Biomass harvesting from buffer strips in Italy: three options compared

There is an urgent need for new, mechanized systems that may restitute some profitability to buffer strip harvesting and motivate regular maintenance. An opportunity for innovation is offered by the growing success of chip-fed boilers, since the production of chips is simpler than that of logs and has a higher potential for cost reduction. Within this context, a study was conducted in Italy with the goals of: (a) designing three alternative chip harvesting methods for buffer strips, (b) field-testing the performance of each alternative, and (c) developing a model for estimating the cost of these methods under varying operational and economic conditions. The three harvesting methods reflected different mechanization levels, with escalating investment requirements. Overall, the study demonstrated that frequent maintenance of young, single row buffer strips generates profits only when thoroughly mechanized. Using a dedicated feller-buncher, a front-end loader for extraction and an industrial truck-mounted chipper brought the delivered cost below the 14 €/m³ loose chips (approximately 4 €/GJ) presently paid by the district heating stations. However, the intermediate-mechanization system showed the highest potential for improvements. The␣study generated a spreadsheet-based model for predicting the effects of varying work conditions and cost hypotheses.     

国外伐区剩余物的利用途径及技术

本文综合论述了国外伐区剩余物的利用途径及技术,并指出伐区剩余区的利用在未来林业中有很大的发展前途。     

Planning and management of the afforestation process in Northern Israel

Afforestation in Israel has matured over a 90 year period into aformalized process of planning, management and control that involves allsections of the Keren Kayemeth Leisrael's (KKL) Forest Department. Over aone to two year period sites in the Northern Region are selected, planned,reviewed, prepared, planted, tended, surveyed and monitored to insure asuccessful start to a full rotation period. Over a ten-year period underdiscussion (1990–1999) old monocultures which declined due to destructiveagents or natural aging were replaced with multispecies, multifunctionalstands.Departmental integration and cooperation in the decision making andimplementation process to meet this end helps guarantee a successfulafforestation investment. In addition, new types of specialty plantings werealso incorporated on a small scale to give added-value to the social andrecreational side of Israel's forests.     

Growth effects of thinning damage in a Corsican pine (Pinus laricio Poiret) stand in central Italy

Damage to residual stand after partial harvesting or thinning may lead to serious economic losses in terms of both timber quality at the final harvest, and tree growth reduction. Logging damages and their effect on tree growth were studied in a long term experiment on Corsican pine in central Italy. Damage frequency, agent (felling, skidding), position (root damage, stem base, between 0.3 and 1 m a.g.l., >1 m a.g.l.) and severity (light, severe) and tree growth were measured after selective thinning from below and at 10 years after the treatment. In detail, we aimed at: monitoring mechanical damages to trees at the end of thinning and after 10 years; and assessing stand stability, growing stock, ring width and basal area at 10 years after the thinning. The thinning removed about 20% of volume, 38% of trees and 26% of basal area. The basal area decreased from 56 m² ha⁻¹ to 42 m² ha⁻¹ but after 10 years it increased again to 56 m² ha⁻¹. Immediately after thinning, 13.6% of the standing trees was damaged, out of these 36.17% showed severe injuries. Damages to standing trees were mainly due to skidding. Ten years after thinning, the percentage of damaged trees was about 17%, out of which 86.67% showed severe wounds. An increase of damaged trees and of trees with severe wounds was observed suggesting that a deeper knowledge on long-term effect of logging damages is needed. This study did not highlight any effect of logging damage on tree growth. In fact, no difference in ring width was recorded between damaged and undamaged trees.     

山地色木槭大苗培育技术

本文介绍了色木槭生物学特征、山地育苗地选择以及栽培技术中苗木选择、起苗、苗木处理、栽植、修剪方法、病虫害防治技术。     

Environmental factors related to damage by Heterobasidion abietinum in Abies alba forests in Southern Italy

A study was carried out in southern Italy to determine the role of some factors in favouring Heterobasidion annosum s. l. spread and damage in eight Silver-fir (Abies alba Mill.) forests. All the studied stands were colonised by H. abietinum. The presence of the fungus (as carpophores on colonised wood) was detected by means of transects and varied from 7.0 to 56.0% of trees. Stand history, precipitation and forest origin, analysed by the χ²-test, had a significant effect on rot severity. Damage was more severe in stands more xerophytic where the woods were planted on pasturelands.     

豫北山地传统民居院落平面类型初探

指出了豫北山地民居在历史长河不断演进,由于地区自然环境和人文环境的差异,其院落空间格局呈现出不同的形态。从院落的空间组合及组合方式等方面对整个豫北山地民居的院落空间平面形态进行了初步探讨。     

冀北山地华北落叶松混交林土壤水分物理性质研究

土壤是森林生长的基础,土壤水分物理性质是土壤质量的重要指标之一。以冀北山区不同树种组成比例(类型1—9落1黑桦;类型2—5落3白桦2椴;类型3—2落6白桦2黑桦)的华北落叶松林为研究对象,分析和比较了不同林分下的土壤水分物理性质。结果表明:土壤容重的均值大小顺序为类型1(1.14g?cm~(-3))类型2(1.01g?cm~(-3))类型3(0.98g?cm~(-3));土壤总孔隙度排序为类型2(53.04%)类型1(51.84%)类型3(51.40%);土壤最大持水量排序为类型2(55.53%)类型3(52.81%)类型1(48.22%);土壤稳渗速率大小排序为类型2类型3类型1。类型2的土壤水分物理性质最好,说明阔叶树种比例的增加有利于发挥林分的土壤水文功能。     

Attitudes of local people towards conservation and Gunung Halimun National Park in West Java,Indonesia

This paper examines local residents attitudes towards conservation and Gunung Halimun National Park, in West Java, Indonesia. A questionnaire survey and informal interviews are conducted among 74 households, in three villages, in and around the park. The survey reveals that almost all people knew about the existence and the laws of the park. Many people recognize and understand the importance of the global conservation of the park. In addition, most people agree that local participation is indispensable for conservation. Furthermore, people tend to be eager to use secondary forests or scrubs rather than primary forests or old secondary, recognizing the use of forest ecosystems in a sustainable manner. However, many people would like to claim the right to use the forests and lands within the park. People are only interested in meeting their daily needs from the park at the moment. Fortunately, they hope to participate in the park administration and are also enthusiastic about cooperating with related stakeholders including government authorities and NGOs. The results of the survey can be summarized as follows. Firstly, the local community does not have enough information about the park and, consequently, people only follow the compulsory laws. Secondly, local conservation knowledge and the global objectives of park management cannot be harmonized because of the lack of information and agreement concerning the park between local people and government authorities. People do not have certain incentives to conserve biodiversity, as they cannot get any benefits from the park. Thirdly, in spite of these adverse findings, it largely depends on the government authorities capabilities whether the integrated park management can succeed or not, because people still have positive attitudes towards local participation.     

冀北山地油松落叶松混交林空间结构特征研究

为探究冀北山地油松(Pinus tabuliformis)、华北落叶松(Larix principis-rupprechtii)混交林的空间结构,以木兰围场油松、华北落叶松为研究对象,通过计算林分角尺度、大小比和混交度3个空间结构指数对林分的结构特征进行分析,结果表明:油松和华北落叶松平均角尺度均在0.5左右,属于随机...     

高海拔山地引种栽培中华圣桃技术

通过对湖南省桑植县引种栽培的中华圣桃,进行环境适应能力和产量及品质的调查,总结出中华圣桃的引种栽培技术。中华圣桃在高海拔山地生长发育情况正常,产量稳定,经济价值高,完全适宜推广栽培。     

兰州北山土壤水分动态变化规律对造林的影响

干旱、半干旱地区土壤水分亏缺是影响造林成效和树木生长的限制性因子。兰州北部山地由于地下水匮乏,土壤水分只能依赖于天然降水。受降水量少、分布不均、有效降水少的影响,不同季节、不同坡向、不同土层深度土壤含水量均存在显著差异,一般差异坡向之间大于>月份之间>土层深度。根据研究结果认为,造林应首先根据坡向选择最适宜的树种,根据不同季节土壤含水量确定造林季节,根据不同土层深度水分变化确定造林技术措施。     

Effectiveness of sloping agricultural land technology on soil fertility status of mid-hills in Nepal

Hedgerows with intercropping systems were established at the ICIMOD test and demonstration site at Godawari to assess the effective-ness of Sloping Agricultural Land Technology (SALT) in reducing run-o...     

华北刺槐林与自然恢复植被土壤微生物量碳、氮含量四季动态

【目的】土壤微生物量碳、氮是植被所需碳、氮的重要“源”或“库”,是公认的综合评价土壤质量或肥力的重要指标,也是土壤生态系统变化的预警及敏感指标,研究其动态变化,可为退耕还林及后期管理决策提供科学依据,并为深入研究林地碳氮循环及温室气体排放提供参考。【方法】以农田( FL)为对照,研究华北土石山区10年生刺槐林、43年生刺槐林、自然恢复植被( NRV)土壤微生物量碳、氮的四季动态变化,并对各样地微生物量碳、氮对土壤营养库的贡献率进行对比研究。【结果】各样地微生物量碳、氮随土层加深而逐渐下降,其季节动态变化差异显著;农田、自然恢复植被、10和43年生刺槐林地0～20 cm 土层微生物量碳、氮含量四季均值分别为251.94,290.68,150.66,197.34 mg·kg －1和30.95,46.46,36.55,45.27 mg·kg －1。其中：自然恢复植被的微生物量碳、氮含量四季均值最高,其微生物量碳含量分别是农田、10和43年生刺槐林的1.15,1.93和1.47倍,微生物量氮含量分别是它们的1.50,1.27和1.03倍;土壤微生物量碳、氮含量随刺槐树龄增大而升高,43年生刺槐林0～20 cm 土层的微生物量碳、氮含量是10年生刺槐林的1.31和1.24倍。各植被样地不同层次土壤微生物量碳氮比季节差异明显,农田、自然恢复植被、10年和43年生刺槐林 0～20 cm 土层碳氮比四季均值分别为8.64,6.26,4.12 和4.36;10,43年生刺槐林碳氮比分别是农田的0.48和0.50倍,是自然恢复植被的0.66和0.70倍。在 0～20 cm 土层中,农田、自然恢复植被、10和43年生刺槐林地微生物量碳对土壤有机碳平均贡献率分别为1.88%,2.00%,1.54%和1.24%,土壤微生物量氮对土壤全氮的平均贡献率分别为1.21%,5.44%,3.55%和2.26%。【结论】各样地土壤微生物量碳、氮之间显著相关,它们与土壤全氮、有机质和速效钾含量均显著相关;除此之外,土壤微生物量碳还与土壤硝态氮含量显著相关。随着树龄的增加刺槐林土壤微生物量尤其是微生物量氮含量显著提高,因而土壤的生物肥力也显著提高;由土壤微生物量碳、氮含量及其对土壤营养库的贡献率可知,自然恢复植被更利于土壤微生物结构、功能的恢复和生物活性的改善。     

不同松树杂种F_1代在浙北和皖南的生长差异及其早期评选

利用4类松树杂种(火炬松×洪都拉斯加勒比松、火炬松×巴哈马加勒比松、湿地松×洪都拉斯加勒比松、湿地松×巴哈马加勒比松)在浙北7 a和6类松树杂种(火炬松×洪都拉斯加勒比松、火炬松×本种加勒比松、火炬松×巴哈马加勒比松、湿地松×洪都拉斯加勒比松、湿地松×本种加勒比松、湿地松×巴哈马加勒比松)在皖南9 a的树高、胸径和材积指标,研究了不同杂种在不同地点的生长表现。结果表明:不同杂种类型在不同地点的生长差异非常显著。在浙北余杭试验点火炬松×洪都拉斯加勒比松生长最好,其中材积增长超过对照40%的杂交组合有PTCH20、PTCH12、PTCH41、PTCH17、PTCH61和PTCH16共6个,全部是火炬松×洪都拉斯加勒比松,占该试验点所有杂交组合的11.11%;在皖南太湖试验点生长较好的杂交组合多为湿地松×古巴本种加勒比松,少量为湿地松×洪都拉斯加勒比松,同时该地区火炬松×洪都拉斯加勒比松杂种也有生长较好的杂交组合,该地区优良杂交组合(材积超过对照40%)包括PECC1-37、PECH12-9、PTCH13-24、PECC18-55、PECH42、PECC18-32、PECC10-6共7个,占所有杂交组合的28%,包括3个杂交组合类型(湿地松×本种加勒比松、火炬松×洪都拉斯加勒比松、湿地松×洪都拉斯加勒比松)。该结论和国内外关于杂种松的适应性及生长优势研究的结论基本一致,对我国南方不同地区发展速生杂种松具有参考意义。     

Tree rings indicate different drought resistance of a native (Abies alba Mill.) and a nonnative (Picea abies (L.) Karst.) species co-occurring at a dry site in Southern Italy

Climate changes induced by the anthropogenic alteration of the atmospheric radiative balance are expected to change the productivity and composition of forest ecosystems. In Europe, the Mediterranean is considered one of the most vulnerable regions according to climatic forecasts and simulations. However, although modifications in the inter-specific competition are envisaged, we still lack a clear understanding of the ability of the Mediterranean vegetation to adapt to climate changes. We investigated how two co-occurring tree species commonly used in afforestation programmes, the native Abies alba Mill. and the nonnative Picea abies L. Karst., adapt to climate change by assessing their growth performance and physiological responses in relation to past climate variability. Growth was addressed by analysing tree-ring width and carbon and oxygen stable isotopes. Statistical relationships between isotopic value and monthly climate data suggest that the two species underwent ecophysiological adaptation to Mediterranean climatic constraints. These adaptations are also expressed in the ring-width data. Based on the carbon isotope ratio reflecting the stomatal response to drought, we found that the precipitation in the first period of the growing season, i.e. early spring, is a major factor influencing the annual growth of A. alba, which although native, proved to be sensitive to drought. P. abies, on the other hand, showed a higher tolerance to summer drought stress. These findings should help define criteria for sustainability and effective forest conservation in the Mediterranean region.