Spatial heterogeneity of soil mineral oxide components in depression between karst hills,Southwest China

In karst regions,the spatial heterogeneity of soil mineral oxides and environmental variables is still not clear.We investigated the spatial heterogeneity of SiO2,Al2O3,Fe2O3,CaO,MgO,P2O5,K2O,and MnO contents in the soils of slope land,plantation forest,secondary forest,and primary forest,as well as their relationships with environmental variables in a karst region of Southwest China.Geostatistics,principal component analysis(PCA),and canonical correlation analysis(CCA)were applied to analyze the field data.The results show that SiO2was the predominant mineral in the soils(45.02%–67.33%),followed by Al2O3and Fe2O3.Most soil mineral oxide components had a strong spatial dependence,except for CaO,MgO,and P2O5in the plantation forest,MgO and P2O5in the secondary forest,and CaO in the slope land.Dimensionality reduction in PCA was not appropriate due to the strong spatial heterogeneity in the ecosystems.Soil mineral oxide components,the main factors in all ecosystems,had greater influences on vegetation than those of conventional soil properties.There were close relationships between soil mineral oxide components and vegetation,topography,and conventional soil properties.Mineral oxide components affected species diversity,organic matter and nitrogen levels.     

Denitrification potential of marsh soils in two natural saline-alkaline wetlands

Little information is available on denitrification potential of marsh soils in natural saline-alkaline wetlands. The denitrification potentials of an open wetland in the floodplain(Erbaifangzi wetland) and a closed wetland(Fulaowenpao wetland) in backwater areas in Jilin Province of Northeast China were monitored by an anaerobic incubation at 30℃ for 25 days. Our results showed that the relative denitrification index(RDI) increased gradually with incubation time, and showed a rapid increase in the first 5 days of incubation. The RDI values declined quickly from surface soils to subsurface soils and then kept a small change in deeper soils along soil profiles over the incubation time. Denitrification proceeded much faster in the top 20 cm soils of open wetland than in the closed wetland, whereas no significant differences in RDI values were observed in deeper soils between both wetlands. The RDIs were significantly negatively correlated with bulk density and sand content, while a significantly positive correlation with clay content, soil organic matter, total nitrogen and phosphorous. The maximum net NO–3-N loss through denitrification in 1 m depth were higher in the open wetland than the closed wetland with higher soil pH values. Future research should be focused on understanding the influencing mechanisms of soil alkalinity.     

山西省和顺县松烟镇关家峪石榴子石加工流程探讨

本文介绍了片岩型石榴子石的的物理和化学性质,对石榴子石分选工艺进行了说明和探讨,为该类型的石榴子石选矿工艺提供依据。     

关注我们脚下的环境

正今年4月22日是第45个世界地球日,一份《全国土壤污染状况调查公报》却让我们对赖以生存的地球担忧起来:我国耕地土壤点位污染物超标率为19.4%,镉、镍、铜、砷、汞、铅、滴滴涕(双对氯苯基三氯乙烷)和多环芳烃成为罪魁祸首。作为百姓"米袋子"、"菜篮子"的耕地土壤正在受到越来越多的污染,甚至威胁到我们每天食用的蔬菜、水果、粮食这些"舌尖上的安全"。或许这些污染并不像烟囱中冒的黑烟、河流里淌的污水那么直观、但它们的确就在我们身边——我们的土壤现状近日,环境保护部和国土资源部联合发布《全国土壤污染状况调查公报》。调查结果显示,全国     

上海:高效用地背后的地质杠杆

正繁华拥挤的上海,建设用地占比45%,几近规划设定的"天花板"。今年上半年,上海连续发布多个土地节约集约利用政策,大力促进存量建设用地盘活利用,进一步提高土地利用质量,以土地利用方式转变促进经济转型升级。日前,记者专程前往上海采访,不过这次吸引记者的并不是土地政策本身,而是上海系列土地新政背后,地质工作为"节约集约利用土地,转变土地利用方式"提供的服务与支撑。     

耕地“净土”探路

正4月17日下午,《全国土壤污染状况调查公报》(简称《公报》)发布十几分钟后,李尧迅速将内容转到公司网站和微信圈里。作为北京一家土壤污染修复企业的负责人,李尧看到了所处行业的前景。"数据公开,表明了政府治理土壤污染的决心。"作为土壤污染的"重灾区",耕地的土壤修复却是业界公认的难点。近期,国家启动了湖南省长株潭重金属污染耕地修复综合治理试点,并提供专     

我国“科学号”在冲绳海槽科考满载而归

正5月12日,我国"科学"号海洋科考船完成首个科考任务返回青岛母港。在本次航行中,"科学"号科考船携带丰硕的成果满载而归:在冲绳海槽发现了2个"黑烟囱"、4个热液溢流区,采集到硫化物、岩石和沉积物等地质样品30多件。"科学"号首航承担的是中国科学院海洋先导性科技专项和国家"973计划"项目的西太平洋     

石旮旯变高产地——贵州省耕作层土壤剥离利用纪略

正地处云贵高原的贵州省,是全国唯一没有平原支撑的省份,山地和丘陵占全省面积的93%,喀斯特地貌占全省面积的62%,山多、石多、土少,优质耕地更少,耕作层土壤尤为稀缺。按照国家耕地质量15个自然等级标准,贵州省没有1~7等耕地,652万亩8~9等耕地是全省最好的耕地,人均仅0.16亩。按照贵州省委、省政府确定的人均0.5亩旱涝保收地的目标,全省还需建设高标准基本农田1398万亩。     

广西北部湾土壤地球化学基准值与背景值特征

文章统计了广西北部湾地区深层土壤地球化学基准值与表层土壤背景值,并且对表深层土壤元素含量特征进行对比研究。结果显示,大部分表层土壤元素对深层土壤有一定的继承性,少部分元素如Cd、N、P、Cl、S、有机碳等受表生迁移活动和人为活动因素影响又与深层土壤有所差异。     

柽柳对盐碱地生态环境的影响

<正>柽柳是一种盐生植物,具有很强的耐盐、抗旱、耐淹的生物学特征,广泛分布在内陆盐碱地和我国北方滨海湿地、滩涂,有"南有红树,北有柽柳"之说。柽柳是典型泌盐盐生植物,在盐碱地(含滨海湿地)种植形成柽柳林,不仅可以显著提高其物质生产、能量转换、气候与水分调节、水质净化、生物多样性保育、防风固沙/护堤等生态与环境功能[1-2],而且也是生物改良盐渍土的一种有效措施。种植柽