Site variation in Pinus radiata plantations and implications for site specific management

685,000 ha of Pinus radiata(D. Don) plantations in Australia werecategorized using a matrix of mean annualrainfall, rainfall regime and Parent Rock Codefrom a Technical Soil Classification. Datawere obtained from a number of differentorganizations which in total managed nearly allthe Australian P. radiata plantations. The selected characteristics were those whichcould be obtained at an acceptable level ofconfidence from all sources. Such acharacterization of plantation sites provided asystem for utilization of technical informationand extrapolation of research results and alsoa basis for the development of Site SpecificManagement systems. Analysis of theinformation indicated the high degree ofvariability of environments in whichplantations have been established withinAustralia and also the distinctive nature ofindividual regions. Such differences betweenareas make extension of silvicultural andrelated information difficult from one area toanother without appropriate validation. Abroad comparison with 1.26 million hectares ofP. radiata plantations in New Zealandindicated only a small overlap of areas of sitetypes between Australia and New Zealand. Assumptions derived in one location on thesites, characteristics, models and/or genotypeswould require significant testing beforeconfident application could be undertaken toanother area. The value of a Site SpecificManagement system for research planning andapplication of research and operational resultswas demonstrated from analysis of a series ofexperimental trials assessing application offertilizer after thinning and from evaluationof soil carbon in P. radiataplantations.     

Impact of site management on changes in soil carbon after afforestation: A review

Afforestation and forest management can increase carbon stocks and account for emission reduction according to the     

The value of six key soil variables for incorporation into a South African forest site classification system

The intensive nature of management practices in the exotic monoculture plantations of South Africa requires reliable decision support systems. Recent socio-economic developments, the need for optimal forest productivity, as well as increasing awareness of broader ecosystem values and environmental risks, highlight the importance of a unified approach to forest site classification and evaluation. This paper highlights the value of specific soil characteristics and its application value for a range of silviculture and management aspects related to site-specific forestry. A limited set of six soil variables are proposed for ecological mapping of forest landscapes at high-resolution operational-level scales. The variables proposed are parent material, soil classification, effective soil depth, depth limiting material, topsoil organic matter and topsoil texture. Each variable is discussed in terms of its significance as well as relevance to plantation forestry in South Africa. Shortcomings in our knowledge base and research requirements are highlighted, and the format of incorporation into a national forest site classification system is proposed. This paper will contribute to unity of purpose and understanding of forest site classification and evaluation in South Africa, and will promote management frameworks and decision support systems with desired environmental, economic and social benefits.     

银合欢和山毛豆幼林土壤肥力分析

分别以土壤化学分析法和酶分析法对银合欢和山毛豆幼林地的土壤养分及酶活性进行测定。结果表明:土壤p H为银合欢幼林地山毛豆幼林地对照,处理间差异显著。银合欢和山毛豆幼林地的土壤有机质、全N和全K含量均大于对照,而碱解N、有效P和有效K含量均显著大于对照。银合欢幼林地的土壤全P含量小于对照,山毛豆幼林地的土壤全P含量与对照无显著差异。山毛豆幼林地的土壤脲酶、磷酸酶和过氧化氢酶活性显著大于银合欢幼林地的,而后者显著大于对照。     

吉林省林地立地质量评价及生产潜力研究

依据一类清查的标准木、样木和样地数据,构建主要树种(组)树高曲线,编制立地形表,用地形和土壤因子拟合立地形估测模型。以此,基于吉林省二类调查数据库,估测全省小班立地形,得到立地质量等级及分布。同时根据全省现实林分状况,综合确定各立地质量等级林地的生产潜力,由此对比分析现实与潜在生产力。结果表明:1)基于清查资料构建的立地形估测模型,经检验,均达到显著相关水平,可用于立地质量的评价;2)吉林省林地质量较好,林地质量等级为好和中等的分别占31.03%和66.00%,合计高达97.03%;3)全省现实生产力为潜在生产力的56.65%,仅7.20%的森林达到林地生产潜力水平,森林生产力仍有较大可提高性;4)基于一类清查和二类调查数据库的立地质量评价和生产潜力测算的方法可靠,具有可推广性。     

Intensive,site-specific silviculture: Manipulating resource availability at establishment for improved stand productivity. A review of South African research

An important window of opportunity to increase and sustain productivity in short-rotation plantations is the period from felling through re-establishment to canopy closure. This paper explores the effects, interactions and response mechanisms of intensive silvicultural practices on plantation productivity and sustainability, using five South African case studies (a–e). (a) Land preparation trials showed that complete surface cultivation by ploughing had a significant beneficial effect when afforestation is done for the first time in grasslands, improving basal area growth by 11–52% over pitting only. However, similar treatments have not resulted in significant growth responses under re-establishment conditions. (b) Stand growth suppression resulting chiefly from soil compaction during mechanised harvesting operations is strongly related to soil type, soil textural class and residue management options. Volume growth reduction in short-rotation eucalypt crops ranged from 25% on compaction sensitive loamy soils to less than 2% in resistant sandy soils. (c) The response mechanism whereby vegetation management improves stand productivity is a reduction in both inter-specific and intra-genotypic competition for resources, as well as a decrease in stand variability. Operationally, the most important criteria in a vegetation management programme relate to the timing of control operations across diverse site conditions. In local trials, the primary factors controlling the time taken for competition-induced tree growth suppression to occur were related to altitude, slash burning and the interaction between these factors, which facilitated the development of regional vegetation management strategies. (d) Empirical fertilizer trials in short-rotation hardwood stands have shown significant improvements in final productivity (commonly 20–90 m³ ha⁻¹ in eucalypts and 30–50 m³ ha⁻¹ in Acacia), as well as wood density (15–30 kg m⁻³ for eucalypts) following improvements in early nutrition. Improved nutrition was achieved through fertilization at planting or indirectly through residue management. The response mechanism is primarily due to early canopy development and associated increases in light capture, coupled with a more modest increase in canopy quantum efficiency and above-ground carbon allocation on a dry site. On sites with abundant water supply, increased quantum efficiency is likely to be the dominant response mechanism. (e) A series of operational gains trials tested the interactive effect of genetic tree improvement, site–genotype interaction, stand density and vegetation management + fertilization on eucalypt stand growth across five sites. There were no significant interactions between factors, but importantly, the results were additive, emphasizing the need to optimise each practice in the value chain to achieve maximum productivity.     

杉木及其人工林自身特性对长期立地生产力的影响

本文系统地研究并综合了有关杉木及其人工林自身特性对长期立地生产力的影响的研究资料,认为杉木及其人工林自身的特性存在许多对地力维护不利的因素：（1）杉木凋落物发生晚,大量凋落物发生在14－15a前后;（2）杉木枯死枝叶具宿存特性,10－15a期间大部分枯死枝叶在树上,影响枯死枝叶的分解;（3）杉木凋落物养分含量低,如N含量只有阔叶树的30％－50％,因此枯落物营养元素积累低;（4）凋落物分解速率慢,分解速度在45％以下,而宿存于树上的枯死枝叶分解速率更慢;（5）杉木为速生树种,尤其在15a年前生长量大,吸收养分多,而养分归还少,杉木人工林养分循环速率不及40％;（6）杉木人工林培育密度较大,在15a前很少有林下植物生长,在20a后才有较好的林下植被发育,人工林长期处在单一的群落结构,很难发挥林下植被对地力的维护和改良作用。从现有的研究资料看,杉木及其人工林自身对地力维护有不利影响,是引起杉木林地土壤肥力及长期生产力下降的重要因素之一。     

土壤因子对立地生产力的影响定量研究进展

地位指数法是目前应用最广泛的评价立地生产力的方法,但对它与土壤因子的关系研究得较少。将土壤因子定量引入基于地位指数的生长模型,可直观地反映土壤对树木生长的影响。文中对国内外基于地位指数表达的立地生产力与土壤因子的关系研究所涉及的模型和方法进行了总结归纳,以期为立地生产力评价和土壤管理提供借鉴。     

The bionomics of whitegrub species (Coleoptera: Scarabaeidae) affecting commercial forestry re-establishment in representative areas of the South African summer-rainfall region

South African commercial forestry plants mainly Eucalyptus, Pinus and Acacia species. Invertebrate pests play a significant role in the establishment phase of these exotic trees. Whitegrubs, in particular, are known to affect seedling survival during this period. Their pest status and community structure patterns associated with slash and weed management regimes were recently reported for Acacia mearnsii in the KwaZulu-Natal (KZN) province. We tested whether the effects of these regimes were congruent over a wider region (the South African summer-rainfall forestry area), including whitegrubs found on Eucalyptus and Pinus species, or if there were other possible factors that better explained the patterns of assembly. Seventeen trials were established in the KZN and Mpumalanga (MP) provinces from which whitegrubs were collected once a month for a period of one year. Multivariate analyses were performed to determine whitegrub prevalence, distribution, pest ranking and community structure patterns. Sixteen whitegrub morphospecies were found of which Maladera sp. 3, Pegylis sommeri, Schizonycha affinis, Maladera sp. 2, Adoretus ictericus, Maladera sp. 1, and the unknown M8, M12 and M14 had a high pest status with an accumulative prevalence of ～99%. Maladera sp. 3 was the most prevalent and widespread species. It was also the most important species attacking E. grandis and P. patula, whereas P. sommeri and S. affinis were the most important whitegrubs on A. mearnsii. Clustering analyses showed two spatial (regional [2× clusters] and locality [10×]) and one silvicultural (slash and weed management [9×]) patterns of whitegrub assembly. As expected, the slash and weed management clustered the whitegrub communities in the forestry area. However, the two regional clusters (KZN-Midlands, MP-South and KZN-Coastal) were preferred because they visually represented the whitegrub community distribution with a listing of high-status whitegrub species. This was meaningful enough to suggest the possible implementation of site-specific and practical control strategies.     

Agroforestry systems and soil surface management of a tropical alfisol:

Field runoff plots, 70 x 10 m each, were established on a tropical Alifisol in southwestern Nigeria to monitor water runoff, soil erosion and nutrient loss in water runoff. The non-agroforestry control treatment (A) was established at two levels: plow-till and no-till systems of seedbed preparation. There were two agroforestry systems based on contour hedgerows of (B) Leucaena leucocephala and (C) Gliricidia sepium established at 4-m and 2-m spacings. Field plots were established in 1982 and hydrological measurements were made for uniform maize-cowpea rotation for 12 consecutive growing seasons from 1982 through 1987. Once established hedgerows of Leucaena at 2-m spacing were extremely effective in reducing water runoff and controlling erosion. Runoff, erosion and nutrient losses were generally more from maize grown in the first season than from cowpea grown in the second. Mean seasonal erosion from maize was 4.3, 0.10, 0.57, 0.10, 0.64 and 0.60 t/ha for plow-till, no-till, Leucaena-4m, Leucaena-2m, Gliricidia-2m treatments, respectively. Mean runoff in the first season from treatments listed in the order above was 17.0, 1.3, 4.9, 3.3, 4.3, and 2.4 percent of the rainfall received. There were high losses of Ca and K in water runoff from the plow-till treatment. In contrast to runoff and erosion, losses of bases in water runoff from agroforestry treatments were relatively high, high concentration of bases in runoff was probably due to nutrient recycling by the deep-rooted perennials.     

Determining the effect of tree size,bark-wood bond strength and tree form on the productivity of an excavator-based harvester in Acacia mearnsii in the KwaZulu-Natal forestry region of South Africa

The aim of this study was to determine the effect of tree size, bark-wood bond strength and tree form on the productivity of cut-to-length harvesting of Acacia mearnsii, using an excavator-based harvester with a SP Maskiner harvester head in the KwaZulu-Natal forestry region of South Africa. Tree diameter and height measurements were used to determine individual tree volumes, after which the trees were classified into different bark-wood bond strength and tree-form classes. Time studies were carried out to determine harvester productivity. The results showed that tree size plays a crucial role in the productivity of the harvester, but bark-wood bond strength and tree form also influence productivity. The harvester productivity varied from 5.5 m³ per productive machine hour (PMH) in 0.05 m³ trees to 16.9 m³ PMH^?1 in 0.25 m³ trees The bark-wood bond strength did not influence harvester productivity when handling small trees of less than 0.1 m³. In small trees, the productivity of the harvester was also not affected by different form classes, but as tree size increased, there was greater productivity variation between the different form classes.     

Progress towards more uniform assessment and reporting of soil disturbance for operations, research, and sustainability protocols

International protocols, such as those of the Montreal Process (MP), specify desired outcomes without specifying the process and components required to attain those outcomes. We suggest that the process and its components are critical to achieve desired outcomes. We discuss recent progress in northwestern North America, on three topics that will facilitate development of and reporting in sustainability protocols: (1) common terms and comparable guidelines for soil disturbance, (2) cost-effective techniques for monitoring and assessing soil disturbance, and (3) improved methods to rate soils for risk of detrimental soil disturbance. Uniform terms for soil disturbance will facilitate reporting and exchange of information. Reliable monitoring techniques and tracking the consequences of soil disturbance for forest growth and hydrology are paramount for improving understanding and predictions of the practical consequences of forest practices. To track consequences, we urge creation of regional research and operations databases that can be used to: (1) address MP values, (2) define detrimental soil disturbances, (3) develop risk rating systems for operational application, and (4) improve best management practices (BMPs) and ameliorative treatments that avoid or correct detrimental disturbances.     

马尾松两种林型土壤养分特征及其与凋落物质量的关系

【目的】研究土壤养分和地被层凋落物养分含量的差异,为马尾松人工林营林措施及地力维持提供科学依据。【方法】以鼎湖山两种典型林型(马尾松纯林和马尾松-黧蒴混交林)为研究对象,对比分析0~60 cm土层的土壤养分含量及地被层凋落物养分含量的差异,探索凋落物质量如何影响土壤养分。【结果】1)林型对土壤有机质、全氮和硫酸根含量有显著影响(P<0.05),对土壤全磷、交换性K+、Ca2+和Mg2+有极显著影响(P<0.01),混交林土壤养分含量(除硝态氮含量和交换性H+含量以外)均高于纯林。2)相同林型不同土层间土壤养分含量差异极显著(P<0.01),其中,土壤有机质和全氮含量随土层的加深而递减,且主要聚集在0~10 cm土层,表聚效应十分明显。3)纯林凋落物有机碳、全氮、C/N和全磷等含量高于混交林;相同林型不同分解层凋落物有机碳、全钙和全镁含量有显著差异(P<0.05),均表现为未分解层>半分解层>腐殖质层。4)土壤养分与地被层凋落物质量的RDA分析表明,0~10 cm土层土壤养分与腐殖质层有机碳呈极显著负相关(P<0.01),与腐殖质层C/N呈显著负相关(P<0.05);在10~20 cm土层,土壤养分与腐殖质层有机碳呈极显著负相关(P<0.05)。【结论】纯林的土壤养分低于混交林的主要原因是纯林凋落物具有较高的C/N和有机碳含量。     

人工林长期生产力保持机制研究的背景、现状和趋势

国内外普遍关注人工林的稳定性问题,人工林长期生产力能否维护是当前人工林研究上的一个重要方面。特别是关于人工林是否导致地力退化,针叶林是否引起土壤酸化,一直是国际上争论的焦点。本文收集了国内外大量资料,全面反映了国内外人工林长期生产力研究现状,包括研究策略、研究方法、生态系统基本过程研究、实施人工林后立地质量变化,包括采伐剩余物处理、整地、抚育、间伐、森林收获、人工林树种本身、人工林群落结构对立地生产力的影响,对各种研究结果与结论作简要概括,同时反映不同观点,并对人工林长期立地生产力研究趋势也作了扼要阐述。     

不同立地、土壤类型对土壤含水量和苹果新梢生长的影响

为了给苹果园土壤水分管理提供依据,以‘长富2’苹果为试材,选取粘壤土平地、粘壤土梯田、壤土平地、壤土梯田、沙土平地、沙土梯田、上层壤土、下层尾矿砂平地7种不同立地、土壤类型苹果园,研究其对土壤含水量及苹果新梢生长的影响。结果表明:不同时期粘壤土平地的土壤含水量均极显著高于沙土平地、沙土梯田、上层壤土下层尾矿砂平地的土壤含水量,沙土平地、沙土梯田的土壤含水量均极显著低于其他立地、土壤类型。各立地、土壤类型长、中、短新梢均只有一次生长,迅速生长期基本一致,在4月初到5月底;除沙土平地和沙土梯田类型外,其他5种立地、土壤类型徒长新梢均出现了二次生长,第1次迅速生长期与其他新梢一致,第2次生长期在7月至8月。不同立地、土壤类型土壤含水量与苹果各类新梢长度均呈正相关,达到显著相关水平的时期多出现在新梢生长高峰期,其中,4月22日至5月13日,壤土梯田、沙土平地的土壤含水量与长梢长度的相关系数分别为0.968、0.966,5月14日至5月31日,壤土梯田的土壤含水量与徒长新梢长度的相关系数为0.986,壤土平地的土壤含水量与长梢长度的相关系数为0.980。     

退耕还林工程信息管理系统研究

河北省由于其特殊的地理位置与环境资源,退耕还林工程具有信息量大、管理任务繁重的特点。本研究立足于河北省退耕还林工作的特殊性与艰巨性,充分利用计算机等现代化管理手段,建立了退耕还林工程信息管理系统。结果表明,该系统在退耕还林管理工作中可以实现多层次、全方位、全过程的现代化信息管理,为工程管理工作及时提供准确、全面的信息,以此推动退耕还林工程建设在科学高效的基础上顺利进行。     

Effect of topography and geology on the site index of Picea abies in the West Carpathian,Poland

Abstract

The effects of topographic features and the soil parent rock on the site index of Norway spruce [Picea abies (L.) Karst.] were examined. Field data were collected on 347 plots located in the Polish West Carpathian. On these plots, the diameter at breast height and the height of trees were measured and the age of trees was determined. On 64 plots one dominant or codominant tree was felled for stem analysis. In addition, topographic features of each site were measured, including elevation above sea level, aspect and slope. Stem analysis data were used in the development of a local site index system, which was used for calculating the site index for particular plots. In order to interpret site index as functions of elevation, aspect, slope, size of a mountain massif and soil parent rock, the multiple regression model was used, which explained 79.0% of the variation in Norway spruce site index. Elevation above sea level was the major factor responsible for variation in site index, and was negatively correlated (R ² _adj=0.610) with site index. Site index also depended on the soil parent rock. The stands growing on the tertiary Magura sandstones had considerably higher site indices than those located on the geological substratum composed of Istebna and Godula sandstones formed during the Cretaceous period. The site index of Norway spruce is also determined by the aspect, slope and height of mountain massif.     

The ecological sustainability of tropical forest management: evaluation of the national forest management standards of Costa Rica and Nicaragua, with emphasis on the need for adaptive management

From a conceptual point of view, national forest management standards in Latin American countries have progressed significantly in recent years. Examples include the Costa Rican Standards and Procedures for Sustainable Forest Management and Certification, developed by the National Commission for Forest Certification and in Nicaragua, the National Institute of Forestry proposal of principles, criteria and indicators for sustainable forest management. In line with general approaches worldwide, these national standards primarily focus on the fulfillment of sound forest practice. There is comparatively little emphasis on the assessment of management outcomes or changes in key components of the eco- and social-systems that result from management impacts. Essentially, there is little emphasis on adaptive management, though arguments that management cannot be sustainable if it is not adaptive are persuasive. This study sought to contribute to the development of standards that include elements for adaptive management that define, communicate and evaluate sustainable forest management in Costa Rica and Nicaragua. Elements from the national standards and the CIFOR generic C&I template (predominantly focused on forest management outcomes) were used as a starting point. The basic research process consisted of three phases of evaluation (in-office, desk and field). The evaluations were carried out by multidisciplinary, international groups of experts in forest ecology, management and policy. This study demonstrated the value of forums and workshops that facilitate exchange between forest scientists and policymakers; the innovation and application of a practical, applicable and scientifically based methodology for developing national level C&I; and acceptance of this methodology by key players in the fields of forest management and policy. These experiences and the resulting proposals of C&I for the evaluation of ecologically sustainable forest management are expected to be used as points of reference for future development of forest policy in Costa Rica and Nicaragua, and to contribute to the overall understanding of C&I development processes in the region.     

林业苗圃地连作和轮作对苗木生长及土壤肥力影响的研究

研究了林业圃地连作与轮作培育杉木、酸枣、厚朴等苗木的生长状况及土壤肥力的变化。结果表明:用水稻等作物与杉木轮作后,杉木苗生长状况改善,土壤有效养分和速效养分增加。     

桉-草经营模式的土壤物理性质及养分含量分析

对桉树人工林间种象草（Pennisetum americanum×P.purpureum）×（Pennisetum purpureum）复合经营模式的土壤物理性质及养分含量进行研究.结果表明：对比桉树纯林,桉-草经营模式的土壤容重降低了14.75％～22.12％,土壤总空隙度和毛管孔隙度分别提高了3.57％ ～ 16.51％和15.39％ ～ 18.67％,土壤饱和持水量和田间持水量分别提高了6.01％～34.14％和16.95％ ～43.99％,林地土壤物理性质得到改善.桉-草模式下林地土壤pH值降低了9.2％～10.5％,土壤有机质含量提高87.5％～24.2％;土壤全量N、P和速效N、P的含量提高7.06％ ～89.99％,提高幅度的大小排列顺序为速效N＞全量P＞全量N＞速效P,全量K和速效K含量减少,单位面积蓄积量提高14.14％.A层土壤理化性状改善幅度大于B层.桉树人工林间种象草复合经营模式,有助于改善林地土壤结构,提高林地养分含量,促进林木生长,是比较适宜推广发展的桉树复合经营模式.