全国营造林实绩综合核查信息管理系统的研制

从2002年起,国家林业局每年开展全国营造林实绩综合核查工作,以取代原有的各单项核查工作。全国营造林实绩综合核查信息管理系统是为配合全国营造林实绩综合核查工作,利用Visual FoxProc 6.0软件开发的信息管理系统,具有界面友好、操作简单、运行速度快等特点;通过四年来的运行与升级,为全国营造林实绩综合核查的统计分析和全国营造林质量综合评价提供了有力的支持。本文着重介绍信息管理系统的系统设计及系统实现的主要功能。     

天水地区屋顶绿化中草坪基质的选用

本文主要介绍了天水地区屋顶绿化中草坪基质的选择和其配比方案,从中体现出屋顶绿化基质拥有的体量轻,营养全,成本低的特点,同时兼备保水、保肥、具有通透性等功能。     

白银地区三倍体毛白杨造林试验初报

分析了1998年引种的10个三倍体毛白杨系号在白银地区造林的生长适应性。结果表明：在同一立地类型和同等抚育条件下，A129、A128、B330、A125、B1008、BT85、A122等7个无性系杂种三倍体毛白杨幼林在白银地区速生、抗寒、耐盐碱、抗黄斑星天牛，对叶锈病、褐斑病和煤污病基本免疫，在白银市表现出较强的适应性和抗逆性，生长量显著高于普通毛白杨、群众杨、新疆杨；由于其速生性使黄斑星天牛不能完成生活史而不至于造成危害；在速生用材林、专用纸浆林、农田防护林和公路绿化等方面大力推广具有良好的发展前景。     

Initial seedling emergence of hairy birch and silver birch on abandoned fields following different site preparation regimes

Experiments were carried out at four sites in Sweden to investigate the possibility of establishing hairy birch (Betula pubescens Ehrh.) and silver birch (Betula pendula Roth) on abandoned fields using natural regeneration and (or) direct seeding. The effects of six soil preparation methods (no preparation, ordinary ploughing, rotary cultivation, deep ploughing, inverted ground, removal of top-soil) and five additional treatments (no treatment, herbicide, peat litter, wood-ashes, slaked lime) on seedling emergence percentages (SEP) and vegetation cover percentages (VCP) were studied. SEP-values were estimated in June (SEP(J)) and October (SEP(O)). The experimental designs used were: 1) split-plot design with whole plots in a randomized complete block design (RCBD); 2) RCBD. The SEP-values observed with no preparation were close to 0% while the SEP-values obtained with mechanical soil preparation methods mostly were much higher (p0.014). Seedbeds with top-soil in the surface, created by ordinary ploughing or rotary cultivation, and seedbeds with mainly bare mineral soil in the surface, created by deep ploughing, inverted ground or removal of top-soil, obtained SEP-values of equal merit on silty soils, reaching SEP(O)-values up to 15%. The latter seedbeds obtained the best results on sandy soil, with as high SEP(O)-values as 47% after removal of top-soil. Seedbeds with top-soil in the surface were quickly colonized by ground vegetation, reaching VCP-values between 70% and 100%. Herbicide spraying with glyphosate and application of peat litter to the seedbed surface promoted seedling emergence. However, herbicide spraying before soil preparation was of little effect when followed by mechanical soil preparation.     

Carbon dioxide price from which an afforestation interest rate becomes maximum in each cutting age: loblolly pine in southeast Georgia, USA

In this study, a forestry profit model for carbon dioxide (CO₂) emission trading was constructed using southeast Georgia, USA, as the model area. The value of CO₂ credits regarding forest stores of carbon was calculated using the stock changing method, the average storing method, the ton-year method, and the returning CO₂ credit method. Based on this model, the CO₂ price at which an afforestation interest rate reaches its maximum in each 5-year interval at a cutting age of 10–50 years was calculated, considering the influence on the cutting age by introducing emission trading. The cutting age at which an afforestation interest rate reaches its maximum was 32 years. The cutting age shortened with the rise of CO₂ price in all four accounting methods. Assuming the dealing CO₂ price, we can forecast what the present cutting age will be according to the stock changing method and the average storing method in regard to this model. Assuming this CO₂ price and using the ton-year method and the returning CO₂ credit method, we can forecast that the present cutting age is not going to change.     

Farmer participation in reforestation incentive programs in Costa Rica

Reforestation programs are a common policy response among developing country governments in the tropics attempting to deal with environmental and economic problems caused by widespread deforestation. The objective of this paper is to examine participation by small-and medium-sized farms in two reforestation programs undertaken in recent years by one country, Costa Rica, which has been at the forefront of developing country environmental protection efforts. Analysis of a survey of 243 program participants and non-participants shows that farm households participating in reforestation programs had generally larger farm sizes, were dedicated to low labor-intensive, land-extensive agricultural activities, faced significant family on-farm labor constraints, were more heavily dependent on off-farm income sources, and had more extensive contact with local extension efforts. Logistic regression is employed to econometrically identify demographic, economic, and land use determinants of farm household participation in reforestation programs; the implications of these findings are analyzed. The limitations of reforestation programs, especially with regard to management factors and quality of reforested plots, are reviewed. Implications for improving the efficiency of reforestation programs and the merits of other policy alternatives are also discussed.     

SITE CLASSIFICATION FOR PROTECTIVE FOREST AFFORESTATION ON THE COAST OF CHINA

Land for protective forest on the coast has special site conditions,and siteclassification is the scientific basis for seaboard afforestation.The site classification systemon the coast zone and islands of China may be classified into five levels-site region(sub-region),district,class,group,and type.The land division for afforestation is carried outby the principle of enviornmental heterogeneity among regions,sub-region and district onlarge scale,according to the difference of air temperature,moisture and type of coastgeomorphy.It may be classified into 7 regions,12 sub-regions and 55 districts.Themedium and small scaled division for site class,group and type,subdivided in a sitedistrict,are based on medium topography,topographic climate,micro-relief and soil conditions.     

保水剂、固体水在干旱荒漠区造林中的应用试验

通过 9种保水剂、3种固体水的不同造林效果及不同浓度的对比试验 ,初步总结出了各种保水剂、干水的节水率及其造林成活率、生长率的影响程度 ,筛选出了适合酒泉市土壤、气候条件下使用的保水剂类型、干水类型 ,并对生产应用过程中存在的问题进行探讨。     

长白落叶松工业用材林初植密度选择及收获研究

黑龙江省东南部地区,在未经人工干扰、发育良好、保持初植密度不变的长白落叶松人工林中典型取样,应用静态标准地树干解析作动态分析,应用林学理论、数学理论和计算机工具分析扩展初植密度。以11.3地位指数分析,15～35a长白落叶松人工林竞争敏感密度(竞争阈)平均1800株/hm2;15～10a密度竞争减弱,竞争敏感密度和有效密度上浮在1900和2000株/hm2为理论依据设计初植密度;10a以下竞争不明显。为培育工业用材,强调收获量和降低成本,适合采用1700～2000/hm2为理论依据设计初植密度。以此密度设计造林能够产生空白生态位,用于生物多样性的发展,为搞复合经营创造条件。     

滇西北程海流域干热河谷区造林树种选择

程海流域地处金沙江干热河谷区,天然植被稀少,生态环境脆弱,造林难度较大,树种选择适当与否是造林成败的关键因子。文中阐述了程海流域现有的植被分布情况和主要造林树种,对程海流域造林存在的自然环境恶劣、自然灾害严重、生态系统退化等问题,提出适地适树、生物多样性丰富和效益最大化等造林树种选择的原则,并对该区域立地条件进行评价。在此基础上,从不同抗逆性特征、不同坡度、不同海拔以及不同坡位等方面,总结出适合程海流域造林的备选树种和干热河谷区造林及树种选择的要点,以期为金沙江流域干热河谷区造林树种选择提供参考。