From the 1950s to 1960s, large area of Populus simonii shelterbelts system was established in northern area of Shanxi Province. For reconstructing the old shelterbelts, more attentions should be paid to selecting suit...From the 1950s to 1960s, large area of Populus simonii shelterbelts system was established in northern area of Shanxi Province. For reconstructing the old shelterbelts, more attentions should be paid to selecting suitable tree species and design of logical shelterbelts structure. In order to provide a profound basis for the efficient establishment of shelterbelts, the study on function and structure of the farmland shelterbelts was conducted in Shuozhou and Datong areas, both are semi-arid areas in Northern Shanxi Province during 1996-2001. The wind-control effects of shelterbelts with different structures (close-spaced, wider-spaced, and widest-spaced) were investigated by portable wind vane and anemometer, wet and dry bulb thermometer, ground thermometer, glass service instrument. The results showed that the wind-control capacity of the shelterbelts during the leafing period should be thought as the criteria index in shelterbelts established. The wider-spaced shelterbelt that was made of 4-6 rows of trees, with a spacing of 2.0 m×3.0 m, had the best wind-control result.展开更多
s: The farmland shelterbelts in Northeastern Plain of China have formed relatively complete net system. The func-tions of shelterbelt net in omnibearing wind check and prevention of frostbite as well as the field of ...s: The farmland shelterbelts in Northeastern Plain of China have formed relatively complete net system. The func-tions of shelterbelt net in omnibearing wind check and prevention of frostbite as well as the field of integrated climate effect within shelterbelt net were analyzed, through located observation of meteorological factors. Within the shelterbelt net, the area with more than 10% efficiency of omnibearing wind check was determined as benefited area. The analysis of yield and quality of crops indicated that the sheltering range of shelterbelt net was 25 times tree height. The mature heights of the various varieties of poplar composed the shelterbelts were determined according to their height growth. Based on the comprehensive analysis above, the suitable size of farmland shelterbelt net in Northeastern Plain of China was decided to be 400 m×400 m.展开更多
On the basis of landscape ecology, combining the Spot 5 high resolution satellite imagery with GIS, a method evaluating the spatial heterogeneity of shelterbelts distribution at landscape scale is put forward in this ...On the basis of landscape ecology, combining the Spot 5 high resolution satellite imagery with GIS, a method evaluating the spatial heterogeneity of shelterbelts distribution at landscape scale is put forward in this paper. The distance coefficients of reasonable and existing landscape indexes of farmland shelterbelt networks were com-puted, and then through the classification of the distance coefficients, and the establishment of evaluation rules, the spatial heterogeneity of farmland shelterbelts was evaluated. The method can improve the evaluating system of previ-ous studies on shelterbelts distribution, resolve the disadvantages of lacking spatiality of overall evaluation, and make the evaluation results have more directive significance for shelterbelt management. Based on this method, spatial het-erogeneity of shelterbelt networks was evaluated in the midwest of Jilin Province, China. The results show that the re-gions with fewer shelterbelts and no closed network account for 34.7% of the total area, but only 4.9% of the area has relative reasonable pattern of shelterbelt networks. Many problems exist in the distribution pattern of shelterbelts, therefore, much attention should be paid to construct farmland shelterbelts in the study area.展开更多
The ＂Three-North＂ Shelterbelt is the largest and most distinctive artificial ecological engineering project in China. It has been conducted since November 25, 1978 in the ＂Three-North＂ （i.e., Northeast China, Nor...The ＂Three-North＂ Shelterbelt is the largest and most distinctive artificial ecological engineering project in China. It has been conducted since November 25, 1978 in the ＂Three-North＂ （i.e., Northeast China, North China and Northwest China） regions. In this study, the background and the essential benefits of the ＂Three-North＂ Shelterbelt project are summarized. The basic status and future development of the ＂Three-North＂ Shelterbelt project are also studied. As well, we tried to discuss the problems existing in the current shelterbelt system and the strategies to conduct this ecological project rationally.展开更多
The coastal shelter forest in China is under threat of destruction and degradation because of the impact of human activities. Protection efficiency assessment of the coastal shelterbelt is an important component of sh...The coastal shelter forest in China is under threat of destruction and degradation because of the impact of human activities. Protection efficiency assessment of the coastal shelterbelt is an important component of shelterforest remediation planning and sustainable management. In this study, a protection efficiency index （PEI） model was established using the projection pursuit method to assess the protective quality of the coastal shelter forest at the coastal section scale of Dongshan Island, China. Three criteria were used, including forest stand structure, forest belt structure, and windbreak effect; each criterion further comprised multiple factors. Based on survey data of 31 plots in the coastal shelter forest of Dongshan Island, we calculated PEI values using a projection of a pursuit model. The result showed 64.5 % of the PEIs fell at or below the middle level, which can indicate the status of the coastal shelterbelt is unsatisfactory. To further explore whether the different bays and land use types create significant differences in PEIs and evaluation indices, we used an ANOVA to test the influence of various bays and forms of land use on coastal shelterbelts. The results showed that PEI and most of the indices differed significantly by bay; mean tree height, mean DBH, mean crown width, stand density, vegetation coverage, and wind velocity reduction differed significantly by land use. Therefore, relevant measures for different locations, bays and surrounding land use can be proposed to improve the existing conditions of the coastal shelterbelt. The results of this study provide a theoretical and technical framework for future changes and sustainable management of coastal shelterbelt on Dongshan Island.展开更多
To examine changes in surface soil quality over time in Populus×xiaohei shelterbelts,we collected soil samples from five shelterbelts of different ages and also from former cropland left fallow for 25 years.Twent...To examine changes in surface soil quality over time in Populus×xiaohei shelterbelts,we collected soil samples from five shelterbelts of different ages and also from former cropland left fallow for 25 years.Twenty-one surface soil(0–20 cm)properties were measured,and variation in soil quality was assessed using one-way ANOVAs and multiple comparison tests.Based on this analysis,16 soil indexes were used in a model evaluating soil quality,with each index given weight as determined by the correlation coefficient.Compared with the control,the postmature forest had greater soil moisture content but lower bulk density(P<0.05).The mature forest also had higher soil pH,total organic carbon,alkali-hydrolyzed nitrogen,available phosphorus,and biomass nitrogen content,but reduced nitrate-nitrogen and total phosphorus content than the control(P<0.05).Total porosity was highly positively correlated with aeration,nitrate-nitrogen,alkali-hydrolyzed nitrogen,available phosphorus,microbial biomass carbon and microbial biomass nitrogen.Soil total organic carbon,ammonium nitrogen,nitrate-nitrogen,alkali-hydrolyzed nitrogen,total nitrogen,available phosphorus,microbial biomass carbon and microbial biomass nitrogen were all strongly correlated.In the soil quality evaluation model,total organic carbon was assigned the highest weight and total potassium content the lowest.The soil quality index was lowest in the near-mature forest and greatest in the postmature forest.Generally,soil quality in P opulus×xiaohei shelterbelts varied with age and was higher in the 10–20 cm versus 0–10 cm soil layer.After a single forest generation,surface soil quality was significantly improved.展开更多
The black soil region of northeast China is one of the most important grain-producing areas in China. Increasingly severe gully erosion in this region has destroyed much farmland and reduced grain production. We analy...The black soil region of northeast China is one of the most important grain-producing areas in China. Increasingly severe gully erosion in this region has destroyed much farmland and reduced grain production. We analyzed SPOT5 imagery from 2007 and TM imagery from 2008 to describe the distributions of gullies and farmland shelterbelts in Kedong County and to assess the effect of farmland shelterbelts on gully erosion. The ima- gery revealed 2311 gullies with average density of 418.51 m km-2, indicating very serious gully erosion. With increasing slope gradient there was an inverse trend between gully density and shelterbelt density, indicating that farmland shelterbelts can prevent gully erosion. The defense effect of farmland shelterbelts against gullyerosion varied with distance： for distances 〈120 m, the defense effect was consistent and very strong; for distances of 120-240 m, a weak linear decrease was found in the defense effect; and for distances 〉240 m, the defense effect of the shelterbelts was significantly weaker. We recommend an optimal planting density of farmland shel- terbelts for the prevention of gully erosion at 1100-1300 m km-2.展开更多
At present, the most researches on the protected effect of shelterbelt are on the basis of the two scales of forest belts and networks. However, with the further research on the global environmental change, more atten...At present, the most researches on the protected effect of shelterbelt are on the basis of the two scales of forest belts and networks. However, with the further research on the global environmental change, more attention was paid to the regional climate effect of shelterbelt. In present study, we analyzed the temperature effect of the shelterbelt at regional scale by using the land surface temperature （LST） data from the moderate resolution imaging spectroradiometer （MODIS） at Yushu, Nong＇an, Dehui, and Fuyu in Jilin Province of China from March to October in 2008. Results show that the shelterbelt can increase the soil temperature of the protected farmland as compared with no shelterbelt zone, with the increment of 0.57oC per day in fine shelterbelt and 0.38oC per day in the normal shelterbelt. Moreover, the correlation analysis of the air temperature, precipitation and the soil type and the shelterbelt effect shows that the air temperature and precipitation are negatively correlated with the shelterbelt effects, that is, the more the temperature and precipitation are, the less the effect produced. While the impact of the soil types on the shelterbelt＇s effect is not very obvious as a whole. This paper draws significance in terms of analyzing the effects of the shelterbelt on the soil temperature at regional scale utilizing the remotely sensed data and GIS technique.展开更多
Shelterbelts are important in defending against natural disaster and maintaining ecological balances in farmland. Understanding of the shelterbelt vegetation fraction is fundamental to regional research of shelterbelt...Shelterbelts are important in defending against natural disaster and maintaining ecological balances in farmland. Understanding of the shelterbelt vegetation fraction is fundamental to regional research of shelterbelts using remote sensing. We used SPOT5 imagery with 10×10m spatial resolution in combination with knowledge of the characteristics of shelterbelts to develop a method for retrieval of the vegetation fraction of shelterbelts by the pixel un-mixing model. We then used the method to retrieve values for shelterbelts in study area. By combining the parameters of photographic images with characteristics of shelterbelts, we developed a method for measuring the vegetation fraction of shelterbelts based on an advanced photographic method. We then measured the actual values to validate the retrieval result. The multiple correlation coefficients between the retrieved and measured values were 0.715. Our retrieval and measuring methods presented in this paper accurately reflect field conditions. We suggest that this method is useful to describe shelterbelt structure using remote sensing.展开更多
This study evaluates the role of shelterbelts on the development and dynamics of vegetation in relation to livelihoods in the study area using geo-information techniques. The study covered the period between 1972 and ...This study evaluates the role of shelterbelts on the development and dynamics of vegetation in relation to livelihoods in the study area using geo-information techniques. The study covered the period between 1972 and 2007. The results show that in 1972 vegetation cover in the study area extended over an area of 6955 hectares (i.e.?shrubs, grasses and trees) which represents 65% of the area;however there was a decrease in 1986 to an area of 5779 hectares (54%). Despite the establishment of shelterbelt in the area in 1987, the trend did not change. This is obvious in the reduction of vegetation cover between 1986 and 2000 to a total area of 3893 hectares (37%). The vegetation cover further decreased to 2791 hectares (26%) in 2005 and 1659 hectares (16%) in 2007 respectively. The study concludes that the establishment of shelterbelts alone cannot guarantee the success of vegetation cover development in the area without a sustainable plan which recognizes the local communities as critical stakeholders. Thus, variables like population growth and GDP have a role to play in vegetation cover depletion. The study recommends that efforts geared towards enlightenment of the local communities on the need for conservation should be encouraged by Government and Non-Governmental Organisations.展开更多
[Objectives]To explore the effects of spatial density of farmland shelterbelts on NDVI on the northern slope of Tianshan Mountains.[Methods]Taking the economic belt of the northern slope of the Tianshan Mountains as t...[Objectives]To explore the effects of spatial density of farmland shelterbelts on NDVI on the northern slope of Tianshan Mountains.[Methods]Taking the economic belt of the northern slope of the Tianshan Mountains as the research area and using the grid method,the spatial density distribution of farmland shelterbelts can be known.Combining the grid method with NDVI data,the average value of normalized difference vegetation index(NDVI)during the growing period of crops can be obtained.In addition,the protection benefits of the shelterbelts on crops were analyzed through comparing the growth of crops within the protection zone with and without protection.[Results]The grids with shelterbelt distribution were better than the grids without shelterbelt distribution,and the shelterbelt played a great role in promoting crop growth.In the middle stage of crop growth,the protection benefit of shelterbelt was significant.The spatial density of shelterbelts was unevenly distributed in the range of 0.6 to 0.8,and the protection benefits were poor.[Conclusions]It is expected to explore the effects of shelterbelts on crop growth at a larger regional scale,so as to provide a basis for the management and design of shelterbelts in the future,and to provide a theoretical basis for studying the protective effect of farmland shelterbelts on crops.展开更多
In China’s three northern regions of the Northwest, North and Northeast (3Ns), there are 1.33 million sq km of desert and sand land, forming a 5,000-km-long wind-sand belt. In 1978, the Chinese government decided to ...In China’s three northern regions of the Northwest, North and Northeast (3Ns), there are 1.33 million sq km of desert and sand land, forming a 5,000-km-long wind-sand belt. In 1978, the Chinese government decided to build the "3Ns" shelterbelt network. The project covers 13 provinces, autonomous regions and cities including Xinjiang, Qinghai, Gansu, Ningxia, Shaanxi, Inner Mongolia, Shanxi, Hebei, Beijing, Tianjin, Liaoning, Jilin and Heilongjiang, eovering an area of 4.06 million sq km, 42％ of the country’s total land. It plans to complete the project in 73 years, in three phases: the first phase展开更多
The shelterbelt is an indispensable barrier to the ecological and economic development of an oasis.Soil moisture,groundwater and irrigation greatly affect the shelterbelt water consumption and development.In this stud...The shelterbelt is an indispensable barrier to the ecological and economic development of an oasis.Soil moisture,groundwater and irrigation greatly affect the shelterbelt water consumption and development.In this study,the transpiration rate of shelterbelt trees,soil moisture and meteorological data were collected to determine the effects of soil moisture and meteorological factors on the water consumption of different shelterbelt tree species via multivariate statistical methods.The results showed that the water consumption rate was positively correlated with solar radiation,air temperature and precipitation.Moreover,the leaf transpiration rate exhibited the trend of P.Russkii Jabl.˃P.alba˃P.simonii Carr.>P.nigracv,while the average daily water consumption decreased in the order of P.alba>P.Russkii Jabl.>P.simonii Carr.>P.nigracv.The average daily water consumption levels of P.alba,P.Russkii Jabl.,P.simonii Carr.and P.nigracv were(9.15±0.92)kg/(tree∙d),(6.95±1.41)kg/(tree∙d),(4.43±1.32)kg/(tree∙d),and(1.58±0.18)kg/(tree∙d),respectively.Over the growing season,the soil water consumption levels of P.alba,P.Russkii Jabl.,P.simonii Carr.,and P.nigracv in each shelterbelt tree stand reached 674.8,336.9,358.1 and 161.7 kg,respectively.More than 96%of the soil moisture lost was provided by the upper 120-cm soil layer.Understanding the influence and contribution of soil water and meteorological factors to shelterbelt water consumption is beneficial for shelterbelt management and protection.展开更多
The Shelterbelt Forest System Program in northeast, north and northwest China （the Three-North Shelterbelt Program, TNSP） is the largest ecological reforestation program in the world. TNSP vegetation research has im...The Shelterbelt Forest System Program in northeast, north and northwest China （the Three-North Shelterbelt Program, TNSP） is the largest ecological reforestation program in the world. TNSP vegetation research has important ecological meaning and profound social and economic signiifcance. Here, spatio-temporal variation in vegetation cover under the TNSP was examined using the NDVI average method, major climatic factors such as temperature and precipitation, and linear regression trend analysis from 1982 to 2006. We found that in the past 25 years, NDVI vegetation in the study area has consistently risen at a rate of 0.007 per decade. Vegetation cover, temperature and precipitation are positively correlated. The area of vegetation associated with precipitation is larger than the area related to temperature;precipitation is the key factor affecting vegetation growth across the TNSP. From 1982 to 2006, regions with improved vegetation cover were found in the central and southern part of the Greater Khingan Mountains, central part of the Lesser Khingan Mountains, northeastern part of the Changbai Mountains, Yanshan Mountians, Western Liaoning Hilly Region, Altai Mountains, Tien Shan Mountains, eastern part of the Qilian Mountains, eastern part of the northwest desert as wel as southern part of the Gul y Region of the Loess Plateau. However, vegetation cover declined on both sides of the Greater Khingan Mountains, western part of the Hulun Buir Plateau, northern part of the Sanjiang Plain, southern part of Horqin Sandy Land, southern part of the northwest desert and northern part of the Gul y Region of the Loess Plateau.展开更多
Water shortage is an important constraint factor in the construction of the Three-North Shelterbelt （TNS）. Here, we analyzed temporal-spatial patterns in water resources and trends in the Three-North region. We eval...Water shortage is an important constraint factor in the construction of the Three-North Shelterbelt （TNS）. Here, we analyzed temporal-spatial patterns in water resources and trends in the Three-North region. We evaluated the water resource carrying capacity （WRCC） of 623 counties in the project area during the fifth phase of the TNS Development Program. Results show that 387 counties are appropriate for forestation, 185 counties can be planted, and 60 counties are inappropriate for forestation because of water resource constraints.展开更多
Wind velocity reduction of coastal shelterbelt system was monitored for 1 month in 3 weather stations in Nanhui,Shanghai,and the benefits of shelterbelt system and trunk shelterbelt forest were compared in this paper....Wind velocity reduction of coastal shelterbelt system was monitored for 1 month in 3 weather stations in Nanhui,Shanghai,and the benefits of shelterbelt system and trunk shelterbelt forest were compared in this paper.The results showed the wind velocity at the first weather station(W1),which located in front of trunk shelterbelt forest by the seaside,was the biggest,with the average of 9.36 m/s;the wind velocity at the second weather station(W2) was lower than that at W1,with the range of 0 to 18.2 m/s and the average of 6.39 m/s,and the wind velocity at the third weather station(W3) was the lowest,with the average of 2.58 m/s.Both the ratio of W2 to W1 and the ratio of W3 to W1 ranged from 0 to 100%,but most of the ratio of W2 to W1(89.59%) was above 20%,and most of the ratio of W3 to W1(95.52%) was below 50%,which shows bigger wind velocity reduction in shelterbelts system than in trunk shelterbelt forest.With the wind scale increased from 1 to 8 scale at W2 and W3,the wind velocity increased.But the reduction in wind velocity decreased.展开更多
基金The study was supported by Shanxi Ninth Five-year Plan Project (No. 961016).
文摘From the 1950s to 1960s, large area of Populus simonii shelterbelts system was established in northern area of Shanxi Province. For reconstructing the old shelterbelts, more attentions should be paid to selecting suitable tree species and design of logical shelterbelts structure. In order to provide a profound basis for the efficient establishment of shelterbelts, the study on function and structure of the farmland shelterbelts was conducted in Shuozhou and Datong areas, both are semi-arid areas in Northern Shanxi Province during 1996-2001. The wind-control effects of shelterbelts with different structures (close-spaced, wider-spaced, and widest-spaced) were investigated by portable wind vane and anemometer, wet and dry bulb thermometer, ground thermometer, glass service instrument. The results showed that the wind-control capacity of the shelterbelts during the leafing period should be thought as the criteria index in shelterbelts established. The wider-spaced shelterbelt that was made of 4-6 rows of trees, with a spacing of 2.0 m×3.0 m, had the best wind-control result.
文摘s: The farmland shelterbelts in Northeastern Plain of China have formed relatively complete net system. The func-tions of shelterbelt net in omnibearing wind check and prevention of frostbite as well as the field of integrated climate effect within shelterbelt net were analyzed, through located observation of meteorological factors. Within the shelterbelt net, the area with more than 10% efficiency of omnibearing wind check was determined as benefited area. The analysis of yield and quality of crops indicated that the sheltering range of shelterbelt net was 25 times tree height. The mature heights of the various varieties of poplar composed the shelterbelts were determined according to their height growth. Based on the comprehensive analysis above, the suitable size of farmland shelterbelt net in Northeastern Plain of China was decided to be 400 m×400 m.
基金Under the auspices of Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX1-YW-08-02)
文摘On the basis of landscape ecology, combining the Spot 5 high resolution satellite imagery with GIS, a method evaluating the spatial heterogeneity of shelterbelts distribution at landscape scale is put forward in this paper. The distance coefficients of reasonable and existing landscape indexes of farmland shelterbelt networks were com-puted, and then through the classification of the distance coefficients, and the establishment of evaluation rules, the spatial heterogeneity of farmland shelterbelts was evaluated. The method can improve the evaluating system of previ-ous studies on shelterbelts distribution, resolve the disadvantages of lacking spatiality of overall evaluation, and make the evaluation results have more directive significance for shelterbelt management. Based on this method, spatial het-erogeneity of shelterbelt networks was evaluated in the midwest of Jilin Province, China. The results show that the re-gions with fewer shelterbelts and no closed network account for 34.7% of the total area, but only 4.9% of the area has relative reasonable pattern of shelterbelt networks. Many problems exist in the distribution pattern of shelterbelts, therefore, much attention should be paid to construct farmland shelterbelts in the study area.
基金support from the National Nature Science Foundation of China(Grant No.30670315)the Global Environmental Research Fund of the Ministry of the Environment of Japan
文摘The ＂Three-North＂ Shelterbelt is the largest and most distinctive artificial ecological engineering project in China. It has been conducted since November 25, 1978 in the ＂Three-North＂ （i.e., Northeast China, North China and Northwest China） regions. In this study, the background and the essential benefits of the ＂Three-North＂ Shelterbelt project are summarized. The basic status and future development of the ＂Three-North＂ Shelterbelt project are also studied. As well, we tried to discuss the problems existing in the current shelterbelt system and the strategies to conduct this ecological project rationally.
基金supported by the National Natural Science Foundation of China(Nos.31200365,31370624,and30870435)the Youth Science Fund of the Forestry College of Fujian Agriculture and Forestry University(No.6112C039V)
文摘The coastal shelter forest in China is under threat of destruction and degradation because of the impact of human activities. Protection efficiency assessment of the coastal shelterbelt is an important component of shelterforest remediation planning and sustainable management. In this study, a protection efficiency index （PEI） model was established using the projection pursuit method to assess the protective quality of the coastal shelter forest at the coastal section scale of Dongshan Island, China. Three criteria were used, including forest stand structure, forest belt structure, and windbreak effect; each criterion further comprised multiple factors. Based on survey data of 31 plots in the coastal shelter forest of Dongshan Island, we calculated PEI values using a projection of a pursuit model. The result showed 64.5 % of the PEIs fell at or below the middle level, which can indicate the status of the coastal shelterbelt is unsatisfactory. To further explore whether the different bays and land use types create significant differences in PEIs and evaluation indices, we used an ANOVA to test the influence of various bays and forms of land use on coastal shelterbelts. The results showed that PEI and most of the indices differed significantly by bay; mean tree height, mean DBH, mean crown width, stand density, vegetation coverage, and wind velocity reduction differed significantly by land use. Therefore, relevant measures for different locations, bays and surrounding land use can be proposed to improve the existing conditions of the coastal shelterbelt. The results of this study provide a theoretical and technical framework for future changes and sustainable management of coastal shelterbelt on Dongshan Island.
基金supported by Forestry Industry Research Special Funds for Public Welfare Projects(2014040202-01)。
文摘To examine changes in surface soil quality over time in Populus×xiaohei shelterbelts,we collected soil samples from five shelterbelts of different ages and also from former cropland left fallow for 25 years.Twenty-one surface soil(0–20 cm)properties were measured,and variation in soil quality was assessed using one-way ANOVAs and multiple comparison tests.Based on this analysis,16 soil indexes were used in a model evaluating soil quality,with each index given weight as determined by the correlation coefficient.Compared with the control,the postmature forest had greater soil moisture content but lower bulk density(P<0.05).The mature forest also had higher soil pH,total organic carbon,alkali-hydrolyzed nitrogen,available phosphorus,and biomass nitrogen content,but reduced nitrate-nitrogen and total phosphorus content than the control(P<0.05).Total porosity was highly positively correlated with aeration,nitrate-nitrogen,alkali-hydrolyzed nitrogen,available phosphorus,microbial biomass carbon and microbial biomass nitrogen.Soil total organic carbon,ammonium nitrogen,nitrate-nitrogen,alkali-hydrolyzed nitrogen,total nitrogen,available phosphorus,microbial biomass carbon and microbial biomass nitrogen were all strongly correlated.In the soil quality evaluation model,total organic carbon was assigned the highest weight and total potassium content the lowest.The soil quality index was lowest in the near-mature forest and greatest in the postmature forest.Generally,soil quality in P opulus×xiaohei shelterbelts varied with age and was higher in the 10–20 cm versus 0–10 cm soil layer.After a single forest generation,surface soil quality was significantly improved.
基金supported by the National Natural Science Foundation of China(31400612,41271305)the Key Technologies Research and Development Program of Henan Province(142102110147)
文摘The black soil region of northeast China is one of the most important grain-producing areas in China. Increasingly severe gully erosion in this region has destroyed much farmland and reduced grain production. We analyzed SPOT5 imagery from 2007 and TM imagery from 2008 to describe the distributions of gullies and farmland shelterbelts in Kedong County and to assess the effect of farmland shelterbelts on gully erosion. The ima- gery revealed 2311 gullies with average density of 418.51 m km-2, indicating very serious gully erosion. With increasing slope gradient there was an inverse trend between gully density and shelterbelt density, indicating that farmland shelterbelts can prevent gully erosion. The defense effect of farmland shelterbelts against gullyerosion varied with distance： for distances 〈120 m, the defense effect was consistent and very strong; for distances of 120-240 m, a weak linear decrease was found in the defense effect; and for distances 〉240 m, the defense effect of the shelterbelts was significantly weaker. We recommend an optimal planting density of farmland shel- terbelts for the prevention of gully erosion at 1100-1300 m km-2.
基金supported by the Knowledge Innovation Program of the Chinese Academy Sciences (No. KZCX1-YW-08-02-01)National High-tech Research and development Program of China(No. 2006AA10Z227)
文摘At present, the most researches on the protected effect of shelterbelt are on the basis of the two scales of forest belts and networks. However, with the further research on the global environmental change, more attention was paid to the regional climate effect of shelterbelt. In present study, we analyzed the temperature effect of the shelterbelt at regional scale by using the land surface temperature （LST） data from the moderate resolution imaging spectroradiometer （MODIS） at Yushu, Nong＇an, Dehui, and Fuyu in Jilin Province of China from March to October in 2008. Results show that the shelterbelt can increase the soil temperature of the protected farmland as compared with no shelterbelt zone, with the increment of 0.57oC per day in fine shelterbelt and 0.38oC per day in the normal shelterbelt. Moreover, the correlation analysis of the air temperature, precipitation and the soil type and the shelterbelt effect shows that the air temperature and precipitation are negatively correlated with the shelterbelt effects, that is, the more the temperature and precipitation are, the less the effect produced. While the impact of the soil types on the shelterbelt＇s effect is not very obvious as a whole. This paper draws significance in terms of analyzing the effects of the shelterbelt on the soil temperature at regional scale utilizing the remotely sensed data and GIS technique.
基金supported by the High-level Personnel Scientific Research Project in North China Institute of Water Resources and Electric Power (No. 201207)the Knowledge Innovation Program of the Chinese Academy Sciences (No. KZCX1-YW-08-02-01)the National Natural Science Foundation of China (No. 41101373)
文摘Shelterbelts are important in defending against natural disaster and maintaining ecological balances in farmland. Understanding of the shelterbelt vegetation fraction is fundamental to regional research of shelterbelts using remote sensing. We used SPOT5 imagery with 10×10m spatial resolution in combination with knowledge of the characteristics of shelterbelts to develop a method for retrieval of the vegetation fraction of shelterbelts by the pixel un-mixing model. We then used the method to retrieve values for shelterbelts in study area. By combining the parameters of photographic images with characteristics of shelterbelts, we developed a method for measuring the vegetation fraction of shelterbelts based on an advanced photographic method. We then measured the actual values to validate the retrieval result. The multiple correlation coefficients between the retrieved and measured values were 0.715. Our retrieval and measuring methods presented in this paper accurately reflect field conditions. We suggest that this method is useful to describe shelterbelt structure using remote sensing.
文摘This study evaluates the role of shelterbelts on the development and dynamics of vegetation in relation to livelihoods in the study area using geo-information techniques. The study covered the period between 1972 and 2007. The results show that in 1972 vegetation cover in the study area extended over an area of 6955 hectares (i.e.?shrubs, grasses and trees) which represents 65% of the area;however there was a decrease in 1986 to an area of 5779 hectares (54%). Despite the establishment of shelterbelt in the area in 1987, the trend did not change. This is obvious in the reduction of vegetation cover between 1986 and 2000 to a total area of 3893 hectares (37%). The vegetation cover further decreased to 2791 hectares (26%) in 2005 and 1659 hectares (16%) in 2007 respectively. The study concludes that the establishment of shelterbelts alone cannot guarantee the success of vegetation cover development in the area without a sustainable plan which recognizes the local communities as critical stakeholders. Thus, variables like population growth and GDP have a role to play in vegetation cover depletion. The study recommends that efforts geared towards enlightenment of the local communities on the need for conservation should be encouraged by Government and Non-Governmental Organisations.
基金Basic Scientific Research Project of Non-profit Scientific Research Institutes in Xinjiang Uygur Autonomous Region(KY2022137).
文摘[Objectives]To explore the effects of spatial density of farmland shelterbelts on NDVI on the northern slope of Tianshan Mountains.[Methods]Taking the economic belt of the northern slope of the Tianshan Mountains as the research area and using the grid method,the spatial density distribution of farmland shelterbelts can be known.Combining the grid method with NDVI data,the average value of normalized difference vegetation index(NDVI)during the growing period of crops can be obtained.In addition,the protection benefits of the shelterbelts on crops were analyzed through comparing the growth of crops within the protection zone with and without protection.[Results]The grids with shelterbelt distribution were better than the grids without shelterbelt distribution,and the shelterbelt played a great role in promoting crop growth.In the middle stage of crop growth,the protection benefit of shelterbelt was significant.The spatial density of shelterbelts was unevenly distributed in the range of 0.6 to 0.8,and the protection benefits were poor.[Conclusions]It is expected to explore the effects of shelterbelts on crop growth at a larger regional scale,so as to provide a basis for the management and design of shelterbelts in the future,and to provide a theoretical basis for studying the protective effect of farmland shelterbelts on crops.
文摘In China’s three northern regions of the Northwest, North and Northeast (3Ns), there are 1.33 million sq km of desert and sand land, forming a 5,000-km-long wind-sand belt. In 1978, the Chinese government decided to build the "3Ns" shelterbelt network. The project covers 13 provinces, autonomous regions and cities including Xinjiang, Qinghai, Gansu, Ningxia, Shaanxi, Inner Mongolia, Shanxi, Hebei, Beijing, Tianjin, Liaoning, Jilin and Heilongjiang, eovering an area of 4.06 million sq km, 42％ of the country’s total land. It plans to complete the project in 73 years, in three phases: the first phase
基金financially supported by the National Science Foundation(Grant No.42361003)the Opening Foundation of Xinjiang Key Laboratory of Water Cycle and Utilization in Arid Zone,the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences(Grant No.XJYS0907-2023-22)+1 种基金Research Team of International Price Analysis and Prediction of Bulk Commodities,Jiangxi University of Finance and Economicsthe Postdoctoral Science Foundation of China(Grant No.2017M612161).
文摘The shelterbelt is an indispensable barrier to the ecological and economic development of an oasis.Soil moisture,groundwater and irrigation greatly affect the shelterbelt water consumption and development.In this study,the transpiration rate of shelterbelt trees,soil moisture and meteorological data were collected to determine the effects of soil moisture and meteorological factors on the water consumption of different shelterbelt tree species via multivariate statistical methods.The results showed that the water consumption rate was positively correlated with solar radiation,air temperature and precipitation.Moreover,the leaf transpiration rate exhibited the trend of P.Russkii Jabl.˃P.alba˃P.simonii Carr.>P.nigracv,while the average daily water consumption decreased in the order of P.alba>P.Russkii Jabl.>P.simonii Carr.>P.nigracv.The average daily water consumption levels of P.alba,P.Russkii Jabl.,P.simonii Carr.and P.nigracv were(9.15±0.92)kg/(tree∙d),(6.95±1.41)kg/(tree∙d),(4.43±1.32)kg/(tree∙d),and(1.58±0.18)kg/(tree∙d),respectively.Over the growing season,the soil water consumption levels of P.alba,P.Russkii Jabl.,P.simonii Carr.,and P.nigracv in each shelterbelt tree stand reached 674.8,336.9,358.1 and 161.7 kg,respectively.More than 96%of the soil moisture lost was provided by the upper 120-cm soil layer.Understanding the influence and contribution of soil water and meteorological factors to shelterbelt water consumption is beneficial for shelterbelt management and protection.
基金National Natural Science Foundation of China(4117111640961038)
文摘The Shelterbelt Forest System Program in northeast, north and northwest China （the Three-North Shelterbelt Program, TNSP） is the largest ecological reforestation program in the world. TNSP vegetation research has important ecological meaning and profound social and economic signiifcance. Here, spatio-temporal variation in vegetation cover under the TNSP was examined using the NDVI average method, major climatic factors such as temperature and precipitation, and linear regression trend analysis from 1982 to 2006. We found that in the past 25 years, NDVI vegetation in the study area has consistently risen at a rate of 0.007 per decade. Vegetation cover, temperature and precipitation are positively correlated. The area of vegetation associated with precipitation is larger than the area related to temperature;precipitation is the key factor affecting vegetation growth across the TNSP. From 1982 to 2006, regions with improved vegetation cover were found in the central and southern part of the Greater Khingan Mountains, central part of the Lesser Khingan Mountains, northeastern part of the Changbai Mountains, Yanshan Mountians, Western Liaoning Hilly Region, Altai Mountains, Tien Shan Mountains, eastern part of the Qilian Mountains, eastern part of the northwest desert as wel as southern part of the Gul y Region of the Loess Plateau. However, vegetation cover declined on both sides of the Greater Khingan Mountains, western part of the Hulun Buir Plateau, northern part of the Sanjiang Plain, southern part of Horqin Sandy Land, southern part of the northwest desert and northern part of the Gul y Region of the Loess Plateau.
基金the Principal of State Science Key Project (NO. 2007FY110300)the National Natural Science Foundation Item (NO. 41101117)
文摘Water shortage is an important constraint factor in the construction of the Three-North Shelterbelt （TNS）. Here, we analyzed temporal-spatial patterns in water resources and trends in the Three-North region. We evaluated the water resource carrying capacity （WRCC） of 623 counties in the project area during the fifth phase of the TNS Development Program. Results show that 387 counties are appropriate for forestation, 185 counties can be planted, and 60 counties are inappropriate for forestation because of water resource constraints.
基金supported by National Project of Scientific and Technical Supporting Programs Funded by Ministry of Science and Technology of China (2009BADB2B0301)Research Institute of Sub-tropical Forestry Fund (RISF6923)
文摘Wind velocity reduction of coastal shelterbelt system was monitored for 1 month in 3 weather stations in Nanhui,Shanghai,and the benefits of shelterbelt system and trunk shelterbelt forest were compared in this paper.The results showed the wind velocity at the first weather station(W1),which located in front of trunk shelterbelt forest by the seaside,was the biggest,with the average of 9.36 m/s;the wind velocity at the second weather station(W2) was lower than that at W1,with the range of 0 to 18.2 m/s and the average of 6.39 m/s,and the wind velocity at the third weather station(W3) was the lowest,with the average of 2.58 m/s.Both the ratio of W2 to W1 and the ratio of W3 to W1 ranged from 0 to 100%,but most of the ratio of W2 to W1(89.59%) was above 20%,and most of the ratio of W3 to W1(95.52%) was below 50%,which shows bigger wind velocity reduction in shelterbelts system than in trunk shelterbelt forest.With the wind scale increased from 1 to 8 scale at W2 and W3,the wind velocity increased.But the reduction in wind velocity decreased.
