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Yiping W.,Wuhan University | Cong C.,Wuhan University | Gaofeng H.,Kunming Survey and Design Institute of State Forestry Administration | Qiuxia Z.,Wuhan University
Stochastic Environmental Research and Risk Assessment | Year: 2013

A large number of reservoir landslides will be impacted under the action of cyclical water level change in Three Gorges Reservoir, therefore its stability analysis and evaluation are important. And various kinds of influencing factors should be considered when landslide stability is analyzed. Taking Liangshuijing landslide as a case, considering the uncertain factors in the landslide stability analysis process, the landslide random-fuzzy reliability is analyzed in the paper, based on the sliding soil shear strength parameters testing and groundwater monitoring data. The results show that the landslide random-fuzzy reliability is the smallest at the process of high water level slowly dropping to low water level, and the landslide is basically at a steady state, which is consistent with landslide body actual deformation. Taking into account the uncertainty of groundwater level in a landslide body is equivalent to taking into account the changes of occurrence conditions in landslide rock and soil. Taking these factors into account is more in line with the actual when compared with only considering shear strength parameters random properties. © 2013, Springer-Verlag Berlin Heidelberg.

Li Z.-Y.,Henan University of Science and Technology | Li Z.-Y.,Chinese Academy of Forestry | Liu G.-J.,Meteorological Bureau of Mengjin County | Wang Y.-H.,Chinese Academy of Forestry | And 5 more authors.
Forest Research | Year: 2011

An evaluation of the impact of scattering limestone powder on acidified soil surface on the growth of young trees of Schima superba under crowns of a Pinus massoniana plantation (three years and four months after treatment) were made by a long-term field fixed position experiment, which was conducted in the Tieshanping Forest Farm of Chongqing City in 2004. The randomized complete block experiment had five treatments and three replicates: the doses of one-time scattering of 0 (control), 1, 2, 3 and 4 t · hm-2 finely ground limestone respectively. The effect was significant: surface limestone could ameliorate health condition of the young trees of S. superba and among them the optimum dose was 2 t · hm-2. The mean canopy thickness, crown size, height and diameter of the base at 20 cm above the ground of the young trees of S. superba treated by 2 t · hm-2 increased by 96.84%, 52.68%, 77.47% and 61.19% respectively (P < 0.05) compared to the control.

Kang W.,Beijing Forestry University | Tian C.,Beijing Forestry University | Kang D.,Beijing Forestry University | Wang M.,Kunming Survey and Design Institute of State Forestry Administration | And 3 more authors.
Forest Systems | Year: 2015

Aim of study: to study the effects of gap size, gap age and bamboo Fargesia denudata on natural regeneration of Abies faxoniana, both of which are the ubiquitous dominants in our research area. Area of study: subalpine coniferous forests in Wanglang Natural Reserve in Southwestern China. Material and Methods: 10 transect belts were randomly established, and a total of 97 gaps were recorded and used. Main results: (1) the number of bamboos with coverage of<17% significantly increased with increases of gap size and age, but the latter had little influence on the numbers of F. denudata with coverage of >17%. (2) F. denudata strongly inhibited A. faxoniana seedlings and saplings in small, young and old gaps, where the amount of A. faxoniana recruitment was relatively abundant, than in other types of gap. (3) The numbers of A. faxoniana seedlings in A-gaps, significantly decreased with the increases in gap size. However, in gaps where F. denudate was also present, A. faxoniana seedlings and saplings were insensitive to gap size or age. Research highlights: thick F. denudata would not be influenced by gap size or age. Because of the low occurrences of A. faxoniana seedlings and saplings, the negative effect of gap size, gap age and F. denudata on A. faxoniana recruitment was unclear. © 2015 INIA.

Kang W.,Beijing Forestry University | Tian C.,Beijing Forestry University | Kang D.,Beijing Forestry University | Wang M.,Kunming Survey and Design Institute of State Forestry Administration | And 3 more authors.
Journal of Plant Interactions | Year: 2015

To clarify the effects of gap size and age, as well as microsites on Abies faxoniana recruitment in gaps with or without dwarf bamboo, the occurrences of A. faxoniana seedlings and saplings on four microsites were examined in a subalpine forest in Wanglang Natural Reserve, southwestern China. Results showed that: (1) while increased gap size had little effect on the seedling densities, it significantly reduced the sapling densities on moss-cover ground in A gaps (without bamboos) and those on moss-cover ground and decaying logs in AF gaps (with bamboos; P < 0.05). (2) Increased gap age also exerted little effect on the seedling densities while significantly reduced the sapling densities on decaying logs in AF gaps (P < 0.05). (3) Most of A. faxoniana seedlings and saplings occurred on decaying logs in AF gaps, but in A gaps A. faxoniana regeneration had no preference on microsites. Compared to gap characteristics, microsites are more important for A. faxoniana regeneration. © 2015 The Author(s). Published by Taylor & Francis.

Li Z.,Henan University of Science and Technology | Li Z.,Chinese Academy of Forestry | Wang Y.,Chinese Academy of Forestry | Yu P.,Chinese Academy of Forestry | And 3 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2011

Chongqing (28°10′-32 13 N, 105°17′-110°11′E) ' as the largest industrial and commercial center in Southwest China, is located in the Three Gorges Reservoir region of the upper reaches of the Yangtze River. Thus a high and healthy forest cover is required to protect the local environment and to guard the ecological safety of downstream regions. However, Chongqing was listed as one of the cities suffering from the most serious acid rain problems, and its extensive soil acidification and catastrophic scenarios of forest decline were first described in the early 1980s. Although great efforts have been made for controlling acid rain and substantial success has been obtained, the continuous economic growth, mountainous landform and low wind speed, which limit the air pollutant diffusion, will make acid rain a long-term problem. It is expected that the accumulating effect of soil acidification and increasing drought caused by climate change will further weaken the stability of the forests and endanger their multiple functions in the Chongqing region. Special forestry countermeasure such as scattering limestone powder on forest floor for alleviating soil acidification and its damage to trees could be one of effective alternative engineering measures to reduce acid pollutant effusion. Pinus massoniana is one tree species that is widely spread throughout Southwest China and is the most important native tree species for afforestation in the Chongqing region. However, the health condition of P. massoniana forests has been seriously damaged by the long-term acid rain and consequential soil acidification, heavy defoliation and high mortality of trees have been observed and reported. Former studies carned out in this region showed that applying limestone powder was helpful to recover the forest health. The recovery of the damaged fine root (≤ 2 mm in diameter) system, in terms of both quantity and depth distribution, should be the main focus in forest health recovery and the most direct and quickest indicator for evaluating the effect of applying limestone powder. Nevertheless, there is scare information about the response of fine root characteristics of P. massoniana to different doses of limestone powder applied under field conditions. This limits the effective and economical use of the limestone powder and the recovery of widely damaged forests. Thus a long-term field experiment to test the dose effect of limestone powder scattered on the floor of pure P. massoniana forest was set up in the Tieshanping Forest Farm of Chongqing in May 2004. The experiment was designed as a random complete block and composed of five dose treatments, i.e., scattering 0 (as control), 1, 2, 3 and 4 t/hm2 of finely ground limestone on forest floor one time. All the treatments were replicated three times. The fine roots of P. massoniana were collected with root augers after a period of time, according to soil layers of humus, 0 -20 cm, 20 -40 cm and 40 -60 cm, respectively. The fine root characteristics used here include the densities of dry weight, length, surface area, volume and the number of root tips. Monitoring results, in October 2006, indicated that applying limestone powder increased all the five densities of fine roots in al layers of the P. massoniana forest significantly (P < 0. 05), compared to the control treatment, especiaUy the fine root densities at the deeper soil layers of 20 -40 cm and 40 -60 cm. This would enhance the resistance of forests to the increasing drought. The fine root densities at the humus layer were also increased. This would improve the nutrient uptake ability of forests against the nutrition poornees caused by soil acidification. This meant that the limestone powder application improved both quantity and depth distribution of fine roots. Within the range of limestone powder doses used in this experiment, all investigated fine root densities increased with rising limestone powder doses, but at different rates. This could be described by the ratios of total densities of fine roots between the limestone powder treatments and the control. Here the total density meant the sum of densities of fine roots of the four layers for the same indicator. For the treatment of 1 thm2, the total density ratios of dry weight, length, surface area, volume and the number of root tips were 1.53, 1.34, 1.39, 1.24 and 1.48, respectively, while they were 2.05, 1.83, 1.94, 1.79 and 2.04 for the dose of 2 t/hm2, 2.17, 2.02, 2.02, 1.78 and 2.32 for the dose of 3 t/hm2, and 2.68, 2.52, 2.62, 3.0 and 2.1 for the dose of 4 t/hm2. From the viewpoint of a more effective and economical application of limestone powder in forest practice, the dose of 2 thm2 is suggested, since this dose induced the highest increase rates of most density characteristics of fine roots. For example, the increase rates of surface area density of fine roots per ton of limestone powder were 1.0, 1.2, 0.9, 1.0 for the dose of 1, 2, 3, 4 t/hm2, respectively. Here it should be emphasized that the surface area density is a more important indicator, which directly influences the uptake ability of trees for both water and nutrition. However, this dose suggestion is based on an investigation of only three growing seasons after limestone powder application. The long-term dose response and corresponding optimal practice suggestion require further monitoring of fine root growth dynamics in the future.

Cairong Y.,Beijing Forestry University | Rong Z.,Kunming Survey and Design Institute of State Forestry Administration
Proceedings - 2010 2nd International Workshop on Intelligent Systems and Applications, ISA 2010 | Year: 2010

land use/land cover classification in the south of the Gaoligong Mountain based on Landsat TM by use of object-oriented classification technique are presented. Through several key steps, such as image pre-processing, feature extract, multi-segmentation, and image classification, Land use/Land cover in the mountainous area is successfully mapped. The accuracy assessment indicates that the object-oriented classification is better than traditional pixel-based method: the overall accuracy and the Kappa coefficient is 88.6% and 0.82 respectively, increasing by 14.9% and 0.22 respectively compared with the pixel-based classification; the object-oriented method can satisfy the demands of land use classification, and can be used as a new technique in land resources survey. ©2010 IEEE.

Wang M.-J.,Kunming Survey and Design Institute of State Forestry Administration | Li J.-Q.,Beijing Forestry University | Zhang Y.-B.,Beijing Forestry University | Liu W.-D.,Chinese Academy of Forestry
Chinese Journal of Ecology | Year: 2012

To validate the applicability of neutral theory in studying the restored plant communities after disturbances, a validation was made on this theory, based on the investigation data of the richness-abundance of restored plant communities in giant panda habitats after the disturbances of different intensity earthquakes. It was observed that neutral theory model could be better predict the species-abundance distribution pattern in the primary forest communities rather severely or not disturbed, but had little effect in predicting this distribution pattern in the primary forest communities under medium disturbances. The homogeneity degree of habitats could be one of the important factors affecting the fitness of the neutral theory model, and thus, neutral theory was considered not fitting the plant communities in poorly homogeneous habitats.

Cao Z.,Kunming Survey and Design Institute of State Forestry Administration | Feng Z.,Beijing Forestry University
Proceedings - 2015 8th International Symposium on Computational Intelligence and Design, ISCID 2015 | Year: 2016

This article proposes a new measurement method to solve the problems of great destruction, high cost, and low efficiency in traditional forestry investigation. This method is to, firstly, measure the diameters of trees at the breast height and the ground height, and then to measure the upper diameter and the relevant height of standing trees via the appromixate section method of analytic cut trees. Then the timber volume is obtained through measurement volume method based on the simulation of summation of conical frustum. Also, the total station embedded operation software is developed using C # language, and the intelligent measurement is realized so as to calculate the diameter, the height, and the volume of the trees. There are 28 sample trees selected in Pinggu District of Beijing and monitored by total station. Next the sample trees are cut down, with their height and timber volume measured through conventional measurement volume method, and the measurements are regarded as truth value. Finally, the data is compared with that obtained by traditional method. The result shows that the average relative error of measuring the height of trees by total station standing timber volume compares with analytic cut trees is -0.83%, the average value of the relative error is 0.85%. As for the volume of timber, the average relative error is 1.58% while the average value of the relative error is 1.79%. Also, this study provides an efficient method for forestry workers to meet the requirement for the accuracy of forestry investigation. © 2015 IEEE.

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