Ecological migration is the process of increasing the population density in the immigration area and transferring the ecological pressure from emigration area to immigration area. This process may result in significan...Ecological migration is the process of increasing the population density in the immigration area and transferring the ecological pressure from emigration area to immigration area. This process may result in significant changes in land use and land cover in the area of immigration and have an important effect on ecosystem services. Therefore, scientifically revealing the effects and differentiation mechanisms of ecological migration on ecosystem services is becoming an important issue related to the implementation of the national ecological migration strategy in China. This study employed the Hongsibu District as a typical example of ecological migration. Hongsibu District is located in the central Ningxia steppe and desert steppe areas. Remote sensing data covering five periods from the period before ecological migration in 1995 and after migration in 2000, 2005, 2010, and 2015 was used to measure the value of ecosystem services(ESV). A geographical detector model and the value of ecosystem services model were used to diagnose the dynamic mechanism of the effects of land use change on ecosystem services. The results showed that: 1) The development of large-scale ecological resettlement has caused the area of cultivated land and urbanized land area to increase significantly in the area of immigration, while the grass area decreased significantly. 2) The overall value of the Hongsibu ecosystem services increased in a form of a ‘V'. Among them, during the period of 1995–2005, the overall ESV decreased and had an annual rate of change of-0.67%. During the period of development 2005–2015, the ESV increased steadily, with an annual rate of change of 0.79%. 3) The proportion and total ESV in soil formation and protection, waste treatment, and biodiversity conservation of the Hongsibu District decreased from 57.61% in 1995 to 56.17% in 2015, indicating that the region's ecological regulation function slightly decreased. 4) The ESV in the Hongsibu District, showed a low distribution pattern of ecosystem services increasing from northeast to southwest, and the capacity of three townships, Hongsibu, Taiyangshan, and Liuquan, to provide ecosystem services gradually declined over time. The ecological service function of Xinzhuangji Township and Dahe Township gradually improved. 5) The sensitivity index of the ESV of each land use type was less than 1, indicating that the environment lacks flexibility in providing a strong ESV index in Hongsibu, which shows that the research results are reliable and believable. 6) During the study period, the decisive force of the change of land use on ecosystem services in Hongsibu District was: grassland(0.9934), climate regulation(0.9413), soil formation and protection(0.9321) and waste treatment(0.9241).展开更多
A three-year experiment was conducted to investigate and compare the economic and ecological benefits of six types of vegetation management measures in citrus orchards of the hilly red soil region of the eastern part ...A three-year experiment was conducted to investigate and compare the economic and ecological benefits of six types of vegetation management measures in citrus orchards of the hilly red soil region of the eastern part of China.Six vegetation treatments,including tillage without herbicide(clean tillage)and no tillage without herbicide(sod culture) and with herbicide paraquat(paraquat),glyphosate(glyphosate),glyphosate-glyphosate-paraquat(G-G-P),and paraquat- paraquat-glyphosate(P-P-G),were applied in the citrus orchards on a clayey red soil with slopes of 8°and 13°and a sandy soil with slope of 25°.The results showed that the sod culture,paraquat,glyphosate,G-G-P,and P-P-G treatments reduced surface runoff by 38.8%,42.5%,18.7%,28.7%,and 37.5%,then the soil-water losses by 55.5%,51.7%,39.9%,46.8%, and 50.0%,and the N,P,and K nutrient losses by 60.3%,50.2%,37.0%,41.8%,and 45.4%,respectively,as compared with the clean tillage treatment.The weed regeneration ratios with the treatments of clean tillage without herbicide,paraquat, glyphosate,G-G-P,and P-P-G were reduced by 55.1%,67.2%,30.3%,36.8%,and 51.2%,respectively,as compared with the sod culture.The sod culture,paraquat,glyphosate,G-G-P,and P-P-G treatments could increase the soil fertility (annual accumulation of N,P,K,and OM)by 7.1%,6.9%,5.3%,6.2%,and 6.6%,respectively,whereas the clean tillage treatment without herbicide reduced soil fertility by 4.4% after the three-year experiment.The citrus fruit yields in the treatments of paraquat,glyphosate,G-G-P,and P-P-G increased by 7%-10%;the soluble solid,total sugar,total acidity,sugar-acid ratio,and single fruit weight of citrus fruits of all treatments except sod culture significantly(P>0.05) exceeded that of the clean tillage treatment.In general,the paraquat treatment showed the best economic and ecological benefits among the six treatments;therefore,it could be regarded as the best available vegetation management measure in citrus orchards of hilly red soil region to retain water and soil,enhance soil fertility,and improve the yield and quality of citrus.展开更多
The region of Tlemcen is situated in the north-west of Algeria. The aridity of the climate had lead to the development of the matorral, a state of degradation of the Mediterranean, and the composed xerophytes plants s...The region of Tlemcen is situated in the north-west of Algeria. The aridity of the climate had lead to the development of the matorral, a state of degradation of the Mediterranean, and the composed xerophytes plants such as doum and diss, had been found. Chamaerops humilis, xerophyte plant, with special morphologic and botanic character presents a resistance of these climatic. The authors have proposed study of fauna closly linked to this plant. A faunistic inventory was realized in the Mansourah area （region of Tlemcen）. Four stations have been described. Collecting sample was performed during June 2003-Mar. 2004, replying on sixteen （16） prelevements. The number of species were estimated of about 136, in which 111 are Arthropoda, the Entomofauna represented by 97 species and the other inventory are Arachnida by 8 species and Myriapoda by 6 species. 18 species are related to Gastropoda. The vertebrates are few. The importance of different groups＇ recolted on the Chamaerops humilis in the four stations is done particular to the insects. Analysis factorial correspondence （A.F.C） show different grouping of animal species.展开更多
Continuing climate changes are strongly associated with status of water, threatening the majority of ecosystems, including the grass ecosystem. The climate changes primarily affect the botanical composition of grassla...Continuing climate changes are strongly associated with status of water, threatening the majority of ecosystems, including the grass ecosystem. The climate changes primarily affect the botanical composition of grassland that is subsequently determined by production of above-ground phytomass which is used like feed for the ruminants. In our field experiment we assessed the impact of climate changes on grass ecosystem during the long-term period （23 years）. We obtained a picture of the preceding development of botanical composition in this stand, due to the assumption that expected climate changes are going to disturb the botanical composition of grassland especially in the grass biome. From the obtained results follows the significant change in botanical composition in grass-herbaceous vegetation with the low share of legumes. It is not possible to confirm strict relation between precipitation during vegetation season and the share of individual botanical group. Analysis of long-term development of the botanical composition of monitored grassland influenced by different pratotechnical interventions demonstrated the significant flexibility this plant community in the times of changing climatic conditions.展开更多
Foliar and root carbon isotope composition(δ13C) of grassland communities on the Qinghai-Tibet Plateau,China,was obtained by the biomass weighting method and direct measurement.We investigated the characteristics and...Foliar and root carbon isotope composition(δ13C) of grassland communities on the Qinghai-Tibet Plateau,China,was obtained by the biomass weighting method and direct measurement.We investigated the characteristics and altitudinal patterns of foliar and root δ13C and determined which environmental factors influenced foliar δ13 C most.Foliar δ13 C of alpine steppe was significantly higher than that of alpine meadow and temperate steppe.For alpine meadow,root δ13C was significantly higher than of foliar δ13C.Foliar δ13C increased with altitude at an average rate of 0.60‰ km 1 for the whole grassland ecosystem.This rate was lower than that at species level.However,there were no significant relationships between root δ13C and altitude.Atmospheric pressure was a more important factor than temperature and precipitation in its influence on the altitudinal pattern of foliar δ13C at the community level.展开更多
基金Under the auspices of the National Natural Science Foundation of China(No.41461039)
文摘Ecological migration is the process of increasing the population density in the immigration area and transferring the ecological pressure from emigration area to immigration area. This process may result in significant changes in land use and land cover in the area of immigration and have an important effect on ecosystem services. Therefore, scientifically revealing the effects and differentiation mechanisms of ecological migration on ecosystem services is becoming an important issue related to the implementation of the national ecological migration strategy in China. This study employed the Hongsibu District as a typical example of ecological migration. Hongsibu District is located in the central Ningxia steppe and desert steppe areas. Remote sensing data covering five periods from the period before ecological migration in 1995 and after migration in 2000, 2005, 2010, and 2015 was used to measure the value of ecosystem services(ESV). A geographical detector model and the value of ecosystem services model were used to diagnose the dynamic mechanism of the effects of land use change on ecosystem services. The results showed that: 1) The development of large-scale ecological resettlement has caused the area of cultivated land and urbanized land area to increase significantly in the area of immigration, while the grass area decreased significantly. 2) The overall value of the Hongsibu ecosystem services increased in a form of a ‘V'. Among them, during the period of 1995–2005, the overall ESV decreased and had an annual rate of change of-0.67%. During the period of development 2005–2015, the ESV increased steadily, with an annual rate of change of 0.79%. 3) The proportion and total ESV in soil formation and protection, waste treatment, and biodiversity conservation of the Hongsibu District decreased from 57.61% in 1995 to 56.17% in 2015, indicating that the region's ecological regulation function slightly decreased. 4) The ESV in the Hongsibu District, showed a low distribution pattern of ecosystem services increasing from northeast to southwest, and the capacity of three townships, Hongsibu, Taiyangshan, and Liuquan, to provide ecosystem services gradually declined over time. The ecological service function of Xinzhuangji Township and Dahe Township gradually improved. 5) The sensitivity index of the ESV of each land use type was less than 1, indicating that the environment lacks flexibility in providing a strong ESV index in Hongsibu, which shows that the research results are reliable and believable. 6) During the study period, the decisive force of the change of land use on ecosystem services in Hongsibu District was: grassland(0.9934), climate regulation(0.9413), soil formation and protection(0.9321) and waste treatment(0.9241).
文摘A three-year experiment was conducted to investigate and compare the economic and ecological benefits of six types of vegetation management measures in citrus orchards of the hilly red soil region of the eastern part of China.Six vegetation treatments,including tillage without herbicide(clean tillage)and no tillage without herbicide(sod culture) and with herbicide paraquat(paraquat),glyphosate(glyphosate),glyphosate-glyphosate-paraquat(G-G-P),and paraquat- paraquat-glyphosate(P-P-G),were applied in the citrus orchards on a clayey red soil with slopes of 8°and 13°and a sandy soil with slope of 25°.The results showed that the sod culture,paraquat,glyphosate,G-G-P,and P-P-G treatments reduced surface runoff by 38.8%,42.5%,18.7%,28.7%,and 37.5%,then the soil-water losses by 55.5%,51.7%,39.9%,46.8%, and 50.0%,and the N,P,and K nutrient losses by 60.3%,50.2%,37.0%,41.8%,and 45.4%,respectively,as compared with the clean tillage treatment.The weed regeneration ratios with the treatments of clean tillage without herbicide,paraquat, glyphosate,G-G-P,and P-P-G were reduced by 55.1%,67.2%,30.3%,36.8%,and 51.2%,respectively,as compared with the sod culture.The sod culture,paraquat,glyphosate,G-G-P,and P-P-G treatments could increase the soil fertility (annual accumulation of N,P,K,and OM)by 7.1%,6.9%,5.3%,6.2%,and 6.6%,respectively,whereas the clean tillage treatment without herbicide reduced soil fertility by 4.4% after the three-year experiment.The citrus fruit yields in the treatments of paraquat,glyphosate,G-G-P,and P-P-G increased by 7%-10%;the soluble solid,total sugar,total acidity,sugar-acid ratio,and single fruit weight of citrus fruits of all treatments except sod culture significantly(P>0.05) exceeded that of the clean tillage treatment.In general,the paraquat treatment showed the best economic and ecological benefits among the six treatments;therefore,it could be regarded as the best available vegetation management measure in citrus orchards of hilly red soil region to retain water and soil,enhance soil fertility,and improve the yield and quality of citrus.
文摘The region of Tlemcen is situated in the north-west of Algeria. The aridity of the climate had lead to the development of the matorral, a state of degradation of the Mediterranean, and the composed xerophytes plants such as doum and diss, had been found. Chamaerops humilis, xerophyte plant, with special morphologic and botanic character presents a resistance of these climatic. The authors have proposed study of fauna closly linked to this plant. A faunistic inventory was realized in the Mansourah area （region of Tlemcen）. Four stations have been described. Collecting sample was performed during June 2003-Mar. 2004, replying on sixteen （16） prelevements. The number of species were estimated of about 136, in which 111 are Arthropoda, the Entomofauna represented by 97 species and the other inventory are Arachnida by 8 species and Myriapoda by 6 species. 18 species are related to Gastropoda. The vertebrates are few. The importance of different groups＇ recolted on the Chamaerops humilis in the four stations is done particular to the insects. Analysis factorial correspondence （A.F.C） show different grouping of animal species.
文摘Continuing climate changes are strongly associated with status of water, threatening the majority of ecosystems, including the grass ecosystem. The climate changes primarily affect the botanical composition of grassland that is subsequently determined by production of above-ground phytomass which is used like feed for the ruminants. In our field experiment we assessed the impact of climate changes on grass ecosystem during the long-term period （23 years）. We obtained a picture of the preceding development of botanical composition in this stand, due to the assumption that expected climate changes are going to disturb the botanical composition of grassland especially in the grass biome. From the obtained results follows the significant change in botanical composition in grass-herbaceous vegetation with the low share of legumes. It is not possible to confirm strict relation between precipitation during vegetation season and the share of individual botanical group. Analysis of long-term development of the botanical composition of monitored grassland influenced by different pratotechnical interventions demonstrated the significant flexibility this plant community in the times of changing climatic conditions.
基金supported by National Key Basic Research Program of China (Grant No.2010CB950902)National Natural Science Foundation of China(Grant No.31070427)National High-tech R&D Program of China(Grant No.2009BAC61B01)
文摘Foliar and root carbon isotope composition(δ13C) of grassland communities on the Qinghai-Tibet Plateau,China,was obtained by the biomass weighting method and direct measurement.We investigated the characteristics and altitudinal patterns of foliar and root δ13C and determined which environmental factors influenced foliar δ13 C most.Foliar δ13 C of alpine steppe was significantly higher than that of alpine meadow and temperate steppe.For alpine meadow,root δ13C was significantly higher than of foliar δ13C.Foliar δ13C increased with altitude at an average rate of 0.60‰ km 1 for the whole grassland ecosystem.This rate was lower than that at species level.However,there were no significant relationships between root δ13C and altitude.Atmospheric pressure was a more important factor than temperature and precipitation in its influence on the altitudinal pattern of foliar δ13C at the community level.
