共查询到20条相似文献，搜索用时 31 毫秒
1.
Andrius Kuliešis Stein M. Tomter Claude Vidal Adrian Lanz 《Annals of Forest Science》2016,73(4):857-869
Key message
Quality and reliability of forest resource assessments depend on the ability of national forest inventories (NFIs) to supply necessary and high-quality data. Over the last decades and especially since the 1990s, the NFIs in European countries have been rapidly developing. Possibilities for obtaining reliable and accurate data on annual increment from different inventory types were evaluated, and sample-based inventories have been found to be superior to standwise inventories in providing reliable data. Simplified methods may be employed when increment cannot be directly estimated from inventory data.Context
An increasing intensity of forest resource use requires more accurate, detailed and reliable information, not only on forest area and growing stock but also on forest stand productivity, wood increment and its components.Aims
The main objectives were to assess the capacities of forest inventories, the methods used for estimation of gross increment and its components and their accuracy and to demonstrate an effective method for estimation of increment when direct inventory methods are not available.Methods
Data about national forest inventory methods were obtained from 30 responses to a questionnaire, distributed amongst national correspondents of all European countries; reports of COST Actions E43 and FP 1001, databases of Temperate and Boreal Forest Resource Assessment (TBFRA) 2000 and State of Europe’s Forests (SoEF) 2011 were used as well. Analysis and comparison of results from different forest inventories were used for evaluation of data reliability. Relationships between growing stock and gross increment in European forests were also analysed, and corresponding models were proposed.Results
Seventy-nine percent of European forest area is covered by national forest inventories (NFIs) based on sampling methods and the rest on stand-level inventory and other inventory methods. Data obtained by aggregating standwise data usually underestimate growing stock by 15–20 % and gross increment even more. Almost half of the European forest area (47 %) is monitored using permanent plots, measured twice or more, allowing the estimation of gross increment and its components to be made directly.Conclusion
Implementation of NFIs based on sampling methods, especially with permanent plots, resulted in an improvement of data quality and in most cases an increase of growing stock and gross increment. The estimation of natural losses is the weakest link in today’s NFIs and in the current assessment of European forest resources. The proposed default values for gross increment and its components is an option to be used in countries not having NFI at all or those which have started it only recently.2.
利用川西米亚罗林区森林资源清查数据,以森林蓄积量和森林生物量之间的关系模型为基础,对川西林业局301林场的森林生物量进行了估算,并对研究地区不同林龄及森林类型的森林生物量进行了分析。研究结果表明:1)研究区域林分总生物量为3 041 229t,林分单位面积平均生物量为87.13 t/hm2,低于全国生物量及四川省生物量的平均值,主要由于占绝对优势的云、冷杉林所处立地条件差,生物量较低造成;2)林分年龄结构不合理,成、过熟林面积较大(占69%);3)水土保持林的生物量在所有森林类型中所占比例最高(占80%)。 相似文献
3.
Stein Michael Tomter Andrius Kuliešis Thomas Gschwantner 《Annals of Forest Science》2016,73(4):849-856
Key message
In order to obtain the necessary information for decision making etc., it is of increasing importance to be able to assess increment in a reliable way. Only repeated measurements on permanent sample plots in national forest inventories can provide accurate and comprehensive information on the various components of annual increment. Such inventory systems are increasingly employed in European countries. The felling/increment ratio, characterizing wood use sustainability, should be expressed as the ratio of felled living trees (excluding dead trees) and net increment.Context
Reporting of gross and net annual increment is an element of international forest resource assessments and crucial for sustainable forest management. A number of approaches exist for the estimation of increment and its various sub-components.Aims
The main objectives of the study are to assess in detail what methods European countries have used and are planning to use in the future for international reporting of increment. Also, the usefulness of the various approaches for the assessment of increment is evaluated.Methods
A questionnaire asking about their assessment methods was distributed among the UNECE/FAO national correspondents of all European countries and members of the UNECE/FAO Team of Specialists on Monitoring Sustainable Forest Management. Databases of the Temperate and Boreal Forest Resource Assessment 2000 and of the State of Europe’s Forests 2011 were also used. Furthermore, the methodological background was described on the basis of relevant literature sources and some examples for country groups presented.Results
Countries have indicated what methods they used for assessment of various increment components, and the percentage of countries, forest area, and growing stock corresponding to these replies has been calculated. With regard to gross annual increment, these metrics represent about one third for inventories based on permanent sample plots, but this percentage is on the increase.Conclusion
The concept of the “control method” for forest management was developed more than 100 years ago but only utilized at the local level. The same methodology is now widely used at the national and regional level due to the implementation of modern national forest inventories using permanent sample plots. Care should be taken to utilize the data correctly for international forest resource assessments, in order to, e.g., avoid double counting of dead trees.4.
西藏自治区森林碳密度及分布规律研究 总被引：1，自引：0，他引：1
利用森林资源连续清查实测样地及样木数据,结合相对树高曲线,构建生物量-蓄积量模型,解决了模型与各类森林资源调查数据的衔接问题,可应用于西藏自治区森林资源连续清查的目测与遥感样地生物量估算及森林资源规划设计调查小班生物量估算等。根据计算的森林资源连续清查各样地生物量密度,结合树种面积数据及含碳率,估算全区森林碳密度,并初步探讨了森林碳库地带性分布规律。 相似文献
5.
6.
以森林蓄积生长量、乔木树种多样性、植物生物量、植被覆盖度、有机质含量、森林灾害程度作为指标,采用综合指数法,构建森林健康评估体系,并结合133个森林资源连续清查生态监测固定样地调查数据,评估广东省森林生态系统健康状况。结果表明,广东森林健康指数平均值为0.41,基本处于亚健康状况;天然林优于人工林,中龄林优于近成熟林;树种结构越复杂,森林健康指数就越高。 相似文献
7.
帽儿山地区次生林椴树单木胸高断面积生长模型的研究 总被引：1，自引：1，他引：0
应用帽儿山天然次生林区不同林分条件下选设的20块椴树（Tilia amurensis）固定样地的解析木调查资料,分析多个单木竞争指标与对象木胸高断面积定期生长量的相关关系,在椴树单木胸高断面积生长模型中引入林木自身大小、单木竞争指标和立地因子,应用回归分析法建立帽儿山地区天然次生椴树单木胸高断面积生长模型。研究表明：天然次生林下椴树的胸高断面积定期生长量与对象木相对直径（RD）和竞争压力指数（SCI）等指标存在比较明显的相关关系。应用主分量线性组合的方法构造的综合竞争指标（MCI）包含了各竞争指标与胸高断面积生长量之间的绝大部分的相关信息,可以作为竞争指标应用于单木胸高断面积生长模型。 相似文献
8.
P.N. BeetsA.M. Brandon C.J. Goulding M.O. KimberleyT.S.H. Paul N. Searles 《Forest Ecology and Management》2011,262(6):1119-1130
The United Nations Framework Convention on Climate Change (UNFCCC) requires reporting net carbon stock changes and anthropogenic greenhouse gas emissions, including those related to forests. This paper describes the design and implementation of a nation-wide forest inventory of New Zealand’s planted post-1989 forests that arose from Land Use, Land-Use Change and Forestry activities (LULUCF) under Article 3.3 of the Kyoto Protocol. The majority of these forests are planted with Pinus radiata, with the remainder made up of other species exotic to New Zealand. At the start of the project there was no on-going national forest inventory that could be used as a basis for calculating carbon stocks and meet Good Practice Guidelines.A network of ground-based permanent sample plots was installed with airborne LiDAR (Light Detection and Ranging) for double sampling using regression estimators to predict carbon in each of the four carbon pools of above- and below-ground live biomass, dead wood and litter. Measurement, data acquisition and quality assurance/control protocols were developed specifically for the inventory, carried out in 2007 and 2008. Plots were located at the intersection of a forest with a 4 km square grid, coincident with an equivalent 8 km square grid established over the indigenous forest and “grassland with woody biomass” (Other Wooded Land). Planted tree carbon within a ground plot was calculated by an integrated system of growth, wood density and compartment allocation models utilising the data from measurements of trees and shrubs on the plots. This system, called the Forest Carbon Predictor, predicts past and future carbon in a stand and is conditioned so that the calculated basal area and mean top height equals that obtained by conventional mensuration methods at the time of the plot measurement. Mean per hectare carbon stocks were then multiplied by an estimate of the total area of post 1989 forests obtained from wall to wall mapping using a combination of satellite imagery and ortho-photography.The network of permanent samples plots and LiDAR double sampling methodology was designed to be simple and robust to change over time. In the future, using LiDAR should achieve sampling efficiencies over using ground plots alone and reduces any problems regarding restricted access on the ground. The network is to be remeasured at the end of commitment period 1, 2012, and the carbon stocks re-estimated in order to calculate change. 相似文献
9.
10.
云南松林碳储量的初步估算 总被引：1，自引：0，他引：1
以云南省第五次森林资源连续清查数据及云南省林业调查规划院专业调查的林木、林下灌木、林下草本植物生物量、林下土壤有机碳含量等资料成果为依据,对云南省的云南松林碳储量进行估算.估算结果,云南松林储碳总量为4.649亿t.文章还以"连清"推算的生长率及消耗率数据为依据预测了云南松林碳储增长量. 相似文献
11.
Pierre Trichet Denis Loustau Catherine Lambrot Sune Linder 《Annals of Forest Science》2008,65(8):814-814
12.
A stratified random sampling approach was employed to quantify total biomass across prevalent non-commercial forest understory species found in six counties of northwest Florida, USA. The moisture content (wet basis) and calorific values of these species were also measured. Total green biomass from forest understory species was estimated to be around 12 million metric tons, mostly comprised of Cliftonia monophylla (titi, buckwheat tree) and Cyrilla racemiflora (white titi, swamp titi). This understory forest biomass would be sufficient to generate about 28.8 million GJ of electricity or 1589.25 million liters of ethanol. A need was identified to determine the inventory of forest understory biomass at the state level and assess the overall sustainability of utilizing forest understory biomass for bioenergy. 相似文献
13.
Quantification of forest parameters in different successional stages is required because of its importance as a source of global emissions and ecosystem changes. This study focuses on a successional tropical forest under logging practices in East Kalimantan province, Indonesia. We modeled the forest attributes using both a parametric multiple linear regression analysis and neural networks approach, with Landsat ETM data acquired in 2000 (ETM00). We compiled sample plot data using forest inventory data collected from 1997 to 1998. A total of 226 plots were used to train the models and 112 plots were used for the validation. The remote sensing data (spectral values, vegetation indices, texture, etc.) coupled with digital elevation model (DEM) were experimented with and selectively used to model basal area, stem volume and above ground biomass (AGB). We investigated the possibility to estimate the forest attributes from bitemporal ETM data by calibrating radiometric properties of the ETM image from 2003 (ETM03) using the multivariate alteration detection method. The Pearson correlations showed that the mean texture index is strongly correlated with the forest attributes. We show that neural networks resulted in a higher coefficient of determination (r2) and lower RMSE than multiple regressions for predicting the forest attributes. The estimated forest properties increased with the forest succession advancement (i.e. from the open forest to advanced secondary forest classes). The modeled basal area, stem volume and AGB varied from 10.7–15.1 m2 ha−1, 123.2–181.9 m3 ha−1, and 132.7–185.3 Mg ha−1, respectively. The RMSEr values of model fitting ranged from 11.2% to 13.3%, and the test dataset estimated slightly higher RMSEr which varied from 12% to 14.1%. The ETM03 forest attributes revealed favorable estimates, showing considerably higher estimates than the ETM00. The estimation of forest properties using neural networks makes Landsat data a valuable source of information for forest management, mainly with the recent free access to its historical dataset. 相似文献
14.
Uncertainty estimation of biomass expansion factors for Norway spruce in the Czech Republic 总被引：1，自引：0，他引：1
Aleksi Lehtonen Emil Cienciala Fedor Tatarinov Raisa Mäkipää 《Annals of Forest Science》2007,64(2):133-140
Nation wide estimates of the changes in forest biomass are needed for the greenhouse gas (GHG) reporting under the Climate Convention. The bases for national GHG reporting concerning forest sector are the national forest inventory (NFI) programmes. Since these programmes were mostly established for monitoring of timber resources, one of the current challenges for the NFIs is the development of methodology, such as biomass expansion factors (BEFs). The methodology for carbon stock change estimation should be transparent and verifiable, but this demand is not currently met due to the fact that the source data and uncertainty in the applied BEFs are not known. Here we developed BEFs with uncertainty estimation applicable to stand wise inventory of Norway spruce forests in the Czech Republic. BEFs were constructed, based on tree wise data from permanent research plots, by applying biomass and volume models to tree-level data. These BEFs were age-dependent and their uncertainty was sensitive to the dependencies among errors. Most of the uncertainty in the BEFs was due to uncertainty in the biomass and volume models applied. 相似文献
15.
《Scandinavian Journal of Forest Research》2012,27(1-4):49-66
Above‐ground biomass has been measured on fertilized and control plots up to stand age 31 years. Each biomass fraction was estimated by two statistically coupled linear models with squared diameter at breast height as independent variable. All fractions except reproductive structures of pine and dead branches of spruce were estimated at high precision levels, R. between 0.93 and 0.99. The above‐ground biomass fractions per hectare could be precisely described by stem volume with bark. Application of the models for prognostic purposes is discussed. Annual above‐ground net biomass production in pine increased from 2.05 to 4.34 MT d.m./ha‐yr on control plots over 11 years, while plots given complete fertilizer mixture ranged from 6.75 to 9.09. Spruce stands with a nearly optimum water relationship and fertilizer programmes yielded from 9.50 to 11.86 MT d.m./ha‐yr. The combination of energy and timber production in highly productive peatland stands is discussed. 相似文献
16.
应用中分辨率遥感数据和地理信息系统改进森林材积和生物量评估策略(英文) 总被引：7，自引：0，他引：7
应用遥感技术、地理信息系统和野外观测数据,评估了热带森林环境下地上生物量和木材蓄积量。用于模拟森林属性的这些数据具有地理特异性和高度的不确定性,因此,这方面需要开展更多的研究工作。选取了16个试样地带1460个样地,测定树木胸径及其他用于评估生物量的其他森林属性。本实验在印尼加里曼丹东部的热带雨林开展。应用现有的胸径-生物量公式来评估地上生物量密度。估测值在研究区修正的GIS地图上重叠显示,计算各种地被物的生物量密度。用样品数据子集表达遥感方法来形成地上生物量和材积线性方程模型。皮尔森相关统计检验采用ETM条带反射率、植被指数、图像变化图层、主成分分析条带、缨帽变换、灰度共生矩阵纹理特征和DEM数据作为预报值。在显著的遥感数据中形成了两个线性模型。为了分析每块地被物总的生物量和材积量,对2000年到2003年卫星ETM图进行了预处理、最大似然估计法分类和主体分析过滤。遥感方法获得的结果表明:材积量为(158±16)m3·hm-2,地上生物量为(168±15)t·hm-2;而野外测定和地理信息系统估计的结果分别是材积量为(157±92)m3·hm-2、地上生物量为(167±94)t·hm-2。用多个瞬间ETM数据评估了从2000年到2003年间的生物量丰富度动态,结果发现这一时期总生物量呈略微的下降趋势。遥感技术评估的生物量丰富度低于地理信息系统和野外测定的结果。前一种测定方法估计2000年和2003年总生物量分别是10.47Gt和10.3Gt,而后一种则估计11.9Gt和11.6Gt。还发现,灰度共生矩阵纹理特征与材积量和生物量之间存在较强的相关性。图7表9参43。 相似文献
17.
18.
Being able to accurately estimate and map forest biomass at large scales is important for a better understanding of the terrestrial carbon cycle and for improving the effectiveness of forest management. In this study, forest plot sample data, forest resources inventory(FRI) data, and SPOT Vegetation(SPOT-VGT) normalized difference vegetation index(NDVI) data were used to estimate total forest biomass and spatial distribution of forest biomass in northeast China(with 1 km resolution). Total forest biomass at both county and provincial scales was estimated using FRI data of 11 different forest types obtained by sampling 1156 forest plots, and newly-created volume to biomass conversion models. The biomass density at the county scale and SPOT-VGT NDVI data were used to estimate the spatial distribution of forest biomass. The results suggest that the total forest biomass was 2.4 Pg(1 Pg = 10~(15) g), with an average of 77.2 Mg ha~(-1), during the study period. Forests having greater biomass density were located in the middle mountain ranges in the study area. Human activities affected forest biomass at different elevations, slopes and aspects. The results suggest that the volume to biomass conversion models that could be developed using more plot samples and more detailed forest type classifications would be better suited for the study area and would provide more accurate biomass estimates. Use of both FRI and remote sensing data allowed the down-scaling of regional forest biomass statistics to forest cover pixels to produce a relatively fineresolution biomass map. 相似文献
19.
Udo Mantau Thomas Gschwantner Alessandro Paletto Marian L. Mayr Christian Blanke Evgeniya Strukova Admir Avdagic Paolo Camin Alain Thivolle-Cazat Przemko Döring Edmundas Petrauskas Hermann Englert Klemens Schadauer Susana Barreiro Adrian Lanz Claude Vidal 《Annals of Forest Science》2016,73(4):885-894
Key message The application of the ITOC model allows the estimation of available biomass potentials from forests on the basis of National Forest Inventory data. The adaptation of the model to country-specific situations gives the possibility to further enhance the model calculations.
Context
With the rising demand for energy from renewable sources, up-to-date information about the available amount of biomass on a sustainable basis coming from forests became of interest to a wide group of stakeholders. The complexity of answering the question about amounts of biomass potentials from forests thereby increases from the regional to the European level.Aims
The described ITOC model aims at providing a tool to develop a comparable data basis for the actual biomass potentials for consumption.Methods
The ITOC model uses a harmonized net annual increment from the National Forest Inventories as a default value for the potential harvestable volume of timber. The model then calculates the total theoretical potential of biomass resources from forests. By accounting for harvesting restrictions and losses, the theoretical potential of biomass resources from forests is reduced and the actual biomass potentials for consumption estimated.Results
The results from ITOC model calculations account for the difference between the amounts of wood measured in the forests and the actual biomass potentials which might be available for consumption under the model assumptions.Conclusion
The gap between forest resource assessments and biomass potentials which are available for consumption can be addressed by using the ITOC model calculation results.20.
文章提出了利用森林资源连续清查固定样地进行植被种类和生物量调查的技术方法。此方法通过选择适当时间，提高调查者相关知识，确定样地数量等措施，可满足植物区系调查的要求，对于植被类型确定，植物蕴藏量统计，经济植物开发利用保护的决策，植被演替规律的观测具有实用价值。 相似文献