千岛湖区林相特色化经营探究

文章在总结以往千岛湖林相保育与改造实践的基础上指出千岛湖的林相富含时代特色,建设美丽中国就有必要加快阔叶化、彩叶化、珍贵化林相的保育与改造步伐,进而提出新时期千岛湖区林相特色化经营的对策建议。       

矿区废弃地森林公园建设研究——以湖北黄梅马尾山森林公园为例

以湖北黄梅马尾山森林公园为例,探讨森林公园建设前期的生态基质修复和植被景观改造措施,以期为同类研究提供参考。       

秦皇岛海滨森林公园森林景观改造

秦皇岛海滨森林公园是秦皇岛沿海防护林的重要组成部分,也是秦皇岛重要的城市森林公园之一,文章针对秦皇岛海滨森林公园阔叶树多、针叶树少、树种单一、林龄老化、景观单调的现状,探讨了森林公园景观改造的原则、措施和技术。       

上海海湾国家森林公园景观林优化改造

在对海湾国家森林公园景观林资源现状调查分析的基础上,根据公园即将向公众开放对林木景观资源的质量和标准要求,针对存在主要问题,提出相应的优化改造措施。通过对本公园人工幼龄林培育过程中,出现的林相单调,密度过大有碍森林赏景、影响森林生态效益的发挥及阻滞森林健康演替等问题提出相应的改造措施,旨在优化提升森林美学等级。       

佛山市农村生态风景林改造

以佛山市村后生态风景林改造试点工程南海西樵百西村"松岗"林相改造工程为例,通过对其改造理念、树种配置、种植与抚育等技术措施以及改造后生态质量、景观效果、游憩功能等改造效益的分析,指出目前佛山市村后生态风景林改造的成功与不足,探讨村后生态风景林改造的合理方法与发展方向。       

紫金山风景林林相改造异龄复层混交模式研究

林相改造异龄复层混交林模式研究表明,在郁闭度0.5~0.75的疏林中"林下植阔、林中插绿"能形成较稳定的地带性异龄复层混交林群落,提高风景林生态系统的质量和生态功能。       

哈尔滨市域范围内森林公园布局研究

文章结合哈尔滨市域范围内国家级森林公园,侧重研究了影响森林公园布局的因素。结果发现森林公园的布局与森林资源的品质有着直接的联系,同时受着城市旅游空间发展战略、经济发展状况,以及公园的建设特色和维护发展等诸多因素的制约。由此归纳出影响区域内森林公园布局的因素并解决因素分析所应用的技术方法。最后针对哈尔滨市域范围内国家级森林公园的布局提出了整合策略。       

广州帽峰山森林公园的“冷岛”效应分析

对帽峰山森林公园和广州市区2004年的月平均气温、月平均最高气温和月平均最低气温进行了统计,进而对帽峰山森林公园的"冷岛"效应进行了分析。结果表明:帽峰山森林公园月平均温度比广州市区月平均温度低2.2℃,森林公园"冷岛"效应显著;森林公园"冷岛"效应月际变化明显,5月到11月雨季的"冷岛"效应较强,而12月到翌年4月旱季"冷岛"效应较弱;森林公园"冷岛"效应日变化呈现昼弱夜强,其季节性也很强,秋冬季节夜间"冷岛"效应要明显的高于白天的效应,而春夏季节两者"冷岛"效应差别缓和。       

广州市森林群落特征与物种多样性研究

广州市的天然次生林,其植物种类丰富,主要的植被类型有常绿季雨林、常绿阔叶林、针阔混交林和常绿灌丛,其地带性植被为南亚热带季风常绿阔叶林;植被组成种类丰富,具有较强的热带性,主要的科有豆科、茜草科、大戟科、樟科、桑科、山茶科、壳斗科、紫金牛科、芸香科、金缕梅科、冬青科等一些以热带亚热带为分布中心的类群;根据实地调查和收集的有关资料统计,目前一些珍稀濒危植物几乎都分布在森林公园内得以很好的保护;建议将兰花40种和另外52种植物列为广州市重点保护植物。       

连云港云台山国家森林公园SWOT分析与发展战略

文章以云台山国家森林公园为研究对象,运用SWOT分析法,探讨该森林公园开展森林生态旅游的优势、劣势、机遇与威胁,并就该森林公园今后的发展提出相应的对策。       

海南吊罗山“山地热带雨林”开发模式探讨

文章主要以吊罗山为例,通过与海南其它山地热带林区发展比较,探讨其适宜的“山地热带雨林”开发模式,从而提高吊罗山森林旅游的竞争力.     

临安市森林城市建设实践与规划

根据城市森林生态网络系统理论及临安市山地森林资源状况,结合城市现代发展战略,提出了临安市"建设山水绿色名城,构筑吴越生态家园"的理念,明确了建设森林城市的规划目标与规划布局,创建具有吴越文化特色、生物种类多样、可持续发展的森林城市,从而有效地改善本区域生态环境,促进区域内社会、经济、环境的协调发展。       

Evaluating the benefit of avalanche protection forest with GIS-based risk analyses—A case study in Switzerland

The protection of people, buildings and infrastructure against natural hazards is one of the key functions of mountain forests. Since the protective function strongly depends on small-scale local conditions such as terrain and stand characteristics, spatially explicit evaluation methods are necessary to provide information required for an effective and cost-efficient forest management. Risk analyses are recognized as the best method for estimating the danger from various natural hazards. Currently, however, risk-based strategies are rarely addressed in the management of protection forest. We present and discuss a risk-based approach to evaluate the protective effect of mountain forests in a spatially explicit manner to demonstrate the advantages of future risk-based protection forest management. We illustrate the approach by performing a GIS-based risk analysis in the case study area ‘Bannwald of Andermatt’ (Switzerland) for a 300-year snow avalanche event. Classifying forest structures based on aerial photographs allowed developing different forest cover scenarios and modeling potential avalanche release areas within the forest. Potential avalanche release areas above the forest and the avalanche run-out distances under five different scenarios of forest cover were calculated by using a two-dimensional avalanche simulation model. We calculated the annual collective risk for each scenario and compared the change in risk to reveal the spatial distribution of the protective effect of the forest. Resulting risks differed strongly between forest cover change scenarios. An enlargement of an existing wind-disturbed area within lower parts of the slope resulted only in a slight increase of risk. In contrast, the effect of an unforested area in the upper parts of the observed forest more than doubled the risk. These results show how a risk-based approach can help to quantify and illustrate the impact of differences in forest cover on the protective effect of mountain forests. It is a promising approach to determine the economic value of protection forests and thus provide quantitative and qualitative information for cost-efficient forest maintenance planning. With regard to the achievements of research to date, the presented approach may serve as a valuable method to support decision-making in a future protection forest management.     

The response of ground vegetation to structural change during forest conversion in the southern Black Forest

The aim of this study is to investigate the effects of forest conversion on forest floor vegetation. ‘Ecological’ forest conversion, as defined by an interdisciplinary southern Black Forest project group, describes the transformation of even-aged spruce (Picea abies L. H. Karst.) stands to structured continuous cover forests consisting of spruce (Picea abies), silver fir (Abies alba Mill.) and beech (Fagus sylvatica L.). In order to analyse the conversion process, four conversion stages were defined in a conceptual forest development model. Four forest districts deemed to be representative of the southern Black Forest region were selected for the study. The ground vegetation was initially classified independently from the stand structures. Subsequently, the relationship between stand structures, as determined by development stage, and ground vegetation was analysed. It was revealed that forest conversion modified the ground vegetation. The main factors influencing ground vegetation were the influence of broadleaves, predominately beech (F. sylvatica), on the canopy composition and litter coverage on the one hand; and the canopy coverage of spruce, the proportion of needle litter and the associated light penetration on the other. The prevalence of moss and vascular plant species preferring acidic sites found in spruce forests decreased during the transition process, whereas, species requiring a moderate base supply increased in abundance. The continuous cover forest representing the final stage of conversion increasingly contained a mixture of ground vegetation species normally associated exclusively with either conifer or deciduous forest. Due to the fact that there is an associated ground vegetation specific to the different stages of forest conversion in stands dominated by Norway spruce or European beech and a mixture in the latest conversion stages, large-scale forest conversion should be avoided in favour of management promoting a diversity of silvicultural goals and treatments in neighbouring stands. Only a variety of treatments ensures the maintenance of floristic diversity in the long-term.     

山区生态公益林限制性利用的探讨

针对山区生态公益林在建设过程中存在的问题,提出林下非木质利用、低效林分改造、树种结构调整等限制性利用的途径。根据各种利用途径,提出相应的研究方法,以期为更好建设与合理利用生态公益林提供科学依据。     

Tree regeneration and future stand development after bark beetle infestation and harvesting in Colorado lodgepole pine stands

In the southern Rocky Mountains, current mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreaks and associated harvesting have set millions of hectares of lodgepole pine (Pinus contorta var. latifolia Engelm. ex Wats.) forest onto new stand development trajectories. Information about immediate, post-disturbance tree regeneration will provide insight on dynamics of future stand composition and structure. We compared tree regeneration in eight paired harvested and untreated lodgepole pine stands in the Fraser Experimental Forest that experienced more than 70% overstory mortality due to beetles. New seedlings colonized both harvested and untreated stands in the first years after the beetle outbreak. In harvested areas the density of new seedlings, predominantly lodgepole pine and aspen, was four times higher than in untreated stands. Annual height growth of pine and fir advance regeneration (e.g., trees established prior to the onset of the outbreak) has doubled following overstory mortality in untreated stands. Growth simulations based on our regeneration data suggest that stand basal area and stem density will return to pre-beetle levels in untreated and harvested stands within 80-105 years. Furthermore, lodgepole pine will remain the dominant species in harvested stands over the next century, but subalpine fir will become the most abundant species in untreated areas. Owing to terrain, economic and administrative limitations, active management will treat a small fraction (<15%) of the forests killed by pine beetle. Our findings suggest that the long-term consequences of the outbreak will be most dramatic in untreated forests where the shift in tree species composition will influence timber and water production, wildfire behavior, wildlife habitat and other forest attributes.     

安徽省宜秀区人工杨树林碳储量研究

森林碳汇是指森林利用光合作用吸收大气中的CO2并以生物量的形式贮存在植物体内和土壤中的能力。近年来,随着人口的增长和经济的发展,人类排放温室气体持续增加,导致地球气候不断变暖,而森林所固有的吸收和固定CO2的功能即森林碳汇功能,能够有效地减少大气中的CO2浓度,起到减缓气候变暖的作用。本研究以安徽省宜秀区人工杨树林为研究对象,设置面积为0.24 hm2的样地一块,采取相邻格子法将其区划为20 m×30 m的乔木样方4块。在样方内进行每木检尺,每块样地选取平均标准木一株,供乔木层生物量测定,林分乔木层总生物量按转换系数进行计算。结果表明：研究地林分径级分布集中在18 cm～28 cm之间,林龄为10 a;无论在单木还是林分中,干生物量都占绝对主体地位;研究地10 a生人工杨树林乔木层每公顷碳储量为196.0016 t。     

ROTATION

The computer model ROTATION was developed to calculate and compare optimal rotation ages for even-aged forest stands according to mean annual increment, money yield table, forest rent, land expectation value, present net worth, internal rate of return, and financial maturity criteria. The program was written in Microsoft QuickBasic and h e input variables consist of volume yield data, stumpage price, land cost, stand establishment cost, stand management cost, and the rate of interest. Results are displayed in tabular format and values indicating the optimal rotation age based on each of the seven criteria are presented. A representative example is included which incorporates normal yield data for ponderosa pine (Pinus oonderosa Doual. ex Laws.) and commercial timber management revenues and expenditures approximating those currently countered in the Sierra Nevada and southern Cascades, USA. Potential users of ROTATION include forest managers and natural resource educators.     

Exploratory analysis of structural diversity indicators at stand level in three Italian beech sites and implications for sustainable forest management

The present study introduces an exploratory data analysis based on structural indicators with the aim to assess the effect of silvicultural practices on tree stand structure. The study was carried out in three Italian beech forests of different ages with stand structures that originated from dissimilar regeneration and cultivation techniques(Cansiglio, northern Italy, Chiarano, central Italy,and Mongiana, southern Italy). Ten structural indicators were considered when investigating the latent multivariate relationship between stand structure attributes before and after thinning operations by using a multiway factor analysis(MFA). The MFA results identified the older stand at Cansiglio as more homogeneous for cultivation regimes,and more stable to practices when compared with the younger sites(Chiarano and Mongiana). Heterogeneous stands were sensitive to silvicultural practice thus suggesting their possible impact on forest attributes. The proposed approach proved to be an operational tool to evaluate comprehensively the response of forest structure to planned interventions.