Subvmission Guidelines
Author Contribute
Reviewer Online
Academic Editor
Academic Editor
Editor-in-chief
Email Alert
RSS2018 Vol. 40, No. 6
Display Method:
2018, 40(6): 1-8.
doi:10.13332/j.1000-1522.20170400
Abstract:
ObjectiveThis study aims to examine whether site form is a valid method for site quality evaluation of
Larix olgensisplantations through analyzing the relationship between site form as well as site index and site productivity.
MethodWe put forward the method of determining the reference diameter at breast height(DBH) on the basis of DBH-age logistic growth equation with 314 observation data from 168 permanent sample plots of
Larix olgensisplantations, and the reference DBH was calculated as the DBH at inflection point of the growth equation. We separately developed the dominant height-age and dominant height-DBH guide curves with the Richards growth equation, calculated the site index and site form for each plot, analyzed the correlation between site index and site form, and the correlation between both of them and productivity.
ResultThe result showed that the coefficient of determination
R
2with the regression equation between site index and site form was 0.3627, RMSE was 1.9930m and MAE was 1.5632m. The correlation coefficients between site index, site form and productivity were 0.6764 and 0.3203, respectively. We successively classified the site index and site form into 8 grades at equal interval. The proportion from grade 1 to grade 8 by site index was 0.64%, 3.82%, 12.74%, 24.84%, 32.48%, 19.43%, 5.10%, 0.96%; and the proportion from grade 1 to grade 8 by site form was 0%, 1.59%, 9.24%, 42.36%, 44.90%, 1.91%, 0%, 0%.
ConclusionFor
Larix olgensisplantations, site form could only explain 36.27% variation of site index, the correlation between site index and productivity was much larger than that of site form and productivity. The classified site quality grades by the site index and site form roughly showed the same trend in proportion at most grades, i.e. most sample plots were at the middle grade and few sample plots at both ends. But the number of sample plots in most site quality grades differs greatly. In general, we do not recommend site form as a method for site quality evaluation with
Larix olgensisplantation.
Abstract:
ObjectiveBased on the data of 5211 sample trees in 61 permanent sample plots in Mongolian pine plantations from Maoershan Experimental Forest Farm, Hengtoushan Forest Farm, Mengjiagang Forest Farm in Heilongjiang Province of northeastern China, the simultaneous equations for tree height model and height to crown base model were developed.
MethodAt first, 2 alternative height-diameter models had been selected by comparing the goodness of fit for 8 height-diameter models. From 5 basic height to crown base(HCB)models, 3 best HCB models including tree and stand variables (tree size, competition index, site condition) were selected as alternative models using the method of all subset regression. Based on the seeming unrelated regression (SUR), the parameters of the simultaneous equations model of height and HCB were estimated considering each kind of combinations for 2 alternative height-diameter models and 3 alternative HCB models, respectively. Finally, we evaluated the fitting effect of the simultaneous equation model.
ResultThe results showed that
Hand HCB were positively correlated with basal area (
G) and average height of dominant tree (
H
0). For the best simultaneous equations, the coefficient determination (
R
a
2) was 0.9520 and the root-mean-square error (RMSE) was 1.17m by fitting height (
H), the
R
a
2was 0.9066, and RMSE was 1.36m by fitting HCB. The validation values of the best simultaneous equations were smaller.
ConclusionOn the whole, the simultaneous equations developed performed well in predicting the tree
Hand HCB simultaneously with the least predicting errors, and the model could handle correlations between tree
Hand HCB. The simultaneous equations considering stand variables developed in this paper could be suitable for predicting
Hand HCB for Mongolian pine plantations with different stand conditions and it will provide basis for future research on the crown structure and dynamics.
2018, 40(6): 19-29.
doi:10.13332/j.1000-1522.20170439
Abstract:
ObjectiveVideo monitoring system is widely used in forest fire detection, in which forest fire position is calculated by cameral coordinate and PTZ parameters such as azimuth, pitch angle. There are three common methods for forest fire positioning, i.e. single-point positioning, double-point positioning and multipoint positioning. At present, some researches have been carried out to enhance the expression of three-dimensional scene by mapping between video images and three-dimensional virtual terrain based on the ray tracing algorithm, which can be applied to smoke and fire positioning in the image. Nowadays, many forest fire monitoring systems have been built up for monitoring, decision-making and fire-fighting, which integrating the hardware and software system including video surveillance, PTZ camera and GIS system. This paper subjects to take advantage of the terrain analysis in GIS and image process technique to match video images to virtual terrain, puts forward a smoke and fire positioning method based on image, and evaluates the positioning accuracy.
MethodFirstly, a virtual terrain was generated from DEM by the camera location and view of field, and forest fire image was mapped to the virtual terrain based on the principle of terrain profile matching. Each pixel in the image can be projected to an area on DEM as the positioning area, and the information of the positioning area can be calculated and analyzed, such as the coordinate, Euclidean distance, azimuth, angle of pitch of center point, shape, area, visibility, the number of crossing the valley of the area.Then the accuracy information of the area was analyzed and a decision was made according to visibility and number of crossing the valley, which divided the area into two classes, one can be positioned accurately and the other can not be positioned accurately.
ResultIn this paper, Jiulong Mountain Nature Reserve in Beijing was selected as the test area, and the proposed positioning method of smoke and fire was verified. The results showed that this method can provide location information in detail, and gave an evaluation about the positioning accuracy, which can help to locate the fire source quickly and make a quick response.
ConclusionIn this paper, the positioning method of smoke and fire makes full use of the matching relationship between virtual terrain and video images, provides abundant location information for forest fire fighting. This method performs better than the traditional PTZ positioning which depends on hardware performance specifications, its positioning accuracy is only related to the resolution of image and the matching accuracy between virtual terrain and real image. At the same time, the method is also applicable to images taken by mobile devices such as smart phones. Locating the coordinates of the shooting point, we can realize the positioning of the targets in the image, which has important significance for the image-based positioning analysis.
Abstract:
ObjectiveThis paper aims to study the contribution of forest fire to PM
2.5in atmospheric environment, and to analyze the changing characteristics of PM
2.5under different fire environment, so as to provide a basis for forest fire particle matter emission pollution.
MethodFuel beds composed of pine needles collected from Korean pine plantations were constructed with varied loading and fuel moisture contents. The mass concentration of PM
2.5was monitored using the tape of 2050 intelligent integrated sampler for air/TSP in the course of 192 burning experiments under varied wind speeds.
ResultThe mass concentration of PM
2.5varied from 166.7 to 7516μg/m
3. And the influence of various factors on PM
2.5was in the order of forest fuel load > wind speed > moisture content. ANOVA showed that in addition to the moisture content, forest fuel load as well as wind speed were correlated significantly (
P< 0.05) with PM
2.5mass concentration, and there was a significant interaction between forest fuel load and wind speed (
P< 0.05). Using forest fuel load and wind speed to match the prediction model of PM
2.5mass concentration, it could accounted for 77% of the variance in PM
2.5mass concentration.
ConclusionBurning pine needles have significant effects on particulate pollution in the atmosphere. The response degree of PM
2.5mass concentration to fuel moisture content, fuel load and wind speed exist significant differences. PM
2.5mass concentration with fuel load and wind speed have significant positive correlations. However, there is no manifest relation between PM
2.5mass concentration and fuel moisture content. The prediction model about PM
2.5mass concentration has high precision, which uses fuel load and wind speed as forecast factors. It can be the basic theory for estimating PM
2.5mass concentration emitted in forest fire.
2018, 40(6): 41-47.
doi:10.13332/j.1000-1522.20180075
Abstract:
ObjectiveForest fire frequently occurs in Fujian Sanming area of southern China, and has high forest fire danger class. Forest fire releases large amount of particulate matter (PM
2.5), which not only causes air pollution, but also has bad effect on human health. Therefore, the research on area forest fire PM
2.5emissions in Fujian Sanming City is of great significance.
MethodBased on forest fire data in Fujian Sanming area during 2000-2011, we used volume-biomass model to calculate fire process consume biomass, volume loss and forest fire area data provided by the local forestry authorities. Using emission factor method can calculate PM
2.5emissions, and the forest PM
2.5emission factor was obtained from historical literature statistics. PM
2.5emissions of four main forest types:
Pinus massonianaforests,
Cunninghamia lanceolataforests, mixed broadleaved forests and coniferous broad leaved mixed forests were assessed individually in Fujian Sanming area. These results will provide theory basis for forest fire prevention work in this area.
ResultThe results showed that forest fire PM
2.5emission estimates were 458.789-2958.339t in Fujian Sanming area during 2000-2011. PM
2.5emission of
Cunninghamia lanceolateforests was 217.117-1072.489t, PM
2.5emission of temperate mixed broadleaved forests,
Pinus massonianaforest, coniferous and broadleaved mixed forests was 94.123-903.154t, 93.379-478.634t, 54.169-504.063t, respectively.
ConclusionFrom comprehensive analysis, as a result of more times of disastrous fire and large fire, PM
2.5emission mainly concentrated in the disastrous fire and large fire; about forest types, PM
2.5emissions are mainly concentrated in
Cunninghamia lanceolataforests and mixed broadleaved forests. Because of its high biomass aboveground and prone to forest fire, these two forest types will be the key management object in future work, and the relevant departments should take good thinning of pruning work before the arrival of fireproofing period.
Abstract:
ObjectiveThe temporal and spatial variations and its formation mechanism on soil bulk density were analyzed in a cold temperate coniferous forest under different intensity fire to understand the dynamic temporal and spatial law of soil bulk density after fire interference and to provide reference for post-fire forest improvement and ecological restoration.
MethodAn autumn experimental fire was conducted in the boreal
Ledum palustre-
Rhododendron dauricum-
Larix gmeliniiforests in Daxing'an Mountains of northeastern China. Before and after the fire, the temporal and spatial variations of soil bulk density were examined continuously by latticed co-coupled sampling method.
ResultThe results showed that: (1) At each time node, soil bulk density of severe burning area was 5%-10% higher than that of mild or moderate burning area after the fire. (2) In time series, soil bulk density variation pattern was depended on fire intensity, i.e., soil bulk density of mild burning area decreased immediately and then increased, that of moderate burning area was not changed immediately and then increased continually, that of severe burning area or of all the monitoring site was risen continually. (3) Significant positive correlation was between spatial pattern of soil bulk density (or soil bulk density change) and fire intensity, correlation appeared immediately after the fire, and correlation coefficient was ascended after snowmelt season and rainy season/growing season.
ConclusionAt the initial stages of post-fire recovery, the original change direction of soil bulk density in
Larix gmeliniforest was different because of fire intensity differences and then all increased after rainy season/growing season, which increased significantly in moderate burning area and severe burning area.
Abstract:
ObjectiveLong maintenance of soil fertility is an important research content of sustainable forest management in plantation.
MethodThis article aims to explore the soil fertility changes on the treatment stands after
Pinus massonianapure forest transferred into uneven-aged conifer-hardwood mixed forest by thinning and then interplanting with
Altingia gralilipes,
Schima superba,
Phoebe bournei, respectively. The soil physical and chemical properties of four treatments were determined after forest interplanting with broadleaved tree species at the 1st, 5th, 10th and 20th years.
ResultThe soil aggregate composition, soil pore, soil organic matter and soil nutrient content of the four treatments of forest soil all showed increasing trend with time, and this trend increased as time went on. The order of the increased amount of soil characteristics showed as
Pinus massoniana×
Altingia gralilipes(MPA)>
Pinus massoniana×
Phoebe bournei(MPP)>
Pinus massoniana×
Schima superba(MPS)> pure
Pinus massoniana(PP). The differences in soil characteristics among the first three mixed stands were small, but the differences between the first three mixed forest and pure
Pinus massonianastands were significant. Compared the soil characteristics of the transformation forest between the first year and the 20th year, it was found that, in 0-2cm soil of MPA, MPP, MPS and PP forest, the water stability aggregates of dry soil diameter >0.25mm increased by 5.21%, 4.67%, 3.78%, 1.24%, the total soil porosity increased by 3.82%, 3.78%, 3.01%, and 0.49%, soil organic matter increased by 9.67, 8.39, 7.26, 2.84g/kg, soil total nitrogen (N) content increased by 0.22, 0.13, 0.14, 0.05g/kg, and soil total phosphorus(P) increased by 0.10, 0.06, 0.05, 0.04g/kg, respectively.
ConclusionThe transformation forest of
Pinus massonianaintercropping with broadleaved tree species has good function in fertilizing soil, and is conducive to the maintenance and sustainable management of the public welfare forest.
Abstract:
ObjectiveForest litter plays an important role in the transmission of nutrients aboveground and underground in forest. Earthworm can influence the decomposition of litter by feeding, digestion, excretion, and burrowing, thereby affecting soil nutrient and soil microbial. This study was conducted to examine the effects of earthworm (
Pheretima guillelmi) and litterfall (
Pinus tabuliformis) addition on soil pH, soil organic carbon (SOC), soil total nitrogen(STN), microbial biomass carbon (SMBC) and microbial entropy (qMB).
MethodThrough indoor incubation experiments, four treatments were set as control(S), adding
Pinus tabuliformisleaf litter (SP), inoculating earthworm (SE), inoculating earthworm and adding
Pinus tabuliformisleaf litter(SPE). Soil samples were collected periodically on the 7 th day(D7), D14, D21, D28, D42, D56 after incubation.
ResultThe results showed that the pH values of treatments SE and SPE were higher than treatment S in all incubation period, but not reached a significant level (
P>0.05); Regardless of adding leaf litter or not, the earthworm all had no significant influence on SOC and STN (
P>0.05). At the end of the experiment, SE treatment decreased SMBC and qMB by 10.8% and 10.9%, respectively compared with control. In each sampling period, the SMBC and qMB of SP treatment were significantly higher than that of its corresponding treatment S(
P< 0.05), and at the end of the experiment, they were significantly increased by 52.3% and 33.6% respectively by treatment SP. In each sampling period, the differences in SMBC and qMB between SPE treatment and SP treatment were significant. At the end of the experiment, compared with SP treatment, SPE treatment increased SMBC and qMB by 19.5% and 19.3%(
P< 0.05), respectively.
ConclusionOur study has shown that, adding litter can increase the conversion efficiency of soil organic carbon to SMBC, and earthworm adding in litter can further promote this effect.
Abstract:
ObjectiveTo provide more scientific data support and theoretical basis for the future snow cover evaporation measurement and regional water resurces requlation, the snow hydrological characteristics in the natural forest of
Larix gmeliniiwas studied in northern Daxing'an Mountains of northeastern China. The snowfall interception and snow cover characteristics were systematically studied from the end of October 2015 to the beginning of May 2016.
MethodDuring the observation period, the snowfall of 16 snowfalls, as well as the snow depth, snow density and snow water equivalent in the forest were periodically observed and statistically analyzed.
Result(1) With the decreasing of snowfall level, the interception rate of
Larix gmeliniiforest showed a gradual increasing trend, which was 6.50% (blizzard), 9.04% (heavy snow), 9.8% (moderate snow), 15.7% (light snow). It can be seen that the maximum interception rate of snowfall in
Larix gmeliniiforest occurred in light snow, and the smallest occurred in blizzard. (2) The difference between the depth of snow inside
Larix gmeliniiforest and that outside the forest was not significant. Among them, the deepest snow depth in larch forest was 68.6cm, and that in outer space was 74.8cm. (3) The density of snow inside and outside the forest decreased with the input of snowfall in the early stage of observation, and did not increase in the absence of snowfall. Snowmelt as the temperature rises, the snow density will decrease faster. (4) Reaching the maximum between April 24 and April 29, with a decrease of 0.07 and 0.11g/cm
3, respectively; the reduction of snow equivalent rate reached the maximum between April 24 and April 29, 30.2 and 46.4mm, respectively.
ConclusionCompared with the open space outside the forest, the
Larix gmeliniiforest has little effect on the snow depth, snow cover density and snow water equivalent, indicating that the effect of
Larix gmeliniiforest on the hydrological characteristics of snow cover is not obvious. The daily change of snow evapotranspiration in this area showed a single-peak curve variation. The daily evaporation and evaporation rates in the snow-covered period were 0.04mm and 0.2×10
-3mm/h, respectively. Daily evaporation fluctuated between 0.02-0.14mm. During the snowmelt period, the average daily evaporation and evaporation rates were 0.38mm and 1.51×10
-3mm/h, respectively, and the factors were analyzed using the grey correlation degree. It is concluded that net radiation is the main factor influencing snowcover evaporation in
Larix gmeliniiforest.
Abstract:
ObjectiveThis paper aims to assess the sensitivity of factors affecting the occurrence of mountain hazards in Beijing, and explore the hazard distribution characteristics and laws in this area.
MethodUsing ArcGis 10.2 as the processing platform, the spatial distribution of avalanche, landslide and debris flow in Beijing mountain region were analyzed. Based on five evaluation-factors including respect to faults, lithology, slope degree, slope aspect and the average rainfall by ARCGIS spatial analysis and sensitivity coefficient.
ResultThe experiments showed that the concerned three kinds of hazards were mainly located in the range of 0-6km to the faults, where 86% hazards were located. The density of hazard site within the area of 2km to fault reached 0.83 points per square kilometers, and the sensitivity coefficient was 1.95; the avalanche, landslide and the debris flow mainly located in the granite strata, and the sensitivity coefficient "
S
ci" was 7.05, 3.46, 5.89, respectively. The maximum
S
ciof avalanche, landslide and debris flow was 1.14, 1.68, 0.90, respectively in the area where the annual precipitation ranged between 710-730mm, 710-730mm, 630-650mm. Three hazards were prone to occur in the slope terrain with average slope gradient of 5°-15°, the corresponding sensitivity coefficient "
S
ci"was 0.75, 0.53, 0.93, respectively. The avalanche and landslide were located in southwest aspect terrain, and the "
S
ci" was 0.37 and 0.64; the debris flow mainly occurred in the river basin while the slope of the disaster was not fixed.
ConclusionIn conclusion, assigning susceptibility of different impact factors for hazards, using spatial overlay analysis and grid accumulation in ARCGIS, we get the susceptibility distribution map of three kinds of disasters and a further understanding of the occurrence of mountain hazards in Beijing mountain area.
2018, 40(6): 92-100.
doi:10.13332/j.1000-1522.20170429
Abstract:
ObjectiveGenetic diversity of germplasm resources of
Leucewas studied to provide reference for the preservation, evaluation and utilization of the germplasm resources of
Poplus tomentosa.
MethodIn this study, capillary electrophoresis with fluorescent-labeled primers was used to analyze clones in
Leuce, and genetic diversity and genetic variation were analyzed based on the results.
ResultA total of 106 alleles were detected in 272 clones using 16 pairs of SSR primers. The number of alleles per locus ranged from 4 to 11, with an average of 6.625 each loci, the average Ho and He were 0.561 and 0.432, respectively, indicating that the genetic diversity was relatively abundant, and the ratio of Ho to He for 9 loci was greater than 1, indicating the high heterozygosity. In addition, the genetic variation of 234 clones from six concentrated areas of
Populus tomentosawas analyzed. The results showed that only 2% of the genetic variation originated among provenances, and 98% within provenances. It could be got to know from the allelic models of different provenances that there were private alleles in five provenances of Shanxi Province, Shaanxi Province, Henan Province, Shandong Province and Hebei Province.Clones with private alleles from different provenances should be selected as parents to broaden the genetic basis of hybrids, or introduced appropriatly to increase the genetic diversity of
P.
tomentosaamong provenances.
ConclusionCluster analysis and principal coordinate analysis showed that the phylogenetic relationship of Beijing and Hebei clones was the closest, and the relationship between Henan and Shanxi, Shandong and Shanxi was closer, respectively. However, clones from the same provenance weren't converged fully one category, owing to genetic variation or the mutual introduction of the provenances. The results provided theoretical basis for the preservation and utilization of germplasm resources of
P.
tomentosa.
2018, 40(6): 101-110.
doi:10.13332/j.1000-1522.20180055
Abstract:
ObjectiveThe concept of pollination syndromes provides a classic hypothesis for the evolution of plants and pollinators. However, in recent years, with more and more generalized pollination systems reported, pollination syndromes have been questioned gradually.
Cymbidium qiubeiensein the Subgen.
Jensoa, is a terrestial orchid with fragrant flower and purplish spots on the labellum. These morphological features are similar to other orchids of Subgen.
Jensoa, such as
C.
lancifoliumand
C.
goeringii, which are pollinated by
Apis cerana cerana. According to the theory of pollination syndromes, we predicted that
C.
qiubeiensewas also pollinated by
A.
cerana cerana. The purpose of our study is to verify the accuracy of pollination syndromes in predicting the pollinators, and explore its scope of application.
MethodPollination biology of
C.
qiubeiensewas investigated during 2010-2012 in the Yachang Orchid National Natural Reserve, which is located in Guangxi of southern China. We investigated its flowering phenology, flower form, pollination behavior of insect, flower color, flower odor and breeding system.
ResultThe unique pollinator of
C.
qiubeiensewas
A.
cerana cerana, and no rewards could be found in the flowers. It was speculated that
C.
qiubeiensehad food-deceptive pollination mechanism and
C.
qiubeienseattracted
A.
cerana ceranaby the purplish spots on the labellum (false nectar). Phenols, aldehydes and esters were identified in its odor, and aldehydes were considered to play an important role in attracting pollinators. We successfully verified the accuracy of pollination syndromes in predicting pollinators.
ConclusionThis study provides a case for the scientific assumptions that the pollination syndromes can predict pollinators accurately. However, the pollination syndromes are composed of a suite of dynamic and evolutionary floral trait. It is necessary to take habitat change, secondary pollinators, pollinator function group, history evolution and gene into account when we use pollination syndromes to predict the pollinators on the premise of knowing the pollinators of closely related plants.
2018, 40(6): 111-116.
doi:10.13332/j.1000-1522.20180097
Abstract:
ObjectiveIn order to provide basis for analyzing hot-press drying mechanism, the temperature and pressure in poplar lumber (
Populus tomentosa) were monitored during hot-press drying, and the effects of platen temperature on temperature, pressure and moisture state in the core layer of poplar lumber were further investigated.
MethodTemperature and pressure in the core layer of poplar lumber were measured with the integrated probe and real-time recorded with a data logger at the same time in hot-press drying, and the effects of platen temperature on moisture state were further analyzed in accordance with the comparison of measured pressure and saturated pressure (theoretical pressure) of vapor calculated with measured temperature in poplar lumber.
ResultWith the increase of platen temperature from 120 to 140? the peak value of pressure increased from 146.4 to 213.1kPa, whereas that of temperature increased from 102.8 to 123.7? The temperature and pressure reached peak values at the same time, and the time to peak values decreased from 17.5 to 11.6min. The moisture in the core layer of poplar lumber with moisture content (MC) beyond fiber saturation point (FSP) was unsaturated water under overpressure condition with the platen temperatures of 120 and 130? the final MC (48.55% and 49.88%) of core layer was greater than FSP. The heat was transferred from platens to the core layer and resulted in the vaporization of free water in poplar lumber when the platen temperature increased to 140? State of the steam in core layer of poplar lumber changed from the saturation state to superheated state with the further increase of steam temperature, and the final core MC (27.70%) was lower than FSP.
ConclusionIt was concluded that the higher the platen temperature was, the higher the peak temperature and pressure reached, and the shorter the duration time for keeping peak pressure was in hot-press drying. When the poplar lumber's MC was greater than FSP, the moisture state in poplar lumber may be liquid state (unsaturated water under overpressure condition), saturated steam or superheated steam states depends on different platen temperature levels in hot-press drying.
2018, 40(6): 117-124.
doi:10.13332/j.1000-1522.20180092
Abstract:
ObjectiveThe obstacle crossing performance and adaptability to different terrain are most important factors for the technical characteristics of the chassis that is the key part of forestry equipment, also they are the key reasons to decide whether the forestry equipment could work in the forest. Since the typical plantations in our country have many short obstacles and gullies, the obstacle crossing performance and adaptability of traditional chassis are not good enough to work in the complex terrain.
MethodFor improving the obstacle crossing performance, a method based on D-H theory was used to establish a kinematics model for a new type of six-wheeled-leg forestry chassis with levelling initiative gait. By space geometry coordinates transformation method, single-cylinder wheeled-legs mechanism was compared with double-cylinder wheeled-legs mechanism in obstacle crossing ability.
ResultIt was concluded that the obstacle crossing ability of double-cylinder wheeled-legs mechanism was always greater than single-cylinder wheeled-legs mechanism. The optimum arrangement of double-cylinder position was achieved with the D-H kinematics solution method. In contrast to prototype test, the highest obstacle crossing numerical similarities of theory analysis and simulation were 99.7% and 97.8%, respectively. The obstacle crossing height of wheeled-legs of chassis was much better than before, and could reach 285.9mm. So it is completely suitable for the application in the field of forestry and a typical unknown terrain. The correctness of the theoretical research method was validated.
ConclusionThis paper provides theory basis for the research on the double-cylinder wheeled-legs mechanism motion characteristics, the obstacle crossing ability of chassis, and the large-scale development and application of intelligent forestry mechanical chassis.
