Past,present and future of industrial plantation forestry and implication on future timber harvesting technology

Plantation forests are established,and expanding,to satisfy increasing global demand for timber products.Shifting societal values,such as safety,productivity,environmental,quality and social are influencing the plantation forestry sector.This is primarily driven through an ever increasing world population,which in turn influences the way nations view the value systems by which they live.More people require more resources-also forest products.Also,the availability of information is influencing the pace of technological development.These changes could result in a difference in the management of plantations that could affect the forest engineering systems of the future.This review aimed to summarize the current status of plantation forests;summarize future developments and possible scenarios in forest plantation management for the various products;and assess whether these developments in a plantation environment could affect the harvesting systems used.Factors influencing the form of plantations include the type and nature of the plantation owner;the change in demand for different and new forest products;climate change factors,including the use of biomass for energy,carbon sequestration and trading;ecosystem services and other products and services;and sustainability certification of forest management.The impact and influence of these factors were summarised into a series of key drivers that will influence the technology used in harvesting machines,as well as the choice of harvesting machines,systems and methods.These drivers were the effect of variations in tree size,the expansion of plantation areas onto more difficult terrain,diversity in plantation design,increased attention towards site impacts and the increased use of biomass for energy.Specific information is provided regarding how the harvesting systems could be affected.

Effects of single-tree selection harvesting on hymenopteran and saproxylic insect assemblages in the canopy and understory of northern temperate forests

Insects respond to changes in microhabitat caused by canopy disturbance, and thus can be used to examine the ecological impacts of harvesting. Single-tree selection harvesting is the most common silvicultural system used to emulate local small-scale natural disturbance and maintain uneven-aged forest structure in temperate forests. Here, we test for differences in richness, abundance, and composition of hymenopteran and saproxylic insect assemblages at four different taxon levels （selected insect orders; and all hymenopteran families, and braconid subfamilies and morphospecies） between the canopy and understory of unharvested and single-tree selection harvested sites in a northern temperate forest from central Canada. Harvesting had no effect on insect assemblage richness, composition or abundance at the three highest taxon levels （order, family and subfamily）. Similarly, richness and abundance at the lowest-taxon level （braconid morphospecies） were similar, although composition differed slightly between unharvested and harvested stands. Insect assemblages were vertically stratified, with generally higher abundance （for Diptera, Hymenoptera, some hymenopteran families and braconid subfamilies） and richness （for braconid morphospecies） in the understory than the canopy. In particular, composition of the braconid morphospecies assemblage showed relatively low similarity between the understory and canopy. Single-tree selection harvesting appears to influence wood-associated insect taxa only subtly through small changes in community composition at the lowest taxon level, and thus is recommended as a conservative approach for managing these northern temperate forests.

New Development in Study of the Faustmann Optimal Forest Harvesting

Chinese forest resources have become very scarce in the face of rapid economic growth demand, while the reform of collective forest right system is in full swing across the country. It will directly affect the regeneration level of forest resources and the diverse ecological value functions. In this article, the mainstream model paradigm of forest economics, that is, the basic framework of the Faustmann model and its evolution process are made in a more detailed explanation, especially the extended model including considered silvicultural effort, tax subsidies, risk dynamic management, and forest regeneration factors are made in more detailed explanations. This article concludes with the future further research directions of forest economics, including the design of dynamic models that includes considered uneven-aged forest management, non-timber goods and services, dynamic forest models. The research reflects the general trend of interdisciplinary and cross-border.

AN ECOLOGICAL APPROACH TO FOREST HARVESTING

This paper deals with the relationships between forest harvesting and forest ccology.Itproposes basing annual cuts and forest operation plans on ecological principles.Harvestable forest re-sources are decreasing and regeneration is slow.The combination of forest harvesting with ccologycan be viewed as a solution to the forest harvesting dilemma in China.This paper also makes sometechnical recommendations for forest operations based on ecological principles.

Rational Harvesting Policy and Sustainable Development of Community in Forest Regions

Forest ecosystem is one of the most important ecosystems in the world that human-beings rely on. Forest harvesting policy is one of the main criteria indicating how and how much the human beings open up and make use offorest. Whether the policy is reasonable or not has high relations with not only the increasing or decreasing of forest system,but also the development speed of human society. In this paper, the author analyzed the development of interaction between human society and forest ecosystem from ancient times to today. Then author stated that the rational harvesting policy should be the harvesting sequences of both harvesting density and harvesting time, which might result in the maximumcomprehensive benefit, including economical profit, social benefit and ecological benefit, of forest to human society. Atlast, according to the analysis of interaction bctween human-beings and her environment, the prediction analysis for humansociety development in forest regions in the future was prescnted using Entropy Growing Analysis.

Regeneration patterns of key pine species in a mixed-pine forest indicate a positive effect of variable retention harvesting and an increase in recruitment with time

Background:Many fire-dependent forests have experienced significant declines in species,structural,and functional diversity.These changes are attributed in part to traditional management approaches that were dominated by even-aged regeneration methods such as clearcutting.Variable retention harvesting(VRH)is an ecologically based forestry practice that involves retention of some mature overstory trees and other biological structures in the postharvest stand to emulate the effects of natural disturbance events.In this study,we examined the effect of a VRH treatment on recruitment of historically dominant pine species and understory vegetation twoand six years after its implementation in a naturally regenerated mixed pine forest in the Upper Peninsula of Michigan,USA.Results:We found greater regeneration of red pine(Pinus resinosa L.)and eastern white pine(Pinus strobus L.)in VRH stands compared to the unharvested controls.Although red pine recruitment was very low during the first 2 years,both species increased significantly from year two to year six.Recruitment responses for the two species did not differ significantly between the aggregated and dispersed retention treatments.We also found high recruitment of deciduous tree species,consisting primarily of sprouts,and red pine exhibited a negative correlation with these sprouts.Treatment,time,and the interaction of treatment and time were significant factors in red pine recruitment.Time had a strong effect on the understory vegetation,with significant decreases in shrubs and ferns over time.Conclusions:The results suggest that VRH enhanced recruitment of red pine and eastern white pine and that this recruitment increased with time.We identify competition from sprouts and unfavorable seedbed conditions as the main factors that limited recruitment of red pine during the first 2 years.To reduce competing vegetation and improve seedbed conditions,we suggest following the VRH with a prescribed fire,mechanically removing sprouts,and implementing herbicide treatments.At a time when changes in global climate exacerbates the effects of traditional drivers of forest degradation,and with the need to maintain biodiversity,new ecologically based forest practices such VRH have the potential to facilitate regeneration of native trees and enhance the resilience of many fire-dependent forests.

Effects of Whole-Tree Harvesting on Species Composition of Tree and Understory Communities in a Northern Hardwood Forest

In the northeastern United States, whole-tree harvesting is widely used to supply fuel to biomass energy facilities, but questions remain regarding its long-term sustainability. We have previously reported findings indicating no short-term decrease in forest productivity in whole-tree harvested sites when compared with similar conventionally (stem-only) harvested sites. Here we present additional results of the same study, but focus on the effect harvest treatment has on the species composition of the regenerating forest. Within northern hardwood forests in central New Hampshire and western Maine, regeneration surveys were conducted on four (4) small clearcuts in 2010 and twenty-nine (29) small clearcuts in 2011. The species and diameter of trees > 2 m in height were recorded within 1 m or 2 m-radius plots and used to calculate the biomass fraction of each species. The 2010 study additionally measured the density of trees 2 m in height and the diversity of understory non-tree species. Non-metric multidimensional scaling and multi-response permutation procedures were used to determine the effect of harvest treatment had on community-wide tree species composition. Potential differences were also examined on a species-by-species basis. Both analytic methods indicated no significant differences in species composition of tree species or understory communities. Within the limits of our data, we conclude that no significant effects of residue removal on species composition are observed within our sample of northern hardwood sites at this early stage of stand development.

Exploring Factors Influencing Species Natural Regeneration Response Following Harvesting in the Acadian Forests of New Brunswick

In the Acadian Forest Region of northeastern North America, forest managers are under increasing public pressure to restore the forest to a more historic, natural condition by reducing in clearcutting and promoting partial-cut treatments that more closely emulate historic, local natural disturbance regimes. However, although numerous studies on the effects of partial-cutting on forest regeneration response have been conducted in surrounding temperate and boreal forest ecosystems, there are few studies that directly explore responses to various forms of harvesting within the Acadian Forest ecosystem, with its unique mixture of northern hardwoods and boreal forest species. Here, we conducted one of the first retrospective studies on forest regeneration following a variety of harvesting methods in the Acadian Forest using univariate and multivariate regression trees to assess regeneration response in 50 naturally-regenerating, harvested forest sites in New Brunswick, Canada. Our study shows that regeneration was highly influenced by harvest type, overstory composition, and environmental conditions as reflected by ecoregion classification. Canopy opening size (as controlled by harvest method) significantly influenced the dominance of regenerating species. The presence of conspecific overstory trees increased the likelihood of their regeneration following disturbance, supporting the direct-regeneration hypothesis, especially for species with limited seed dispersal (e.g., sugar maple (Acer saccharum Marsh.) and American beech (Fagus grandifolia Ehrh.). Despite reported problems elsewhere in eastern North America, neither American beech nor balsam fir (Abies balsamea (L.) Mill.) constituted significant competition for the desired species on a broad scale, but the presence of beech was a significant deterrent for yellow birch (Betula alleghaniensis Britt.).

Impact of Tree Stump Harvesting on Soil Carbon and Nutrients and Second Rotation Tree Growth in Mid-Wales, UK

The drive to develop renewable energy is increasing the interest in energy forestry. Woody biomass from forest residues has the potential to make a significant contribution to greenhouse gas emission reduction through fossil fuel substitution. However, there is a danger of operational practice running ahead of the understanding of the environmental impacts of such activities. Consequently, there is an urgent requirement for scientifically underpinned guidance on the best management practices to ensure soil and water protection, including sustaining forestry’s key role in carbon capture. This study addresses the main issues associated with stump harvesting practices and their impacts on soil carbon and nutrient capital and effects on the second rotation tree growth. It reports results from a clearfell site in the UK where experimental stump harvesting was carried out in 2005 before replanting with Sitka spruce Picea sitchensis (Bon.)Carr. Both stump harvested and conventional harvested areas (Control) were studied in 2009 and 2010, five years after harvesting, on the two distinct soil types at the site: podzolised brown earth and peaty gley soils. Results show impacts of stump harvesting on soil carbon and nitrogen stocks, residual water, base cations (K+, Ca2+ and Mg2+) concentrations and stocks and bulk density in both soil types. The organic peaty gley soil showed larger and deeper profile changes after stump harvesting compared with the podzolised brown mineral soil, where some of the negative changes in C, N and base cations in the top soil were compensated by increases at depth. Tree assessment showed positive effect of stump harvesting on K and Ca uptake by young seedlings, but N and P nutrient status was reduced on the peaty gley soils. The overall results support the current UK forestry guidance for stump harvesting which identifies that soil type is the most important site factor determining the sustainability of the practice.

Effects of harvest intensity on the marketable organ yield,growth and reproduction of non-timber forest products(NTFPs):implication for conservation and sustainable utilization of NTFPs

Background:Non-timber forest products(NTFPs)are an important part of forest biodiversity,and the subsistence and trade of local people,especially in less developed countries.Because of the high ecological and economic value,NTFPs have faced the problem of over-exploitation,and the key to solve this problem is to determine the feasible way of sustainable utilization of NTFPs.Harvest intensity is one of the most important and easily controlled utilization factors,which can greatly influence the plant individual survival,growth and reproductive performances,and even the population structure and dynamics.Therefore,we chose two common and important NTFPs species with different marketable parts(i.e.,Acanthopanax senticosus with tender leaves and Aralia elata with tender buds)as our study objects.Aiming to determine the optimum harvest intensity for sustainably utilizing both NTFPs species,five levels of harvest intensity treatments(i.e.,control,light,medium,high and severe)were designed to assess the effects of harvest intensity on their marketable organ yield,plant growth and reproductive performances.Results:The biomass growth rates of marketable organ and plant growth of A.senticosus under light harvest intensity treatment were significantly higher than those under other harvest intensities.The plant height growth and 1000-seed weight of A.elata under severe harvest intensity treatment were significantly lower than those under control treatment.Conclusions:The light harvest intensity with 25% leaf removal and the high harvest intensity with all terminal buds harvested are the optimum harvest intensity to maintain the sustainable utilization of A.senticosus and A.elata,respectively.These findings could provide managers with basic but practical guidance for making decisions about the sustainable harvest management plan for the cultivated NTFPs species,and further provide a theoretical basis for managers to establish the harvest regulations for wild NTFPs species.Consequently,the local residents or communities can improve their income while ensure the sustainable development of wild NTFPs.

A Simple Geospatial Nutrient Budget Model for Assessing Forest Harvest Sustainability across Nova Scotia, Canada

A geospatial GIS-linked spreadsheet model (Nutrient Budget Model—Nova Scotia: NBM-NS) was developed for Nova Scotia to assess the long-term sustainability of forest harvest scenarios as constrained by primary nutrient inputs and outputs due to atmospheric deposition, soil weathering, and leaching. Harvest scenarios refer to user-defined stand-specific removal rates of bole wood, bark, branches, and foliage, based on current or projected forest inventories. These scenarios are evaluated within the context of existing data layers for current climate (mean annual precipitation and air temperatures), atmospheric deposition (N, S, Ca, Mg, K), and soil/substrate types, supplemented by species-specific look-up tables containing expected biomass fractions and nutrient concentrations. This article introduces this model to assess relative site quality and limiting nutrients for red spruce and sugar maple across Nova Scotia. This is followed by an output comparison involving 25 spruce plantations whereby NBM-NS determinations derived using “default” soil survey data are compared with those derived using plantation-specific soil data. Model output shows that (i) Ca and N are the main growth-limiting nutrients across Nova Scotia, (ii) currently projected plantation yields are generally not sustainable on sites underlain by slowly weathering soils, (iii) current soil base cation contents are generally lower than what is reported in historic soil survey reports, and (iv) model results are expected to vary within the context of changing climate, acid deposition levels, and data accuracy.

Ideal Point Method Applied in Forest Harvest Regulation

Ideal point method is one of the methods to solve multi-objective problem. It is applied to forest harvest regu-lation, and showed very good results by analyzing changes of quantitative indexes of forest resource structure before andafter the regulation. This method can be applied as one of the mathematical tools in forest harvest regulation.

Chaotic Genetic Algorithm-Based Forest Harvest Adjustment

Forest harvesting adjustment is a decision-making,large and complex system. In this paper,we analysis the shortcomings of the traditional harvest adjustment problems,and establish the model of multi-target harvest adjustment. As intelligent optimization,chaotic genetic algorithm has the parallel mechanism and the inherent global optimization characteristics which are suitable for multi-objective planning the settlement of the issue,specially in complex occasions where there are many objective functions and optimize variables. In order to solve the problem of forest harvesting adjustment,this paper introduces a genetic algorithm to the Forest Farm of Qiujia Liancheng Longyan for forest harvesting adjustment firstly. And the experimental result shows that the method is feasible and effective,and it can provide satisfactory solution for policy makers.

Do forest health threats affect upland oak regeneration and recruitment?Advance reproduction is a key co-morbidity

We analyzed national forest inventory data collected from circa 2000–2018 across 37 states in the eastern United States to better understand the influence of forest health related canopy disturbances on the regeneration and recruitment dynamics of upland oaks(Quercus).We found low levels of oak recruitment across all disturbance types examined but limited evidence of any direct effects from the type of disturbance on the population of regenerating oaks.The general lack of differences in oak regeneration response between forest health disturbances and disturbances caused by harvested or non-disturbed plots does not indicate that the effects of forest health disturbances were benign,however.Instead,low level of oak recruitment across all disturbance types highlights the pervasiveness of the trend of shifting composition in once oak-dominated forests where oak is absent or sparse in the regeneration layer.Our results show that oak recruitment was higher when oak was present as advance reproduction prior to disturbance from any cause examined.Collectively,these results lead us to conclude that the widespread inadequacy of oak advance reproduction in mature oak-dominated forests is the prevailing threat to oak forest health and sustainability.We suggest the status of advance reproduction be treated as a co-morbidity when weighing the risk and potential outcomes from other threats to upland oak forests in the eastern United States.

竹笋采挖下克隆整合对毛竹林发笋成竹规律的影响

【目的】为研发毛竹林高产高效生态经营技术提供一定参考。【方法】调查浙西南地区采挖毛竹林竹笋后的笋-幼竹生长过程,通过存活曲线分析毛竹林挖笋后的发笋成竹规律,探讨挖笋对竹笋中单宁、粗脂肪、粗蛋白等品质指标的影响。【结果】竹笋采挖提高了毛竹林地的发笋能力,挖笋样地的发笋数比未挖笋样地增加了12.8%(P<0.05),而挖笋后选留竹笋的存活率也显著高于未挖笋样地;与未挖笋样地相比,挖笋样地内毛竹新分株的平均胸径并未发生显著改变(P>0.05),挖笋不会降低新分株胸径而使林分衰退;竹笋间的非对称性竞争有利于竹笋地径的径级为Ⅰ-Ⅲ级竹笋的生长与存活,随着地径的提高竹笋死亡率显著降低,而径级Ⅳ级以上竹笋则有着较高的死亡率。盛笋早期以后,径级相对较小(Ⅳ级以上)的竹笋开始大量萌发,这类竹笋若不及时采挖,大部分会出现退笋,造成资源浪费;挖笋和未挖笋样地竹笋的含水率、蛋白质和粗脂肪含量在各笋期均未见显著差异(P>0.05),尽管挖笋样地竹笋的单宁含量在末笋期显著高于未挖笋样地,但两种样地其他笋期单宁含量均未见显著差异。【结论】毛竹林竹笋的采挖,可缓解竹笋间的非对称性的资源竞争,有效避免大量退笋导致的毛竹母株营养消耗,实现母株资源的克隆整合,增加竹笋产量。因此,合理的竹笋采挖有利于毛竹笋用林的高效生产及可持续性经营。

阔叶红松林林木与林分生长对采伐干扰的响应

提升森林质量、修复生态功能是东北阔叶红松林生态修复的核心,而阐明林木与林分生长对采伐干扰的响应机理是其中的关键。森林对采伐干扰的响应会受到空间尺度、时间尺度以及干扰程度等因素的综合影响。以往的研究侧重于比较不同采伐处理下林木生长的相对大小,而忽视了不同恢复时间下,林木和林分生长随干扰程度的变化。以吉林蛟河阔叶红松林采伐样地为对象,基于连续四次样地调查数据(2011、2013、2015、2018年),分别探讨了林木和林分生长在不同恢复阶段对不同程度采伐干扰的响应,并通过构建分段模型确定采伐干扰阈值。结果显示:林木和林分生长对采伐干扰的响应并不一致,采伐促进了林木生长,并且林木生长量随采伐强度的升高而升高;采伐降低了林分生产力,林分生产力随采伐强度的升高而降低。林木和林分生长对采伐干扰的响应存在时滞效应:林木和林分生长在采伐后两年内并无显著变化,而在采伐三年后才发生明显变化。此外,分段模型的结果显示:当保留木断面积为21.6 m^(2)/hm^(2)时,林分生产力最高,表明通过密度调整使阔叶红松林胸高断面积维持在21.6 m^(2)/hm^(2)附近,可使林分处于较高的生产力水平、促进森林恢复。研究结果能够为制定科学的阔叶红松林生态修复策略提供技术支撑。

受甲虫影响的木材与非木材产品的联合收获策略

基于森林中木材和非木材产品的开发现状,考虑甲虫与森林木材的相互作用关系建立生态数学模型。首先,分析该模型的动力学行为,运用常微分方程的定性理论分析系统平衡点的存在性以及稳定性条件;其次,研究该模型下的最优收获问题,选取收获努力量和对甲虫的人为消杀率为最优控制变量,求出最优解的表达式;最后,结合数值模拟给出具有实际意义的最优收获策略,为林业生态经济的可持续发展提供一定的理论依据。

国外机械振动式林果收获装备研究现状与展望

随着林果产量的不断提高、劳动力的短缺,林果的采收问题越来越突出,机械化采收是林果产业发展的必然选择。文章介绍了机械振动式林果采收装备对林果产业发展的重要意义,描述了振动式采收机理的两种形式,将现有林果机械化采收装备系统地划分为五种方式,并分析了五种方式的优缺点,列举了一些国外具有代表性的机型,并对其特点进行了分析,围绕国外采收装备的作业模式、结构形式以及设计理念,结合我国实际情况提出发展意见,为我国进一步研制开发林果采收装备系列产品提供参考。

林木采伐调查设计技术流程探究

林木采伐调查设计工作作为精准开展林业资源管理的重要前提,其调查设计的精确性与科学性直接会影响林业资源能够合理被利用。因此,如何有效完善与优化林木采伐调查设计技术流程至关重要,开展对林木采伐调查设计技术流程的研究具有一定的现实意义。鉴于此,本文使用文献查阅法和经验总结法,以林木采伐调查设计工作基本原则为切入点,从外业调查和内业计算两个层面分析与探究林木采伐调查设计要点及技术流程,指出相关技术流程要点,以期为提高林业资源利用、促进林业高质量发展提供参考与借鉴。

山西省太宽河国家级自然保护区集水造林效果研究

以山西省太宽河国家级自然保护区山杏和油松为研究对象,在水平沟和V型坑2种整地方式下,采用3种单一保水保湿技术及4种综合保水保湿技术进行造林试验,分析了不同造林技术对造林地土壤含水量及对幼苗生长情况的影响。研究结果表明,水平沟整地和V型坑整地对造林地土壤含水量的影响不大,但不同保水保湿技术均可有效提高造林地土壤含水量。从造林效果来看,水平沟和V形坑整地对山杏和油松造林成活率及苗木生长情况的影响相差不大。从不同集水造林技术来看,覆盖防草布是保证造林成活率和苗木生长的关键技术。综合比较来看,覆盖防草布(A)+膨润土(B)+黄腐酸(C)效果最好,其次是覆盖防草布(A)+膨润土(B)或覆盖防草布(A)+黄腐酸(C)。