Food safety is an important issue for the development of the national economy and society.Studying regional food supply and demand from the perspective of land resource carrying capacity can provide new references for...Food safety is an important issue for the development of the national economy and society.Studying regional food supply and demand from the perspective of land resource carrying capacity can provide new references for regional resource sustainability.This study uses the data from farmer and herdsmen household questionnaires,statistical data,land use data,and other sources to construct a land resource carrying capacity(LCC)assessment framework,targeting the food supply and demand of residents in representative areas,specifically the typical grassland pastoral areas,sandy pastoral areas and agro-pastoral areas on the Xilin Gol grassland transects.The three food nutritional indicators of calories,protein and fat were selected for analyzing the balance of land resource carrying capacity.We found that:1)Along the Xilin Gol grassland,the main local food supply showed a shift from meat and milk to grains,vegetables and fruits.2)From north to south along the grassland transects,the calorie intake increased gradually,while the intake of protein and fat was highest in pastoral areas and lowest in agricultural areas.3)The overall land resource carrying capacity of the Xilin Gol grassland transects was in a surplus state,but the land carrying capacity of typical grassland pastoral area was higher than the two other types of areas.This study provides an empirical reference for the sustainable development of regional food nutrition.展开更多
Investigating the spatial and temporal variance in productivity along natural precipitation gradients is one of the most efficient approaches to improve understanding of how ecosystems respond to climate change. In th...Investigating the spatial and temporal variance in productivity along natural precipitation gradients is one of the most efficient approaches to improve understanding of how ecosystems respond to climate change. In this paper, by using the natural precipitation gradient of the Inner Mongolian Plateau from east to west determined by relatively long-term observations, we analyzed the temporal and spatial dynamics of aboveground net primary productivity (ANPP) of the temperate grasslands covering this region. Across this grassland transect, ANPP increased exponentially with the increase of mean annual precipitation (MAP) (ANPP=24.47e0.005MAP, R2=0.48). Values for the three vegetation types desert steppe, typical steppe, and meadow steppe were: 60.86 gm-2a-1, 167.14 gm-2a-1 and 288.73 gm-2a-1 respectively. By contrast, temperature had negative effects on ANPP. The moisture index (K ), which takes into ac- count both precipitation and temperature could explain the spatial variance of ANPP better than MAP alone (ANPP=2020.34K1.24, R2=0.57). Temporally, we found that the inter-annual variation in ANPP (cal- culated as the coefficient of variation, CV) got greater with the increase of aridity. However, this trend was not correlated with the inter-annual variation of precipitation. For all of the three vegetation types, ANPP had greater inter-annual variation than annual precipitation (PPT). Their difference (ANPP CV/PPT CV) was greatest in desert steppe and least in meadow steppe. Our results suggest that in more arid regions, grasslands not only have lower productivity, but also higher inter-annual variation of production. Climate change may have significant effects on the productivity through changes in precipitation pattern, vegetation growth potential, and species diversity.展开更多
Using a dark enclosed chamber technique, the fluxes of CO2, N2O and CH4 from nature and disturbed grassland were measured on the spot in Inner Mongolian Temperate Grassland along the annual rainfall gradient section r...Using a dark enclosed chamber technique, the fluxes of CO2, N2O and CH4 from nature and disturbed grassland were measured on the spot in Inner Mongolian Temperate Grassland along the annual rainfall gradient section ranging from 450 to 200 mm. The results showed that the measured mean fluxes of CO2, N2O and CH4were (1 180.4 ±308.7), (0.010 ± 0.004) and (-0.039 ± 0.016) mg · m-2/h, respectively. The decrease of the fluxes of CO2, N2O and CH4 follows with that of annual rainfall gradient in the measurement area. Human activities, such as grazing and reclamation are also critical factors to affect the fluxes of these gases from grassland. Daily continuous measurement of CO2, N2O and CH4 fluxes showed a strong diurnal variation with higher emission in the daytime. A good relationship between the fluxes of CO2, N2O, CH4 and temperature was exposed in this study.展开更多
基金The National Natural Science Foundation of China(41671517)The National Key Research and Development Program of China(2016YFC0503700)The Strategic Priority Program of Chinese Academy of Sciences(XDA20010202)
文摘Food safety is an important issue for the development of the national economy and society.Studying regional food supply and demand from the perspective of land resource carrying capacity can provide new references for regional resource sustainability.This study uses the data from farmer and herdsmen household questionnaires,statistical data,land use data,and other sources to construct a land resource carrying capacity(LCC)assessment framework,targeting the food supply and demand of residents in representative areas,specifically the typical grassland pastoral areas,sandy pastoral areas and agro-pastoral areas on the Xilin Gol grassland transects.The three food nutritional indicators of calories,protein and fat were selected for analyzing the balance of land resource carrying capacity.We found that:1)Along the Xilin Gol grassland,the main local food supply showed a shift from meat and milk to grains,vegetables and fruits.2)From north to south along the grassland transects,the calorie intake increased gradually,while the intake of protein and fat was highest in pastoral areas and lowest in agricultural areas.3)The overall land resource carrying capacity of the Xilin Gol grassland transects was in a surplus state,but the land carrying capacity of typical grassland pastoral area was higher than the two other types of areas.This study provides an empirical reference for the sustainable development of regional food nutrition.
基金Supported by the National Key Research and Development Program (Grant No. 2002CB412501)the National Natural Science Foundation of China (Grant No. 30590381)
文摘Investigating the spatial and temporal variance in productivity along natural precipitation gradients is one of the most efficient approaches to improve understanding of how ecosystems respond to climate change. In this paper, by using the natural precipitation gradient of the Inner Mongolian Plateau from east to west determined by relatively long-term observations, we analyzed the temporal and spatial dynamics of aboveground net primary productivity (ANPP) of the temperate grasslands covering this region. Across this grassland transect, ANPP increased exponentially with the increase of mean annual precipitation (MAP) (ANPP=24.47e0.005MAP, R2=0.48). Values for the three vegetation types desert steppe, typical steppe, and meadow steppe were: 60.86 gm-2a-1, 167.14 gm-2a-1 and 288.73 gm-2a-1 respectively. By contrast, temperature had negative effects on ANPP. The moisture index (K ), which takes into ac- count both precipitation and temperature could explain the spatial variance of ANPP better than MAP alone (ANPP=2020.34K1.24, R2=0.57). Temporally, we found that the inter-annual variation in ANPP (cal- culated as the coefficient of variation, CV) got greater with the increase of aridity. However, this trend was not correlated with the inter-annual variation of precipitation. For all of the three vegetation types, ANPP had greater inter-annual variation than annual precipitation (PPT). Their difference (ANPP CV/PPT CV) was greatest in desert steppe and least in meadow steppe. Our results suggest that in more arid regions, grasslands not only have lower productivity, but also higher inter-annual variation of production. Climate change may have significant effects on the productivity through changes in precipitation pattern, vegetation growth potential, and species diversity.
文摘Using a dark enclosed chamber technique, the fluxes of CO2, N2O and CH4 from nature and disturbed grassland were measured on the spot in Inner Mongolian Temperate Grassland along the annual rainfall gradient section ranging from 450 to 200 mm. The results showed that the measured mean fluxes of CO2, N2O and CH4were (1 180.4 ±308.7), (0.010 ± 0.004) and (-0.039 ± 0.016) mg · m-2/h, respectively. The decrease of the fluxes of CO2, N2O and CH4 follows with that of annual rainfall gradient in the measurement area. Human activities, such as grazing and reclamation are also critical factors to affect the fluxes of these gases from grassland. Daily continuous measurement of CO2, N2O and CH4 fluxes showed a strong diurnal variation with higher emission in the daytime. A good relationship between the fluxes of CO2, N2O, CH4 and temperature was exposed in this study.
基金supported by the National Science and Technology Basic Resources Survey Program of China(2019FY101300)the National Natural Science Foundation of China(42071303,31961143022,31988102)the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK060602)。
