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2012 Vol.10 No.6
Published 2012-12-31
Articles
1
TAN Zhen-Hua, WANG Tie-Li, WANG Sha, LIU Dun-E
Rill erosion processes on loess hillslope
Based on multi-plot-based experiments of simulated rainfall with steady in-flow rate, the erosion processes of rill on loess hillslope were simulated. Results show that: Power functions could preferably describe the rise trend of rill erosion rate with increasing runoff under different slopes and rainfall intensities,especially under different slopes. Rill erosion modulus increases with increasing slope and rainfall intensities, which could be described by exponential equation for different slopes, logarithmic equation for different rainfall intensities, and dual power equation for different slopes and rainfall intensities at the same time. Flow shear stress is the dynamic source for the development of rill erosion processes.
2012 Vol. 10 (6): 1-5 [
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Liu Tiehui
Landuse change and its dynamic driving forces in Hilly-Gully Area of Loess Plateau: A case study in Zichang County from 1990 to 2006
Based on RS/GIS techniques，the TM/ETM satellite images in Zichang County of 1990, 1999 and 2006 were used as basic data，field investigation, land use dynamic, annual change rates and land transfer matrix were used to analyze the land use characteristics and its driving factors. The result shows: 1) from 1990 to 2006, the cultivated land and unused land decreased, while the grassland, forest, construction land increased significantly, the water area increased at beginning and then decreased; 2) during this period, the cultivated land, grassland, forest and unused land changed dramatically, and the change rates occurred more sharply from 1999 to 2006 than the period from 1990 to 1999; 3) cultivated land and unutilized land decreased significantly among all kinds of lands, due to the increase of grass land and forest land contributed by the cultivated land; 4) the human factors such as society, economy, policy are playing important roles in the change of land utilization, especially the policy factor has been the maim driving power for the change of landuse structure.
2012 Vol. 10 (6): 6-11 [
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WANG Pei-Jiang, DAI Quan-Hou, DING Gui-Jie, CHENG Fu-Dong
Infiltration characteristics of soil and its affecting factors in the process of vegetation recovery in Karst region
Effect mechanism of vegetation recovery on soil infiltration capability could provide scientific bases for soil and water conservation in Karst region. Compared with Nicotiana tabacum farmland and Cryptomeria fortunei plantation, this study selected different vegetation restoration stages and different young economic fruit forests as subject. Interchangeable space-time method were employed to study soil infiltration characteristic and its affecting factors. The results showed that: 1) soil infiltration capability was given as the sequence of Prunus salicina intercropped with Lonicera japonica>Rosa kweichowensis intercropped with Actinidia deliciosa>Prunus salicina intercropped with Rosa kweichowensis >Ziziphus montana intercropped with Zea mays, and thin arbor forest>shrub>shrub and grass>arbor and shrub>grassland>plantation forest. 2) The Nicotiana tabacum farmland had better soil infiltration capability as a result of its mean infiltration and steady infiltration rate were only lower than thin arbor forest. 3) Infiltration process was performed well by Kostialov model for different vegetation restoration stages in this region. However, to young fruit forests soil, Philip or Horton models could give better performance. Initial soil infiltration rate and steady infiltration rate simulated by Horton model were similar to the measured values. So Horton infiltration model was the best model to describe soil infiltration process in the study region. 4) There were significant positive correlation between sand concentration (1-0.05mm in diameter) and soil infiltration (P<0.05). Soil infiltration were obviously negatively related to silt concentration (0.05-0.001mm in diameter) (P<0.01). Sand concentration（1-0.05mm in diameter）and silt concentration (0.05-0.001mm in diameter) were main affecting factors to soil infiltration.
2012 Vol. 10 (6): 12-18 [
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19
YAN Li, WANG Fei, MU Xin-Min
Analysis of the runoff cost for sediment control by slope soil and water conservation measures
Runoff cost for sediment control, shown as ratio of detained runoff and sediment (Rrs) of different soil and water conservation measures is an important integrated indicator to intuitive evaluate the impact of different soil and water conservation measures on runoff and sediment synchronously. Based on the experimental data measured in runoff plots in Xifeng and Tianshui stations for many years, the runoff cost for sediment control under different tillage measures and biological measures were analyzed. The results showed that the Rrs of different tillage and biological measures were greatly impacted by I30 and slope, and the RRS was negatively correlated to the two factors. As to the tillage measures and biological measures, the relationship between Rrs and slope appeared as a exponential function as I30 was more than 0.29mm/min and 0.48mm/min respectively. The orders of runoff cost for sediment control for different tillage measures were: level ditch tillage>shallow plowing>deep plowing, and Rrs of level ditch tillage is higher than that of deep plowing by 33.8%. As to biological measures the orders of runoff cost for sediment control were: intercropping between low-stem and high-stem crops (corn/soybean)>monoculture of low-stem crops (lentils)>rotation between middle-stem crops (winter wheat/buckwheat).
2012 Vol. 10 (6): 19-24 [
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25
LI Gang, LIANG Yin, CAO Long-Xi
Effects of different vegetation restoration patterns on soil erosion in secondary Pinus massoniana pure forest
in this study, based on the measured data of runoff and sediment of the runoff plots during 2010 to 2011 in secondary Pinus massoniana forest in the Ganxian County of Jiangxi province, the benefits of soil and water conservation of different vegetation restoration patterns (Paspalum notatum, herbal; Lespedeza bicolor, shrub) in the secondary Pinus massoniana pure forest were analyzed. The results indicated that soil erosion is serious in secondary Pinus massoniana sparse pure forest, annual runoff coefficient was 0.50-0.60 and erosion modulus was in the range of 2700-6000t/(km2·a). Soil erosion intensity was reduced by surface vegetation restoration. However, the benefits of soil and water conservation of different vegetation restoration patterns were closely related to surface coverage and canopy structure. Benefits of water detention and soil conservation of vegetation restoration were 50%-60% and 65%-70% respectively when tree-herbal or tree-shrub structure formed a complex hierarchy in pure forest. Meanwhile, benefits of soil and water conservation were also affected by vegetation and rainfall types. Benefit of water detention initially increased then decreased with rainfall, and rainstorm was the inflexion for Paspalum notatum, and changed complex for Lespedeza bicolor. However, benefit of soil conservation reduced with rainfall, especially declined rapidly in heavy rainstorm.
2012 Vol. 10 (6): 25-31 [
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32
ZHANG Dun, NIU Wen-Quan, ZHANG Lin-Lin, SHI Li-Yan
Experimental Study on Characters of Wetted Soil in Moistube Irrigation
This study was conducted to investigate the soil water movement of line source infiltration under miostube-irrigation. Soil box experiments was used to study soil water distribution and analyze the effect of the soil texture and bulk density on the characteristic of wetted soil.The results showed that the wetted soil looked like cylindrical object which with pipe as it’s axle centre and clay loam soil was approximate with cylinder, the cross section of sandy soil as obpyriform shape. The ratio of R∶X∶H was 1∶0.90∶0.99 in clay loam soil and 1∶ 0.81∶0.95 in sandy soil, respectively. (R: horizontal migration distance; X: vertical upward distance; Y: vertical downward distance). The relationship between the horizontal or vertical moving distance of wetting front with irrigation time appeared as a power function. The effects of the soil texture and bulk density on the characteristic of wetted soil were significant in mois-tube irrigation. Miostube-irrigation has small flow, the unit length flow rate was not exceed 210mL·m-1·h-1, which could automatically adjust with the change of soil water content, cumulative infiltration has a linear relation with irrigation time. Water distribution in the volume of wetted soil was a concentric circle with the pipe. Most of soil water content lied between 80% and 90% of field capacity. Miostube-irrigation has high irrigation uniformity, which reached 95.62%. The effect of water saving of miostube-irrigation is prominent, which is suitable for crop water demand in the arid regions.
2012 Vol. 10 (6): 32-38 [
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39
BI Chao, ZHOU Yu-Chi, DIAO Yun-Jie, YANG Xiao-Hui
Spatial pattern analysis of two herbaceous plants on semi-fixed sand dune in Kubqi Desert
Kubqi Desert consists mainly of mobile sand dunes. Therefore, Revegetation is necessary to in some key parts such as highway and agricultural or animal husbandry developing areas. This paper studied the spatial pattern of herbaceous plants on typical semi-fixed sand dune using spatial point analysis method. Results show that number variation of perennial Inula salsoloides is greater than that of annual Agriophyllum squarrosum. The general pattern of total plants is basically clumped and becomes less clumped from top to bottom of the sand dune. The relationship of I. salsoloides and A. squarrosum changes from facilitation to competition from top to bottom of sand dune. The main reason for the spatial pattern may result from soil moisture change. A. squarrosum, as a pioneer colonizer, plays an important role in mobile sand dune fixation, hence, seeds of this annual plant should be sprayed for fast revegetation with other non-biological sand-fixation measures during mobile sand dune fixation.
2012 Vol. 10 (6): 39-44 [
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45
JIANG Chong, WANG Fei, MU Xin-Min, LI Rui
Effects of climate change on net primary productivity of vegetation in the northern and southern regions of the Qinling Mountains（Ⅱ）：Effects of climate change on net primary productivity of vegetation
Based on the daily data from 54 meteorological stations in Northern and Southern Regions of the Qinling Mountains between 1960 and 2011, with the help of Zhou Guangsheng-Zhang Xinshi Model, Penman-Monteith Model, climate trend rate, correlation analysis and Spline interpolation method, the climate change in the northern and southern region of the Qinling Mountains during last 52a and its effect on Net Primary Productivity (NPP) as well as the variation of NPP in different scenarios were analyzed. The results showed that: 1）According to the size of NPP, NPP increased from north to south gradually. and the order was given as Ba-Wu Valley, Han River Basin, the southern slope and northern region of Qinling Mountains. According to the percent of NPP increasing stations accounted for the total stations, the sub regions had different change trend with the order of Han River Basin, Ba-Wu Valley, southern slope and northern region of Qinling Mountains. The extreme ratio of inter-annual variability of NPP in ecological regions were not very big, ranging from 1.34 to 1.89. 2）Humid index, precipitation and humid index correlated positively with NPP, which reached 0.01 significant level. According to the size of correlation coefficient, the order was given as humid index, precipitation and relative humid. The increase of precipitation would promote accumulation of NPP, which indicated that water was the main restricting factors. 3）Water use efficiency of vegetation decreased from south to north with the order Ba-Wu Valley, Han River Basin, southern slope and northern region of Qinling Mountains. Most of the area had insignificant upward trend, and in last 52a, water use efficiency increased insignificantly and maintained at stable level.
2012 Vol. 10 (6): 45-51 [
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52
LUO Ting, LI Hong-Wei, DAN Song, LI Jian-Meng, WANG Wen-Long
Field experiment of soil erosion characteristics under different surface conditions in Shenfu-Dongsheng coalfield exploitation area
The objective of this paper was to determine soil erosion characteristics of different surface conditions (original ground, disturbed road, unhardened road, spoil, waste slag with more sand than stone and waste slag with less sand than stone) on soil erosion by washout experiment in Shenfu-Dongsheng coalfield area. The results show that: 1) There were positive linear correlations between erosion amount and runoff amount or flow shear stress for all of underlaying surfaces. There were positive power function relations between erosion amount and runoff amount for original soil, disturbed road and unhardened road. There were positive linear relationships between erosion amount and runoff amount for spoil and waste slag with more sand than stone. There were logarithmic regressions between erosion amount and flow shear stress for all of surface conditions. On waste slag with less sand than stone, it was a exponential function relation between erosion amount and runoff amount and a positive linear relationship between erosion and flow shear stress. 2) Earth-dump could be eroded easily compared to original soil. The average erosion amount of spoil was the maximum 22.68kg/m2 reached to 45.27 times as great as that of original soil. The erosion amount of sand more than stone waste slag increased by 19.61 times than original soil. The erosion amount of waste slag with more sand than stone increased by 10.61 times than original soil. However，the erosion amount of disturbed soil and unhardened road only increased by 4.35, 4.41times compared to original soil.
2012 Vol. 10 (6): 52-57 [
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58
YANG Yong-Hui, LI Zong-Jun, WU Ji-Cheng, LI Xue-Jun, HE , YANG Xian-Ming
Effects of water-retaining agent onsoil water retention and supplying water under different water conditions
In order to ascertain the effects of water-retaining agent on soil moisture characteristics under different soil moisture conditions after the growth of winter wheat, the effects of different dosage of water-retaining agent (T1：0；T2：27mg/kg；T3：54mg/kg；T4：81mg/kg) on soil water retention, supplying water and infiltration capacity were studied through potting experiment condition were studied. The results indicated that water-retaining agent increased the capability of soil water retention, supplying water, infiltration and available moisture. Under mild stress condition, the capability of soil water retention, infiltration and available moisture of treatment 3 were the best compared with other treatments, while treatment 4 was the best for the capability of supplying water compared with other treatments. Under sufficient irrigation, the capability of soil water retention, supplying water, infiltration and available moisture increased with the dosage of water-retaining agent, but there was not significant difference between treatment 3 and treatment 4. Compared with mild water stress, the capability of soil water retention, supplying water and infiltration under the condition of sufficient irrigation were higher. Soil available moisture of treatment 3 under mild water stress was highest among all treatments, which increased by 18.6% compared to the control. In all, from economical aspect, treatment 3 was the best to improve the soil properties.
2012 Vol. 10 (6): 58-63 [
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64
HU Xi-Sheng, HONG Wei, Wu Cheng-Zhen
Evaluating the non-use value of Minjiang estuary wetland ecosystem based on contigent valuation method
Taking Minjiang estuary wetland as a case study, which is an important post on the migration route of migratory bird from Eastern Asia to Australasia. The contingent valuation method (CVM) was used in this paper to evaluate the non-use value of the wetland. 500 payment card CVM questionnaires were distributed and 482 were fed back as useful questionnaires. On the basis of the questionnaires, the mean willingness to pay (WTP) and the median to the wetland ecosystem were calculated. Which were 151.16 yuan(RMB) and 56.36 yuan(RMB) per person every year in future 5 years. The relative frequency distribution curve of the WTP was a monotonically decreasing distribution curve. Taking research purpose into account, mean WTP was adopted to evaluated the non-use value of the wetland, which was 5.01×108 yuan(RMB) per year. The impacts of factors on WTP were also analyzed by Spearmans rank correlation coefficient, which showed that WTP was related to income, educational level, age, gender, and profession of the respondents.
2012 Vol. 10 (6): 64-70 [
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Ge Rile， Er Dunhua， Song Xiangbin， Sun Baoping
Branch quantity characteristic of six kinds of soil and water conservation plants
The biomechanical properties of branches is the basis for the study on effect of aerial part of plants on the windbreak and soil erosion reduction. In this paper the branches of six kinds of soil and water conservation plants (Caragana microphylic, Hippophae rhamnoides, Medicago sativa, Astragalus adsurgens, Hedysarum fruticosum, and Melilotus officinalis) in Waste Dump of Strip Mine in Heidaigou were taken as research object. Through studying the the characteristic of branch quantity, representative branches of plants were determined, thus the bais data and relevant parameter were supplied to the study of biomechanical properties of branches. The process of selecting representative branches is that: firstly, the diameters of branches were divided into several classes with distance of 0.5 millimeter. Then,the percentage of cumulative amount, cumulative length, surface area and dry weight of branches of each diameter class was calculated respectively, and diameter classes with high percentage of these values were selected as representative diameter classes. The results showed representative diameter classes of several plants, respectively, i.e. Caragana microphylia 0.5-1mm, 1-1.5mm, Hippophae rhamnoides 1-1.5mm, 1.5-2mm, Hedysarum fruticosum 0-0.5mm, 0.5-1mm, Medicago sativa 0.5-1mm Astragalus adsurgens 0.5-1mm, 1-1.5mm, Melilotus officinalis 1-1.5mm. In the study of the biomechanical properties of branches, it is recommended that in Inner Mongolia Zhungeer coal mining area and similar areas, representative diameter classes of the six kinds of soil and water conservation plant is the main study focus.
2012 Vol. 10 (6): 71-76 [
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BO Nan, YU Li-Rong, MaWan-Li, WANG Tie-Juan, ZHOU Hong-Sheng, BI Jian-Ling, SUN Ke
Physiological changes of Swainsona formosa under different water conditions
Under different water conditions some physiological indexes of Swainsona formosa, such as Malondialdehyde (MDA)，soluble sugar, soluble protein, proline, protective enzymes ( SOD,POD and CAT), were determined by using the conventional method of plant physiology in this paper. The results are as follows:1) with increased drought stress the proline content increased gradually, soluble protein content decreased and the increased, there was a mutual compensation relationship between the two indexes. The tendency of content of soluble sugar increasing initially and then decreasing showed the regulation function of osmotic adjustment material to the drought stress. 2) The activities of defense enzymes changed differently under various water conditions, the CAT activities raised with the drought stress. The SOD activity increased at moderate drought stress and declined at severe drought stress. In contrast to SOD activity, but POD activity changes were opposite to SOD. The cooperative synergistic effect among protective enzymes maintained the integrity of cell membrane of leaves. 3) The MDA content increased with drought stress, which means that damage to.Swainsona formosa due to drought stress can be reduced by increasing soluble content, strengthening activity of protective enzymes and antioxygenic ability.
2012 Vol. 10 (6): 77-81 [
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82
DENG Yan-Xia
Heavy rainfall disaster on July 21,2012 in Tongzhou district in Beijing and urban soil and water conservation
Heavy rainfall disaster on July 21, 2012 in Beijing had aroused wide concerns in China. Tongzhou district，being one of the key development cities in Beijing municipality, suffered a serious disaster in this heavy rail. This paper gives a series of measures on urban soil and water conservation from new views and practices of soil and water conservation in order to provide ideas and practices for disaster prevention and mitigation in urban regions. It includes control of soil erosion source and utilization of surface runoff comprehensive utilization of dregs and soil resources of earth and stone reducing the ground hardening rate and increasing vegetation coverage and utilization of rainwater resources.
2012 Vol. 10 (6): 82-85 [
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HUA Dang-Ling, ZHANG Shi-Hui, WANG Rui, LIU Wei-Qun, Zhao Ying, Huo Guang
Regulation of soil inorganic nitrogen by applying different nitrogen rate on flue-cured tobacco-planting soil
Different nitrogen fertilizer rate were applied in the flue-cured tobacco planting soil to evaluate the nitrogen dynamic in different soil layers at different growth stages. In field trial nitrogen fertilizer with 5 different rates were applied to soil at 3 stages before and after transplanting. Soil were sampled at 3 layers for 7 times during tobacco growth, and the soil sample were stored under refrigeration and then analyzed with flow injection analyzer. The results are as follows: the nitrate nitrogen(NO-3-N) content within the upper 0-20cm was larger than the content of ammonium nitrogen(NH+4-N) since 6th weeks before the transplanting of flue cured tobacco and the more the nitrogen fertilizer applied, the higher inorganic nitrogen content was. The effect of nitrogen fertilizer on the inorganic nitrogen content in 0-20cm depth was larger than that in 20-40cm and 40-60cm depth. The nitrate decreased dramatically since 7th weeks after transplanting. The varied range of ammonium was much bigger than that of nitrate, ammonium begin to fluctuate from 6th week after transplanting and waved around about 50mg/kg for all applied nitrogen rates and in all soil layers, and a peak of ammonium content occured in 8th week in all soil layers. The decrease of NO3-N content stopped in 7th week, and then entered into a stage of smoothly fluctuation in the range of 0-100mg/kg. It was concluded that during earlier groth stages nitrogen fertilizer rates have profound impact on the inorganic nitrogen in layer of 0-20cm, ammonium regulation is the critical measure for optimizing nitrogen supply in the later growth stage.
2012 Vol. 10 (6): 86-91 [
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CHEN Zhi-Cheng, WANG Zhi-Wei, WANG Rong-Rong, ZHANG Yong-Tao, YANG Ji-Hua, Ren Li-Gang
Effects of soil moisture on characteristics of photosynthesis response to light of Diospyros Kaki
We measured the light response of photosynthetic physiology parameters by CIRAS-2 portable photosynthesis system, such as net photosynthetic rate, transpiration rate, water use efficiency and stomatal conductance, in two-year-old Diospyros Kaki under different soil water conditions. The light response rule of Diospyros Kaki was studied under series of soil moisture. The results show that soil water content had significant effects on the photosynthetic parameters of Diospyros Kaki. With the decreasing soil moisture, net photosynthetic rate and apparent quantum yield increased first, and then decreased. Meanwhile light compensation point decreased first, and then increased. Light saturation point represented a decreasing tendency. Higher net photosynthetic rate and water use efficiency were observed when the relative soil water contents (Rwc) were from 48.8% to 76.7% and the photosynthetic active radiation were from 800 to 2000μmol/(m2·s). Diospyros Kaki had the higher ability to utilize strong light, but lower to utilize weak light. When Rwc was 48.8%, the main reason of photosynthesis declination was stomatal limitation. As Rwc was 25.5%, the declination was changed from stomatal limitation turned to non-stomatal limitation. Judging from stomatal factor and non stomatal factor, we can get the conclusion that the drought resistance of Diospyros Kaki is very strong. The results in this study could provide theory for water saving activity and high yield cultivation of Diospyros Kaki.
2012 Vol. 10 (6): 92-97 [
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Qiu Xueli, Li Junying, Li Xiangyang, Hu Wanli, Duan Zongyan, Fu Bin, Lu Yao
Effects of different slope farming measures on soil erosion and nutrient loss in tobacco area, Qujing City, Yunnan Province
The characteristics of soil erosion and nutrient loss under different slope farming measures of red soil in Yunnan were studied based on rainfall-runoff process. The results showed that for the down slope tillage, the different amounts of fertilizer would lead to different vegetation coverage, which will affect the amounts of soil erosion and nutrient loss. Compared with the treatment of covering film, contour tillage after uncovering film could improve soil moisture-holding capacity and reduce soil erosion, especially straw mulching after uncovering film performed better. At early stage, the main factors affecting soil erosion and nutrient loss by tobacco plant were farming measures; and at maturity stage, the main affecting factor was vegetation coverage. Compared with nitrogen loss, the phosphorus loss was affected greater by runoff.
2012 Vol. 10 (6): 98-103 [
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YE Gong-Fu, GAO Wei, YI Liang, WANG Heng, HUANG SHI-De
Dynamic of transpiration and water use efficiency of Casuarina eguisetfolia in coastline forest
The dynamic change pattern of transpiration rate and water use efficiency of Casuarina eguisetfolia in coastline forest were measured using Li6400 portable photosynthesis system. The results showed that the diurnal variation of transpiration rate was single-peak curve, the peak occurred at 12:00 in wet season and 14:00 in dry season, the daily mean in wet season（1.33mmol/(m2·s)）was greater than that in dry season（1.022mmol/(m2·s)），the diurnal variation of transpiration rate was significantly positively correlated with air temperature and photosynthetically active radiation in wet season and significantly positively correlated with air temperature and stomatal conductance in dry season. The seasonal variation of transpiration rate was single-peak curve, which was highest in June and lowest in January，and the average of transpiration rate in different season was summer（1.74mmol/(m2·s)）>spring（1.28mmol/(m2·s)）> autumn（1.24mmol/(m2·s)）>winter（1.06mmol/(m2·s)），the seasonal variation of transpiration rate was significantly positively correlated with air temperature and photosynthetically active radiation and vapor pressure deficit at the leaf. The diurnal variation of water use efficiency was single-peak curve, and the daily change in wet season was greater than that in dry season，the water use efficiency in the morning of dry season was higher than that in wet season, the seasonal variation of water use efficiency was double-peak curve, and the peak occurred at September and January in turn. Therefore, the Casuarina eguisetfolia performed high transpiration rate and water use efficiency under better moisture condition，when the moisture condition was worse, Casuarina eguisetfolia can reduce transpiration rate and improve water use efficiency to maintain its growth, which showed strong adaptability to moisture change.
2012 Vol. 10 (6): 104-109 [
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110
LI Zhen, ZHANG Yan, YAO Wen-Jun
A review of monitoring and predicting technology on gully erosion
As a major process of soil erosion, gully erosion destroys land resources and is the main contribution to watershed sediment on the gully Loess Plateau. The complex mechanism of gully erosion and lack of techniques resulted in the slow progress of research on gully erosion. Measuring and monitoring techniques are the base for assessment and prediction of gully erosion rate. In the past years, some new techniques have been used in the research of gully erosion, including Global Positioning System (GPS), three-dimensional Laser measurement and high resolution remote sensing. In particular, high resolution remote sensing presents a possibility for monitoring gully erosion in a larger scale than before. Worldwide researches showed that gully erosion rate ranged from 0.16m/a to 15m/a. The technique of gully erosion prediction develops slowly, and there is still no widely applicable gully erosion prediction model at present. Assessment of gully erosion rates with high-resolution sensing, LADAR or 3D laser measuring is a hot topic in the research of gully erosion recently and also a constant trend in the near future; however, development of gully erosion model and predicting gully erosion at different scales will be the long term research direction.
2012 Vol. 10 (6): 110-115 [
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WU Hai-Long, XU Xin-Xiao, SHI Chen, ZHANG Yan, ZHANG Zhen-Ming
Advances in the study of PM2.5 characteristic and the regulation of forests to PM2.5
The harm of PM2.5 on human is increasing with the quick development of industry and human activities. How to reduce the harm of PM2.5 is an urgent problem. By summarizing domestic and foreign researches on PM2.5, the paper analyzed its characteristics of temporal and spatial distribution, composition and sources. Also it introduced the monitoring standards of main countries or areas in the world. Finally, the relationship of PM2.5 and vegetation was emphasized. Suitable structure vegetation could help human to prevent PM2.5 effectively, so as to reduce its harm.
2012 Vol. 10 (6): 116-122 [
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