对林业造林技术方法的思考

随着社会不断发展,森林造林的发生与扩展,促进森林植物及其生态系统的优化与健康,在进行造林规划设计时,必须努力做到物种适地化、品类多样化、结构复层化、混交合理化和种苗本土化。

Reforestation Programs in Southwest China:Reported Success,Observed Failure, and the Reasons Why

Ever since the disastrous floods of 1998, the Chinese government has used the Natural Forest Protection and Sloping Land Conversion Programs to promote afforestation and reforestation as means to reduce runoff, control erosion, and stabilize local livelihoods. These two ambitious programs have been reported as large-scale successes, contributing to an overall increase in China’s forest cover and to the stated goals of environmental stabilization. A small-scale field study at the project level of the implementation of these two programs in Baiwu Township, Yanyuan County, Sichuan, casts doubt upon the accuracy and reliability of these claims of success; ground observations revealed utter failure in some sites and only marginal success in others. Reasons for this discrepancy are posited as involving ecological, economic, and bureaucratic factors. Further research is suggested to determine whether these discrepancies are merely local aberrations or represent larger-scale failures in reforestation programs.

Effects of thinning on microsites and natural regeneration in a Larix olgensis plantation in mountainous regions of eastern Liaoning Province, China

In order to understand the effects of thinning on microsite conditions and natural regeneration in the larch plantation, thinning experiment was conducted in a 40-year-old Larix olgensis plantation in Qingyuan County in eastern Liaoning Province, China in 2003-2004 Five thinning treatments （0%, 10.2%, 19.8%, 29.7% and 40.3% thinned） were designed on the same site. After thinning, canopy openness and the microsite conditions such as photosynthetic photon flux density （PPFD）, soil moisture content, and soil temperature were measured in one growing season. Meanwhile, the investigation of natural regeneration was conducted at the end of the growing season. The results showed that the canopy openness increased with the increase of thinning intensities. PPFD and soil temperature and soil moisture content in different soil layers were positively relative with canopy openness after thinning. The richness of regenerating tree species did not significantly increase （p=0.30） after one growing season since thinning, but the regeneration density and frequency of tree species increased significantly （p〈0.05）. In addition, the number of regenerating tree species increased, and the increment was correlated with the characteristics of iudividual tree species. The increasing percentage of regenerating seedlings of the shade-intolerant tree species was more than that of shade-tolerant tree species. Among the investigated regeneration species, the biggest response of seedling emergency to the canopy openness was Phellodendron amurense. This paper confirmed the following conclusions： after thinning, the variety of regenerating tree species was correlative with the characteristics of regenerating tree species, and the distribution of unthinned trees and the site conditions in the investigated larch plantation were the additional factors influencing, the regeneration.

Anthropogenic Impacts on the Sediment Flux in the Dry-hot Valleys of Southwest China—an Example of the Longchuan River

The sediment flux data, measured from a dry-hot valley of the Longchuan River, a tributary of the lower Jinsha River, were analyzed with Mann-Kendall test, Seasonal Mann-Kendall test and Sen’s test. In both the upper reaches (Xiaohekou) and the lower reaches (Xiaohuangguayuan), the sediment fluxes showed a significant increase from 1970 to 2001, despite the fact that the water discharge did not change significantly during the period and numerous reservoir constructions which contribute to the trap of sediment. This can be attributed to the intensification of human activities, especially the activities related to land surface disturbances such as deforestation and afforestation, expansion of agriculture land, and road constructions. This increase is more significant in the lower reaches of the river observed at the place of Xiaohuangguayuan due to the dry-hot climate. The profound increase in sediment flux has significant implications for effective management of the sedimentation problems of the on-going Three Gorges Reservoir.

Effect of Afforestation on Soil Properties and Mycorrhizal Formation

A study was conducted on Cambisols in Northern Germany to analyze the effect of fast growing trees （Salix and Populus spp.） used in agroforestry on soil chemical and physical properties and also on endo- and ectomycorrhizal colonization of the fine roots. Representative plots of three trials, Giilzow （GUL）, Vipperow （VIP） and Rostock （ROS）, were used to measure the topsoil inventories at the very beginning and after six （GUL）, seven （VIP） and ten （ROS） years of afforestation with fast growing trees. The effect on soil organic carbon, plant available nutrients, reaction, bulk density, porosity and water conditions was analyzed, Arable soils without tree coppice were used as controls. Additionally, the endoand ectomycorrhizal colonization of two Salix and two Populus clones were investigated at one site （GUL） in 2002. The amounts of organic carbon in the topsoil increased significantly （P 〈 0.01） presumably induced by leaf and root litter and also by the lack of tillage. The soil bulk density significantly decreased and the porosity of the soil increased significantly （both P 〈 0.01）. The proportion of medium pores in the soil also rose significantly （P 〈 0.05 and 0.01）. Generally, afforestation of arable soils improved soil water retention. Ectomycorrhizas dominated the mycorrhizal formation of the Salix and Populus clones, with the accumulation of organic matter in the topsoil suspected of supporting the ectomycorrhizal formation. Thus, agroforestry with Salix and Populus spp. conspicuously affected chemical and additionally physical properties of the top layer of Cambisols within a period of six years.

提高人工长白落叶松原木出材量设计精度的探讨

针对所设计的采伐作业小班,对人工长白落叶松样木进行原木出材率测算,在"吉林省森林采伐更新造林设计系统"微机软件内上调出材率,提高原木出材量的精度。

Biomass Carbon Sequestration by Planted Forests in China

The planted forest area and carbon sequestration have increased significantly in China,because of large-scale reforestation and afforestation in the past decades.In this study,we developed an age-based volume-to-biomass method to estimate the carbon storage by planted forests in China in the period of 1973-2003 based on the data from 1209 field plots and national forest inventories.The results show that the total carbon storage of planted forests was 0.7743 Pg C in 1999-2003,increased by 3.08 times since the early 1970s.The carbon density of planted forests varied from 10.6594 Mg/ha to 23.9760 Mg/ha and increased by 13.3166 Mg/ha from 1973-1976 to 1999-2003.Since the early 1970s,the planted forests in China have been always a carbon sink,and the annual rate of carbon sequestration was 0.0217 Pg C/yr.The carbon storage and densities of planted forests varied greatly in space and time.The carbon storage of Middle South China was in the lead in all regions,which accounted for 23%-36% of national carbon storage.While higher C densities (from 17.79 Mg/ha to 26.05 Mg/ha) were usually found in Northeast China.The planted forests in China potentially have a high carbon sequestration since a large part of them are becoming mature and afforestation continues to grow.

Historical Changes and Characteristics of Rehabilitation,Management and Utilization of Forest Resources in South Korea

This study analyzed the causes of forest devastation,the characteristics of forest rehabilitation process,and the success factors of reforestation. And it reviewed the management of rehabilitated forest resources and identified the income sources of mountain villages in South Korea. The devastation of forest starting from the early twentieth century was continued to the 1950’s. The main causes of deforestation were the illegal cutting of trees for fuel and the slash-and-burning agriculture in forest. The success factors of reforestation were the decrease in the dependence on forest of fuel source,strict administration system and national participation. Sustainable forest management could be made possible through the practical use of social issues like public work project for prevention of landslide damages caused by the thinned logs left in the forest. Also it could be possible by making people realize that the public benefit was obtained from forest and the income sources of mountain villages were supplemented by non-timber forest products and tourism. Food and Agriculture Organization indicated Korea as the country that forestation was succeeded in a very short period. Korea seems to be not ordinary because economic growth was accomplished with rehabilitating natural environment. Korean forestation can become a good prototype of combining environmental rehabilitation and economic development.

Extent and Consequences of Tropical Forest Degradation： Successive Policy Options for Bangladesh

This paper is conceived at a time when new paradigms are sought for the development of a framework to deal with the problem of forest resources degradation. Deforestation in Bangladesh, has reached an alarming rate in recent years. The forest coverage of Bangladesh is one of the lowest and the deforestation rate is the highest of any country in the world. Coupled with the process of deforestation, flawed afforestration programmes have seriously exposed Bangladesh to environmental vulnerability. Considering this situation various strategies should be taken at different levels. The main objective of this paper is to suggest the possible steps that Bangladesh could halt and reverse the trend of deforestation. An extensive literature review and structured interviews of key informants have been used to collect relevant information to understand the reasons and consequences of forest degradation in the country. Based on the information gathered, this paper suggests some positive steps where the Government could be the main mitigating actor by implementing integrated programmes, which will also ensure mass awareness and wider impact.

Identifying indigenous tree species for land reforestation,forest restoration, and plantation transformation on Hainan Island, China

Selecting suitable species is the most important issue for bare land reforestation, degraded secondary forest restoration, and single-species plantation transformation. However, little information has been documented related to tree species selection for these silvicultural endeavors on tropical Hainan Island of Southern China. The present study employed Baisha County, the ecological core area of Hainan Island, as a case study area. We initially inventoried a slightly disturbed primary forest and attempted to produce diameter distribution curves for each tree species. Second, the tree species were classified into shade intolerant, opportunist, and shade tolerant species based on shape of their diameter distribution curves. Third, market value was determined for each tree species based on published literature and on-site investigations at local wood trading companies. Totally 118 tree species were encountered in the inventoried forest and 13 tree species present were finally identified as potential tree species for our silvicultural endeavor on Hainan Island, of which 3 species are shade intolerant, 5 species are opportunist and 5 species are shade tolerant. Additionally, we also selected 12 tree species that were not in the inventoried forest but were extremely economically valuable and ecologically important. This study should contribute to the formulation of a sustainable forest management strategy on Hainan Island and the methodology might be replicated in other tropical region where suitable species also need to be identified for silvicultural endeavor.

A Case Study on Environmental Evaluation and Planning for Range and Forest Management by Means of Geographic Information System （GIS）

The aim of this research is to identify the most suitable land for forestry, afforestation and rangeland management in Hamadan province. This research has been accomplished using Makhdoum＇s model. In this research 30 digital data layers are used. The Geographic Information System （GIS） has been used as main tool and overlay method has been used to implement the mentioned model. The results of this research revealed that the extent of favorite areas for fifth grade forestry, favorite areas for fourth grade afforestation, and favorite areas for third grade and fourth grade range management in the studied area. Based on the results of this research, the studied area has limited potentials for forestry and afforestation activities. The obtained results of evaluation also showed that the rangelands of Hamadan province are extremely poor. Since the rangelands have a substantial role in preservation of soil and water, therefore it is necessary to take appropriate measures for better exploitation of rangelands.

Investigation of forest-resources potential of Selenge River Basin on transboundary territory of the Republic of Buryatia and Mongolia

The author studied the issues of the present-day status of forest resources and forest management of the Selenge River Basin on the transboundary territory of the Buryat Republic and Mongolia. It is necessary to establish a good policy for wood cutting of the main and secondary use and reforestation.

INVESTIGATING SILVICULTURAL CHARACTERISTICS OF YEW （TAXUS BACCATA L.） STAND USING FULL-CALLIPERING IN NORTHERN FORESTS OF IRAN

In this research, some of site and silvicultural characteristics of Yew stand in northern forests of Iran was studied. For this purpose, compartment number 16 of district 4 Shir-ghalaye was selected. According to research purposes, stands with an area of 20 ha were chosen in center of the compartment and was separated from map. Due to restricted area of region and according to few number of Yew trees in the stand, the full-callipering method was conducted for measuring quantitative and qualitative characteristics. In the stand diameter at breast height （D.B.H.）, height and canopy diameter of all Yew trees were measured. The results showed that the diameter distribution curve and height distribution curve of Yew trees were similar to even-age forests curve. But according to average annual increment, mixture type of Yew trees in stand, diameter distribution of other species and low rate regeneration of Yew, it can be concluded that the studied Yew stand, is an uneven-age stand and because of low rate regeneration in previous years the number of young Yew trees were reduced and even-age forest curve was formed subsequently. The maximum height and diameter of Yew trees were recorded 26.8 m and 112 cm, respectively. Also, the number of trees per hectare and basal area per hectare of Yew trees were calculated 14.55 and 3.23 m2 respectively.

Status, Potentials and Constraints of Green Infrastructure of Malaysia: Case Study of Kuala Lumpur City

Green infrastructure is classic public goods which can be utilized by everybody simultaneously atany time of the day. Green infrastructure which is the interconnected system of green spaces that conservesnatural ecosystem values and functions, sustains clean air and water, not only provide a pleasant and naturalenvironment but also contribute to improving quality of life in urban areas. In other words green infrastructureis the communitys natural life support system and the ecological framework needed for environmental andeconomic sustainability in urban areas. Within this context, this paper offers an overview of green infrastructuredevelopment in Malaysia, its status, constraint, potential and future directions. The case study of KualaLumpur city, which is one of the fastest growing cities in the country, highlights the scenario of urban areasdevelopment in Malaysia. This includes the role played by the government agencies and non-governmentorganizations in developing and promoting forest areas as public parks. The provisions of recreational andeducational facilities in the parks as well as the protection measures of the resources undertaken by relevantauthorities are also discussed. This paper also highlights the response of the public to the opportunities beingprovided in these areas for recreation and education purposes.

Role of Trees in Urban Areas and Challenges of their Establishment

The trees in urban landscapes, independent of whether they are in urban forests or stand alone,can improve environment quality, enhance individual and community well-being, provide a wide range ofservices to individuals and communities, and produce a more healthful and comfortable environment forthe vast majority of the population. Knowledge of the potential significance of trees in urban landscapesis expanding rapidly as research continues to document the important role that urban forests and trees canplay in improving the quality of urban life. The environmental conditions in urban landscapes are, however,very different from the natural conditions that the tree species are adapted to. This poses big challenges tothe urban forestry in its efforts to create healthy and valuable trees in urban landscapes. Only throughimplementing some important measures we can ensure high survival rate of saplings and well-being andlongevity of urban trees.

Restoring Mountain Slope Forests by Strip-cutting Shrubs in the Upper Reaches of Minjiang River,Sichuan, China: A Biodiversity-oriented Silvicuture Experiment

The aims of forest restorationRestoration on of mountain slopes forests is often used to achieveone or a combination of the following aims, should be diverse, and includeincluding increased production, soilprotection and wildlife conservation, .and each development scheme should have a combination of thepurposes In this paper, we proposed biodiversity-oriented silviculture was proposed as a design principle inforest restoration design principle to meet the requirements and then described from which strip-cutting ofshrubs was used as the restoring technology of restoring forests by strip-cutting shrubs that developed formthe design principle. More than 10-year-observations, and experimentals and results of from more than 10years research on the afforestation practices in the upper reaches of Minjiang River, Sichuan, China, indicatedthat the technology was feasible and had many advantages. In the technology, sStrip-cutting of shrubsameliorated microclimate conditions, and improved soil nutrient level for the growth of target tree speciesand. increased The the physical survival of pine species was increased. Structural diversity, in terms ofspecies, was did not much increased, but a shrub species was observed to differentiate from shrub layer andtended to form mixed forests. Preserve belts of the technology were supposed to cover meet public demandsincluding biodiversity conservation and soil protection, and lay a foundation foract as a basic stage inecologically progressive succession. Although it is too early to conclude that this approach is successful in allfunctions, The promising initial resultslook promising indicate that strip-cutting of shrubs may be an effectivepractice for forest restoration in the upper reaches of Minjiang River, Sichuan, China.

Economic Benefit Analysis of Sedimentation Reduction by Forests in Miyun Watershed, Beijing

The economic benefit of sediment reduction by pine forest and black acacia forest at different age classes in Miyun reservoir watershed was studied using the approach of relocation cost based on the field survey from 1996 to 1999. The results show that if the transportation of eroded soil into Miyun reservoir was estimated as 100%, the economic benefit of sediment reduction by pine forest would be 59-164 RMB yuan/ha（RMB yuan = Renminbi yuan, or yuan） per year （US$1=8.27 RMB yuan during the period of research）, and 58-134 yuan/ha by black acacia forest. The average economic benefit of sediment reduction by forest is 130 yuan/ha per year. If r （the rate at which the eroded soil will enter a reservoir） varies, the economic benefits of sediment reduction also change. To estimate the economic benefit of sediment reduction more accurately, r should be measured from the field test. The results from this study provide information to help assess the feasibility of the environmental project in thids area.

Practice and Use of Tree Species in Urban Forestry in Thailand

Urban forestry is now increasingly practiced in Thailand. This has gained impetus because ofgradual deterioration of visual amenity and environmental quality in many of the rapidly developing urbancenters. Various urban beautification programs are being implemented to rehabilitate blighted landscape,polluted atmosphere and deteriorating weather conditions, as well as to maintain a clean, healthy and pleasantenvironment so as to ensure a better quality of life. Planting of suitable trees for shade, climatic ameliorationand aesthetic values form the principal activity under these beautification programs. It is regarded as not onlyan important component of socio-economic development but also contributive to the restoration of the urbanecosystem. The responsibility of the implementation of most of these programs falls to the BangkokMetropolitan, Administration, Provincial and District Municipalities. The Royal Forest Department playsthe supporting role of supplying seedlings of the species required for planting and providing technical adviceon the growing of these trees. In this paper tree species commonly planted in urban and populated areas inThailand are identified. It is envisaged that with the vast amount of flora available in Thailand and through theintegrated efforts of all agencies involved, this program will achieve the target of beautifying the cities andtowns of Thailand.

Close-to-nature Design and Management:Developing Effective and Harmonious Urban Forest in China

The plantation occupies great proportion in urban forest in many cities in China. The design and managementforurban forest supplementseach other.Thedesign decides theorientation of management, while the management also affects the landscape effects and ecological benefits of the design in reverse. There are many issues on design and management of urban forest. For example,somedesignsonly emphasizethe visualimpressionwhileignoring theecologicalbenefits, the problems of simplifying the forest layer structure and purifying its species composition are ubiquitous,It isshort ofcomprehensiveanalysisof local environment conditions, the phenomena are very outstanding in learning foreign or other city’s model by copying mechanically. The management model is not only monotonous, but also behind the step of urban development and thehuman demand for returning to nature.These unreasonable designs and managements areone of the main reasons for lower ecological benefits, and also caused some other bad aftereffects, such as lower biodiversity and high cost of management, etc. So the thought of close-to-nature design and management in urban forest is proposed and its feasibility and methods are discussed in the paper.