The Role of Calcium Supply In The Structure and Function of a Northern Hardwood Forest

摘要建议#：9726837调查员(S)：德里斯科尔机构：锡拉丘兹大学在新罕布夏州和北美东部其他地方的哈伯德布鲁克实验森林的长期研究表明，酸雨会耗尽贫碱土壤中的大量钙。钙是森林生态系统的重要营养物质。钙的供应控制着土壤和水的酸度，并影响着北方森林和溪流的重要特征。这项研究将调查钙在森林和溪流生态中的作用。哈伯德布鲁克试验性分水岭的钙供应将通过试验性添加高度风化的硅酸钙矿物硅灰石来增强。硅灰石将在直升机上应用。添加的硅灰石将在大约七年内溶解，取代过去50年来从分水岭中耗尽的钙。硅灰石具有明显的稳定同位素特征，这将使添加的钙的运输和去向能够高灵敏度地被追踪。将测定土壤和水的化学性质、土壤微生物、土壤无脊椎动物群落、森林植被和溪流生物群的变化。持续监测将试图量化土壤钙含量与北部森林和溪流在很长时间尺度(即50年)的生态特征之间的因果关系。

ABSTRACT PROPOSAL # : 9726837 INVESTIGATOR(S) : DRISCOLL INSTITUTION: SYRACUSE UNIVERSITY Long-term studies at the Hubbard Brook Experimental Forest in New Hampshire and elsewhere in eastern North America have shown the depletion of large quantities of calcium from base-poor soil by acid rain. Calcium is an important nutrient of forest ecosystems. The supply of calcium controls the acidity of soil and waters, and influences important characteristics of northern forests and streams. This research will investigate the role of calcium in the ecology of forests and streams. The supply of calcium to an experimental watershed at Hubbard Brook will be enhanced by the experimental addition of a highly-weatherable calcium-silicate mineral, wollastonite. The wollastonite will be applied by helicopter. The added wollastonite will dissolve in approximately seven years, replacing the calcium that has been depleted from the watershed over the last 50 years. The wollastonite has a distinct stable isotope signature that will enable the transport and fate of added calcium to be traced with high sensitivity. Changes in the chemical characteristics of soil and water, the activity of soil microbes, soil invertebrate communities, forest vegetation and stream biota will be determined. Continued monitoring will attempt to quantify the cause-effect relationship between the soil calcium content and the ecological characteristics of northern forests and streams over very long time scales (i.e. 50 yr).