Future impacts of climate change on forest fire danger in northeastern China

Climate warming has a rapid and far-reaching impact on forest fire management in the boreal forests of China. Regional climate model outputs and the Canadian Forest Fire Weather Index （FWI） Sys- tem were used to analyze changes to fire danger and the fire season for future periods under IPCC Special Report on Emission Scenarios （SRES） A2 and B2, and the data will guide future fire management planning. We used regional climate in China （1961 1990） as our validation data, and the period （1991–2100） was modeled under SRES A2 and B2 through the weather simulated by the regional climate model system （PRECIS）. Meteorological data and fire danger were interpolated to 1 km 2 by using ANUSPLIN software. The average FWI value for future spring fire sea- sons under Scenarios A2 and B2 shows an increase over most of the region. Compared with the baseline, FWI averages of spring fire season will increase by 0.40, 0.26 and 1.32 under Scenario A2, and increase by 0.60, 1.54 and 2.56 under Scenario B2 in 2020s, 2050s and 2080s, respectively. FWI averages of autumn fire season also show an increase over most of the region. FWI values increase more for Scenario B2 than for Scenario A2 in the same periods, particularly during the 2050s and 2080s. Average future FWI values will increase under both scenarios for autumn fire season. The potential burned areas are expected to increase by 10% and 18% in spring for 2080s under Scenario A2 and B2, respectively. Fire season will be prolonged by 21 and 26 days under ScenariosA2 and B2 in 2080s respectively.

Simulating responses of Northeastern China forests to potential climate change

A simulation study on the responses of forests in Northeastern China to possible climate change was done by running NEWCOP, a computer model of forest stands “gap” dynamics with a set of parameters of 24 tree species. Based on the simulation, climate change will continue to make coniferous trees less and less and deciduous trees more and more. By the end of 100a transient process and 100a equilibrium climate period, forest biomass is reduced by a total of 6,531 million t dry material for the whole region of NE China. There is only a small area in the north on which there stands more biomass than without climate change. Korean pine will be first tree species which decrease by the most amount. In the northern part of NE China, oak forest will cover much more area with climate change and the larch forest may cover less area than it does at present. In the middle part areas, coniferous and broad-leaved mixed forest will remain, but the portion of deciduous species in composition of forest will increase. In the southem part areas, Korean pine will become companion tree species and its distribution area will greatly decrease.

Examining Forest Net Primary Productivity Dynamics and Driving Forces in Northeastern China During 1982–2010

Forest net primary productivity(NPP) is a key parameter for forest monitoring and management. In this study, monthly and annual forest NPP in the northeastern China from 1982 to 2010 were simulated by using Carnegie-Ames-Stanford Approach(CASA) model with normalized difference vegetation index(NDVI) sequences derived from Advanced Very High Resolution Radiometer(AVHRR) Global Inventory Modeling and Mapping Studies(GIMMS) and Terra Moderate Resolution Imaging Spectroradiometer(MODIS) products. To address the problem of data inconsistency between AVHRR and MODIS data, a per-pixel unary linear regression model based on least squares method was developed to derive the monthly NDVI sequences. Results suggest that estimated forest NPP has mean relative error of 18.97% compared to observed NPP from forest inventory. Forest NPP in the northeastern China increased significantly during the twenty-nine years. The results of seasonal dynamic show that more clear increasing trend of forest NPP occurred in spring and autumn. This study also examined the relationship between forest NPP and its driving forces including the climatic and anthropogenic factors. In spring and winter, temperature played the most pivotal role in forest NPP. In autumn, precipitation acted as the most important factor affecting forest NPP, while solar radiation played the most important role in the summer. Evaportranspiration had a close correlation with NPP for coniferous forest, mixed coniferous broadleaved forest, and broadleaved deciduous forest. Spatially, forest NPP in the Da Hinggan Mountains was more sensitive to climatic changes than in the other ecological functional regions. In addition to climatic change, the degradation and improvement of forests had important effects on forest NPP. Results in this study are helpful for understanding the regional carbon sequestration and can enrich the cases for the monitoring of vegetation during long time series.

Forest Carbon Storage and Tree Carbon Pool Dynamics under Natural Forest Protection Program in Northeastern China

The Natural Forest Protection(NFP) program is one of the Six Key Forestry Projects which were adopted by the Chinese Government since the 1980s to address important natural issues in China. It advanced to protecting and restoring the structures and functions of the natural forests through sustainable forest management. However, the role of forest carbon storage and tree carbon pool dynamics since the adoption of the NFP remains unknown. To address this knowledge gap, this study calculated forest carbon storage(tree, understory, forest floor and soil) in the forest region of northeastern(NE) China based on National Forest Inventory databases and field investigated databases. For tree biomass, this study utilized an improved method for biomass estimation that converts timber volume to total forest biomass; while for understory, forest floor and soil carbon storage, this study utilized forest type-specific mean carbon densities multiplied by their areas in the region. Results showed that the tree carbon pool under the NFP in NE China functioned as a carbon sink from 1998 to 2008, with an increase of 6.3 Tg C/yr, which was mainly sequestrated by natural forests(5.1 Tg C/yr). At the same time, plantations also acted as a carbon sink, reflecting an increase of 1.2 Tg C/yr. In 2008, total carbon storage in forests covered by the NFP in NE China was 4603.8 Tg C, of which 4393.3 Tg C was stored in natural forests and 210.5 Tg C in planted forests. Soil was the largest carbon storage component, contributing 69.5%–77.8% of total carbon storage; followed by tree and forest floor, accounting for 16.3%–23.0% and 5.0%–6.5% of total carbon storage, respectively. Understory carbon pool ranged from 1.9 to 42.7 Tg C, accounting for only 0.9% of total carbon storage.

Forest fire danger ratings in the 2040s for northeastern China

The average temperature of northeastern China is expected to increase 2.22 and 2.55℃ under two scenarios selected from the Intergovemmental Panel on Climate Change （IPCC）, i.e., A2 and B2, during the 2040s （2041-2050）, which will have an impact on fire activities in those areas. We calculated the output of regional climate models, using the Canadian Forest Fire Weather Index （FWI） on a scale of 50 km × 50 km. Meteorological data and fire weather index were interpolated to a scale of 1 km × 1 km by using ANUSPLIN software. The results show that the model of Providing Regional Climate for Impacts Studies （PRECIS） had the ability to provide good temperature and precipitation estimates of the study area in the baseline period, by simulation. In the 2040s the mean FWI values of the study area will increase during most of the fire seasons under both selected scenarios, compared with the baseline period. Under scenario B2 the peak fire season will appear in advance. The changes of FWI ratio （2×CO2/l ×CO2） show that the potential burned areas will increase 20% under scenario B2 and lightly increase under scenario A2 in 2040s. The days of high, very high and extreme fire danger classes will add 5 and 18 d under scenarios A2 and B2, respectively. It suggests adapting the climate change through improving fuel management and enhancing the fighting abilities.

Mapping Soil Organic Carbon Stocks of Northeastern China Using Expert Knowledge and GIS-based Methods

The main aim of this paper was to calculate soil organic carbon stock(SOCS) with consideration of the pedogenetic horizons using expert knowledge and GIS-based methods in northeastern China.A novel prediction process was presented and was referred to as model-then-calculate with respect to the variable thicknesses of soil horizons(MCV).The model-then-calculate with fixed-thickness(MCF),soil profile statistics(SPS),pedological professional knowledge-based(PKB) and vegetation type-based(Veg) methods were carried out for comparison.With respect to the similar pedological information,nine common layers from topsoil to bedrock were grouped in the MCV.Validation results suggested that the MCV method generated better performance than the other methods considered.For the comparison of polygon based approaches,the Veg method generated better accuracy than both SPS and PKB,as limited soil data were incorporated.Additional prediction of the pedogenetic horizons within MCV benefitted the regional SOCS estimation and provided information for future soil classification and understanding of soil functions.The intermediate product,that is,horizon thickness maps were fluctuant enough and reflected many details in space.The linear mixed model indicated that mean annual air temperature(MAAT) was the most important predictor for the SOCS simulation.The minimal residual of the linear mixed models was achieved in the vegetation type-based model,whereas the maximal residual was fitted in the soil type-based model.About 95% of SOCS could be found in Argosols,Cambosols and Isohumosols.The largest SOCS was found in the croplands with vegetation of Triticum aestivum L.,Sorghum bicolor(L.) Moench,Glycine max(L.) Merr.,Zea mays L.and Setaria italica(L.) P.Beauv.

Comparison and Analysis of Agricultural and Forest Land Changes in Typical Agricultural Regions of Northern Mid-latitudes

The northeastern China, the United States, and the western Europe are important agricultural regions both on the global and regional scales. The western Europe has a longer history of agricultural land development than the eastern United States. These two regions have changed from the deforestation and reclamation phase in the past to the current land abandonment and reforestation phase. Compared with the two regions, large-scale land exploitation has only been practiced in the northeastern China during the last century. After a short high-intensity deforestation and reclamation period, agricultural and forest lands are basically in a dynamic steady state. By comparing domestic and international agro-forestry development and considering the ecological environment and socio-economic benefits that can be derived from agro-forestry, this paper suggests that large area of reforestation would be inevitable in future though persistent and large agricultural demand in coming decades even more. And local reforestation at slope farmland with ecological vulnerability should be imperative at present to avoid severer damage. At the same time, from the perspective of Land Change Science, the results demonstrate that the research on land use change in the agro-forestry ecotone is typical and critical, particularly those dealing with the analysis of spatial and temporal characteristics and the simulation of climate, hydrology, and other environmental effects.

Forest Fire Environment and Characteristics in Northeastern China

Forest fires occurrence is influenced by many factors, such as inter-annual weather variations and regional fuel distributions. Fires occurrence in different forest region has distinct spatial and temporal characteristics. The paper studied the natural forest fire environment in Northeastern China, as well as forest fires occurrence, burned area and fire seasons in Northeastern Forest Region. The result shows that more than 50% of annual burned area occurred in Northeast China Forest Region. Main fire seasons in the region are spring and autumn. Fires occurrence in spring is larger than that in autumn. There are few fires in summer. The authors' suggestions for fire management department are to emphasize the fuel management, improve the roads conditions, and enhance the fires control ability.

东北过伐林灌木层物种多样性与林分因子的典型相关分析

研究林分特征尤其是经营上可以控制的因子对生物多样性的影响 ,将有助于制定合理的经营措施来维持和保护生物多样性 .本文作者以我国东北过伐林区 3种典型天然林类型为对象 ,采用典型相关分析方法 ,研究影响灌木层物种多样性的主要因子 .结果表明 :影响灌木层物种多样性的主要因子包括土壤含水率、树种多样性和林分密度 ;灌木层多样性组的变异被林分组第一典型变量解释的比例为 6 8.32 % ,仍有 31.6 8%的变异不能得到解释 .表 8参

中国东北森林生长演替模拟模型及其在全球变化研究中的应用

NEWCOP模型是一个新的适于模拟东北森林的种类组成动态的林窗类计算机模拟模型 ,它通过模拟在每一个林分斑块上的每株树木的更新、生长和死亡的全过程来反映森林群落的中长期生长和演替动态。由于NEWCOP模型是一个由气候变量驱动的生态系统模型 ,故可用于评价气候变化对东北森林生长和演替的影响。在东北大兴安岭、小兴安岭和长白山地区对 NEWCOP模型进行了验证和校准。沿环境梯度对 NEWCOP模型的数字模拟实验表明 :它能准确地再现顶极森林中树种组成及其在东北地区的垂直分布规律和水平分布规律 ;能准确地再现大兴安岭、小兴安岭和长白山的主要类型森林的生长和演替规律 ;在一定的场合 NEWCOP还可反映林分的径级结构 ;NEWCOP模型还具有对现有森林的跟踪模拟能力。应用 NEWCOP模型评估了东北森林生态系统对可能气候变化的敏感性。在 GFDL 2× CO2 和 GISS 2× CO2 气候变化情景下 ,东北森林的种类组成将发生很大变化 ,落叶阔叶树将取代目前长白山、小兴安岭的红松 (Pinus koraiensis)和大兴安岭的兴安落叶松 (L arix gmelinii)成为东北森林主要树种 ,而针叶树将在地带性森林中占很小的比重 ,阔叶树中蒙古栎 (Quercus mongolica)将是最重要的树种 ,它将成为小兴安岭和大兴安岭最主要树种 ;

南海东北部陆坡天然气水合物藏特征

2013年下半年,国土资源部中国地质调查局、广州海洋地质调查局在南海东北部陆坡水深664~1 420m范围内钻探13个站位,取心获取了大量、多种类型的天然气水合物（以下简称水合物）实物样品,其中甲烷气体含量超过99%。对南海东北部陆坡天然气水合物成藏特征的研究结果表明：1地震反射剖面上具有多道似海底反射层（BSR）、振幅空白带（BZ）、BSR与地层斜交、速度反转等地震异常;2测井曲线揭示含水合物沉积层具有高电阻率（200Ω·m）、高纵波速度（2 700m/s）的特征;3地震和测井异常特征暗示该区具有单、双层水合物藏组合特征;4该区域水合物藏位于海底之下埋深220m以内的粉砂质黏土及生物碎屑灰岩沉积物中,水合物饱和度为45%~100%;5自然状态下,水合物呈块状、层状、瘤状、脉状、分散状等5种赋存形式;6研究区天然气水合物赋存类型多、饱和度高、甲烷纯度高,初步估算该区天然气水合物地质储量约为1 250×108 m3（50%概率条件下）,是有利的勘探目标区。

东北地区落叶松林碳储量估算

碳储量既是评价森林生态系统结构和功能以及森林质量的重要指标，也是评估森林生态系统碳平衡的基础（王效科等，2000）。森林生物量和碳储量将为一个国家准确地评估其固碳潜力、发掘维护全球气候平衡的作用提供有效的数据支持（ Fang et al．，2001）。

东北温带森林早春类短命植物种类及区系分布

在对现有文献资料查阅和统计的基础上,结合早春类短命植物的生长周期特点,对东北温带森林早春类短命植物种类及区系分布特征进行了统计与分析.结果显示:东北地区有林下早春类短命植物60种,8个变种,15个变型,分属于8科22属.科的组成以毛茛科和罂粟科为主,包括早春类短命植物49种,占所有早春类短命植物的59.0%;紫堇属和银莲花属植物居多,占所有早春类短命植物的1/3以上.属的区系分为4个类型1个变型,其中北温带分布类型是早春类短命植物的主要成分,包括10属49种,其次为旧世界分布类型,包括6属11种.

东北地区地表NDVI的时空变化规律

为了分析天然林保护工程等人类活动和气候变化对东北地区地表植被的影响,依据天然林保护工程一期期间东北地区高分辨率NDVI数据,采用统计和相关分析等数学方法,计算得到1999—2008年间东北地区地表NDVI的空间分布及其随时间的变化。结果表明:东北地区年均NDVI的分布具有明显的地域性差异,人类活动的扰动是影响植被稳定性的主要原因;在天然林保护工程与气候变化的综合作用下,东北地区年均NDVI呈显著增加趋势,其中森林NDVI的增加占主导地位;东北地区不同季节NDVI的空间分布与年均NDVI的空间分布基本相似,NDVI的季节变化与植被的生物学特征和物候变化一致,夏季NDVI在1999—2008年间呈极显著增加趋势。研究表明天然林保护工程促进了东北地区地表植被的恢复性增长。

试论中国东北部森林沼泽景观区化探工作的发展

通过对中国东北部森林沼泽景观区多年来化探方法技术研究的回顾和总结 ,肯定了取得的成果 ,指出了不足。提出加强表生地球化学研究 ,特别是对有机质的研究 ,确定适合于森林沼泽区异常追踪查证方法技术的化探工作发展方向。

东北国有林区如何开展森林认证

我国开展森林认证的目的,主要是改善森林经营状况和促进林产品的国际市场准入。作为我国木材产品主要供应基地之一的东北国有林区应该在这样一个有利的契机下,抓住机遇,改变现有国有林区普遍出现的森林资源危机、经济危困和生态环境遭受严重破坏的局面。新形势下,东北国有林区如何开展多种经营,并通过森林认证这一市场机制来实现森林可持续经营值得我们进一步研究。

略论我国林化工业及其在东北地区的发展

概述了我国林产化学工业状况，介绍并提出东北地区林化工业的现状及发展设想。强调林化工业要利用高新技术发展高附加值产品，开发利用东北地区的松根资源。

中国非法采伐林木行为的空间分布及其驱动因子

基于2014—2020年中国50 094份非法采伐犯罪的刑事一审判决书,运用空间自相关分析与地理加权回归模型,探究中国非法采伐的空间分布特征及其驱动因素。结果表明:1)非法采伐多发于胡焕庸线东南侧,集中在云贵高原东南边缘、巫山―雪峰山沿线、武夷山脉―南岭沿线、大别山沿线、长白山沿线等地区;2)受自然、社会、经济条件的影响,上述高发区域的非法采伐特征存在明显的区域差异。3)非法采伐具有较强的空间集聚效应,相同地理分区内相邻地市非法采伐在空间上具有较强的稳定性;但不同区域间又呈各异的空间集聚特征,其中西南与东南地区主要呈高-高集聚态势、西北与华北地区为低-低集聚,东北地区与长江沿线地市则不显著。4)不同影响因子在空间上对非法采伐的驱动作用各异,其中自然禀赋是非法采伐产生的必要不充分条件,区域随着城市化与社会经济发展水平的提高能够有效抑制非法采伐的发生。

全面停伐背景下国有林区职工主观福祉及其影响因素分析

在全面停止天然林商品性采伐背景下,准确掌握国有林区职工主观福祉水平,为政府部门精准实施全面停伐后的配套扶持政策提供科学依据。本文首次利用覆盖东北五大森工集团的1004个重点国有林区民生改革监测跟踪调查数据,基于阿玛蒂亚·森的可行能力理论框架和千年生态系统评估福祉要素,构建国有林区职工主观福祉影响因素理论模型,运用多项有序Logit模型展开实证检验。研究结果表明:①龙江森工、内蒙古森工和长白山森工全面停伐与国有林区改革效果良好,大兴安岭林业集团和吉林森工滞后;全面停伐后国有林区基础设施建设较快,但医疗条件改善缓慢,收入与就业有待提升。②82.77%国有林区职工生活满意度处于一般满意水平以上,但低于中国农民主观福祉和城镇居民生活满意度水平。③身体状况、附属医院、家庭总支出、住房满意度、物价水平满意度、行政服务满意度、社会保障满意度、收入满意度和双重就业满意度对国有林区职工主观福祉有正向影响。④尽管山上林场和山下社区职工主观福祉影响因素不同,但家庭总支出、物价水平、社会保障、双重就业与收入满意度是提升国有林区职工主观福祉的核心要素。

林改背景下中国原木供需和进口贸易预测——基于CGTM模型的空间均衡分析

随着中国对原木需求量的日益增加,中国原木进口量加速扩大。为有效提高中国原木的自给量,保证中国的木材供给安全,中国推行了新一轮集体林权制度改革政策。文中在集体林权制度改革的背景下,通过CGTM模型和计量经济模型估计中国原木供给方程,并利用该模型预测中国原木供需量和净进口贸易量的变化趋势,结果显示林权改革政策对原木供给有积极促进作用,但由于供给的增长幅度并不能满足需求的增长,原木的净进口量还将继续增加,进口原木市场结构将进一步优化。