宝密桥林场森林资源动态与分析评价

通过对宝密桥林场1999年和2009年的二类调查资料进行对比分析,研究了该林场在这10年里的森林资源变化情况,评价其经营管护效果,并提出了经营利用意见。     

Risks to forest carbon offset projects in a changing climate

When included as part of a larger greenhouse gas (GHG) emissions reduction program, forest offsets may provide low-cost opportunities for GHG mitigation. One barrier to including forest offsets in climate policy is the risk of reversal, the intentional or unintentional release of carbon back to the atmosphere due to storms, fire, pests, land use decisions, and many other factors. To address this shortcoming, a variety of different strategies have emerged to minimize either the risk or the financial and environmental implications of reversal. These strategies range from management decisions made at the individual stand level to buffers and set-asides that function across entire trading programs. For such strategies to work, the actual risk and magnitude of potential reversals need to be clearly understood. In this paper we examine three factors that are likely to influence reversal risk: natural disturbances (such as storms, fire, and insect outbreaks), climate change, and landowner behavior. Although increases in atmospheric CO₂ and to a lesser extent warming will likely bring benefits to some forest ecosystems, temperature stress may result in others. Furthermore, optimism based on experimental results of physiology and growth must be tempered with knowledge that future large-scale disturbances and extreme weather events are also likely to increase. At the individual project level, management strategies such as manipulation of forest structure, age, and composition can be used to influence carbon sequestration and reversal risk. Because some management strategies have the potential to maximize risk or carbon objectives at the expense of the other, policymakers should ensure that forest offset policies and programs do not provide the singular incentive to maximize carbon storage. Given the scale and magnitude of potential disturbance events in the future, however, management decisions at the individual project level may be insufficient to adequately address reversal risk; other, non-silvicultural strategies and policy mechanisms may be necessary. We conclude with a brief review of policy mechanisms that have been developed or proposed to help manage or mitigate reversal risk at both individual project and policy-wide scales.     

长白山典型林区森林资源变化及目前质量分析

利用研究区1985年和1999年两期遥感数据,将两期图像的矢量化图像中变动幅度较大的主要类别进行叠加,通过图像单元统计及图像叠加分析,得知各类地物在十五年间的变化情况及相应类别变化的量化归属。研究表明,十五年间采伐迹地、人工幼林变化剧烈,人类活动是造成研究区地物剧烈变化的最主要原因。选择研究区中二个干扰与经营状况不同的林场进行重点剖析,结果表明经营强度及方式的不同,对森林资源质量有较大的影响。东升林场采伐利用强度相对较小,目前仍保存有面积约占该林场1/3左右的地带性植被,过熟林面积比例较高,成熟针叶林单位面积蓄积量高达536.27m3hm-2,与长白山自然保护区的阔叶红松林单位面积蓄积量大体相当;西林河林场因采伐强度较大,目前林分多为原始林被破坏后形成的次生林,成过熟林比例相对较低,单位面积蓄积量也较小。二个林场森林状况以及营林措施方面具有一定代表性,其森林演替具有天然、人为干预两个方面的性质,作为重点剖析对象对研究区未来森林资源经营具有一定的指导意义。本文还就研究中发现的问题进行了剖析,并对当地的营林策略提出了可行性建议。图6表4参13。     

平坝县森林资源动态变化与发展对策

通过对平坝县1985年、1995年和2005年连续3次森林资源二类调查资料和2013年平坝县林地变更调查数据的比较分析表明:平坝县的林地面积、森林面积蓄积和森林覆盖率均稳步提高,森林资源保持了高速度增长;但也存在森林资源结构不合理,森林资源整体质量和森林资源管理水平较低等问题。针对问题提出了科学制定森林可持续发展规划、推进森林分类经营等措施,以期保障平坝县森林资源的可持续发展。     

十八站林业局森林资源情况及变化评价

基于国家林业和草原局大兴安岭调查规划设计院2016年十八站林业局森林资源二类调查数据,对其森林资源情况进行描述及评价,与前期二类调查数据进行比较,分析资源变化趋势。     

贵州省天保工程区森林资源变化评价

本文对贵州省实施的天然林资源保护工程所带来的森林资源数量和质量的变化进行了阶段性评价,同时对工程区和非工程区进行了实施效果的对比分析。结合工程区实际,建议工程到期后应该延续实施,以保障和扩大工程成果。     

STUDY ON THE EFFECT OF CLIMATE CHANGE ON FOREST FIRE IN HEILONGJIANG PROVINCE

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Decision support for evaluating landscape departure and prioritizing forest management activities in a changing environment

We evaluated changes (hereafter, departures) in spatial patterns of various patch types of forested landscapes in two subwatersheds (“east” and “west”) in eastern Washington, USA, from the patterns of two sets of reference conditions; one representing the broad variability of pre-management era (∼1900) conditions, and another representing the broad variability associated with one possible warming and drying climate-change scenario. We used a diagnostic set of class and landscape spatial pattern metrics to compare current spatial patterns of test subwatersheds against the two sets of reference conditions. In a companion decision support model built with the EMDS modeling system, we considered the degree of departure in the subwatersheds, relative to the two sets of reference conditions along with two additional criteria (vulnerability to severe wildfire and timber harvest opportunity), to determine the relative priority of landscape restoration treatments, and the potential for timber harvest to underwrite the treatments. In the decision support model, the current spatial pattern conditions of physiognomic types, cover types, forest structural classes, and those of late-successional and old forest patches of the two subwatersheds were compared against the two sets of reference conditions. The degree of departure in spatial patterns of physiognomic conditions was moderate in both subwatersheds in the pre-management era and climate-change comparisons. The situation was similar for the cover-type departure analysis, but spatial patterns of cover types increased in similarity to the reference conditions in the western subwatershed under the climate-change scenario. Spatial patterns of structural conditions showed a high degree of departure in both subwatersheds when compared to either set of reference conditions, but similarity improved in the eastern subwatershed under the climate-change scenario. Spatial patterns of late-successional + old forest structure were strongly similar to the broad envelope of conditions represented by the pre-management era reference in the western and moderately similar in the eastern subwatershed, but declined in both subwatersheds when compared with the climate-change reference conditions. When the degree of departure in spatial patterns of all patch types was considered along with vulnerability to severe wildfire and timber harvest opportunity, the eastern subwatershed rated higher priority for landscape improvement using either set of reference conditions. We conclude by considering uncertainties inherent in the analysis approach, types of sensitivity analysis needed to investigate model performance, and broad implications for forest managers.     

吉文林业局森林资源动态及经营效果评价

文章依据内蒙古吉文林业局1997年和2007年两次森林资源二类调查的数据资料,在分析2007年森林资源总量、天然林和人工林、生态公益林和商品林、森林资源质量、森林生态状况以及森林资源权属的基础上,对1997~2007年的10 a间各类林地面积、各类林木蓄积量、天然林和人工林、生态公益林和商品林、森林资源结构、森林资源质量、森林资源数量等方面的动态变化进行了分析。     

试论森林集约经营

本文论述了森林集约经营的概念,并提出了实施集约经营应采取的几项技术措施.     

浅谈国有公益林的经营方案

通过研究国有大围山林场森林经营方案的编制过程与方法 ,就当前国有林场公益林的经营方案编制进行分析 ,从多方面阐述编案过程中的一些具体方法、步骤以及注意事项 ,为同行提供参考     

项目范围管理——提升我国森林经营方案编制质量的新途径

针对我国以往森林经营方案编制和实施过程中暴露出来的具体问题,着重从项目范围管理角度,阐述了项目范围管理技术和工具对我国森林经营方案编制的现实意义,探讨并指出了这一先进管理工具对提升我国森林经营方案编制质量的有效性和必要性,以期为我国即将展开的新一轮森林经营方案编制作出一定的有益探索。     

气候变化对昆明园林环境的影响

通过对昆明1951～2007年气候资料的分析得知,近60年来,昆明平均气温变暖,最为突出的是近十余年增温幅度高达0.4℃/10a,同时年较差缩小,体现在最低气温的显著升高,昆明的冬天正在变暖;伴随气温变暖,降水量却显著减少,过去14年中降水量减少幅度约为18.05mm/a;相对湿度与降水量呈正相关,这导致昆明将更加缺水和干燥;日照时数的下降率约107h/10a,主要原因之一就是昆明快速城市化过程。昆明城市的四个重要气候指标近60年来的变化呈现一高三低态势,应对其年平均气温的升高、降水量减少以及城市整体气候变化提出园林建设对策。     

森林资源一类和二类调查存在的主要问题与对策

对森林资源一类清查和二类调查本身存在的主要问题及其调查成果因诸多原因存在的不可比性问题进行了探讨,研究提出了相应的对策。     

威宁森林火灾与气象条件的相互关系研究

利用威宁冬春林火资料及同期气象资料,从影响森林火灾发生的气象因子着手,分析了气象条件对森林火灾发生的影响和作用,揭示了二者间的相互关系,建立了简单而又直观的气候干燥度公式,计算了可燃物潜在火险程度的等级指标,为林火预测预报提供了科学依据。     

黑龙江省勃利县林业局国有森林资源现状及今后经营利用分析

根据2008年勃利县林业局国有林区森林调查结果,与前11年资源调查数据比较分析,进行数量和质量差异对比,制定今后发展对策。     

Management Strategies and Research Orientations of Forest Diseases and Pests in China

Forest diseases and pests are perceived as a growing hazard to China economy. It is a common conclusion that the actualities of forest pests in china are no effective measures to the old important pests, some secondary pests are ascending to chief pests, increasing devastation from exotic pests, frequent ecological pest eruption induced by environmental detriment and host-leading diseases to threaten the "Western Development Project "in China, which is the most important economical strategy to China; that inducement of current forest pests results from ecological function loss and dangerous exoticpest intruding, On the basis of these cognitions, we suggest that strategies of management pests to natural forest would be stressed to maintain its innate capacities to adjust pests in virgin forest and resume such function in intermpted one, that to artificial forest would establish self-control in afforestated stands and develop resistant tree varieties and species, especially those in landscape trees. In re     

Climate change and the probability of wind damage in two Swedish forests

We simulated how possible changes in wind and ground-frost climate and state of the forest due to changes in the future climate may affect the probability of exceeding critical wind speeds expected to cause wind damage within one northern and one southern study area in Sweden, respectively. The topography of the study areas was relatively gentle and the forests were dominated by Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.). Using estimated changes in the net primary production (NPP) due to climate change and assuming a relative change in the site productivity equal to a relative change in NPP, we simulated possible future states of the forest under gradual adjustment of the site index in response to climate change using the model The Forest Time Machine. Global climate change scenarios based on two emission scenarios and one general circulation model were downscaled to the regional level. The modified WINDA model was used to calculate the sensitivity of the forest to wind and the probability of wind damage for individual forest stands for the periods 2011–2041 and 2071–2100 and for a control period 1961–1990. This was done while taking into account effects on stability of the forest from expected changes in the occurrence of ground frost. Increasing sensitivity of the forest to wind was indicated for both study areas when adhering to recommended management rules of today. Adding also a changed wind climate further increased the probability of wind damage. Calculated probabilities of wind damage were generally higher in the southern study area than in the northern one and were explained by differences in wind climate and the state of the forests, for example with respect to tree species composition. The indicated increase in sensitivity of the forest to wind under the current management regime, and possibly increasing windiness, motivate further analysis of the effects of different management options on the probability of wind damage and what modifications of Swedish forest management are possibly warranted.