CHALLENGES PROVIDING MULTIPLE ECOSYSTEM BENEFITS FOR SUSTAINABLE MANAGED SYSTEMS

Since humans started practicing agriculture at the expense of natural forests,8000 years ago, they have affected atmospheric CO₂ concentrations. Their impact on atmospheric CH₄ started about 5000 years ago, as result of the cultivation of paddy rice. A challenge of modern agricultural practices is to reverse the impact cropping has had on greenhouse gas emissions and the global climate. There is an increasing demand for agriculture to provide food security as well as a rang...     

高校图书馆多元化信息资源开发与应用研究

针对目前以传统印刷型文献资源的配置为主导的"实体馆藏"已经不能满足需要,文章扩展了信息资源的涵义,通过分析高校图书馆信息资源的内在多元化的特质,指出开发多元化信息资源应遵循的原则,具体探讨了多元化信息资源开发与应用的策略创新,得出各馆应根据自身实力充分挖掘多元化信息资源,期待更好地为读者服务,构建和谐校园.     

京津冀地区土地利用/覆被与景观格局变化及驱动力分析

本文利用土地利用转移矩阵和景观破碎化指数、景观多样化指数采用典型样带对京津冀地区1990年、2000 年土地利用数据进行了土地利用/覆被变化(LUCC)和景观格局变化(LPC)的定量及定性分析, 探讨了其影响因素, 为该区域土地资源可持续利用提供依据。结果发现区域内居民地附近LUCC 和LPC 强度最大, 尤其北京、石家庄等地变化明显。利用多年社会经济统计数据, 通过相关分析和主成分分析, 定量地确定社会经济、农业生产条件和交通是京津冀地区LUCC 和LPC 的主要驱动因子。而后,定性分析了地形复杂度和政策对京津冀地区LUCC 和LPC 的影响, 发现西部及北部山区地形较复杂, 人类活动干扰较小, 故LUCC 和LPC在平原地区表现更突出。但生态政策如退耕还林还草和土地开发整理等对西部山区LUCC 和LPC 有不同程度的影响。最后, 综合分析各驱动力在不同地区影响的差异, 发现社会经济发达的大城市的驱动因素主要为社会经济, 而传统农业区主要受农业生产条件的影响。通过以上定量及定性分析京津冀地区LUCC 和LPC 的驱动因子, 尤其是对驱动因素的时空分异规律分析, 为土地管理决策、土地资源保护等提供了科学的依据和指导。     

First results of spawning and larval rearing of longfin yellowtail Seriola rivoliana as a fast‐growing candidate for European marine finfish aquaculture diversification

The present study describes the adaptation of longfin yellowtail Seriola rivoliana as broodstock and first larval rearing trials under intensive and semi‐intensive conditions. Fifteen sub‐adults were captured in the South coast of Gran Canaria (Canary Islands, Spain) in June 2007. Fish (initial weight 1.76 ± 0.25 kg) reached a weight of 6.0 ± 1.1 kg in July 2010. Once a year, fish were sampled to determine individual growth in weight and size. In addition, the state of sexual maturity was established based on gonadal biopsies. On the basis of repeated hormonal injection (GnRHa, 20 μg/kg), 10 successful spawns were obtained between July and October 2009, with 92.5 ± 5.5% and 72.6 ± 17.2%, fertilization and egg viability respectively. First results of larval rearing under semi‐intensive conditions, showed an average survival at 30 DAH of 2.5% as compared with 0.5% under intensive conditions. The low survivals under the two rearing conditions in addition to their failure to pass a stress test could be attributed to deficiencies in essential fatty acids as could be seen in both eggs and feeds. Morphometric parameters showed no significant difference between the two rearing systems in 230 DAH larvae.     

应用单体分析法对三个冬小麦品种（系）进行抗白粉基因定位的研究

用单体分析法对3个冬小麦品种（系）进行了基因定位研究。结果表明：小白冬麦和复壮30对白粉病的抗性，分别由1个位于1A染色体、1个位于4D染色体上的隐性基因所控制。由于1A染色体上的两个已知Pm基因Pm3和Pm17的苗期抗性均不如小白冬麦的强，也由于已知Pm基因中没有位于4D染色体上者，故认为小白冬麦和复壮30所含隐性抗白粉基因可能是新的Pm基因。结果还表明，Fr81－8所含抗白粉基因很可能是Pm4b。对于关键组合F2抗感分离比例偏离97∶3标准比例的原因亦作了分析。     

中国大豆多元化布局和替代战略前景

【目的】优化中国大豆进口贸易格局,为保障国内产业链、供应链平稳运行提出政策建议。【方法】从大豆进口多元化布局和大豆替代战略两个视角分析降低中国大豆进口依赖的前景。【结果】研究发现,短期内具备一定大豆进口潜力的国家和地区包括中亚和俄罗斯地区、南美地区;从长期看,非洲地区后备耕地资源丰富,具备较强的大豆生产潜力。同时,大豆潜在替代品的产量,如油菜籽、葵花籽等均远低于大豆,替代能力有限。低蛋白日粮等新型饲料配方技术可以提升大豆使用效率,减少大豆使用量接近3000万吨。【结论】建议从推动进口多元化、推广先进技术、提高国内大豆产量等方面入手。     

质量功能展开在高校食堂功能多元需求分析中的应用

对国内外高校食堂功能构成进行对比分析,指出高校食堂不应仅是满足学生就餐需要的必要设施,应成为大学生重要的社交活动场所,其功能要向多元化方向发展.将质量功能展开方法引入到食堂功能要素的规划中,以东北林业大学食堂为例,基于学生需求调查结果,运用质量功能展开方法对食堂的功能要素进行分析,建立各功能要素的相关矩阵并进行定量评价,从物流和人流角度给出了食堂各功能区域规划建议.     

Agricultural diversification among smallholder rattan cultivators in Central Kalimantan,Indonesia

Many developing countries are trying to promote agricultural diversification among smallholders because they feel that smallholders are too dependent upon a narrow range of crops. Fieldwork among smallholder rattan cultivators in Southern Borneo, Indonesia, suggests that smallholders do maintain a poorly diversified portfolio of agricultural activities. Farmers rely heavily upon rattan because of its superior profitability. A number of economic and agronimic constraints however prevent farmers from diversifying out of rattan into other crops.     

宝泉林场森林资源变化及经营效果评价

本文根据1989年和2004年两次森林资源二类调查资料,分析了宝泉林场的森林资源变化及趋势,并对其经营效果作出了评价。