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1.
Content and densities of soil organic carbon in urban soil in different function districts of Kaifeng 总被引：2，自引：0，他引：2
Urban soil, forming along with the development of city, has unique properties of soil organic carbon. On the basis of field
investigation and laboratory analysis, soil organic carbon (SOC) of Kaifeng city was studied, and the results showed that
the characteristics of SOC were different not only among function districts in urban area, but also between urban area and
suburbs. The order of SOC in topsoil was industrial district > recreational district > traffic district > cultural/educational
district > residential/administrative district. The density of soil organic carbon (SOCD) in both topsoil and profile followed
the orders of recreational district > industrial district > traffic district>cultural/educational district > residential/administrative
district, and cultural/educational district s>traffic district>industrial district>recreational district > administrative/residential
district, respectively. SOCD in both topsoil and profile decreased along the transection line from urban area to suburbs and
urban area had 2.53-fold more SOCD in topsoil and 1.56-fold more SOCD in profile than suburbs, respectively. SOC decreased
with the depth and was mainly distributed within the scope of 0–30 cm. The variances of SOC in urban area were more complicated
than that in suburbs. 相似文献
2.
Urban soil, forming along with the development of city, has unique properties of soil organic carbon. On the basis of field investigation and laboratory analysis, soil organic carbon (SOC) of Kaifeng city was studied, and the results showed that the characteristics of SOC were different not only among function districts in urban area, but also between urban area and suburbs. The order of SOC in topsoil was industrial district > recreational district > traffic district > cultural/educational district > residential/administrative district. The density of soil organic carbon (SOCD) in both topsoil and profile followed the orders of recreational district >industrial district > traffic district>cultural/educational district > residential/adminis- trative district, and cultural/educational district > traffic district>industrial district>recreational district > administrative/residential district, respectively. SOCD in both topsoil and profile decreased along the transection line from urban area to suburbs and urban area had 2.53-fold more SOCD in topsoil and 1.56-fold more SOCD in profile than suburbs, respectively. SOC decreased with the depth and was mainly distributed within the scope of 0-30 cm. The variances of SOC in urban area were more complicated than that in suburbs. 相似文献
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安徽省土壤有机碳空间差异及影响因素 总被引：26，自引：2，他引：26
区域土壤碳储量和碳固定潜力及影响因素分析是全球变化中碳循环研究的重要前沿问题。本文采用第二次土壤普查资料,研究了安徽省不同类型土壤的有机碳密度和碳库,分析了影响土壤有机碳分布的自然和人为因素。结果表明,安徽土壤有机碳库为0.71Pg,表层土壤有机碳库为0.28Pg;土壤平均有机碳密度达117.54 t/hm2,碳密度的空间分布为:皖南山区>皖西大别山区>沿长江平原>江淮丘陵区>淮北平原区;气候和植被控制着表层土壤有机碳的省域分布,降水与土壤有机碳含量呈正相关。地形和母质影响土壤亚类间有机碳的差异;土壤总氮与土壤有机碳呈极显著相关,平原区土壤粘粒含量与表层土壤有机碳固定有较大关系。 相似文献
5.
研究了科尔沁沙地南缘土地覆盖由流动沙地向人工林地、农田及固定沙地等转变后,0~60 cm土层有机碳储量的变化。结果表明：农田土壤有机碳含量增加最明显,为流动沙地的3.97倍且相同层间差异均显著;樟子松（Pinus sylvestris var. mongolica）林地、新疆杨（Populus alba var. pyramidalis）林地、小叶锦鸡儿（Caragana microphylla）群落土壤有机碳含量较流动沙地分别增加79.78%、138.20%、73.07%,差异主要在0~20 cm土层;围封草地和中度放牧草地分别增加116.85%和133.71%,差异主要在0~40 cm土层;固定沙地比流动沙地增加49.44%,差异主要在0~20 cm土层。土地覆盖类型转变后,由于受到土壤容重的影响,土壤有机碳密度在0~20 cm土层变化较明显。8种土地覆盖类型可分为4组：CL1（农田）、CL2（新疆杨林地、围封草地、中度放牧草地）、CL3（樟子松林地、小叶锦鸡儿群落、固定沙地）和CL4（流动沙地）。另外,土壤有机碳含量和密度在土壤剖面上的分布也随着土地覆盖类型的变化而不同。 相似文献
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松辽平原黑土有机碳含量时空分异规律 总被引：15，自引：2，他引：13
松辽平原典型黑土分布区土壤有机碳的空间分异规律及不同开垦年限土壤有机碳含量变化的研究结果表明:随着纬度的增加,黑土总有机碳平均含量由11.43g/kg增加至20.83g/kg,有机碳组分含量和HA/FA比值均表现出增加的趋势。随着土壤剖面加深,黑土总有机碳及其组分含量均呈下降的趋势,土壤中的HA-C逐步被FA-C和HU-C所替代。土壤开垦前50年,黑土总有机碳及其组分含量下降迅速,以后下降趋于缓慢,至开垦130年后,有机碳含量水平基本处于相对稳定状态,变化不明显。 相似文献
8.
Land-use and soil management affects soil organic carbon （SOC） pools, nitrogen, salinity and the depth distribution. The objective of this study was to estimate land-use effects on the distribution of SOC, labile fractions C, nitrogen （N） and salinity in saline-alkaline wetlands in the middle reaches of the Heihe River Basin. Three land-use types were selected： intact saline-alkaline meadow wetland, artificial shrubbery （planting Tamarix） and farmland （cultivated for 18 years） of soils previously under meadow wetland. SOC, easily oxidized carbon, microbial biomass carbon, total N, NO3--N and salinity concentrations were measured. The results show that SOC and labile fraction carbon contents decreased significantly with increasing soil depth in the three land-use wetlands. The labile fraction carbon contents in the topsoil （0-20cm） in cultivated soils were significantly higher than that in intact meadow wetland and artificial shrubbery soil. The aboveground biomass and soil permeability were the primary influencing factors on the contents of SOC and the labile carbon in the intact meadow wetland and artificial shrubbery soil, however, the farming practice was a factor in cultivated soil. Agricultural measures can effectively reduce the salinity contents; however, it caused a significant increase of NO 3--N concentrations which posed a threat to groundwater quality in the study area. 相似文献
9.
皖江自然湿地土壤碳密度及其开垦为农田后的变化 总被引：7，自引：1，他引：6
于2005年分别采集了安徽沿江4个淡水湖泊的自然湿地及其周边围垦农田的代表性土壤剖面样品,测定了总有机碳含量,讨论了天然淡水湿地有机碳密度与深度分布特征及其开垦为农田后的变化。结果显示,湿地表层（0～30cm）和全剖面（0～100cm）中的碳密度分别为42．5～57．4t／hm^2和81．5～91．6t／hm^2;而农田则分别为22．4～48．4t／hm^2和41．4～76．5t／hm^2。湿地开垦为农田后,土壤表层和全剖面的土壤有机碳含量明显降低,且有机碳含量的变异性增大。表明湿地开垦为农田后,其碳库失去稳定性。但是,开垦的旱地土壤的有机碳含量和碳密度显著低于开垦的稻田,故湿地开垦为旱地更不利于湿地碳库保护。因而,将湿地垦殖为水田是相对较有利于湿地碳库保护的人为土地利用方式。湿地开垦的碳库损失可能是土壤的大气CO2源效应的主要途径。 相似文献
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城市土壤有机碳（SOC）分布受城市建设、工业发展等人为因素的影响表现出明显的空间差 异。为揭示石嘴山市 SOC 受城市化、工业化等人类活动的影响，分别利用普通克里格法（OK）、多元 线性回归克里格法（RK）、遥感反演方法（RS）和遥感-地理加权回归克里格法（RGWRK）预测石嘴 山市 SOC 空间分布。结果表明：石嘴山市 SOC 含量在 1.31 ~ 66.92 g·kg- 1 之间变化，其平均值为 17.61 g·kg-1。石嘴山市不同功能区 SOC 含量存在显著差异（p < 0.05），具体表现为工业区>医疗区> 商业区>道路>住宅区>公园>农田>科教区；SOC 含量变异系数为 66.27%，呈中等程度变异；其最佳
拟合模型为高斯模型，C0（/
C0+C）为 0.02，属于强空间自相关。SOC 与遥感影像波段 DN 值的差值
（B1-B7、B3-B7、B4-B7）和地形因子（高程、坡度、起伏度）之间存在着极显著的相关性（p < 0.01）； 通过对 4 种方法的结果进行对比可知以各波段 DN 值差值与地形因子为输入量，利用 RGWRK 预测 的 SOC 精度最高，相比 OK 精度提高了 10.05%，相比 RK 精度提高了 8.79%，相比 RS 精度提高了 8.92%；研究区 SOC 含量呈北高南低的趋势，工业区 SOC 含量是郊区农田 SOC 含量的 1.92 倍，表明 城区 SOC 含量有富集的趋势。 相似文献
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土壤碳氮是高寒植被响应多年冻土区生态环境变化的重要营养和能源物质,但对其调查仍以生长季的单次采样为主,缺乏对其他季节的研究,这对于准确把握多年冻土区土壤碳氮含量及储量评估存在明显局限性。为此,本研究以青藏高原东北缘祁连山西段疏勒河源多年冻土区高寒草甸为对象,对0—50 cm土层土壤有机碳（Soil Organic Carbon, SOC）、全氮（Total Nitrogen, TN）含量及其比值（C/N）的剖面分布和季节变化及其影响因素进行分析。结果表明：（1）SOC、TN剖面分布规律一致,0—10 cm土层均显著高于10—50 cm各层（P<0.05）,0—50 cm深度仅秋季逐渐下降,而春夏冬季0—30 cm递减。（2）SOC、TN含量存在季节变化,SOC表现为夏季>冬季>春季>秋季,TN表现为春秋冬季含量一致,夏季略低。（3）C/N季节变化显著,夏季显著最高,秋季显著最低（P<0.05）。（4）土壤含水量和生物量是影响SOC、TN及C/N剖面分布和季节变化的关键因素。（5）夏季土壤碳氮密度均高于全年平均。可见,仅单一节点（生长季为主）调查以表征全年土壤碳氮储量存在高估趋势。 相似文献
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对祁连山中段冰沟流域土壤有机C、N、P含量垂直分布与化学计量特征及其影响因素进行研究。结果表明：冰沟流域土壤有机C、N、P含量在各样点随土层深度而降低,并在表层土中聚集较明显;在0—40 m土层中,土壤有机C、N、P平均含量随海拔升高总体呈现先增高后下降的趋势,在中、高海拔处最高,P含量变异较小。0—40 cm土层中土壤C/N在海拔3 128—2 814 m处高于其他海拔,在3 075 m处C/N最高,土壤C/N、C/P随海拔升高总体呈下降趋势,均在中高海拔处最高,而土壤N/P在海拔3 454 m处最高,在低海拔2 814 m处最低。不同植被类型土壤的C/N、N/P差异性不显著,而土壤SOC/P差异显著,3种植被类型影响土壤C/N和C/P的大小为乔木林>高山灌丛>高山草地,而土壤N/P为灌丛>乔木林>高山草地;植被类型、海拔是影响土壤C、N、P含量和化学计量比的主要因素,其次为盖度、坡向。 相似文献
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中国城市的快速发展加速了城市内部人口的居住迁移,精细测度居民迁居行为及其空间分异特征,对于从人的行为视角来分析城市居住空间结构演进过程具有现实意义。本文以武汉都市发展区为例,基于手机信令大数据,提出净活跃度指标和总活跃度指标来量化描述迁居活跃度,并依据两个指标的分类及组合,将居民居住地划分为高迁入型活跃区、平稳型活跃区、高迁出型活跃区、高迁入型非活跃区、平稳型非活跃区与高迁出型非活跃区六种空间类型,进而探讨居民迁居的空间分布特征。结果表明：① 武汉都市发展区内部人口迁移总体呈现出从主城区向近郊区逐步迁移的趋势,且主城区人口总活跃度相较更高。② 主城区以高迁出型活跃区和高迁入型活跃区为主,近郊区则以平稳型非活跃区为主。③ 不同空间类型内的居住类型存在差异：高迁入型活跃区内以新建小区、高校住区、学区房、城中村为主;平稳型活跃区以农村居住地、园区周边住宅为主;高迁出型活跃区以老旧小区、园区周边住宅、城中村、农村居住地为主;非活跃区则以农村居住地为主。本文提出了一种基于时序手机信令大数据的居民迁居活跃度评价指标体系,并以实证研究证明其对于居民迁居地空间类型划分的有效性,研究结果可为相关规划决策部门掌控城市内部的人口迁移特征提供数据支撑、为城市不同区域针对性的进行公共资源配置提供参考依据。 相似文献
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基于人口特征的城市生态游憩空间配置——以常熟市为例 总被引：4，自引：1，他引：3
生态游憩空间配置是休闲城市建设的重要内容,对城市生态文明建设、城市优质生活环境营造具有重要意义。本文以国家休闲城市综合标准试点市——常熟市为研究对象,以人口特征为切入点,对该市不同功能区内各年龄段人口数量、可进行生态游憩的时间、生态游憩意愿、对不同生态游憩空间的偏好,以及全市不同功能区人口对生态游憩空间的配置需求进行了调查研究。人口特征影响城市生态游憩空间的配置需求,全市不同功能区的人口特征有显著差异,因此对各类生态游憩空间的配置需求不同。在人口量、人口平均生态游憩可能性、人口生态游憩空间类型偏好等因素的影响下,商业活动区内人口对各类生态游憩空间的配置需求指数均最高,其次为生活居住区、商务办公区、工业生产区;全市不同功能区内人口对草地游憩空间的配置需求指数均最高,其次为水域和林地。可根据城市不同功能区人口数量、类型、分布特征,以及对各类生态游憩空间的配置需求来指导城市规划建设中生态游憩空间的配置实践。 相似文献
17.
Soil organic carbon density(SOCD) and soil organic carbon sequestration potential(SOCP) play an important role in carbon cycle and mitigation of greenhouse gas emissions. However, the majority of studies focused on a two-dimensional scale, especially lacking of field measured data. We employed the interpolation method with gradient plane nodal function(GPNF) and Shepard(SPD) across a range of parameters to simulate SOCD with a 40 cm soil layer depth in a dryland farming region(DFR) of China. The SOCP was estimated using a carbon saturation model. Results demonstrated the GPNF method was proved to be more effective in simulating the spatial distribution of SOCD at the vertical magnification multiple and search point values of 3.0×10~6 and 25, respectively. The soil organic carbon storage(SOCS) of 40 cm and 20 cm soil layers were estimated as 22.28×10~(11) kg and 13.12×10~(11) kg simulated by GPNF method in DFR. The SOCP was estimated as 0.95×10~(11) kg considered as a carbon sink at the 20–40 cm soil layer. Furthermore, the SOCP was estimated as –2.49×10~(11) kg considered as a carbon source at the 0–20 cm soil layer. This research has important values for the scientific use of soil resources and the mitigation of greenhouse gas emissions. 相似文献
18.
大连城市居住适宜性的空间评价 总被引：8，自引：0，他引：8
为创造更好、更适宜人们居住、生活和工作的空间,不断提高市民的生活质量,选择城市的生活方便性、健康性、居住安全性、环境舒适度和出行方便性等为指标,在问卷调查量化数据的基础上,采用层次分析法和Q型聚类分析方法,从行政区和不同功能片区两个角度,进行了大连城市居住适宜性空间评价,以期为大连城市建设提供参考。研究表明:大连城市居住适宜性以位于市区政治经济商业中心的区域得分最高,西、北部市郊结合部排名最后,部分远郊区宜居性虽然较好,但各指标分值差异却很大。总体而言,大连城市宜居性在空间格局上体现出由中心城区向外围逐渐降低、差异程度变大的特性,该空间特征分析结论与行政区评价结果具有很好的一致性。 相似文献
19.
气候变化及人类活动对中国土壤有机碳储量的影响 总被引：64，自引：1，他引：63
对中国1998年第二次土壤普查中的2000多个土壤剖面中碳储量与年平均温度 (T)、年降水量 (P) 的相关性研究表明：它们之间的相关性在不同的温度带下具有很大的差异,在T ≤10oC的地区,土壤有机碳储量与温度的负相关性最强;在10oC< T ≤ 20oC的地区,受与降水正相关的影响,土壤有机碳储量与年平均温度表现出一种正相关性;而在T > 20oC的地区,土壤有机碳储量与温度和降水的相关性都很差。由于温度和降水在中国存在很强的正相关性,因此在相关分析中宜采用偏相关分析方法。受人类耕种的影响,耕地土壤有机碳储量与温度、降水相关性远低于非耕地土壤。对具有相同土壤属性和气候条件的同一地区的耕地土壤与非耕地土壤样本进行的配对检验表明,耕地土壤与非耕地土壤有机碳储量之间存在显著差异,土地利用的改变在总体上导致了土壤碳的释放。 相似文献
20.
Detecting the storage and change on topsoil organic carbon in grasslands of Inner Mongolia from 1980s to 2010s 总被引：2，自引：2，他引：0
Soil carbon sequestration and potential has been a focal issue in global carbon research. Under the background of global change, the estimation of the size as well as its change of soil organic carbon（SOC） storage is of great importance. Based on soil data from the second national soil survey and field survey during 2011–2012, by using the regression method between sampling soil data and remote sensing data, this paper aimed to investigate spatial distribution and changes of topsoil（0–20 cm） organic carbon storage in grasslands of Inner Mongolia between the 1980 s and 2010 s. The results showed that：（1） the SOC storage in grasslands of Inner Mongolia between the 1980 s and 2010 s was estimated to be 2.05 and 2.17 Pg C, with an average density of 3.48 and 3.69 kg C·m–2, respectively. The SOC storage was mainly distributed in the typical steppe and meadow steppe, which accounted for over 98% of the total SOC storage. The spatial distribution showed a decreased trend from the meadow steppe, typical steppe to the desert steppe, corresponding to the temperature and precipitation gradient.（2） SOC changes during 1982–2012 were estimated to be 0.12 Pg C, at 7.00 g C·m–2·yr–1, which didn＇t show a significant change, indicating that SOC storage in grasslands of Inner Mongolia remained relatively stable over this period. However, topsoil organic carbon showed different trends of carbon source/sink during the past three decades. Meadow steppe and typical steppe had sequestered 0.15 and 0.03 Pg C, respectively, served as a carbon sink; while desert steppe lost 0.06 Pg C, served as a carbon source. It appears that SOC storage in grassland ecosystem may respond differently to climate change, related to vegetation type, regional climate type and grazing intensity. These results might give advice to decision makers on adopting suitable countermeasures for sustainable grassland utilization and protection. 相似文献