School of Natural Resources, University of Missouri, Columbia, MO 65211, USA.
Water Resources Program, School of Natural Resources, Department of Forestry, University of Missouri, Columbia, MO 65211, USA.
Sci Total Environ. 2015 Oct 1;529:82-90. doi: 10.1016/j.scitotenv.2015.05.052. Epub 2015 May 22.
Considering the increasing pace of global land use change and the importance of groundwater quality to humans and aquatic ecosystems, studies are needed that relate land use types to patterns of groundwater chemical composition. Piezometer grids were installed in a remnant bottomland hardwood forest (BHF) and a historic agricultural field (Ag) to compare groundwater chemical composition between sites with contrasting land use histories. Groundwater was sampled monthly from June 2011 to June 2013, and analyzed for 50 physiochemical metrics. Statistical tests indicated significant differences (p<0.05) between the study sites for 32 out of 50 parameters. Compared to the Ag site, BHF groundwater was characterized by significantly (p<0.05) lower pH, higher electrical conductivity, and higher concentrations of total dissolved solids and inorganic carbon. BHF groundwater contained significantly (p<0.05) higher concentrations of all nitrogen species except nitrate, which was higher in Ag groundwater. BHF groundwater contained significantly (p<0.05) higher concentrations of nutrients such as sulfur, potassium, magnesium, calcium, and sodium, relative to the Ag site. Ag groundwater was characterized by significantly (p<0.05) higher concentrations of trace elements such as arsenic, cadmium, cobalt, copper, molybdenum, nickel, and titanium. Comparison of shallow groundwater chemical composition with that of nearby receiving water suggests that subsurface concentration patterns are the result of contrasting site hydrology and vegetation. Results detail impacts of surface vegetation alteration on subsurface chemistry and groundwater quality, thereby illustrating land use impacts on the lithosphere and hydrosphere. This study is among the first to comprehensively characterize and compare shallow groundwater chemical composition at sites with contrasting land use histories.
考虑到全球土地利用变化的步伐不断加快，以及地下水质量对人类和水生生态系统的重要性，需要研究土地利用类型与地下水化学组成模式之间的关系。在残留的底层硬木林（BHF）和历史悠久的农田（Ag）中安装了测压计网格，以比较具有不同土地利用历史的地点的地下水化学组成。从 2011 年 6 月到 2013 年 6 月，每月从地下水取样一次，并分析了 50 种物理化学指标。统计检验表明，在 50 个参数中的 32 个参数中，研究地点之间存在显著差异（p<0.05）。与 Ag 地点相比，BHF 地下水的 pH 值显著（p<0.05）较低，电导率较高，总溶解固体和无机碳浓度较高。BHF 地下水的所有氮物种浓度均显著（p<0.05）高于硝酸盐，而硝酸盐在 Ag 地下水中的浓度较高。BHF 地下水的养分浓度（如硫，钾，镁，钙和钠）明显（p<0.05）高于 Ag 地点。Ag 地下水的微量元素浓度（如砷，镉，钴，铜，钼，镍和钛）明显（p<0.05）较高。与附近受纳水的浅层地下水化学成分比较表明，地下浓度模式是由于对比地点的水文和植被不同造成的。结果详细说明了地表植被变化对地下化学和地下水质量的影响，从而说明了土地利用对岩石圈和水圈的影响。这项研究是首次全面描述和比较具有不同土地利用历史的地点的浅层地下水化学组成的研究之一。
