Indices of soil nitrogen availability for an ecological site classification of British forests

An adequate supply of nitrogen (N) is essential for the successful establishment and sustainable productivity of forest stands. N deficits may necessitate the use of artificial fertilisers. Availability of N in the inorganic forms, and the relative abundance of the NO₃-N and NH₄-N components, influences the species composition of natural forest vegetation. Hence it is essential to use reliable measures of soil N supply that fully reflect its ecological significance. The new Ecological Site Classification (ESC) used in British forestry employs a multi-factorial definition of soil nutrient regime (SNR), including soil N. To develop this, a soil and vegetation study was made at 89 forest sites throughout Great Britain covering the major soil types used for forestry. “Total N” levels were compared with separate pre- and post-incubation measures of the two inorganic N components as potential indices of soil N supply. Multivariate statistical analysis showed that the major discriminant chemical variables for the sampled soils were pH, calcium and NO₃-N and that these were also the main variables influencing the species composition of the ground vegetation. Total N and NH₄-N were less effective discriminant variables for these sites. In some infertile soils the levels of NH₄-N or total N may be of greater importance, as NO₃-N is usually in very limited supply. A multivariate gradient of SNR, which incorporates the NO₃-N measures, has been adopted for use within the ESC system. The position of a site on this gradient can be estimated quantitatively from soil type, ground vegetation species composition and humus type. This enables soil N supply and overall SNR to be assessed in a simple but effective way that guides the operational management of British forest soils for sustainable productivity. It will also be possible to use these techniques to monitor the nutritional status of forest sites over time.     

废旧材料在景观设计中的再利用——以三峡截流纪念园景观设计为例

以三峡截流纪念园景观设计项目为例,介绍其利用废旧材料进行景观设计的做法,对废旧材料的再利用不仅能表达废旧材料所代表的特定文化含义,更体现了一种循环经济思想。希望为大家解决工程废旧材料问题提供参考。     

The influence of regulatory forest policy tools on biodiversity measures for forests in Ukraine

The transition from a state-oriented forest economy to a market-oriented one requires a critical analysis of the set of tools designed to implement state forest policies. One of the important goals of Ukrainian forest policy is conservation of the biodiversity of forest ecosystems. This paper analyzes the influence of two of the regulatory forest policy instruments (zoning and prohibition of final harvesting) on the diversity of woody vegetation using Tobit regression. Data on the forest resources of the Sumy administrative province in Ukraine are used for the analysis. Additionally, we look at how diversity of woody vegetation is affected by the form of forest tenure.     

集体林区阔叶化改造实施组织模式的探讨

为了将集体林生态退化区域阔叶化改造的责任主体落实到农户,解决集体林区阔叶化实施难的问题。本文针对集体林区特点,建立县、乡（镇）、村三级联动组织实施体系,并以稳定的山林经营权为依据,分别探讨了村集体统一实施、农民家庭实施、村户合作实施、招标承包实施和国有林场实施五种模式的具体做法,将农民的愿望与国家生态建设的要求统一起来,推动了集体林区阔叶化进程。     

东乌珠穆沁旗林地资源对草原生态环境的影响

文章通过对东乌珠穆沁旗林地资源及其质量的分析,研究林地资源的发展对保护草原牧区生态环境的重要作用。     

Multi-source land cover classification for forest fire management based on imaging spectrometry and LiDAR data

Forest fire management practices are highly dependent on the proper monitoring of the spatial distribution of the natural and man-made fuel complexes at landscape level. Spatial patterns of fuel types as well as the three-dimensional structure and state of the vegetation are essential for the assessment and prediction of forest fire risk and fire behaviour. A combination of the two remote sensing systems, imaging spectrometry and light detection and ranging (LiDAR), is well suited to map fuel types and properties, especially within the complex wildland–urban interface. LiDAR observations sample the spatial information dimension providing explicit geometric information about the structure of the Earth's surface and super-imposed objects. Imaging spectrometry on the other hand samples the spectral dimension, which is sensitive for discrimination of surface types. As a non-parametric classifier support vector machines (SVM) are particularly well adapted to classify data of high dimensionality and from multiple sources as proposed in this work. The presented approach achieves an improved land cover mapping adapted to forest fire management needs. The map is based on a single SVM classifier combining the spectral and spatial information dimensions provided by imaging spectrometry and LiDAR.     

森林浴及森林浴场的开发

开展森林浴活动,既是对森林的一种新的利用途径,又能满足人们渴望“回归大自然”、休闲保健的需求。开发森林浴场具有广阔的发展前景,但必须具备一定的资源环境条件,在森林浴场的选址和项目设施建设方面,也必须综合考虑森林浴的保健、休闲旅游功能。     

Carbon inventory methods and carbon mitigation potentials of forests in Europe: a short review of recent progress

The role of European forests and forest management in the carbon balance has received much attention in research recently. This was particularly motivated by the recognition of forest management as one possible measure countries may adopt in the framework of the Kyoto Protocol to reduce the concentration of greenhouse gases in the earth’s atmosphere. The main method to assess carbon budget in forests is based on traditional forest inventories. This method requires the conversion of measured stem volume to carbon pools. This conversion has been identified as a large source of uncertainty in past assessments. Over the last 5 years, intensive research efforts have resulted in significant advances in the reliability of forest inventory based carbon budgets. In parallel, the impact of forest management on the carbon balance of forest ecosystems has been investigated and the carbon mitigation potential of these activities has been analysed. This paper reviews the progress that was made in these two fields of research with a particular focus on European forests.

PDA在森林资源规划设计调查工作中的应用

从若干方面介绍了PDA在森林资源调查规划设计中的应用范围及使用的方式方法。     

对森林经营有关问题的思考

论述了当前森林经营工作中存在的问题,提出了科学合理经营森林的建议。