesocosm experiments, mathematical models should be established to predict the responses of ecosystem to the environmental disturbance. Finally, it is necessary to improve the techniques for nematode analysis, to enhance the efficiency of data acquisition.     

基于选择实验法的胶州湾滨海湿地生态补偿标准研究

采用选择实验法从湿地面积、植被覆盖率、生物多样性、湿地水质、生态功能、湿地景观6个属性出发,在胶州 湾滨海湿地构建选择模型. 在实地调查的基础上,运用随机参数 Logit模型定量评估了不同属性的支付意愿,计算得出 胶州湾滨海湿地生态补偿标准为425.95元·(a·户) -1. 与其他区域湿地相比,该补偿标准占青岛市人均可支配收入的比 值相对较小. 农户受偿意愿主要受教育程度、家庭收入、个人健康状况和是否参加过环保活动4个变量的显著影响. 其中 农户受教育程度越高,家庭收入越高,个人健康状况越好,参加过的环保活动越多,个体支付意愿就越强烈.6个属性中, 公众对湿地景观、水质和面积变化的关注程度更高,因为湿地景观变化、水质下降和面积减少会直接或间接的影响居民 的福利和生活水平. 因此,保护湿地景观、净化湿地水质和恢复湿地面积应成为未来胶州湾滨海湿地保护和管理的重点.      

西双版纳森林火险气象等级区划研究

采用西双版纳州防火期网格化的月平均降水量、月平均气温、月平均风速、月平均蒸发量、月平均相对湿度等5个气象因子,以及西双版纳州树种和土地利用分布图作为火险区划因子,通过将其标准化并赋予各因子不同的权重,利用ARCGIS的栅格分析计算功能,对西双版纳州防火期内进行森林火险气象等级划分,并以历史林火统计结果作为验证.从区划结果来看,12月至次年5月森林火险气象等级的发展趋势基本符合西双版纳州的实际情况.对照历史林火统计结果,该结果能反映西双版纳州大部地区在防火期不同月份的森林火险气象等级分布规律,具有较高的实用价值.     

经济地理格局差异性背景下的公益林生态补偿模式初探——以贵州省江口县为例

现阶段我国森林生态效益补偿仅仅是以国家财政补偿为主导,资金来源渠道和补偿方式单一,经济地理格局的差异性导致的补偿标准地区间差距的存在,使得少数民族聚居地区及经济发展落后地区的林农对林木保护的情绪极其消极。统计分析江口县三大公益林区调查问卷,根据林农的需求,探索性地建立市场主导—政府干预—林业搭台—部门唱戏—社会参与的间接补偿模式,旨在加强间接补偿的力度,弱化政府直接支付补偿,提高林农的自我发展能力,使林农的收入增加并且来源多元化,逐步降低他们对于政府直接支付补偿的依赖性,从根本上实现由被动输血式补偿向主动造血式补偿的转变,实现公益林区经济、社会、生态可持续发展的目的。     

阻断精神分裂症的发病进程——精神病高危人群的识别和干预

 以精神分裂症为主要代表的重性精神障碍的诊疗一直是临床医学中较为棘手的问题。近年来,越来越多的科研团队开始将这一群体的临床和基础研究提前到了精神病高危综合征阶段,这在很大程度上促进了精神病早期干预技术和理念的发展。本文综述了精神病人群的临床和行为学特征、生物学标记和有效干预手段等相关研究最新进展,探讨了精神病早期识别和干预技术的未来发展方向。     

GA在改善证券市场风险测量精度中的实证研究

应用遗传算法(GA)估计线性GARCH(1,1)模型和非线性EGARCH(1,1)的参数,建立两个模型计算中国证券市场的风险值(VaR).通过对比传统算法和遗传算法的风险值,计算数据显示:线性GARCH(1,1)模型和非线性EGARCH(1,1)模型下,GA得到的风险值均大于真实值,可以解决传统算法中预测精度不高的问题.