By selecting a typical peak-cluster depression area of karst region in Southwest China, we evaluated the effect of land use types and topographic factors on soil nutrients. Grid and line sampling methods were used to ...By selecting a typical peak-cluster depression area of karst region in Southwest China, we evaluated the effect of land use types and topographic factors on soil nutrients. Grid and line sampling methods were used to sample soil in depression and slope lands respectively, and classical statistical tools were applied to analyze the spatial variability character of soil organic carbon （SOC）, total nitrogen （TN）, total phosphorus （TP）, total potassium （TK）, available nitrogen （AN）, available phosphorus （AP）, available potassium （AK）, pH, and C/N. It was found that land use type was the dominant factor that effected the spatial heterogeneity of SOC, TN, TP, TK, AN, and AP. The content of SOC, TN, and AN decreased with the increase of land use intensity. Due to high fertilizer input, TP and AP in tillage fields were higher than those in the other land use types. TK had no obvious change trend among various land use types. Topographic factors had a significant effect on SOC, TN, TP, AN, AP, AK, and pH. Habitat factor was the dominant factor that effected AK. Altitude factor was the dominant factor for pH. However, all of these factors had no significant effect on C/N. Tillage practice had important effect on soil nutrients loss and soil degradation in the fragile karst ecosystem, and the input of organic manure should be increased in this region.展开更多
青藏高原生态系统脆弱且稳定性低,对气候变化和人类活动敏感。研究该区域草地物种多样性及其生产力,对评估生态系统结构功能与区域生态保护意义重大,但其对环境因子的响应及环境因子、物种多样性对生产力的调控机制仍存争议。本研究基...青藏高原生态系统脆弱且稳定性低,对气候变化和人类活动敏感。研究该区域草地物种多样性及其生产力,对评估生态系统结构功能与区域生态保护意义重大,但其对环境因子的响应及环境因子、物种多样性对生产力的调控机制仍存争议。本研究基于三江源国家公园(唐北区域)144个样点的实测数据,包括群落结构、土壤因素和气候指标,采用回归分析、层次分割和结构方程模型相结合的方法,解析该区域物种多样性与生产力的关系及其影响机制。研究结果表明:物种丰富度与地上净初级生产力(Aboveground net primary productivity, ANPP)的关系(R^(2)=0.18)比Shannon-Wiener指数与ANPP的关系(R^(2)=0.09)更为紧密;土壤速效磷对物种丰富度的解释率最高(33.51%),年均降水量对Shannon-Wiener指数的解释率为20.98%,均呈正相关关系;气候因子和土壤因子对ANPP具有直接影响,而地理因子通过调控气候因子间接影响ANPP。本研究阐明了三江源国家公园(唐北区域)物种多样性与生产力关系的分异特征,发现土壤速效磷、年均降水量等对物种丰富度和Shannon-Wiener指数影响显著,且气候、土壤和地理因子以直接或间接方式调控了草地生产力,为解析高寒草地生态系统结构与功能关系提供了依据。展开更多
Understanding soil nutrient distributions and the factors affecting them are crucial for fertilizer management and environmental protection in vulnerable ecological regions.Based on 555 soil samples collected in 2012 ...Understanding soil nutrient distributions and the factors affecting them are crucial for fertilizer management and environmental protection in vulnerable ecological regions.Based on 555 soil samples collected in 2012 in Renshou County,located in the purple soil hilly area of Sichuan Basin,China,the spatial variability of soil total nitrogen(TN),total phosphorus(TP)and total potassium(TK)was studied with geostatistical analysis and the relative roles of the affecting factors were quantified using regression analysis.The means of TN,TP and TK contents were 1.12,0.82 and 9.64 g kg^(–1),respectively.The coefficients of variation ranged from 30.56 to 38.75%and the nugget/sill ratios ranged from 0.45 to 0.61,indicating that the three soil nutrients had moderate variability and spatial dependence.Two distribution patterns were observed.TP and TK were associated with patterns of obvious spatial distribution trends while the spatial distribution of TN was characterized by higher variability.Soil group,land use type and topographic factors explained 26.5,35.6 and 8.4%of TN variability,respectively,with land use being the dominant factor.Parent material,soil group,land use type and topographic factors explained 17.5,10.7,12.0 and 5.0%of TP variability,respectively,and both parent material and land use type played important roles.Only parent material and soil type contributed to TK variability and could explain 25.1 and 13.7%of TK variability,respectively.More attention should focus on adopting reasonable land use types for the purposes of fertilizer management and consider the different roles of the affecting factors at the landscape scale in this purple soil hilly area.展开更多
Microbial biomass represents a relatively small standing stock of nutrients, compared to soil organic matter, but it can act as a labile source of nutrients for plants, a pathway for incorporation of organic matter in...Microbial biomass represents a relatively small standing stock of nutrients, compared to soil organic matter, but it can act as a labile source of nutrients for plants, a pathway for incorporation of organic matter into the soil, and a temporary sink for nutrients. This review describes several factors controlling the dynamics of soil microbial biomass. These factors mainly include organic carbon and nitrogen limitation, residue and nutrient management, differences in plant species, soil texture, soil moisture and temperature. On the basis of detailed analysis, it is reasonable that future research would be focused on the impact of land use change on soil MB in tropical and subtropical ecosystems.展开更多
文摘By selecting a typical peak-cluster depression area of karst region in Southwest China, we evaluated the effect of land use types and topographic factors on soil nutrients. Grid and line sampling methods were used to sample soil in depression and slope lands respectively, and classical statistical tools were applied to analyze the spatial variability character of soil organic carbon （SOC）, total nitrogen （TN）, total phosphorus （TP）, total potassium （TK）, available nitrogen （AN）, available phosphorus （AP）, available potassium （AK）, pH, and C/N. It was found that land use type was the dominant factor that effected the spatial heterogeneity of SOC, TN, TP, TK, AN, and AP. The content of SOC, TN, and AN decreased with the increase of land use intensity. Due to high fertilizer input, TP and AP in tillage fields were higher than those in the other land use types. TK had no obvious change trend among various land use types. Topographic factors had a significant effect on SOC, TN, TP, AN, AP, AK, and pH. Habitat factor was the dominant factor that effected AK. Altitude factor was the dominant factor for pH. However, all of these factors had no significant effect on C/N. Tillage practice had important effect on soil nutrients loss and soil degradation in the fragile karst ecosystem, and the input of organic manure should be increased in this region.
文摘青藏高原生态系统脆弱且稳定性低,对气候变化和人类活动敏感。研究该区域草地物种多样性及其生产力,对评估生态系统结构功能与区域生态保护意义重大,但其对环境因子的响应及环境因子、物种多样性对生产力的调控机制仍存争议。本研究基于三江源国家公园(唐北区域)144个样点的实测数据,包括群落结构、土壤因素和气候指标,采用回归分析、层次分割和结构方程模型相结合的方法,解析该区域物种多样性与生产力的关系及其影响机制。研究结果表明:物种丰富度与地上净初级生产力(Aboveground net primary productivity, ANPP)的关系(R^(2)=0.18)比Shannon-Wiener指数与ANPP的关系(R^(2)=0.09)更为紧密;土壤速效磷对物种丰富度的解释率最高(33.51%),年均降水量对Shannon-Wiener指数的解释率为20.98%,均呈正相关关系;气候因子和土壤因子对ANPP具有直接影响,而地理因子通过调控气候因子间接影响ANPP。本研究阐明了三江源国家公园(唐北区域)物种多样性与生产力关系的分异特征,发现土壤速效磷、年均降水量等对物种丰富度和Shannon-Wiener指数影响显著,且气候、土壤和地理因子以直接或间接方式调控了草地生产力,为解析高寒草地生态系统结构与功能关系提供了依据。
基金supported by grants from the National Key Research and Development Program of China (SQ2018YFD080041)the Science Fund of the Education Department of Sichuan Province, China (16ZB0048)
文摘Understanding soil nutrient distributions and the factors affecting them are crucial for fertilizer management and environmental protection in vulnerable ecological regions.Based on 555 soil samples collected in 2012 in Renshou County,located in the purple soil hilly area of Sichuan Basin,China,the spatial variability of soil total nitrogen(TN),total phosphorus(TP)and total potassium(TK)was studied with geostatistical analysis and the relative roles of the affecting factors were quantified using regression analysis.The means of TN,TP and TK contents were 1.12,0.82 and 9.64 g kg^(–1),respectively.The coefficients of variation ranged from 30.56 to 38.75%and the nugget/sill ratios ranged from 0.45 to 0.61,indicating that the three soil nutrients had moderate variability and spatial dependence.Two distribution patterns were observed.TP and TK were associated with patterns of obvious spatial distribution trends while the spatial distribution of TN was characterized by higher variability.Soil group,land use type and topographic factors explained 26.5,35.6 and 8.4%of TN variability,respectively,with land use being the dominant factor.Parent material,soil group,land use type and topographic factors explained 17.5,10.7,12.0 and 5.0%of TP variability,respectively,and both parent material and land use type played important roles.Only parent material and soil type contributed to TK variability and could explain 25.1 and 13.7%of TK variability,respectively.More attention should focus on adopting reasonable land use types for the purposes of fertilizer management and consider the different roles of the affecting factors at the landscape scale in this purple soil hilly area.
基金This study was supported by the Teaching and Research Award program for MOE P. R. C. (TRAPOYT)
文摘Microbial biomass represents a relatively small standing stock of nutrients, compared to soil organic matter, but it can act as a labile source of nutrients for plants, a pathway for incorporation of organic matter into the soil, and a temporary sink for nutrients. This review describes several factors controlling the dynamics of soil microbial biomass. These factors mainly include organic carbon and nitrogen limitation, residue and nutrient management, differences in plant species, soil texture, soil moisture and temperature. On the basis of detailed analysis, it is reasonable that future research would be focused on the impact of land use change on soil MB in tropical and subtropical ecosystems.
