Douglas-fir planted forests

A combination of superior wood quality and high productivity has made Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) one of the premier timber trees in the world. As such, it is grown as a plantation species in several countries in Europe, South America, New Zealand, and Australia, as well as throughout its extensive natural range in western North America. Decades of experience with the silviculture of young stands have demonstrated that practices such as planting, the use of genetically improved seedlings, precommercial and commercial thinning, and fertilization may dramatically increase the yield of industrial products over that of natural forests. Further, such silviculture is compatible with the production of desired amenities. Vigorous implementation of such practices wherever Douglas-fir is cultivated will increase the world's timber resources, and be an effective strategy for reducing the pressure, occasioned by the world's rapidly increasing population, to harvest the fragile tropical and boreal forests.     

The need for planted forests and the example of radiata pine

Ten thousand years ago our 5 million hunter-gatherer ancestors used, over the period of a year, about 200 species of local food items. Now, the nearly 6 billion global population gets 70 percent of its food from nine species of plants, one species of bird, and two species of mammals. This is despite global access to about 50,000 edible plants, as well as large numbers of bird and other animal species. We have concentrated our agricultural efforts on those species which are the most desirable, the most convenient, the most productive, and the most easily stored. Of equal importance, the species must be responsive to both genetic improvement and to management manipulation (i.e., domestication). Globally, very little of our food, except fish, now comes from wild sources.Although we use at least as much wood as we do food, wood supply (which still comes mostly from natural forests) is only now becoming limiting. There are no energy-efficient or environmentally acceptable substitutes for wood. The most likely means we have of satisfying the increasing global demand for wood is to obtain more of our wood from deliberately planted forests. Management of planted forests will increasingly parallel intensive agriculture. One consequence is that, of the 1,000 tree species we now use globally, we may eventually get most of our wood from four or five species. One of these tree species will be radiata pine (Pinus radiata D. Don). Radiata grows fast on a wide range of sites, has desirable wood properties, and responds well to both genetic improvement and stand management. The planted forest technology for radiata pine is probably the most advanced of any potential tree species. The evolution and success of radiata pine in New Zealand has major implications and lessons for the rest of the world.     

Forests planted for ecosystem restoration or conservation

Although the phrase, planting for ecosystem restoration, is of recent origin, many of the earliest large-scale tree plantings were made for what we now refer to as restoration or conservation goals. Forest restoration activities may be needed when ecosystems are disturbed by either natural or anthropogenic forces. Disturbances can impact (1) basic components of the system (e.g., plant and animal composition, soil pools, and atmospheric pools), (2) ecosystem processes, i.e., interactions among basic components, or (3) both components and processes. Early efforts at restoration or site rehabilitation focused primarily on reducing off-site impacts, such as sediment introduced into streams from ecosystems that had been severely disturbed. More recent restoration programs include ecosystems in which only some of the components are missing or some of the processes have been impacted. Restoration activities can begin immediately after the disturbance has ended. Although forest restoration projects can include many activities, planting is almost always a key component.When planning an ecosystem restoration project, land managers need to be aware that commonly used plant establishment and management procedures may need to be altered to meet project objectives. Some systems may have been so severely impacted that ameliorative activities, e.g., fertilization, liming, land contouring, and microsite preparation, will be necessary prior to planting. Managers may also need to take special measures to reduce herbivory, control competing vegetation, or reduce physical damage from wind or sun. Choice of species needs careful consideration. Desired species may not grow well on degraded sites, may need a nurse species to become established, or may not provide an opportunity to harvest a short-term crop to reduce restoration costs. New methods may need to be developed for projects that require underplanting or interplanting. The end result of restoration should be an ecosystem with the same level of heterogeneity inherent in an undisturbed system; thus, managers should consider how pre- and postplanting activities will affect system variability.As our understanding of ecosystems has increased, so has our expectation that restored ecosystems have the same components and function in the same manner as do undisturbed systems. These expectations require that land managers have more sophisticated information than was considered necessary previously. In the absence of more pertinent information, we can prescribe restoration activities based on results from related ecosystems or on theoretical considerations. Additional research, careful monitoring, and adaptive management are critical to our long-term success.     

防治新植林鼠害的药剂对比试验

黑龙江省黑河地区鼠害越来越重，1999年在孙吴县新植林使用不同剂型的鼠药进行交叉对比防治实验，从而确定在不同立地条件，林型的新植林，根据不同鼠药的不同特性防治森林鼠害。     

克拉玛依地区人工林病虫害调查初报

2003—2004年,首次对克拉玛依市所属的克拉玛依区、白碱滩区、乌尔禾区、独山子区、小拐乡、乌尔禾乡的人工林常见病虫害进行了全面系统的调查。经鉴定病虫害共153种,其中害虫123种,病害30种。     

丘陵岗地人工防护林退化成因分析

以桃江县人工防护林为研究对象,分析了导致林地退化的主要原因,包括管护措施不到位、造林技术缺陷、自然灾害侵害、生理老化、环境污染等。针对退化原因,提出了相应的改造措施。     

Small-scale planted forests in Zululand,South Africa: an opportunity for appropriate development

Forestry in South Africa is sharply divided between commercially driven private enterprise which controls 1.3 million ha of plantation forests, and government and nongovernment organizations which promote a variety of social forestry programs. One area of crossover is that of small-scale (1–2 ha) commercial woodlots being promoted by private timber companies as an additional source of fiber for their pulpmills, but grown and managed by individual farmers. Inputs, such as plants and fertilizers, as well as expertise in the form of extension foresters, are provided by the company, whereas the farmers supply the land and the labor. The company guarantees to buy the timber at the time of harvest. Under such arrangements, the risk is spread between the farmers and the company; the farmers assume most of the risks of production, and the company takes on the marketing risks. The possibilities for appropriate and sustainable development do exist under such a program, but issues involving both ecological and social sustainability must be addressed. This paper suggests that four key characteristics are needed to achieve appropriate development in Zululand. These characteristics are participation, flexibility, empowerment, and commitment. When compared to the current arrangement, the company would have to make a fundamental paradigm shift to achieve these goals. However, the long-term support of the farmers, and ultimately more fiber in the mills, would be the reward. This revised version was published online in June 2006 with corrections to the Cover Date.     

Co-occurring tree species show contrasting sensitivity to ENSO-related droughts in planted dipterocarp forests

This study explores the diversity in sensitivity to drought of moist tropical forest tree species. Yearly tree growth records collected over a ten-year period in two one-hectare 70-year-old damar agroforest plots in Sumatra are analysed. These agroforests are mixed tree plantations, dominated by Shorea javanica K. & V., a dipterocarp tree cultivated and tapped for its commercially valuable resin (damar). Many indigenous fruit tree species grow in these agroforests, as well as timber tree species originating from the nearby natural forest. During the census period the multi-species stands were subjected to three El Nino Southern Oscillation (ENSO)-related droughts (1994, 1997 and 2002). At the tree community level, these droughts were associated with a marked decrease in radial stem growth. Multilevel modelling was used to explore the relative contribution of species, tree size and individual tree characteristics to the observed response to drought.All tree species appeared to be sensitive to drought but the amplitude of the response varied significantly across species. Predicted species mean decrease in stem radial growth rate on drought years (i.e. years with 6 months with less than 50 mm/month rainfall) ranged from less than 5% to more than 80%. Shared species were ranked consistently between plots indicating that the results were robust. Stem diameter significantly affected tree sensitivity to drought in two species only, but in opposite ways: in S. javanica, larger trees appeared to be less sensitive while the opposite was true for Lansium domesticum, an abundant fruit tree. Individual tree sensitivity to drought contributed significantly albeit to a small extent to the overall response to drought. This individual tree effect did not show any pattern of spatial correlation and hence could not be related to topographic features. It is likely to reflect the individual's unique history and genotype.     

Trees outside forests: agro-, community,and urban forestry

Planted forests are often considered to consist of tree plantings at a scale large enough to satisfy such objectives as commercial production of timber and fiber, protection of watersheds, and preservation of natural habitats. However, trees are planted also at greatly reduced scales in agroforestry systems or as community woodlots to provide a mixture of products and services to resident households, local communities, and regional cultures.Agroforestry systems represent a major form of small-scale tree planting, where trees are grown in purposeful combinations with agricultural crops and/or livestock in order to take advantage of tree-crop interactions, and thereby enhance crop production, diversify farm output, stabilize or improve soils, or ameliorate harsh environmental conditions. Some important examples of these systems in tropical countries include homegardens, alley cropping, improved fallows, intercropped trees for shade and fodder production, and trees planted in hedgerows and along fence lines. Throughout the tropics, there is a large variety of indigenous practices and species mixtures that represent adaptations of these systems to meet localized needs and opportunities. Research and development programs have supported the expansion and refinement of many of these systems during the last 20 years, but substantial constraints on tree planting still exist in the form of land-tenure practices, population pressures that relegate agroforestry practices to degraded lands, subsistence needs that prevent extended periods of tree growth, and insufficient technical information or technology dissemination.Agroforestry systems in temperate, industrialized countries include combinations of trees, pasture, and livestock; fruit or nut trees interplanted with vegetable or grain crops; windbreaks and shelterbelts; multispecies riparian buffer strips; and forest farming systems for specialty crops. Compared to the tropics, however, temperate-zone systems tend to focus on one or two high-value crops, often involve some level of mechanization, and frequently represent an opportunistic approach to improving the economic profitability of farms rather than meeting subsistence needs. In both tropical and temperate regions, agroforestry systems and community woodlots will be an important component of new sustainable agriculture and environmental protection programs.Although species diversity is an essential feature of all agroforestry systems, community forests generally involve planting only a few species in small woodlots near farms, around villages, along roads, and as riparian buffers. Provincial or state governments and the local populace are often involved in landownership and plantation establishment. Major objectives of these forests are production of fuelwood for local consumption and of other tree products for market; soil stabilization, reclamation, or improvement; and protection of water quality. As with many other planted forests, the number of species widely used in community forests has been relatively small, with the genera Eucalyptus, Pinus, and Acacia providing the bulk of the species. Major issues with these planted forests focus on rights for use of the products, tending responsibilities once trees are established, protection until trees are large enough for their designated use, increasing interest in using native species, and greater community involvement in planning and management.Trees planted along streets and waterways, or as woodlots in parks and other public places, represent a major group of planted forests in many urban and periurban landscapes. In addition to providing many of the same environmental services that agroforests and community forests do, these urban plantings have unique aesthetic and recreational value. For much of the world's ever-increasing urban population, these may be the only tangible reference points for understanding planted forests.These relatively little-recognized forms of planted forests -- planted trees, to be more appropriate -- are now receiving much greater attention. There are, however, some serious technical and sociopolitico-institutional constraints to their development as more widely adopted systems in both tropical and temperate regions.     

Planted forests: views and viewpoints

Planted forests in many forms are parts of landscapes in many regions of the world. These forests contribute to the economic welfare and potential sustainability of human communities. They provide wood, forage, wildlife habitats, watershed protection, recreational settings, aesthetic vistas, and ecological conditions for many other forest values. Forests and other versions of tree plantations have been planted to replace harvested Douglas-fir forests in Oregon, to provide fuelwood and forage in Senegal, for pulpwood in Brazil, for lumber in New Zealand, for watershed protection in Nepal, and for aesthetic enhancement in Scotland and Denmark. As human pressures on native forests continue to increase -- for reasons ranging from fuelwood needs to desires to preserve old-growth ecosystems -- it is clear to many of us that planted forests, intensively and extensively managed, are essential to our present and future societies and cultures, whatever forms they take.     

On the sustainable productivity of planted forests

Planted forests have more than a millennium of history and represent the world's best hope for meeting global wood requirements in the twenty-first century. Advances in genetic improvement, nursery practices, stand establishment, and tending, harvesting, and manufacturing have boosted plantation yields to a higher level than at any point in history. Despite this, forest managers face a mounting challenge to demonstrate that plantation productivity is sustainable. Tackling this challenge requires a sound understanding of the principles of forest productivity, how they apply to a developing plantation, and how they are influenced by management. In this paper criticisms of plantation forestry are discussed from the basis of world experience, and examples of productivity decline are described. Obvious declines are rare, and can be attributed to poor soil management. However, ambiguities exist and controversy will continue until sustainable productivity can be demonstrated conclusively. Proposed programs aim to provide the technical base needed for sound soil management and sustainable plantation productivity.     

甘肃白龙江林区森林病虫害发生原因及防治对策

本文介绍了甘肃省白龙江林区森林病虫害发生的特点和原因,对云杉落针病、云杉叶锈病、落叶松落叶病;、狭冠网蝽、苗圃地下害虫、蛀干害虫、森林鼠害等主要病虫害的发生动态及原因进行了分析,并提出了综合防治对策。     

拉萨半干旱河谷新植林鼠(兔)害调查及防治试验

2009—2010年对拉萨半干旱河谷地带新植林采用堵洞与夹日法进行了鼠(兔)种类和密度调查,结果表明鼠(兔)种类有黑唇鼠兔Ochotona curzoniae Hodgson和白尾松田鼠Pitymys leucurusBlyth,在新植林地洞口密度为905.07洞/hm2,有效洞口率是31.66%,有效洞口系数为0.18,鼠(兔)密度为50.64只/hm2。饲养和实地监测发现,两种鼠(兔)对新植林地的金丝垂柳、白榆、藏青杨、北京杨4种树的危害株率均在25%以上。选用P-1拒避剂、0.2%莪术醇抗生育剂和克鼠星1号杀鼠剂单独、交叉施药进行防治实验,结果表明单独施用克鼠星杀鼠剂的效果是暂时的,单独施用拒避剂和莪术醇抗生育剂的效果是缓慢的,同时混合施用3种药剂18个月后捕鼠(免)率、有效洞数、植株受害率分别下降了90%,81.23%,85%,效果较持久。     

Anthropogenic disturbances and status of forest and wildlife in the dry deciduous forests of Chhattisgarh state in India

The advent of modern forces and the changes in socioeconomic patterns of forest dwellers have increased the pressures on the forests. In order to mitigate such pressures and also to protect the forests and wildlife the model of protected areas networks has shifted and enhanced such pressures in the unprotected natural forests due to several reasons. Being a low profile category of protected status and continuous human settlements, the present study highlights the case of dry deciduous forests of Sarguja district of Chhattisgarh state of India. The major objectives of this study were to quantify the status of forests and wildlife and also to determine the extent of anthropogenic disturbances faced by the dry deciduous forests of central India. Transect and silent drive count methods were used for sampling wildlife and quadrat method was used for sampling vegetation. Besides, the local uses of various forest produces were also studied in view of understanding the people dependency on forests. The forest vegetation, in the study area, was pre-dominated by Shorea robusta, which had Madhuca indica, Diospyrus melanoxylon and Buchnania lanzan as the major companion species. The forest had either the high girth class mature tree species or the saplings. The low vegetation cover and density were due to the high anthropogenic pressures mainly in the form of heavy livestock grazing and collection of ethnobotanically important species. The study though reveals that the area is not rich in wildlife and the forest is fragmented, the area still supports some important species, which include many rare and endangered plants and animals. The findings of this study have been discussed in view of the management and conservation of the forest and wildlife in the dry deciduous forests.     

Soil fractal features of subalpine coniferous forests in western Sichuan under different anthropogenic disturbances

Fractal theory, used to study natural figures and images with self-similarity but without characteristic lengths, offers an effective tool to investigate quantitatively the complex systems such as soil. In this paper, we have discussed about our study of the fractal features of the subalpine coniferous forests, soil particles, and microaggregates under different intensities of anthropogenic disturbances in the Miyaluo area of west Sichuan and investigated the effects of the disturbances on the forest soils attributed to different fractal dimensions. The study introduces a new way to investigate the recovery and reestablishment of subalpine coniferous forests. __________ Translated from Chinese Journal of Ecology, 2005, 24(8): 878–882 [译自: 生态学杂志, 2005, 24(8): 878–882]     

Securing African forests for future drier climates: applying ecophysiology in tree improvement

Increasing incidences of drought-induced tree mortality are being recorded worldwide, including Africa. African forests cover a significant proportion of the continent, which implies that African forest sustainability is threatened from a climate-change perspective. This is especially problematic in a developing nation context, because forest ecosystems such as plantation forestry provide important goods and services that sustain human well-being and economic growth. Disentangling the likely triggers of tree mortality (including those linked to drought) in landscapes would not only explain the mechanisms underlying local die-offs, but also better predict future mortality events. Methods applied in the field of ecophysiology are particularly useful to study in situ plant responses to an environment. We consider the status quo of global peer-reviewed publication outputs during the past century that have made use of key ecophysiological research approaches, specifically studies concerning ‘tree xylem anatomy’, ‘tree xylem cavitation’, ‘tree leaf gas-exchange’ and ‘tree xylem hydraulic conductivity’. We highlight the growth and applicability of this research field in understanding tree ecology. We also assess the role that the forestry sector has had in promoting such research to ensure future-proof forest products. Most importantly, we consider how Africa with its vast forested landscapes fits within this research spectrum. The last decade saw an increase of up to 60% in the total number of articles published, particularly with a focus on tree xylem cavitation and conductivity. Although forest research contributed greatly to the global tally of ecophysiological studies, and such studies in Africa have also increased by up to 88% in the past decade, there remains a general lack of this research topic in the continent. It is clear an optimisation of applied ecophysiological concepts and techniques will promote an improved understanding of tree mortality patterns. We argue that ecophysiological data will be crucial to future-proof tree improvement strategies in African commodity production landscapes, especially given future drier climates.     

Dry forests in the Southern Interior of British Columbia: Historic disturbances and implications for restoration and management

We critically examine the hypothesis that dry forests in southern British Columbia evolved in the context of a low-severity fire-dominated disturbance regime, that fire suppression has led to ecological conditions which are radically different from the past, and that “restoration” initiatives are required to re-establish former ecological conditions. Four sources of information were used to infer historic disturbance regimes and forest condition and to quantify the nature of disturbance since the early 1900s: (1) patterns of annual and seasonal weather and lightning strikes, (2) topographic variability, (3) records of wildfire, insect attack, and timber harvesting practices, and (4) early systematic forest surveys.     

The influences of forest stand management on biotic and abiotic risks of damage

? This article synthesizes and reviews the available information on the effects of forestry practices on the occurrence of biotic and abiotic hazards, as well as on stand susceptibility to these damaging agents, concentrating on mammal herbivores, pest insects, pathogenic fungi, wind and fire.

? The management operations examined are site selection, site preparation, stand composition, regeneration method, cleaning and weed control, thinning and pruning, and harvesting. For each of these operations we have examined how they influence the occurrence of biotic and abiotic damaging agents, the susceptibility of European forests, and describe the ecological processes that may explain these influences.

? Overall, we find that the silvicultural operations that have the largest influence on both biotic and abiotic risks to European forest stands are closely related to species composition and the structure of the overstorey. Four main processes that drive the causal relationships between stand management and susceptibility have been identified: effect on local microclimate, provision of fuel and resources to biotic and abiotic hazards, enhancement of biological control by natural enemies and changes in individual tree physiology and development.

? The review demonstrates an opportunity to develop silvicultural methods that achieve forest management objectives at the same time as minimising biotic and abiotic risks.

     

The integration of planted and natural forests in a regional landscape

The 10,700 km² region of northwestern Oregon, USA, is dominated by mountainous forested landscapes fringed by agricultural lands and rapidly expanding urban areas. The Douglas-fir/western-hemlock trees, admixed with other species, in the mild, moist regional climate with rich soils are among the most highly productive of temperate forests. Timber harvest has been the dominant land use for much of this century. Many current forest stands are planted, and have the potentials to be managed and shaped for a variety of traditional and evolving forestry objectives. The ages, resilience and productivity of these forests and mosaics of land ownerships permit a variety of future scenarios of forested landscapes, constrained largely by capacities of social organizations to plan and execute management for desired future conditions. This revised version was published online in June 2006 with corrections to the Cover Date.     

森林昆虫的合理开发与利用

森林昆虫是1个有待开发的资源,利用森林昆虫,可制成食品及医药保健品,可作为林副特产,可发展昆虫文化及旅游业,但对森林昆虫不能乱捕滥采,必须注意合理开发利用。