[Objective] The aim was to explore the management mode on optimal re-sources al ocation of family ranch in meadow steppe. [Method] Three double repre-sentative family ranches were selected in meadow steppe of Hulunber...[Objective] The aim was to explore the management mode on optimal re-sources al ocation of family ranch in meadow steppe. [Method] Three double repre-sentative family ranches were selected in meadow steppe of Hulunber Old Barag Banner, and the study was carried out with the baseline survey. Three family ranches were selected as the demonstrative households for the corporation study, while other three family ranches with the similar conditions were looked as the non-demonstrative households for the comparison. Demonstrative households of the fami-ly ranches reduced the stocking rate, optimized the flock structure and took a winter feeding and other means to explore the different management models on plant com-munity characteristic of family ranch. [Result] The seasonal dynamic of community characteristic in family ranches showed the single-peaks curves. The seasonal dy-namics of community coverage, height and biomass in the demonstrative households showed higher compared with the non-demonstrative households, and community density in the experiment households was lower than that of the control experiment households. Community coverage, height and biomass of degraded grassland in family ranch have a great improve after optimization of management. Community coverage, height , density and biomass were increasing in fencing plot, but decreas-ing in free grazing area. Enclosure improved grassland coverage, vegetation height, density and forage yield. Leymus chinensis played an important role in plant com-munity. The important values of Leymus chinensis, Stipa baicalensis, Cleistogenes squarrosa, and Carex duriuscula were high. Leymus chinensis important value in the demonstrative households of optimal management was higher than that in the non-demonstrative households, and Carex duriuscula important value of the non-demon-strative households was significantly higher than that of the demonstrative house-holds. The indexes of Margalef richnes,Shannon-Wiener diversity, Simpson diversity and Pielou uniformity showed that the demonstrative households were higher than the non-demonstrative households. [Conclusion] The research provides theoretical ref-erences for sustainable development of pastures dominated by family ranch.展开更多
Grassland fire is one of the most important disturbance factors in the natural ecosystems.This paper focuses on the spatial distribution of long-term grassland fire patterns in the Hulun Buir Grassland located in the ...Grassland fire is one of the most important disturbance factors in the natural ecosystems.This paper focuses on the spatial distribution of long-term grassland fire patterns in the Hulun Buir Grassland located in the northeast of Inner Mongolia Autonomous Region in China.The density or ratio of ignition can reflect the relationship between grassland fire and different ignition factors.Based on the relationship between the density or ratio of ignition in different range of each ignition factor and grassland fire events,an ignition probability model was developed by using binary logistic regression function and its overall accuracy averaged up to 81.7%.Meanwhile it was found that daily relative humidity,daily temperature,elevation,vegetation type,distance to county-level road,distance to town are more important determinants of spatial distribution of fire ignitions.Using Monte Carlo method,we developed a time-dependent stochastic ignition probability model based on the distribution of inter-annual daily relative humidity and daily temperature.Through this model,it is possible to estimate the spatial patterns of ignition probability for grassland fire,which will be helpful to the quantitative evaluation of grassland fire risk and its management in the future.展开更多
Numerous studies have focused on vegetation traits and soil properties in grassland, few of which concerned about effects of human utilization patterns on grassland yet. Thus, this study hypothesized that human distur...Numerous studies have focused on vegetation traits and soil properties in grassland, few of which concerned about effects of human utilization patterns on grassland yet. Thus, this study hypothesized that human disturbance(e.g., grazing, mowing and fencing) triggered significant variation of biomass partitioning and carbon reallocation. Besides, there existed some differences of species diversity and soil fertility. To address these hypotheses of grassland with diverse utilization patterns in Hulun Buir City, Inner Mongolia, China, we sampled in situ about aboveground biomass(AGB) and belowground biomass(BGB) to evaluate their biomass allocation. Species diversity and soil properties were also investigated. Subsequently, we discussed the relationship of species diversity with environmental conditions, using data collected from 23 sites during the ecological project period of Returning Grazing Lands to Grasslands(RGLG) program. The results were as follows: 1) both AGB and BGB were lower on grazing regime than those on fencing and mowing, but the ratio of root-to-shoot(R/S) was higher on grazing regime than the other two utilization patterns; 2) neither of evenness and Simpson Index was different significantly among all grassland utilization patterns in desert, typical, and meadow grassland at 0.05. In meadow grassland, species richness of fencing pattern was significantly higher than that of grazing pattern(p < 0.05); 3) both of soil organic carbon content and soil available phosphorous content were increased significantly on fencing pattern than grazing pattern(p < 0.05) in desert grassland, and mowing patterns increased the soil nutrients(soil organic carbon, soil total phosphorous, soil available phosphorous, and soil total nitrogen) significantly compared with grazing patterns(p < 0.05) in typical grassland. However, there were no significant differences among utilization patterns in meadow grassland. In conclusion, both of AGB and BGB were increased significantly by fencing. Moreover, species diversity and soil nutrients can be promoted via mowing and fencing. This study suggested that implementation of Ecological Project played a positive role in sustainable grassland utilization of Hulun Buir City and a strong positive influence on the entire temperate grassland.展开更多
Soil organic carbon(SOC)can act as a sink or source of atmospheric carbon dioxide;therefore,it is important to understand the amount and composition of SOC in terrestrial ecosystems,the spatial variation in SOC,and th...Soil organic carbon(SOC)can act as a sink or source of atmospheric carbon dioxide;therefore,it is important to understand the amount and composition of SOC in terrestrial ecosystems,the spatial variation in SOC,and the underlying mechanisms that stabilize SOC.In this study,density fractionation and acid hydrolysis were used to assess the spatial variation in SOC,the heavy fraction of organic carbon(HFOC),and the resistant organic carbon(ROC)in soils of the southern Hulun Buir region,northeastern China,and to identify the major factors that contribute to this variation.The results showed that as the contents of clay and silt particles(0–50μm)increased,both methylene blue(MB)adsorption by soil minerals and microaggregate contents increased in the 0–20 and 20–40 cm soil layers(P<0.05).Although varying with vegetation types,SOC,HFOC,and ROC contents increased significantly with the content of clay and silt particles, MB adsorption by soil minerals,and microaggregate content(P<0.05),suggesting that soil texture,the MB adsorption by soil minerals,and microaggregate abundance might be important factors influencing the spatial heterogeneity of carbon contents in soils of the southern Hulun Buir region.展开更多
Soil moisture is a key parameter in agricultural irrigation. The L band(1.58GHz) on board global position system (GPS) satellite is well suited for monitoring the change of soil moisture. In order to investigate t...Soil moisture is a key parameter in agricultural irrigation. The L band(1.58GHz) on board global position system (GPS) satellite is well suited for monitoring the change of soil moisture. In order to investigate the potential of retrieving soil moisture using the L-band GPS bistatic radar, this paper analyzed a retrieval method by using field experiment data. In order to investigate the relation- ship between the soil moisture ( corresponding roughly to the 0 - 5cm top soil layer) and the signal- to-noise ratio (PT-S-R) to the direct GPS signal-to-noise ratio (Pd_sNR), an experiment was conducted in Hulunber grassland of China in 2009 and 2011. Six field sites in the soil moisture experiment were utilized to analyze the relationship between soil moisture and the ratio of Pr-SNR to Pd-SN~ and the square of correlation coefficient was about 0.9 when the surface type was known and the elevation angle of the satellite ranged from 65 to 85 degrees approximately. The analysis shows that ratio of Pr-SNR to Pd-SNR can be used to monitor the soil moisture, because the ratio of Pr-SVR to Pd-SNR maxi- mized the elimination of the influence of different signals from different GPS satellites. The estimation accuracy could be improved if we make full use of the empirical knowledge on elevation angles of GPS satellites and ground roughness of different surface types.展开更多
Call admission control (CAC) and resource reservation (RR) for mobile communication are two important factors that guarantee system efficiency and quality of service (QoS) required for different services in a very sca...Call admission control (CAC) and resource reservation (RR) for mobile communication are two important factors that guarantee system efficiency and quality of service (QoS) required for different services in a very scarce resource as the radio spectrum. A new scheme was proposed which extends the concepts of resource sharing and reservations for wideband code division multiple access (WCDMA) systems with a unique feature of soft capacity. Voice and data traffic were considered. The traffic is further classified into handoff and new requests. The reservation thresholds were dynamically adjusted according to the traffic pattern and mobility prediction in order to achieve the maximum channel utilization, while guaranteeing different QoS constraints. The performance of proposed scheme was evaluated using Markov models. New call blocking probability, handoff call dropping probability, and channel utilization were used as benchmarks for the proposed scheme.展开更多
A relative humidity series of April-August during 1825-2009 AD was reconstructed based on tree- ring width of Pinus sylvestris var. mongolica for the Hulunbuir area. During the past 185 years, 25 humid years and 26 ar...A relative humidity series of April-August during 1825-2009 AD was reconstructed based on tree- ring width of Pinus sylvestris var. mongolica for the Hulunbuir area. During the past 185 years, 25 humid years and 26 arid years were identified in the reconstruction, as well as 6 wet periods and 6 dry periods. The relative humidity has decreased since approximately the 1950s, suggesting a warm and dry climate trend in the study area. The reconstruction can be compared with those of the surrounding tree ring reconstructed precipitation and rela- tive humidity series at the decadal scale, reflecting the consistency of the regional climate variations. Besides, significant positive correlations are revealed between the reconstruction and the normalized difference vegetation index of the Hulunbuir grassland. And the decrease in relative humidity will cause negative impacts on the Hulunbuir grassland. Comparisons between the sandstorm records and the relative humidity of the study area indicate that strong sandstorms occurred more frequently in Hulunbuir when the relative humidity was low. Therefore, under the downward trend in relative humidity, more effort should be made to protect the grassland ecology and treat the bare sand land for the local and surrounding areas.展开更多
The unique alpine-living kea parrot Nestor notabilis has been the focus of numerous cognitive studies, but its com- munication system has so far been largely neglected. We examined 2,884 calls recorded in New Zealand...The unique alpine-living kea parrot Nestor notabilis has been the focus of numerous cognitive studies, but its com- munication system has so far been largely neglected. We examined 2,884 calls recorded in New Zealand's Southern Alps. Based on audio and visual spectrographic differences, these calls were categorised into seven distinct call types: the non-oscillating 'screech' contact call and 'mew'; and the oscillating 'trill', 'chatter', 'warble' and 'whistle'; and a hybrid 'screech-trill'. Most of these calls contained aspects that were individually unique, in addition to potentially encoding for an individual's sex and age. Additionally, for each recording, the sender's previous and next calls were noted, as well as any response given by conspecifics. We found that the previous and next calls made by the sender were most often of the same type, and that the next most likely pre- ceding and/or following call type was the screech call, a contact call which sounds like the 'kee-ah' from which the bird's name derives. As a social bird capable of covering large distances over visually obstructive terrain, long distance contact calls may be of considerable importance for social cohesion. Contact calls allow kea to locate conspecifics and congregate in temporary groups for social activities. The most likely response to any given call was a screech, usually followed by the same type of call as the ini- tial call made by the sender, although responses differed depending on the age of the caller. The exception was the warble, the kea's play call, to which the most likely response was another warble. Being the most common call type, as well as the default response to another call, it appears that the 'contagious' screech contact call plays a central role in kea vocal communication and social cohesion [Current Zoology 58 (5): 727-740, 2012].展开更多
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201003019,201003061,201303060)the National Natural Science Foundation of China(41201199)+1 种基金International Science and Technology Cooperation Project(2012DFA31290)Modern Agricultural Technology System of Special Funding~~
文摘[Objective] The aim was to explore the management mode on optimal re-sources al ocation of family ranch in meadow steppe. [Method] Three double repre-sentative family ranches were selected in meadow steppe of Hulunber Old Barag Banner, and the study was carried out with the baseline survey. Three family ranches were selected as the demonstrative households for the corporation study, while other three family ranches with the similar conditions were looked as the non-demonstrative households for the comparison. Demonstrative households of the fami-ly ranches reduced the stocking rate, optimized the flock structure and took a winter feeding and other means to explore the different management models on plant com-munity characteristic of family ranch. [Result] The seasonal dynamic of community characteristic in family ranches showed the single-peaks curves. The seasonal dy-namics of community coverage, height and biomass in the demonstrative households showed higher compared with the non-demonstrative households, and community density in the experiment households was lower than that of the control experiment households. Community coverage, height and biomass of degraded grassland in family ranch have a great improve after optimization of management. Community coverage, height , density and biomass were increasing in fencing plot, but decreas-ing in free grazing area. Enclosure improved grassland coverage, vegetation height, density and forage yield. Leymus chinensis played an important role in plant com-munity. The important values of Leymus chinensis, Stipa baicalensis, Cleistogenes squarrosa, and Carex duriuscula were high. Leymus chinensis important value in the demonstrative households of optimal management was higher than that in the non-demonstrative households, and Carex duriuscula important value of the non-demon-strative households was significantly higher than that of the demonstrative house-holds. The indexes of Margalef richnes,Shannon-Wiener diversity, Simpson diversity and Pielou uniformity showed that the demonstrative households were higher than the non-demonstrative households. [Conclusion] The research provides theoretical ref-erences for sustainable development of pastures dominated by family ranch.
基金Under the auspices of National Science & Technology Support Program of China(No.2006BAD20B00)
文摘Grassland fire is one of the most important disturbance factors in the natural ecosystems.This paper focuses on the spatial distribution of long-term grassland fire patterns in the Hulun Buir Grassland located in the northeast of Inner Mongolia Autonomous Region in China.The density or ratio of ignition can reflect the relationship between grassland fire and different ignition factors.Based on the relationship between the density or ratio of ignition in different range of each ignition factor and grassland fire events,an ignition probability model was developed by using binary logistic regression function and its overall accuracy averaged up to 81.7%.Meanwhile it was found that daily relative humidity,daily temperature,elevation,vegetation type,distance to county-level road,distance to town are more important determinants of spatial distribution of fire ignitions.Using Monte Carlo method,we developed a time-dependent stochastic ignition probability model based on the distribution of inter-annual daily relative humidity and daily temperature.Through this model,it is possible to estimate the spatial patterns of ignition probability for grassland fire,which will be helpful to the quantitative evaluation of grassland fire risk and its management in the future.
基金Under the auspices of Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA05060100)National Natural Science Foundation of China(No.41105117)
文摘Numerous studies have focused on vegetation traits and soil properties in grassland, few of which concerned about effects of human utilization patterns on grassland yet. Thus, this study hypothesized that human disturbance(e.g., grazing, mowing and fencing) triggered significant variation of biomass partitioning and carbon reallocation. Besides, there existed some differences of species diversity and soil fertility. To address these hypotheses of grassland with diverse utilization patterns in Hulun Buir City, Inner Mongolia, China, we sampled in situ about aboveground biomass(AGB) and belowground biomass(BGB) to evaluate their biomass allocation. Species diversity and soil properties were also investigated. Subsequently, we discussed the relationship of species diversity with environmental conditions, using data collected from 23 sites during the ecological project period of Returning Grazing Lands to Grasslands(RGLG) program. The results were as follows: 1) both AGB and BGB were lower on grazing regime than those on fencing and mowing, but the ratio of root-to-shoot(R/S) was higher on grazing regime than the other two utilization patterns; 2) neither of evenness and Simpson Index was different significantly among all grassland utilization patterns in desert, typical, and meadow grassland at 0.05. In meadow grassland, species richness of fencing pattern was significantly higher than that of grazing pattern(p < 0.05); 3) both of soil organic carbon content and soil available phosphorous content were increased significantly on fencing pattern than grazing pattern(p < 0.05) in desert grassland, and mowing patterns increased the soil nutrients(soil organic carbon, soil total phosphorous, soil available phosphorous, and soil total nitrogen) significantly compared with grazing patterns(p < 0.05) in typical grassland. However, there were no significant differences among utilization patterns in meadow grassland. In conclusion, both of AGB and BGB were increased significantly by fencing. Moreover, species diversity and soil nutrients can be promoted via mowing and fencing. This study suggested that implementation of Ecological Project played a positive role in sustainable grassland utilization of Hulun Buir City and a strong positive influence on the entire temperate grassland.
基金Project supported by the National Natural Science Foundation of China(Nos.40321101 and 40071036)the Major State Basic Research Development Program of China(973 Program)(No.2002CB412503)
文摘Soil organic carbon(SOC)can act as a sink or source of atmospheric carbon dioxide;therefore,it is important to understand the amount and composition of SOC in terrestrial ecosystems,the spatial variation in SOC,and the underlying mechanisms that stabilize SOC.In this study,density fractionation and acid hydrolysis were used to assess the spatial variation in SOC,the heavy fraction of organic carbon(HFOC),and the resistant organic carbon(ROC)in soils of the southern Hulun Buir region,northeastern China,and to identify the major factors that contribute to this variation.The results showed that as the contents of clay and silt particles(0–50μm)increased,both methylene blue(MB)adsorption by soil minerals and microaggregate contents increased in the 0–20 and 20–40 cm soil layers(P<0.05).Although varying with vegetation types,SOC,HFOC,and ROC contents increased significantly with the content of clay and silt particles, MB adsorption by soil minerals,and microaggregate content(P<0.05),suggesting that soil texture,the MB adsorption by soil minerals,and microaggregate abundance might be important factors influencing the spatial heterogeneity of carbon contents in soils of the southern Hulun Buir region.
基金Supported by the National Key Basic Research Program of China(No.2010CB951503,2013BAC03B00)
文摘Soil moisture is a key parameter in agricultural irrigation. The L band(1.58GHz) on board global position system (GPS) satellite is well suited for monitoring the change of soil moisture. In order to investigate the potential of retrieving soil moisture using the L-band GPS bistatic radar, this paper analyzed a retrieval method by using field experiment data. In order to investigate the relation- ship between the soil moisture ( corresponding roughly to the 0 - 5cm top soil layer) and the signal- to-noise ratio (PT-S-R) to the direct GPS signal-to-noise ratio (Pd_sNR), an experiment was conducted in Hulunber grassland of China in 2009 and 2011. Six field sites in the soil moisture experiment were utilized to analyze the relationship between soil moisture and the ratio of Pr-SNR to Pd-SN~ and the square of correlation coefficient was about 0.9 when the surface type was known and the elevation angle of the satellite ranged from 65 to 85 degrees approximately. The analysis shows that ratio of Pr-SNR to Pd-SNR can be used to monitor the soil moisture, because the ratio of Pr-SVR to Pd-SNR maxi- mized the elimination of the influence of different signals from different GPS satellites. The estimation accuracy could be improved if we make full use of the empirical knowledge on elevation angles of GPS satellites and ground roughness of different surface types.
文摘Call admission control (CAC) and resource reservation (RR) for mobile communication are two important factors that guarantee system efficiency and quality of service (QoS) required for different services in a very scarce resource as the radio spectrum. A new scheme was proposed which extends the concepts of resource sharing and reservations for wideband code division multiple access (WCDMA) systems with a unique feature of soft capacity. Voice and data traffic were considered. The traffic is further classified into handoff and new requests. The reservation thresholds were dynamically adjusted according to the traffic pattern and mobility prediction in order to achieve the maximum channel utilization, while guaranteeing different QoS constraints. The performance of proposed scheme was evaluated using Markov models. New call blocking probability, handoff call dropping probability, and channel utilization were used as benchmarks for the proposed scheme.
基金supported by the State Key Laboratory of Loess and Quaternary Geology(SKLLQG1316)the Scientific Research Plan Projects of Shaanxi Education Department(15JK1796)+1 种基金the Dominant Discipline Construction Projects of Shaanxi(Historical Geography 0602 SZXKY1302)the Specialized Research Fund Project of Xianyang Normal University(12XSYK0310)
文摘A relative humidity series of April-August during 1825-2009 AD was reconstructed based on tree- ring width of Pinus sylvestris var. mongolica for the Hulunbuir area. During the past 185 years, 25 humid years and 26 arid years were identified in the reconstruction, as well as 6 wet periods and 6 dry periods. The relative humidity has decreased since approximately the 1950s, suggesting a warm and dry climate trend in the study area. The reconstruction can be compared with those of the surrounding tree ring reconstructed precipitation and rela- tive humidity series at the decadal scale, reflecting the consistency of the regional climate variations. Besides, significant positive correlations are revealed between the reconstruction and the normalized difference vegetation index of the Hulunbuir grassland. And the decrease in relative humidity will cause negative impacts on the Hulunbuir grassland. Comparisons between the sandstorm records and the relative humidity of the study area indicate that strong sandstorms occurred more frequently in Hulunbuir when the relative humidity was low. Therefore, under the downward trend in relative humidity, more effort should be made to protect the grassland ecology and treat the bare sand land for the local and surrounding areas.
文摘The unique alpine-living kea parrot Nestor notabilis has been the focus of numerous cognitive studies, but its com- munication system has so far been largely neglected. We examined 2,884 calls recorded in New Zealand's Southern Alps. Based on audio and visual spectrographic differences, these calls were categorised into seven distinct call types: the non-oscillating 'screech' contact call and 'mew'; and the oscillating 'trill', 'chatter', 'warble' and 'whistle'; and a hybrid 'screech-trill'. Most of these calls contained aspects that were individually unique, in addition to potentially encoding for an individual's sex and age. Additionally, for each recording, the sender's previous and next calls were noted, as well as any response given by conspecifics. We found that the previous and next calls made by the sender were most often of the same type, and that the next most likely pre- ceding and/or following call type was the screech call, a contact call which sounds like the 'kee-ah' from which the bird's name derives. As a social bird capable of covering large distances over visually obstructive terrain, long distance contact calls may be of considerable importance for social cohesion. Contact calls allow kea to locate conspecifics and congregate in temporary groups for social activities. The most likely response to any given call was a screech, usually followed by the same type of call as the ini- tial call made by the sender, although responses differed depending on the age of the caller. The exception was the warble, the kea's play call, to which the most likely response was another warble. Being the most common call type, as well as the default response to another call, it appears that the 'contagious' screech contact call plays a central role in kea vocal communication and social cohesion [Current Zoology 58 (5): 727-740, 2012].