香榧适生环境研究进展

综述了气候、土壤和地形地貌等环境因子对香榧Torreya grandis‘Merrillii’生长和结实性状的影响,初步总结了香榧适生区域的环境条件,并指出目前香榧适生环境条件研究中存在的问题。结合我国现有香榧分布区划研究现状,认为开展小气候等环境因子的长期定量观测和利用3S（全球定位系统GPS,地理信息系统GIS和遥感RS）技术进行香榧适生区域环境宏观分析是今后香榧适生环境条件研究的重要内容之一。     

VBM框架下企业财务管理目标的实现

近十年来,VBM理论已受到财务管理、薪酬、战略等众多理论研究的支持.文章从VBM的内涵出发,牵引出企业财务管理目标的选择问题.通过对比分析,选出一个VBM下合理的目标,并对该目标实现的驱动因素进行探讨.     

Application of Risk Analysis to the Financial Evaluation of Construction Projects

Every sort of financial indexes of the construction project is a value occurred in future. It has a random character, so the estimation of these indexes in early stage is surely a matter of risk. In practice, the investors often choose a construction project only by simple estimation rather by deep financial evaluation and risk analysis. In this paper, taking the project NPV as an example and applying risk analysis to its estimation, the authors develop a totally new economic evaluation method for construction projects.     

环境与可持续发展信息透明度对企业价值的影响——以农林业上市公司面板数据为例

以2009-2019年沪深A股农林等相关行业上市公司48家公司为研究对象,依据上市公司财务报告及国泰安(CSMAR)数据库数据,应用最小二乘(OLS)回归法评价企业环境与可持续发展信息透明度对企业价值的影响。结果表明:环境与可持续发展信息透明度和企业价值呈显著正相关;国有资本持股在二者关系中起到促进作用。依据研究结果提出建议——上市公司应当重视对这一社会责任的公开报告,不断提高信息透明度;科学引导国有资本投资,使得国家干预对可持续发展战略有所作为。     

榧树天然群体中种子表型特征与化学成分的变异分析

对安徽省黄山市天然榧树Torreya grandis群体内种子表型性状和化学成分的变异进行分析研究,为优良榧树种质资源收集、品种选育及榧树遗传研究奠定基础。结果表明:①种蒲质量、种蒲横径、种蒲纵径、种核横径、种核纵径、种核质量、种形指数、核形指数和出核率的变幅分别为5.24～12.23 g,1.963～3.018 cm,2.255～3.685 cm,1.438～2.270 cm,2.009～3.208 cm,2.30～5.19 g,0.695～0.902,0.555～0.823,34.80%～66.49%;②营养成分粗脂肪、淀粉和蛋白质的质量分数变幅分别为232.96～425.54 g·kg-1,59.95～114.40 g·kg-1和153.22～231.85 g·kg-1;矿质元素磷、钾、钙、镁、铜、锌、锰和镉的变幅分别为0.81～2.29 g·kg-1,23.90～53.72 g·kg-1,80.18～224.38 mg·kg-1,765.84～798.57 mg·kg-1,8.10～31.60 mg·kg-1,40.43～128.00 mg·kg-1,1.45～23.32 mg·kg-1,0.01～0.11 mg·kg-1;多数单株样品砷和铅呈现未检出状态;③种蒲质量、种蒲横径、种蒲纵径、种核横径、种核纵径及种核质量两两之间极显著正相关(P<0.01);种蒲和种核的形状与质量的关系无规律;种蒲质量与种形指数、种核质量与核形指数之间无明显的相关关系,而种核质量与种形指数之间存在显著的负相关关系(P<0.05);出核率与种蒲横径、种蒲纵径、种核横径、种核纵径均存在极显著的负相关(P<0.01),与种核指数极显著正相关(P<0.01),与种形指数无显著的相关关系;3种营养成分质量分数之间不存在任何的相关关系,除粗脂肪与种核质量间存在显著的负相关关系外(P<0.05),营养成分与种子表型性状及矿质元素间不存在相关关系。钾与镁、铜与磷、铜与锰的质量分数间均存在显著的正相关(P<0.01);锰的质量分数与种形指数和核形指数间呈极显著正相关(P<0.01)。     

Combining holding-level economic goals with spatial landscape-level goals in the planning of multiple ownership forestry

In Finland, management of biological diversity at the landscape level is complicated by the relatively small size of the holdings. To alleviate this problem, this study presents a hierarchical planning model that aims at combining spatial landscape-level ecological goals with holding-level owner-specific goals. The influence of ecological objectives extends across holding borders, but their impact is greatest in areas where they are least in conflict with the owners goals. This feature, which results in minimum losses to individual landowners, can be called ecological efficiency. In the case study, the ecological objective was to cluster the breeding and foraging areas of flying squirrel (Pteromys volans). Other sets of objectives were related to individual holdings according to the various preferences of the forest owners. The forest plan produced by the presented planning model was compared with two other forest plans: 1) a combination of independent forest holding level plans, which were assumed to represent the outcome of the current planning tradition, and 2) an area-level plan, where the holding borders and holding-specific objectives were not taken into account. The same objective variables and objective weights were used in all plans. All the plans were produced for six planning areas (ranging from 404.6 to 984.9 ha) and 110 forest holdings (ranging from 0.6 to 449.8 ha) within these areas. The case-study results were promising: with the model presented here, the spatial structure of flying squirrel breeding and foraging areas could be improved with only minor losses in holding-level objectives. The spatial structure of the landscape after the 60-year planning period was very close to the area-level plan. This outcome was made possible by synchronizing the treatment proposals across forest-holding borders. The outcome of the model seems promising also from the practical standpoint: because the variation in the objectives of forest owners is efficiently taken into account in optimization, only rarely do the solutions suggest that the holding-level targets be compromised.This revised version was published online in May 2005 with corrections to the Cover Date.     

Changes of land tenure and the introduction of tree cash crops by shifting cultivators: The case of the Paluan Muruts in Sabah, Malaysia

Shifting cultivation is one of the main factors that has caused forest degradation in many tropical countries. In Sabah, Malaysia, the government has granted land titles to local farmers outside the Forest reserve, and introduced tree cash crops to reduce farmers’ dependence on shifting cultivation. Granting land titles, however, was not always an incentive for farmers to plant tree cash crops. Farmers often planted tree cash crops on land without secure legal rights. The Land Ordinance and illegal logging had introduced exclusive and (semi-)permanent rights to land into this region, and the Forest reserve also was divided among villagers. The Land Ordinance stipulates that planting trees confers permanent heritable and transferable rights of use and occupancy but not within Forest reserves. Local farmers who were anxious about their land rights believed that they could obtain those rights even within the Forest reserve, and applied for land titles. Farmers planted tree cash crops not only for future income but also to secure their land rights. At present, the policy of Forest reserve has nearly collapsed in this region and it is impossible to neglect or remove local farmers if the government utilizes Forest reserves for any purpose. Lands in the interior regions will be reclassified in the near future out of necessity.     

缘何有机肥在经济作物中推广更顺利？——基于市场环境的讨论

为探究有机肥替代技术在经济作物和粮食作物种植中应用存在差距的原因,通过构建“作物类型-市场环境感知-有机肥施用行为”的逻辑框架,基于豫鄂两省987个农户的微观调查数据,利用Probit和Tobit模型,分析农户主营作物类型对有机肥施用行为的影响效应,并使用层级回归法检验其作用机制。结果表明：1）相较于种粮户,有机肥替代技术在经济作物种植户中的采纳率及采纳程度明显更高;2）农户主营作物类型通过影响价格感知作用于其有机肥施用行为,在控制作物特性差异后该效应仍然存在,而销量感知的中介作用不显著;3）作物类型通过价格感知影响农户有机肥施用行为的作用路径,仅存在于以市场收益为导向的利润型农户中,对自给型农户有机肥施用行为的影响有限。因此,应该进一步规范粮食农产品市场秩序,保障优质优价机制的有效运行,并强化技术推广举措的针对性,促进有机肥替代技术入户,助力农业绿色发展。     

利用AFLP进行榧树雌雄株鉴定的初步研究

为了解决榧树Torreya grandis苗期雌雄株鉴别的问题,利用已建立的扩增片断长度多态（AFLP）体系及T-A克隆测序,就榧树的雌雄株开展了研究。结果从15对引物中用引物对E-AGC/M-CAT得到了一条雌性榧树特异的条带。这条榧树雌性性别特异条带,仅在雌株、雌雄同株的个体中有,雄株中没有,推测榧树雌雄同株由雌性榧树变异而来。GenBank序列比对结果发现,数据库没有与此特异条带相匹配的序列。     

油茶开花习性的观察研究

对油茶Camellia oleifera花期变异、授粉习性、落花落果过程及其影响因子的多年多点试验研究表明：①影响油茶花期因子有遗传因子和气候因子,前者决定花期类型,如早、中、晚花类型,性状稳定;气候因子主要是9月平均气温决定“入秋”早迟和花期早迟,进而影响授粉条件和次年产量。②油茶自花不孕．辅助授粉坐果率普遍高于自然授粉,随着花期推迟两者差距越大,说明开花授粉受花期气候和授粉媒介双重影响。不同单株间双列交配,出现一些平均坐果率高的母本、父本植株和坐果率高的特殊交配组合．说明单株间花粉活力和交配亲和力存在差异。③油茶花期长,在正常情况下,花后10d开始落花,高峰在花后30d内。早、中花类开花时气温高,花期集中,坐果率高,落花也集中：晚花类相反．花期长,坐果率低。落花分散。3—10月为落果期,前期落果主要为受精不良、胚珠发育停滞;8-10月为后期落果高峰期,落果数可占总落果量的50％,对产量影响极大,主要是病害引起。