Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1029/2007JG000588 |
Hot spots and hot moments of carbon and nitrogen dynamics in a semiarid riparian zone | |
Harms, Tamara K.; Grimm, Nancy B. | |
通讯作者 | Harms, Tamara K. |
来源期刊 | JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
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ISSN | 0148-0227 |
出版年 | 2008 |
卷号 | 113期号:G1 |
英文摘要 | Riparian ecosystems are characterized by spatial and temporal heterogeneity in physical and biological attributes, with consequences for nutrient cycling. We investigated the responses of carbon (C) and nitrogen (N) cycling processes to the hydrogeomorphic template in the riparian zone of the San Pedro River, Arizona, a large (catchment area similar to 11,500 km(2)), free-flowing, semiarid river. Over an annual period we documented spatial and temporal patterns in soil, shallow groundwater, and stream nutrient chemistry as well as rates of N-transforming processes in soils of the surface (0-17 cm) and region of seasonal saturation (RoSS). A hot moment of N retention and removal was indicated by elevated rates of microbial processes during the summer monsoon season. At the same time, elevated C was observed in soil microbial biomass for both surface soils and soils in the RoSS. Analyses of C-use profiles for soil microbes, coupled with trends in stream and shallow-groundwater chemistry, further suggest that this hot moment of N removal was fueled by newly available, labile organic material. In a spatial context, patchiness in soil resources, microbial biomass, and potential denitrification were best explained by variation in microtopography; low-elevation landscape positions were hot spots of resource availability and microbial activity. Vertical heterogeneity also corresponded with variation in the factors influencing N transformation rates. Organic matter was more frequently a significant factor explaining N transformation rates in RoSS soils whereas soil water content was more often important in surface soils. Together, these patterns suggest that understanding the points on the hydrogeomorphic template, both in space and in time, that bring together water and labile organic matter will lead to greater predictive capability regarding C and N cycling in semiarid river-riparian corridors. |
类型 | Article |
语种 | 英语 |
国家 | USA |
收录类别 | SCI-E |
WOS记录号 | WOS:000254166100002 |
WOS关键词 | DISSOLVED ORGANIC-CARBON ; SAN-PEDRO RIVER ; NITRATE DYNAMICS ; DESERT STREAM ; FLOODPLAIN FOREST ; LANDSCAPE ECOLOGY ; FLASH FLOODS ; ECOSYSTEM ; SOIL ; DENITRIFICATION |
WOS类目 | Environmental Sciences ; Geosciences, Multidisciplinary |
WOS研究方向 | Environmental Sciences & Ecology ; Geology |
来源机构 | Arizona State University |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/158223 |
作者单位 | Arizona State Univ, Sch Life Sci, Tempe, AZ 85287 USA |
推荐引用方式 GB/T 7714 | Harms, Tamara K.,Grimm, Nancy B.. Hot spots and hot moments of carbon and nitrogen dynamics in a semiarid riparian zone[J]. Arizona State University,2008,113(G1). |
APA | Harms, Tamara K.,&Grimm, Nancy B..(2008).Hot spots and hot moments of carbon and nitrogen dynamics in a semiarid riparian zone.JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES,113(G1). |
MLA | Harms, Tamara K.,et al."Hot spots and hot moments of carbon and nitrogen dynamics in a semiarid riparian zone".JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES 113.G1(2008). |
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