Identifying cost-effective indicators to assess the conservation status of forested habitats in Natura 2000 sites

The Natura 2000 (N2000) network represents one of the most important actions for biodiversity conservation in Europe; its main aim is to assure the favourable conservation status of Europe's natural habitats and wild species. Monitoring of N2000 sites is required under the Habitats Directive, and Member States are required to report monitoring results to the European Commission. However, there is a widespread lack of understanding about precisely what should be monitored and which methods should be used. This research aimed to identify potential indicators and evaluate their suitability for evaluating the conservation status of forested habitats in N2000 sites. In addition, the cost-effectiveness of monitoring methods was assessed. Three monitoring methods were assessed in two N2000 sites, the Foresta del Cansiglio (IT) and the New Forest (UK): (i) sample plots, (ii) a point-transect method and (iii) a visual assessment method. Indicators were selected on the basis of a literature review, and related to forest structure and composition, dead wood volume, tree regeneration and ground flora composition. Results suggested that mean values of indicators did not differ between the plot and the point-transect-based methods (P > 0.05; paired t-test and Wilcoxon signed rank test). However, the survey method employed influenced the extent of variation within the indicators (as indicated by Z scores), a measure of their sensitivity. Correlations between indicators differed between the two sites. Of the three methods considered, the point-transect method was the most efficient in terms of set-up and total time required, but required the longest time per indicator and surveyed the smallest area (P < 0.001, Kruskal–Wallis test). The visual assessment method assessed the largest forest area; however, total scores of the reference values obtained from the plot-based and point-transect methods were poorly correlated with those obtained from this subjective approach. The contrasting results obtained between different methods and between different sites suggest that a general approach to monitoring N2000 sites may be difficult to develop; rather, a framework that can be adapted to the specific needs and characteristics of individual sites may be required.     

Genetic succession and spatial genetic structure in a natural old growth Cryptomeria japonica forest revealed by nuclear and chloroplast microsatellite markers

Spatial genetic structure and diversity of Cryptomeria japonica trees in old growth forest but selectively logged in approximately 300 years ago were analyzed using seven nuclear microsatellite markers and one chloroplast microsatellite marker. The individuals were sampled from a 4-ha natural forest plot (200 m × 200 m), which are consisted of three size classes including newly regenerated individuals such as regenerated individuals (REG class; stem diameter at breast height (DBH), 5–110 cm), remaining individuals (REM class; DBH ≥ 110 cm), and old stumps. Genetic diversity was similar between the three groups. These results suggest that genes from the old growth forest may have been passed on to the next generation (i.e., the current forest). DNA extraction and analysis from old stumps was partly successful and we could compare the genetic diversity between old stumps and living trees using four microsatellite loci. Patterns of spatial genetic structure detected by analyses of the nuclear and chloroplast markers differed substantially; all nuclear markers showed significant positive autocorrelation (P < 0.05) over short distances, but the chloroplast marker showed no significant autocorrelation over any distance. We concluded that Moran's I spatial autocorrelation pattern for the chloroplast microsatellite may have been influenced by the extensive pollen flow characteristic of this species, because chloroplast DNA of C. japonica is paternally inherited through pollen and is a wind-pollinated species that produces abundant pollen every few years. In contrast, Moran's I spatial autocorrelation pattern for nuclear microsatellites may reflect limited seed dispersal in gaps where the forest has regenerated and low levels of seed shadow overlap due to past logging. The average seed dispersal distance was 86.0 m at the study site and about 34.0% of the seeds were from the outside of the site, which revealed by parentage analysis. The individuals remaining after logging, and the extensive pollen flow from outside our study plot, may play important roles in maintaining the forests on this island. Gaps created by the selective logging activities appear to have been important for the regeneration of this species in the past but in the present time, natural disturbances such as typhoon and landslide are also important for gap creation.     

我国的湿生竹资源及其开发利用

湿生竹是竹类植物中一个十分罕见的类群,目前我国仅发现有5个种和1个变型,本文着重介绍了它们的种类、特点及分布情况,并对湿生竹的资源保护和开发利用提出了建设性意见.     

Use and conservation of forest resources in the municipality of San Agustin Loxicha,Sierra Madre del Sur,Oaxaca, Mexico

The Sierra Madre del Sur, Oaxaca is considered an area with high diversity of ecosystems, and low levels of fragmentation due to human disturbance. An indigenous people, the Zapotecs, have inhabited this area for centuries and Zapotec communities have used and continue to make use of local resources for their subsistence. Agroforestry systems provide timber, firewood, and non-timber forest products to local communities. Despite the ecological and cultural relevance of this region, basic information about local practices of management and harvesting are lacking. Little is known about the possible effects of these practices on biodiversity conservation. The objectives of this study were: to determine the local uses of forest wood resources in the municipality of San Agustín Loxicha, to determine the tree species most used by the inhabitants of this municipality and to discuss the implications of this management in the conservation of plant cover in this Priority Terrestrial Region. The reported main use of tree species was firewood, obtained by gathering dry branches and bark, as well as by felling dead trees. To a lesser extent, tree species are used to build houses and make furniture. Local people collect trees from the surrounding vegetation, so the richness and abundance of tree species in the area surrounding each community will always influence the ability of the communities to meet their needs. These practices do not have drastic effects on plant cover, mainly in areas of established forests. These traditional practices are involved in an empirical strategy to conserve and manage local resources.     

元认知策略在农林院校英语专业文化学习中的运用研究

以四川农业大学外语系英语专业高年级117名学生为调查对象,对其在英语文化学习过程中的元认知策略使用情况进行考查并分析了他们的元认知策略使用水平与英语文化成绩之间的关系。结果表明:①英语专业高年级学生在文化学习过程中元认知策略使用频率处于中等水平;②高分组和低分组在目标与计划、注意力安排、自我监控与管理策略使用上的差别具有统计学意义;③多元回归分析结果显示目标与计划、自我监控与管理对英语文化成绩有一定影响,注意力安排策略是英语文化成绩的主要影响因素。     

江苏省大豆种质资源现状分析及保护对策

通过调查分析江苏省大豆种质资源的现状,探讨了影响该省大豆种质资源变动的因素,提出了保护该省大豆种质资源的建议。     

Reservoir operation management through optimization and deficit irrigation

One of the methods for increasing productivity of water consumed in agriculture is by improved water supply management. This paper presents results from an optimization study of the Malampuzha irrigation project of the Bharathapuzha river basin of Kerala in India. The objective of this study is to determine whether significant improvements might be realized from optimization of operation of the reservoir system. To do this a mixed integer linear programming (MILP) model is developed and five different management strategies are tested. The result indicates that a management strategy with deficit irrigation by supplying less water in non-critical growth period and maximum water during stress sensitive periods is a best viable solution for better performance. A MILP model, rather than a linear programming (LP) model, is used to ensure that the reservoir does not spill before reaching its capacity.     

关于农产品质量安全检测工作中存在的问题及应对分析

当前随着社会发展,农业产品受污染情况越来越严重,食品安全问题也层出不穷,对人 们的身体健康造成了严重的危害,因此农产品安全检测工作是保障人们饮食安全的重中之重, 农产品质量安全检测的质量决定着食品安全的程度。目前我国农产品质量安全检测工作仍才 存在着诸多问题,严重影响着人们的饮食安全。详细分析这些问题,并提出相应的解决措施是 当前工作的迫切需要。     

农村区域经济协调发展制约因素及应对策略

城市区域经济发展进一步带动农村周围区域经济的协调发展。但从现阶段总体情况来看,农村区域经济协调发展依然存在许多问题,农村区域经济建设还是相对落后,区域经济发展程度较低,发展不平衡,城乡之间生产要素不均等,这些问题的存在都在很大程度上制约着农村区域经济的协调发展。新时期,需要进一步理清发展思路,认真分析制约农村区域经济协调发展的因素,制定出切实可行的发展对策,从而为解决三农问题和促进新农村建设增添活力。该文结合实际情况,对农村区域经济协调发展的制约因素和策略进行分析,以期研究结果可为同行提供参考。     

衡阳生态农业发展现状及对策探讨

生态农业是我国现代农业发展的重要模式和主导方向.阐述了衡阳市生态农业发展现状、存在的问题,提出了发展生态农业的对策,最后介绍了衡阳市重点生态种养典型模式——稻田养虾.