我国近海捕捞经营组织形态的现状调查与分析——基于福建省的调研数据

在界定我国近海捕捞经营形态内涵的基础上,基于福建省各地区的调研,利用股份集中度指数、持股均匀度指数以及雇工劳动力指数考察我国海洋捕捞股份经营形态出现的异化现象。研究结果表明:福建省沿海渔船的股份集中度指数均40%,最高超过80%,而持股均匀度指数也均在1以上;另外,雇工劳动力指数≥35%,闽南地区则高达80%。应用新制度经济学的观点对该异化现象的影响因素进行理论探讨,认为经济基础因素、内部管理因素、制度环境因素和风险控制因素是产生该现象的原因。基于以上结论,提出成立新型渔业合作组织、实行公司化管理是近海捕捞经营体制改革的探索新方向。     

河南省农村劳动力就业结构与转移特征研究

河南省是我国人口大省,其中农村劳动力资源数量较大也是河南省社会经济发展的重要因素之一.而农村劳动力的就业结构和转移特征对区域产业结构有着重要影响.将常用于产业结构特征分析的偏离-份额分析法应用于劳动力结构分析,可以较好地了解劳动力就业和转移特点,为区域社会经济的发展提供参考.研究表明:河南省农村劳动力转移仍呈现传统农业大省的典型特征;农村劳动力的农业就业基础优势逐渐削弱,而工业、建筑业和批发零售餐饮业等行业的竞争优势较强,同时,河南省各地市农村劳动力就业的部门偏离存在区域差异.     

中国割胶制度的发展历程及解决胶工短缺建议

割胶是橡胶生产的重要工作,橡胶生产工作条件相对较差,再加上近几年胶价连续低迷和人工成本的增加,造成胶工严重短缺,严重制约了天然橡胶产业的发展。本文就中国割制的改革历程进行了综述,并针对胶工严重短缺的问题提出几点建议和看法。     

安徽岭南优势树种(组)生物量特征

森林是陆地生态系统的主体,在全球陆地生态系统碳循环和碳储量中占有十分重要的地位(Dixon et al.,1994;Watsonetal.,2000;史军等,2004;徐新良等,2007)。测定森林群落生物量,可以反映群落利用自然的潜力,衡量群落生产力的高低,也是研究森林生态系统物质循环的基础(薛立等,2004)。森林乔木层生物量研究是开展森林群落生物量碳库研究的基础,国内外已有不少该方面的研究,分别从不同角度分析了树种生物量的组成与分配特征,并进行了相关因子分析(Chidumayo,1990;林开敏等,1996;Arashkevich et al.,2002;樊后保等,2006;陈美高,2006)。冯宗炜等(1999)总结了全国不同森     

紫穗槐表型可塑性及植株资源分配对高寒生境的响应

对在西藏拉萨市和甘肃玛曲县青藏高原区种植的紫穗槐（Amorpha fruticosa）17项形态特征指标及其5个不同构件11种营养元素含量进行比较分析。结果表明,1）两地区紫穗槐表型特征存在差异,特别是地下部分形态指标差异显著;2）紫穗槐不同构件生物量比重、各个营养元素含量存在不同程度差异,且地区间相应指标也存在差异,是植株资源分配对高寒生境的响应所引起的;3）两地区紫穗槐形态指标与其营养元素含量均存在复杂的相关关系。     

Nitrogen retranslocation, allocation, and utilization in bare root Larix olgensis seedlings

We quantified biomass accumulation and nitrogen (N) retranslocation, allocation, and utilization of Changbai larch (Larix olgensis) seedlings subjected to four fertilization treatments (24, 59, 81, 117 kg·ha-1 N) with an unfertilized control during summer and autumn 2009. Ammonium phosphate (18-46-0) was the fertilizer used in all treatments. On both sampling dates, the needles had greater biomass and N content than new (2009) stems and old (2008) stems, and coarse, medium and fine roots (diameters of >5, 2-5 mm, and 0-2 mm, respectively). Higher N concentration was observed in old stems and coarse roots than that in new stems and medium roots. In mid-summer, fine roots had higher N concentration than coarse roots. The treatment with 24 kg·ha-1 N had the greatest biomass and N content in needles and old stems, and highest net N retranslocation (NRA) and amount of N derived from soil. On September 21, no N translocation was observed, while the treatment with 24 kg·ha-1 N had the highest N utilization efficiency and fertilizer efficiency. Vector analysis revealed that all four fertilization treatments induced N excess relative to the control. The treatments with 59, 81, 117 kg·ha-1 N induce N excess compared with treatments at 24 kg·ha-1 N. We conclude that the traditional local fertilizer application rates exceeded N requirements and N uptake ability for Changbai larch seedlings. The application rate of 24 kg·ha-1 N is recommended.     

Spatial Para Allocation of a Small Watershed Protection Forest System

With the interpreted IKONOS4 satellite images collected in 2005,a 1:10 000 forest map,the data collected in ClassⅡforest survey in 2007,and surface runoff data obtained in the permanent runoff monitoring station,six site factors of slope gradient, slope position,soil thickness,soil thickness of A layer,soil type and soil water content were selected to establish a matter element model suitable to 297 forest sub-compartments.Further,the AHP was applied to modify the spatial structure and form the spatial para allocation of the protection forest system. The results showed that:1) the area allocation of different vegetation types was irrational,the area of a mixed coniferous and broad-leafed forest was 124.39 ha,accounting for 14.97%of the forested land,the mixed forest was consisted of two coniferous species accounted for 27.37%of the total forest land,and the pure forest was consisted of one coniferous species accounted for 42.48%.2) After optimization,the area allocation of different vegetation types in the protection forest system ranked as:the mixed coniferous and broad-leafed forest(31.12%)>shrub land(15.5%)>the economic tree crops(12.28%)>the mixed forest consisting of two coniferous species(11.46%)>the pure broad-leafed forest(11.41%)>the pure coniferous forest(9.51%)>grass land(8.70%). Besides,the annual surface runoff could reduce 43 171 mm or 62.15%,annual soil erosion could decrease 465.97 t or 79.66%.3) The following suggestions for spatial para allocation of the small watershed protection forest system were proposed: (1) Reducing pure cypress or pine forest,and increasing alder-cypress,oak-cypress or pine-cypress mixed forest.As for the current cypress and pine pure forests,alder or oak could be introduced to develop a mixed forest.(2) The canopy closure of pure cypress forest and alder-cypress forests should be maintained within 0.60-0.75,and the canopy closure of oak-cypress,pine-cypress or oak-pine forests should be controlled within 0.60-0.80. (3) For improvement of current pure     

Responses to temperature and shade in Abies alba seedlings from diverse provenances

Abstract

Intraspecific variability in responses to temperature and shade was studied at Champenoux, north-eastern France, with seedlings from five Polish provenances of silver fir (Abies alba Mill.). Acclimation of photosynthesis to temperature was investigated in seedlings exposed to 10, 25 and 35°C in a climate chamber for 1 week. During two growth seasons, a population of seedlings was grown in the nursery under four different irradiance regimens: 100, 48, 18 and 8% of natural irradiance. Maximum carboxylation rate (V _cmax), maximum light driven electron flow (J _max) and maximum net carbon dioxide assimilation rate (A _max) measured at 25°C increased with population altitude. One week of exposure to 35°C caused discoloration and massive needle shedding. After 2 years’ acclimation to different levels of irradiance, a significant interprovenance variability was evidenced in growth, total biomass, biomass allocation and photosynthetic performance. This study provided evidence for the existence of functional variation among the examined provenances.     

苦瓜植株水浸提液对水稻种子萌发和秧苗生长的影响

旨在明确苦瓜植株对后茬水稻的化感作用潜力,为稻菜轮作制度的应用提供指导.以苦瓜植株残体为试验材料,用培养皿法和水培法研究其水浸提液对3种水稻('特籼占25'、'博Ⅱ优818'和'Ⅱ优129')种子萌发和秧苗生长的影响.结果 表明:水浸提液仅在浓度达0.20g/mL时降低了3种水稻种子的发芽率,降低'博Ⅱ优818'和'Ⅱ...     

Changes in Ectomycorrhizal Colonization and Root Peroxidase Activity in Pinus sylvestris Nursery Seedlings Planted in Forest Humus

Plant biomass, root colonization by ectomycorrhizal (ECM) fungi and root peroxidase (POD) activity were monitored in Scots pine (Pinus sylvestris L.) nursery seedlings during the first growing season after planting (after 4, 8 and 16 weeks, in July, August and October, respectively) in forest humus in outdoor open-top chambers with gaseous atmospheric pollutants (combinations of low levels of ozone, sulfur dioxide and nitrogen oxides). The number of ECM morphotypes as well as root biomass increased towards the end of the growing season, while root POD activity decreased. Fungal biomass estimated as ergosterol concentration peaked in August, 8 weeks after planting. The seedling growth, mycorrhizal status and POD activity in the roots were not affected by the gaseous pollutants.