Yanchi County is located in the agro-pastoral ecotone and belongs to the ecologically fragile area of Northwest China.It is important to study the evolution of landscape pattern to curb its environmental degradation.I...Yanchi County is located in the agro-pastoral ecotone and belongs to the ecologically fragile area of Northwest China.It is important to study the evolution of landscape pattern to curb its environmental degradation.In order to intuitively show how the landscape pattern of the study area changes over time,Landsat Thematic Mappers(TM)and Landsat Operational Land Imager(OLI)data of 1991,2000,2010 and 2017 were used.This paper attempts to apply niche theories and methods into landscape ecology,and constructs a niche model of landscape components by using"n-dimentional hypervolume niche theory"and landscape pattern indices.By evaluating the spatial and temporal evolution of niche from the perspective of two-dimensional space to reflect the changes of landscape pattern in the study area over the past 26 years,new theories and methods were introduced for the characterization of landscape pattern.The results indicate that:1)The larger the attribute and dominance value of landscape components,the higher the ecological niche and the stronger the control effect on the overall landscape.2)The ecological niche of each landscape component was significantly different,just as its control effect on the overall landscape.3)The dynamic change of the ecological niche of each landscape component was different,with grassland,unused land and arable land always in a high dominant position,although the ecological niche of construction land and water area was always low.In general,the introduction of niche theory into the landscape ecology provided a new method to study the changes in regional landscape pattern.展开更多
High vocal center (HVC) can produce single sound with one or two syllables by the sin-gle-type vocal control pattern in songbirds ruddy bunting (Emberiza rutila). It obviously shows left-side dominance in controlling ...High vocal center (HVC) can produce single sound with one or two syllables by the sin-gle-type vocal control pattern in songbirds ruddy bunting (Emberiza rutila). It obviously shows left-side dominance in controlling double syllables, principal frequency (PF) and increasing sound intensity of the evoked calls. Meanwhile, the complex-type control pattern can produce complex calls with multisyllable, and also shows significant left-side dominance in controlling the number of syllables, tone changing and sound intensity. These indicate that left-side HVC controls higher frequency and complicated sentence structure. The basic vocal center, dorsomedial nucleus of the intercollicular complex (DM), controls the monosyllable sound in songbirds, and shows left-side dominance in controlling both the number of syllable and sound intensity. These results not only provide some direct evidence for left-side dominance in high vocal center, but also indicate that there is some internal connection between the high and basic vocal centers in songbirds.展开更多
Taking different forests in Aershan of Inner Mongolia as sample plots, diversity and dominant species of arthropods were studied. The results show that two classes, 17 orders, 68 families, 130 species and 3742 individ...Taking different forests in Aershan of Inner Mongolia as sample plots, diversity and dominant species of arthropods were studied. The results show that two classes, 17 orders, 68 families, 130 species and 3742 individuals were identified and 92.31% of total species appeared in natural forests, and 75.38% of total species appeared in plantations. The orders of Lepidoptera, Coleoptera, Diptera and Hymenoptera covered most of the collected arthropods. In different forest types, diversity indices is natural mixed forests （Betula platyphylla x Larix gmelinii）〉 natural pure B. platyphylla forests〉natural pure L. gmelinii forests〉plantations with pesticide treatment〉plantations without pesticide treatment. In natural forests, more than 70% of the arthropod families, species and individuals were distributed in shrub and herb layer, while in plantations 75% of the arthropod families, 78% of species and 80% of individuals were also distributed in shrub and herb layer. Lepidoptera, including Loxostege sticticalis （Linnaeus）, Chilo suppressalis （Walker） and Lymantria dispar （Linnaeus）, had the highest dominant degree.展开更多
Introduction:The spatial association dynamics of free-ranging cattle herds are not fully understood;however,they can have a direct influence on the spatial patterns of resource utilization.The aim of our study was to ...Introduction:The spatial association dynamics of free-ranging cattle herds are not fully understood;however,they can have a direct influence on the spatial patterns of resource utilization.The aim of our study was to examine new analytical methods of identifying the spatio-temporal patterns of behavioral dynamics that determine cattle herd dispersal in the semi-arid rangelands of South Texas.We fitted 10 free-ranging cows with global positioning system collars and obtained positions every 5 min for each animal for 21-day trials,twice during the summer and winter period.We used an association pattern recognition software(ASSOC1)and the herd center of gravity to identify the spatial and temporal thresholds that defined dispersion-aggregation patterns and individual position to determine their relation to social dominance.Results:The association pattern defining herd membership was that animals spent 70%of their time within 200 m of each other.Dominance ranking did not appear to influence association membership or position within the herd.The cattle showed a more dispersed distribution during summer,but in winter,herd members behaved in a more aggregated pattern.This distribution is contrary to patterns described in more northerly and mountainous regions.Conclusions:The spatial thresholds of the cattle herd and the overall distance of all members to the center of the herd were smaller during winter and larger during summer,indicating that this study herd congregated during the winter and dispersed during the summer.Although this study uses a herd of 10 individuals in a 100 ha pasture to evaluate spatio-temporal dynamics,our results provide evidence of the ability of current tracking and spatial association tools to detect and quantify seasonal changes in cattle herd dispersion-aggregation patterns.The use of these data collection and analysis methods could prove useful in larger cattle herds,increase our understanding of herd spatiotemporal behavior,and subsequently help in the development of improved management pra展开更多
基金supported by the Fundamental Research Funds of Gansu Provincial Natural Science Fund of"Research on Land Use and Ecological Security in Ecologically Vulnerable Areas"(Project No.GSANZL-2015-045)
文摘Yanchi County is located in the agro-pastoral ecotone and belongs to the ecologically fragile area of Northwest China.It is important to study the evolution of landscape pattern to curb its environmental degradation.In order to intuitively show how the landscape pattern of the study area changes over time,Landsat Thematic Mappers(TM)and Landsat Operational Land Imager(OLI)data of 1991,2000,2010 and 2017 were used.This paper attempts to apply niche theories and methods into landscape ecology,and constructs a niche model of landscape components by using"n-dimentional hypervolume niche theory"and landscape pattern indices.By evaluating the spatial and temporal evolution of niche from the perspective of two-dimensional space to reflect the changes of landscape pattern in the study area over the past 26 years,new theories and methods were introduced for the characterization of landscape pattern.The results indicate that:1)The larger the attribute and dominance value of landscape components,the higher the ecological niche and the stronger the control effect on the overall landscape.2)The ecological niche of each landscape component was significantly different,just as its control effect on the overall landscape.3)The dynamic change of the ecological niche of each landscape component was different,with grassland,unused land and arable land always in a high dominant position,although the ecological niche of construction land and water area was always low.In general,the introduction of niche theory into the landscape ecology provided a new method to study the changes in regional landscape pattern.
基金supported by the National Natural Science Foundation of China(Grant No.39570195)Outstanding Youth Foundation of Ministry of Education of China,Science and Technology Research Project of Ministry of Education of China(Grant No.01062)Laboratory of Visual Information Processing Foundation of the Chinese Academy of Sciences.
文摘High vocal center (HVC) can produce single sound with one or two syllables by the sin-gle-type vocal control pattern in songbirds ruddy bunting (Emberiza rutila). It obviously shows left-side dominance in controlling double syllables, principal frequency (PF) and increasing sound intensity of the evoked calls. Meanwhile, the complex-type control pattern can produce complex calls with multisyllable, and also shows significant left-side dominance in controlling the number of syllables, tone changing and sound intensity. These indicate that left-side HVC controls higher frequency and complicated sentence structure. The basic vocal center, dorsomedial nucleus of the intercollicular complex (DM), controls the monosyllable sound in songbirds, and shows left-side dominance in controlling both the number of syllable and sound intensity. These results not only provide some direct evidence for left-side dominance in high vocal center, but also indicate that there is some internal connection between the high and basic vocal centers in songbirds.
基金supported by Biodiversity and Forest Pest Problems in Northeast China (BIOPROC)a cooperative project between Beijing Forestry University and Helsinki Universitythe Program for Changjiang Scholars and Innovative Research Team in Universities (PCSIRT0607)
文摘Taking different forests in Aershan of Inner Mongolia as sample plots, diversity and dominant species of arthropods were studied. The results show that two classes, 17 orders, 68 families, 130 species and 3742 individuals were identified and 92.31% of total species appeared in natural forests, and 75.38% of total species appeared in plantations. The orders of Lepidoptera, Coleoptera, Diptera and Hymenoptera covered most of the collected arthropods. In different forest types, diversity indices is natural mixed forests （Betula platyphylla x Larix gmelinii）〉 natural pure B. platyphylla forests〉natural pure L. gmelinii forests〉plantations with pesticide treatment〉plantations without pesticide treatment. In natural forests, more than 70% of the arthropod families, species and individuals were distributed in shrub and herb layer, while in plantations 75% of the arthropod families, 78% of species and 80% of individuals were also distributed in shrub and herb layer. Lepidoptera, including Loxostege sticticalis （Linnaeus）, Chilo suppressalis （Walker） and Lymantria dispar （Linnaeus）, had the highest dominant degree.
基金Funding to C.Cheleuitte-Nieves was provided through Hispanic Leaders in Agriculture and the Environment(HLAE)fellowships,the Alfred P.Sloan Foundation Minority PhD fellowship,Texas A&M University Graduate Diversity fellowship,and Department of Ecosystem and Management(Texas A&M University)Tom Slick fellowship.
文摘Introduction:The spatial association dynamics of free-ranging cattle herds are not fully understood;however,they can have a direct influence on the spatial patterns of resource utilization.The aim of our study was to examine new analytical methods of identifying the spatio-temporal patterns of behavioral dynamics that determine cattle herd dispersal in the semi-arid rangelands of South Texas.We fitted 10 free-ranging cows with global positioning system collars and obtained positions every 5 min for each animal for 21-day trials,twice during the summer and winter period.We used an association pattern recognition software(ASSOC1)and the herd center of gravity to identify the spatial and temporal thresholds that defined dispersion-aggregation patterns and individual position to determine their relation to social dominance.Results:The association pattern defining herd membership was that animals spent 70%of their time within 200 m of each other.Dominance ranking did not appear to influence association membership or position within the herd.The cattle showed a more dispersed distribution during summer,but in winter,herd members behaved in a more aggregated pattern.This distribution is contrary to patterns described in more northerly and mountainous regions.Conclusions:The spatial thresholds of the cattle herd and the overall distance of all members to the center of the herd were smaller during winter and larger during summer,indicating that this study herd congregated during the winter and dispersed during the summer.Although this study uses a herd of 10 individuals in a 100 ha pasture to evaluate spatio-temporal dynamics,our results provide evidence of the ability of current tracking and spatial association tools to detect and quantify seasonal changes in cattle herd dispersion-aggregation patterns.The use of these data collection and analysis methods could prove useful in larger cattle herds,increase our understanding of herd spatiotemporal behavior,and subsequently help in the development of improved management pra
