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Huang S.,Chinese Academy of Forestry | Wang B.J.,FPInnovations Wood Products | Lu J.,Chinese Academy of Forestry | Dai C.,FPInnovations Wood Products | And 2 more authors.
BioResources | Year: 2012

Changbai larch (Larix olgensis Henry) is one of the main plantation species in the northern part of China, but so far its utilization has been limited to solid wood, pulping, and paper products. As part of a national initiative, the objective of this work was to develop a good understanding concerning how stand management practices affect larch wood and veneer properties. To cope with the variation of initial and final stand density, the term "relative thinning intensity (RTI)" was introduced to describe the effect of stand thinning on the resulting wood and veneer properties. Nine representative sample trees each from four stands were harvested, then trimmed and bucked. Six 1.25 m long bolts along the entire tree stem were systematically cut to peel 2.6 mm thick veneers. Clear wood specimens were also sawn from matched bolts for mechanical testing for the purpose of comparison and validation. The correlation between the main tree variables and properties of clear wood and veneer was analyzed, and the influence of RTI on key wood and veneer properties was examined and compared. A good correlation was found in density and modulus of elasticity (MOE) between larch clear wood and veneer, giving an R2 of 0.75 and 0.71, respectively. This indicates that veneering can be potentially used to characterize this larch species. The stand with the lowest RTI had the shortest rotation but yielded the best properties of both clear wood and veneer, which highlights the importance of stand management in terms of thinning.

Qin X.L.,Research Institute of Forest Resource Information Techniques | Zhang Z.H.,State Laboratory for Remote Sensing and Information Techniques | Yan H.,State Laboratory for Remote Sensing and Information Techniques
WIT Transactions on Ecology and the Environment | Year: 2012

FengYun-3 (FY-3) is the second generation Polar Orbiting Meteorological Satellite Series of Chinese meteorological satellite. FY3A and FY3B were launched in the year 2008 and the year 2010 respectively. The Visible and Infrared Radiometer (VIRR) carried by FY3A/B (FY3A/B-VIRR), which spatial resolution is 1,100 meter at nadir and saturation temperature is more than 350k in central wavelength at 3.74μm channel. Based on the analyzing results of related bands of FY3A/B-VIRR by using typical samples, the algorithm applies dynamic thresholds to fire identification according to the character of FY3A/B-VIRR images. The automatic forest fire identification program has been developed and integrated the background GIS data in IDL language. At the same time, the methodology and identification results have been validated by selecting forest fires which have taken place in the northeast or south forest region of China in nearly four years. The validation results showed that the commission is more than 90% and the average omission is less than 10%. So, the fire identification methodology can be satisfied regarding the need for the forest fire identification operation in China. © 2012 WIT Press.

Huang S.,Chinese Academy of Forestry | Wang B.J.,FPInnovations Wood Products | Lu J.,Chinese Academy of Forestry | Lei Y.,Research Institute of Forest Resource Information Techniques | And 2 more authors.
BioResources | Year: 2012

This is the second part of a large research initiative aimed at characterizing Changbai larch (Larix olgensis Henry) for veneer and high-valued product potential. The objective of this work was to investigate the effect of the tree growth characteristics, particularly diameter at breast height (DBH) and radial growth from pith (or peeler core) to bark on clear wood and veneer properties. A population of 36 trees was chosen and classified into three DBH classes, namely 20, 25, and 30 cm, and crosscut into six segments each along the vertical stem. With the entire veneer ribbon peeled from the pith to bark for each segment, the effect of sapwood and heartwood on wood properties was revealed. The tree DBH and height were moderately and positively correlated. The tree DBH significantly affected properties of both clear wood and veneer in a similar pattern. For the larch veneer population, veneer mean ultrasonic propagation time (UPT) and density decreased but veneer mean dynamic modulus of elasticity (MOE) increased from the heartwood to sapwood or from the pith to bark. Among the three DBH classes, the 25 cm DBH yielded the highest mean veneer density and MOE, followed by the 20 cm DBH and 30 cm DBH. This was found to be caused by the radial evolution of veneer properties from the pith to bark in combination with the variation of veneer yield and stem position.

Wang Y.,CAS Institute of Geographical Sciences and Natural Resources Research | Cheng S.,A+ Network | Ju H.,Research Institute of Forest Resource Information Techniques | Zhang H.,Research Institute of Forest Resource Information Techniques | And 2 more authors.
African Journal of Agricultural Research | Year: 2011

The functions of wetlands are of significant value to social economy and ecology. However, in the past 50 years, wetlands in China have suffered severely from development pressure and are confronted with the threats of area loss. In recent years, assessment of wetland resources has aroused enormous attention, since it can further protect wetland resources and provide scientific basis for decision-makers. In this paper, wetland ecosystems are studied in terms of its ecological, social, and economic benefits, and integrated assessment system of the sustainability of the wetland resources of East Dongting Lake Nature Reserve has been built, adopting DELPHI method, analytic hierarchy process (AHP) and PSR model. First, an index system of integrated assessment of wetland resources was constructed, and the indexes involve the following five aspects, ecological environment, safeguard system, reasonable utilization of wetlands, social culture and economic system. An index system of integrated assessment for wetland resources established was composed of 5 subsystems, with 34 indicators involved. By conducting field investigation in East Dongting Lake and by performing remote sensing data processing, an integrated assessment score of 1.035 was given to East Dongting Lake. Finally, a general analysis of the study area was given and a few countermeasures were suggested. © 2011 Academic Journals.

Hua L.,Research Institute of Forest Resource Information Techniques | Wentao Z.,CAS Institute of Remote Sensing | Wentao Z.,Research Institute of Forest Resource Information Techniques | Bingfang W.,CAS Institute of Remote Sensing | Hongbo J.,Research Institute of Forest Resource Information Techniques
IOP Conference Series: Earth and Environmental Science | Year: 2014

The aim of this study was to investigate the utility of datasets composed of texture measures and other features for the classification of vegetation cover, specifically wetlands. QUEST decision tree classifier was applied to a SPOT-5 image sub-scene covering the typical wetlands area in Three River Sources region in Qinghai province, China. The dataset used for the classification comprised of: (1) spectral data and the components of principal component analysis; (2) texture measures derived from pixel basis; (3) DEM and other ancillary data covering the research area. Image textures is an important characteristic of remote sensing images; it can represent spatial variations with spectral brightness in digital numbers. When the spectral information is not enough to separate the different land covers, the texture information can be used to increase the classification accuracy. The texture measures used in this study were calculated from GLCM (Gray level Co-occurrence Matrix); eight frequently used measures were chosen to conduct the classification procedure. The results showed that variance, mean and entropy calculated by GLCM with a 9*9 size window were effective in distinguishing different vegetation types in wetlands zone. The overall accuracy of this method was 84.19% and the Kappa coefficient was 0.8261. The result indicated that the introduction of texture measures can improve the overall accuracy by 12.05% and the overall kappa coefficient by 0.1407 compared with the result using spectral and ancillary data.

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