中外退耕还林还草比较及其启示

在全面回顾总结世界各国退耕还林还草概况的基础上，论述了中外退耕还林还草的三大不同特点，分析了国外退耕还林还草的历史实践对我国目前正在进行的退耕还林还草试点的四方面启示，以期推动我国退耕还林还草的健康发展。     

试论实施退耕还林还草的必要性及对策措施

实施退耕还林还草 ,是我国生态环境建设中的重大举措。分析了西部大开发中实施退耕还林还草的必要性和紧迫性 ,并结合当前国家对退耕还林还草的优惠政策 ,提出了进一步搞好退耕还林还草工程的对策措施。     

退耕还林还草行政指导的法律界定

退耕还林还草行政指导的出现与运用是市场经济发展的需要,它既是现代行政法中合作、协商、民主精神发展的结果,也是现代市场经济发展过程中对市场调节失灵和政府干预双重缺陷的一种补救方法。我国从2002年开始,陆续对退耕还林还草进行了立法,其中对行政指导内容有不同程度的涉及。文章从退耕还林还草行政指导的定义和特征、退耕还林还草行政指导的方法及基本类型三个方面,试对我国退耕还林还草行政指导作一简述。     

退耕还林还草高质量发展策略

退耕还林还草是世界著名生态工程,是"两山"理念的生动实践。文中在分析退耕还林还草面临的新形势的基础上,系统回答了什么是退耕还林还草高质量发展、为什么要推动退耕还林还草高质量发展、怎样推动退耕还林还草高质量发展,提出了退耕还林还草高质量发展的基本思路、发展目标、核心内容和政策对策。     

中外退耕还林还草历史背景比较

论述了美国和欧洲林业发达国家退耕还林的历史背景及其退耕还林的目的与政策,并比较了我国退耕还林的历史背景与政策措施,同时,阐述了我国的退耕还林还草的主要特点,有助于深刻理解我国退耕还林政策。     

关于合理确定退耕还林还草土地范围的思考

通过比较分析国内外退耕还林实施背景，指出我国退耕还林还草政策对退耕土地范围的规定尚存在不足。并在调查研究基础上，提出了辽宁省退耕还林还草土地范围。     

我国累计实施退耕还林还草5.08亿亩 工程区森林覆盖率平均提高了4个多百分点

正今年是我国实施退耕还林还草工程20周年。9月5日,记者在陕西延安召开的全国退耕还林还草工作会议上了解到,1999年以来,我国累计实施退耕还林还草工程总面积5.08亿亩,占我国重点工程造林总面积的40%,成林面积近4亿亩,超过全国人工林保存面积的三分之一。中央累计投入5112亿元,相当于三峡工程动态总投资的两倍多。据介绍,退耕还林还草工程的实施取得了显著的生态、经济和社会效益。20年来,全国累计实施退耕     

关于黑龙江省新一轮退耕还林还草工程的几点思考

坡耕地退耕还林还草可有效减少水土流失,改善生态环境。针对新一轮退耕还林还草工程,分析了黑龙江省15°以上坡耕地现状,明确可退耕地情况,总结了国家最新退耕还林还草相关配套政策。并提出黑龙江省退耕还林还草面临的挑战与对策,以期为顺利开展退耕还林还草工作提供一定参考。     

退耕还林还草连片地区林业二三产业转型策略

退耕还林还草的目的在于进一步优化生态资源配置,加强生态资源保护。从长期发展来看,退耕还林还草对实现可持续发展理念有着重要作用。但在短期内,退耕还林还草虽然为生态恢复及生态环境保护做出了贡献,但对农户收入有一定影响。为解决农户收入问题,退耕还林还草连片地区的林业二三产业亟待转型发展。概述了退耕还林连片地区经济发展特点,分析了退耕还林还草地区林业产业转型难点,提出了退耕还林还草连片地区林业二三产业转型策略。     

乌拉特中旗石哈河镇退耕还林工程建设成效与经验

退耕还林(还草)工程是我国政策性最强、农牧民参与程度最高的一项生态建设工程。文章以乌拉特中旗石哈河镇为例,阐述了该镇退耕还林工程取得的成效及落实退耕还林政策的经验及做法,以期为巩固退耕还林(还草)成果,推进生态工程高质量发展,助力乡村振兴提供参考。     

日本的森林资源及林业管理状况

介绍了日本的森林资源现状,有关的林业政策法规,森林的经营管理体制,以及从事林业的人员状况和机械设备情况等;还说明了日本当今木材的供需和国际林业合作交流的情况;最后指出为我国林业提供的借鉴。     

Root Ecological Niche Index and Root Distribution Characteristics of Artificial Phytocommunities in Rehabilitated Fields

In the implementation phase of the Conversion of Cropland to Forest and Grassland (CCFG) project in China, it is important, from a scientific point of view, to recognize phytocommunities’ characteristics, species compatibility, and ecological function. The ecological niche that roots occupy, their abundance and distribution, and the factors that affect them must be acknowledged. Following the methodology of community ecology, the total root mass of a phytocommunity is measured as cubic volume. Root biomass, length, and the number of roots in every diameter class, for each soil layer and for each plant species, are regarded as observation variables. In the first instance therefore, a new method to calculate the root ecological niche index (RENI) is proposed, embracing the entire phytocommunity of plantations. Using the new method, the roots of phytocommunities in Datong County, Qinghai Province (one of the counties selected for the national CCFG experiment), are dealt with in this paper. The results show that most of the vertical distributions of plant roots belong to the type wherein the roots are concentrated in the topsoil layer (0–20 cm), far more than those in the lower soil layers. The RENI of phytocommunities is higher than that of pure stands or monocultures. The distribution of RENI by root diameter can be divided into four types: J-type, inverse J-type, recumbent S-type, and U-type. RENI is positively correlated with the wet biomass of aboveground level stems, branches, and plant leaves, and with the species richness of phytocommunities. Although the RENIs of plantations in rehabilitated fields are a little lower than those of natural forests, they are higher than those of cultivated crops. The RENIs of three community types (Picea crassifolia + Hippophae rhamnoides ssp. sinensis, H. rhamnoides ssp. sinensis, and P. crassifolia) in rehabilitated fields benefit greatly from the restoration project. The implementation of the CCFG project is important for the increase in RENI and the multiple functions of plant roots. Translated from Acta Ecologica Sinica, 2005, 25(3) (in Chinese)     

Land-use and land-base patterns in non-industrial private forests: Factors affecting forest management in Northern Spain

There is increasing worldwide interest in land-use allocation and management within the sphere of rural planning and development. The study of land-use patterns mainly focuses on understanding the practices and values of individuals involved, and no debate of this issue would be complete without taking into account non-industrial private forest (NIPF) ownership as a key component in most rural areas worldwide. This paper empirically explores and assesses NIPF owners' management in terms of analysing dynamics in farming and forestry practices (past conversions from forestland to meadow and from marginal meadow to woodland, and intentions to change the current productive forest species and to extend the area of woodland) and landholding attributes (size and degree of parcellation in productive forestland). Logistic regression models were also used to investigate the probabilities and influencing factors involved in transforming marginal meadows to woodland, and attempts on the part of NIPF owners to change the current productive forest species and increase productive forestland. For this, a total of 103 NIPF owners in Northern Spain were interviewed in person, in March 2004, about their commitment to and involvement in land management during 1999–2003. The models correctly explained 73.3%, 83.7% and 73.3% of the variability in having converted marginal meadow in woodland and of future intentions to change the productive forest species and increase the area of productive forestland, respectively. The results of the study indicate that forest management mainly responds to investment and increasing the productivity of the land as a capital asset, which is directly influenced by the size and degree of parcellation of the holding, and directly or indirectly related to the owner's interest in timber production. The results may be used by forest professionals, researchers and policymakers in order to design and execute successful forest policies related to land management and planning.     

林木低磷胁迫适应机制研究进展

土壤有效磷缺乏在自然环境中是一种非常普遍的现象,近年来世界各国针对植物的觅磷和耐磷机制进行了大量研究,然而目前相关的综述性报道多限于农作物,对林木低磷胁迫适应性的综述性报道尚不多见。在长期进化过程中,林木为利用土壤中现有的含量极低的有效磷,形成了各种适应低磷胁迫的机制。文中从林木根系的形态学变化、根系分泌物对土壤难溶性磷的活化作用、林木对土壤低浓度有效磷的吸收利用以及应对低磷胁迫的遗传调控等方面综述了低磷环境中林木的适应机制,为揭示林木对缺磷环境的适应机理、发掘林木自身对土壤有效磷高效率的吸收利用能力、以及进一步筛选林木的磷高效品种和合理经营管理人工林提供参考。     

关于人工林的地力下降问题

栽培生长迅速和对土壤肥力要求高的树种, 有导致地力下降的趋势。早期欧洲, 近期新西兰、澳大利亚以及我国南方杉木林区, 都有人工林地力下降的报道。从林业技术措施来说。促进人工林地力下降的主要因素有轮伐期短、全树采伐利用、火烧清理采伐剩余物和强度整地等。栽培固氮植物和肥土植物, 可显著改善土壤肥力。在造林中遵循适地适树的原则, 避免同一树种的大面积集中连片, 也有助于地力的维持。     

江西省峡江县城市森林建设规划

以江西省峡江县城市森林为研究对象,通过对城市森林数量、布局等现状的调查和分析,提出了峡江县城市森林建设总体规划目标、总体布局以及建设内容。研究结果表明:按照规划实施,至2020年峡江县城市森林覆盖率将由2010年的60.5%升至68.0%,建成区绿地率由44.6%升至49.7%,建成区绿化覆盖率由49.9%升至53.2%,人均公共绿地面积由12.2m2升至15m2,城市森林生态效益将得到更大发挥,城市生态环境质量将显著提高。该规划的研究成果也将为其他县级城市森林建设规划提供参考。       

Changes in volatile terpene and diterpene resin acid composition of resistant and susceptible white spruce leaders exposed to simulated white pine weevil damage

Induced (traumatic) resin in white spruce (Picea glauca (Moench) Voss) leaders resistant or susceptible to the white pine weevil (Pissodes strobi Peck) was analyzed for volatile terpenes and diterpene resin acids after simulated white pine weevil damage. Leaders from 331 trees were wounded just below the apical bud with a 1-mm diameter drill, coinciding with the natural time of weevil oviposition in the spring. Leaders were removed in the fall, and the bark and xylem from the upper and lower regions of the leader extracted and analyzed by gas chromatography. Unwounded trees had low amounts of resin in xylem compared with bark. In response to wounding, volatile terpenes and diterpene resin acids increased in the upper xylem (area of wounding), with resistant trees showing a greater increase than susceptible trees. Wounding caused monoterpenes in particular to decrease in the lower region of the leader (away from the drilled area) in greater amounts in susceptible trees than in resistant trees. In response to wounding, the proportion of monoterpene to resin acid increased in the upper and lower xylem of resistant trees, and slightly increased in the upper xylem of susceptible trees. Monoterpene-enriched resin is more fluid than constitutive resin, and probably flows more readily into oviposition cavities and larval mines, where it may kill immature weevils. Loss of resin components in the lower xylem suggested catabolism and transport of these materials to the site of wounding; however, energetic and regulatory data are necessary to confirm this hypothesis. This study provides a basis for measuring the ability of a tree to undergo traumatic resinosis that could be used to screen for resistance to white pine weevil.     

Effects of phenology,water availability and seed source on loblolly pine biomass partitioning and transpiration

One-year-old loblolly pine (Pinus taeda L.) seedlings from four seed sources (Arkansas, Georgia, Texas and Virginia) grown in 1-m-deep sand-filled pits in two water regimes (well-watered and drought) were studied, to gain insight into the process of seedling establishment. Whole-plant transpiration was measured biweekly from July to December. Whole-plant harvests were conducted at 6-week intervals from April to December. Whole-plant transpiration and transpiration per unit leaf and root area were affected by treatment, seedlot and phenology. Seedlings of the Arkansas seedlot maintained significantly higher transpiration rates per unit leaf and root area during drought than seedlings of the Virginia, Georgia or Texas seedlots, but did not accumulate greater biomass. The high transpiration rates of the Arkansas seedlings were attributed to their deep root systems. Allometric relationships indicated that, relative to the whole plant, biomass allocation to needles of drought-treated seedlings was enhanced during the summer (allometric ratio 1.09), whereas allocation to roots was enhanced in the spring and fall (allometric ratios of 1.13 and 1.09, respectively). Relative to the whole plant, biomass allocation to needles of well-watered seedlings was enhanced throughout the experiment (allometric ratio of 1.16 declining to 1.05), whereas the allometric ratio of root to total biomass was 0.89 or less throughout. Allometric relationships also indicated variation in biomass partitioning to roots in three soil layers (0-30, 30-60 and 60-100 cm), which differed among harvests in each soil layer. Root growth in both well-watered and drought-treated seedlings was concentrated in the top soil layer in the spring, shifted to the middle and bottom soil layers in the summer, and then increased in the top soil layer in the fall. Compared with well-watered seedlings, drought-treated seedlings had higher rates of root growth in the bottom soil layer in the fall, a characteristic that would confer tolerance to future periods of limited soil water availability.     

Reviewing natural resources law in the light of bioeconomy: Finnish forest regulations as a case study

Development of bioeconomy is high on political agendas around the world. As part of bioeconomy policies governments have initiated reviews of the contemporary laws in order to identify and remove potential barriers and address the shortcomings as well as develop new tools to facilitate transition to bioeconomy. This paper discusses the role of natural resources law in bioeconomy and considers the needs for developing legislation to better meet the future challenges. As a concrete case study the article evaluates regulations governing the use of forests in Finland from the perspective of bioeconomy. The paper shows that major deficiencies in regulations governing the use of forests in Finland in developing bioeconomy relate to ecological and social sustainability, resource efficiency, and conflict management. The article concludes that there is a need to increase integration, adaptability, transparency and public participation in Finnish forest regulation to facilitate the transition to and maintain sustainable bioeconomy.