东海区海洋渔业资源近况浅析

根据渔获产量统计和鱼类生物学资料对东海区海洋渔业资源动态作了分析。结果表明：近几年东海区海洋渔业捕捞产量虽连年增长，但主要是靠大幅度提高捕捞强度等措施获得。渔获物中增加的主要是经济鱼类的幼鱼和低值小杂鱼类，渔获物小型化、低龄化等过度捕捞现象仍然十分严重。渔业资源结构日趋恶化，渔业资源状况并没有明显改善。     

立用型地方本科院校土地资源管理专业校企合作实践教学保障——以池州学院为例

应用型地方本科院校是我国高等教育现阶段培养应用型人才的重要基地。校企合作实践教学则是应用型地方本科院校在人才培养模式改革方面的重要探索。通过校企合作实践教学既可以实现应用型人才培养目标、提高人才培养质量,还可以加强高校与社会的联系,充分利用社会资源来培养市场所需的应用型人才。以应用型地方本科院校池州学院土地资源管理专业为例,从构建循序渐进的校企合作实践教学体系、构建校内外“双导师”制、建设多元化专业实践教学基地以及校方与合作单位协同组织等方面对如何保障应用型地方本科院校进行校企合作实践教学加以探讨,以期为同类院校开展校企合作实践教学、培养应用型人才提供参考。     

Microencapsulation of Peony Oil

目的]探讨牡丹油微胶囊化技术。[方法]利用β-环糊精、阿拉伯胶和大豆蛋白作为壁材采用喷雾干燥技术制备牡丹油的工艺,对牡丹油微胶囊的制备工艺参数进行了单因素和正交实验分析。[结果]得到制备牡丹油微胶囊的最优工艺参数∶壁材β-环糊精∶阿拉伯胶∶大豆蛋白的配比3∶1∶2,固形物含量35%,芯壁材配比3∶1,乳化剂添加量0.2%。在此条件下,牡丹油包埋率达到92%。[结论]在此工艺下牡丹油的包埋率高,为牡丹油的进一步开发打下了基础。     

仙翁山国家森林公园大型真菌资源调查

为了使野生资源得到合理的开发与利用,对黑龙江省仙翁山国家森林公园大型菌类资源进行调研,并对采集的菌株进行分类分析。在仙翁山森林公园,共采集食用菌类18科48种、药用菌类10科15种、毒菌10科15种。该地区有丰富、珍贵的菌类资源,应通过科学的规划和管理,合理开发利用,使得生态环境可持续平衡发展。     

不同供氮水平多花黑麦草化感抑草作用与资源竞争分析

[目的]为了判断黑麦草与猪殃殃的化感作用与资源竞争关系。[方法]运用化感一竞争分离法,通过盆栽混播不同比例的供、受体植株,测定受体植株干重的变化规律,以探讨黑麦草对猪殃殃杂草的化感作用或资源竞争的关系。[结果]当黑麦草和猪殃殃混播比例较大时（供受体混播比例为12：10）,会由竞争作用转为化感作用;而在氮素胁迫条件下,两者的关系均会加强,在氮水平为10kg／667m2时,化感作用最强,随着氮水平的加大,抑制作用减弱,竞争作用逐渐加强。[结论]明确黑麦草与猪殃殃的资源竞争与化感作用的关系,为黑麦草化感抑草作用研究提供理论依据。     

不同浓度赤霉素对盆栽牡丹催花影响研究

研究了不同浓度赤霉素(GA3)(200 mg/kg涂蕾、500 mg/kg涂蕾、800 mg/kg涂蕾、1 000 mg/kg浇根)对中原牡丹品种胡红催花效果的影响。结果表明:500 mg/kg赤霉素(GA3)催花涂蕾效果比较明显。催花周期为40~45 d,处理后花径为16.2 cm,明显大于CK的13.21 cm。     

我国土地资源利用中存在的问题与对策

土地资源是人类的宝贵财富,也是一切生产部门,首先是农业部门为实现生产过程所不可缺少的生产资料。从界定土地资源的基本概念出发,分析了土地资源存在的主要问题,并针对问题提出有有针对性的对策措施,以期促进我国土地资源利用与环境、经济发展相协调。     

Supply of tree-holes limits nest density of cavity-nesting birds in primary and logged subtropical Atlantic forest

Tree cavities are proposed to limit populations and structure communities of cavity-nesting birds. Although the greatest diversity of cavity-nesting birds is found in tropical and subtropical moist forests, little is known about how tropical logging affects the abundance of cavities or cavity-nesting birds. We compared the abundance of cavities and cavity nests between primary and selectively-logged subtropical moist Atlantic forest in Argentina, and conducted the first before-after controlled nest-box addition experiment to determine whether nest sites limit the breeding density of cavity-nesting birds in tropical or subtropical moist forest. Visual inspection of 86 cavities identified through ground-surveys revealed that only 19% were suitable for nesting birds, suggesting that cavity abundance may be overestimated in the literature on tropical forests. Suitable cavities were found in fewer than 1% of 1156 trees <60 cm dbh but 20% of 20 trees >100 cm dbh. Logged forest had half the basal area of primary forest, one third the density of large trees, nine times fewer cavities suitable for nesting birds, and 17 times fewer active nests. When we added nest boxes, nesting density increased on treatment plots but not on control plots in both logged and primary forest, suggesting that cavity supply can limit nest density even in relatively undisturbed forest. This is the first experiment to show how reduced cavity supply in logged tropical forest can limit breeding density of cavity-nesting birds. International initiatives such as forest certification should promote tropical timber management strategies that conserve large live cavity-bearing trees.     

垫江牡丹栽种期试验研究

通过田间试验研究了不同栽种期对垫江牡丹生长和产量的影响,结果表明:9月15日-10月5日期间栽种的牡丹产量较高,此外在此期间栽种牡丹所收获的根的粗度和长度均具有较好优势,综合各性状指标,最佳栽种期为10月5日.     

Land Equivalent Ratio of Groundnut-Fingermillet Intercrops as Affected by Plant Combination Ratio,and Nitrogen and Water Availability

Abstract

Field experiments were conducted to characterize intercropping advantages in groundnut-fingermillet intercrop in relation to crop combination ratios, soil moisture and nitrogen (N) availability. Three intercrops in 1 : 2, 1 : 1 and 2 : 1 alternating rows of groundnut and fingermillet were examined for their growth and yield in comparison with their respective sole crops in 1996. The effect of well watered (W) and water stressed (D) conditions on the intercropping advantage was also examined for 1 : 1 intercrops in 1995 and 1996. Fertilizer N was applied at the rate of 20 kg ha^?1 in 1995 and 50 kg ha^?1 in 1996. The total above-ground biomass (DM) and its land equivalent ratio (LER) were highest in the 1 : 1 combination ratio. The DM production of intercropped fingermillet was higher in 1996 with higher N than in 1995 with low N application, while those of groundnut were similar in both years. The intercropped groundnut exhibited significantly higher DM production after the fingermillet harvest. The LERs in grain yield were higher in 1996 (1.43 under W and 1.45 under D), than in 1995 (0.87 under W and 1.22 under D). Also, LERs were consistently higher under D than W conditions. Water stress severely reduced the leaf area index (LAI) of fingermillet at a low N, especially in the later stages, whereas higher N alleviated the water stress effect. A close linear relationship was observed between LAI and leaf area (LA) per unit leaf N both for groundnut and fingermillet, with intercrops producing larger LA per unit leaf N than sole crops. Intercropping maintained higher ability in leaf net photosynthesis and transpiration of groundnut up to later stages, and significantly reduced water evaporation from the soil surface under the canopy than sole cropping of fingermillet. These results suggest that three processes associated with the intercropping yield advantages in the groundnut-fingermillet intercrop; 1) higher leaf photosynthesis and vigorous growth of groundnut after the fingermillet harvest, 2) higher LA production per unit N and 3) efficient water use. In conclusion, interspecific shading was considered to be the key mechanism associated with these processes, leading to the intercropping advantages. The degree of the interspecific shade and its effect on growth and yield depended on the available soil N and water.