Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1890/1051-0761(2001)011[1301:EPIAND]2.0.CO;2 |
Exotic plant invasion alters nitrogen dynamics in an arid grassland | |
Evans, RD; Rimer, R; Sperry, L; Belnap, J | |
通讯作者 | Evans, RD |
来源期刊 | ECOLOGICAL APPLICATIONS
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ISSN | 1051-0761 |
出版年 | 2001 |
卷号 | 11期号:5页码:1301-1310 |
英文摘要 | The introduction of normative plant species may decrease ecosystem stability by altering the availability of nitrogen (N) for plant growth. Invasive species can impact N availability by changing litter quantity and quality, rates of N-2-fixation, or rates of N loss. We quantified the effects of invasion by the annual grass Bromus tectorum on N cycling in an arid grassland on the Colorado Plateau (USA). The invasion occurred in 1994 in two community types in an undisturbed grassland. This natural experiment allowed us to measure the immediate responses following invasion without the confounding effects of previous disturbance. Litter biomass and the C:N and lignin:N ratios were measured to determine the effects on litter dynamics. Long-term soil incubations (415 d) were used to measure potential microbial respiration and net N mineralization. Plant-available N was quantified for two years in situ with ion-exchange resin bags, and potential changes in rates of gaseous N loss were estimated by measuring denitrification enzyme activity. Bromus invasion significantly increased litter biomass, and Bromus litter had significantly greater C:N and lignin:N ratios than did native species. The change in litter quantity and chemistry decreased potential rates of net N mineralization in sites with Bromus by decreasing nitrogen available for microbial activity. Inorganic N was 50% lower on Hilaria sites with Bromus during the spring of 1997, but no differences were observed during 1998. The contrasting differences between years are likely due to moisture availability; spring precipitation was 15% greater than average during 1997, but 52% below average during spring of 1998. Bromus may cause a short-term decrease in N loss by decreasing substrate availability and denitrification enzyme activity, but N loss is likely to be greater in invaded sites in the long term because of increased fire frequency and greater N volatilization during fire. We hypothesize that the introduction of Bromus in conjunction with land-use change has established a series of positive feedbacks that will decrease N availability and alter species composition. |
英文关键词 | Bromus tectorum Canyonlands National Park, Utah, USA denitrification enzyme activity desert vegetation ecosystem carbon ecosystem nitrogen grasslands invasive species litter, changes in biomass and chemistry N mineralization plant-available N following plant invasion plant invasion, litter quality |
类型 | Article |
语种 | 英语 |
国家 | USA |
收录类别 | SCI-E |
WOS记录号 | WOS:000171417700005 |
WOS关键词 | EXCHANGE RESIN BAGS ; CHEATGRASS BROMUS-TECTORUM ; CANYONLANDS-NATIONAL-PARK ; SOIL MICROBIAL BIOMASS ; SHRUB-STEPPE ECOSYSTEM ; BIOLOGICAL INVASIONS ; N-MINERALIZATION ; SHORTGRASS STEPPE ; GLOBAL CHANGE ; DESERT SOILS |
WOS类目 | Ecology ; Environmental Sciences |
WOS研究方向 | Environmental Sciences & Ecology |
来源机构 | United States Geological Survey |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/140604 |
作者单位 | (1)Univ Arkansas, State Isotype Lab, Fayetteville, AR 72701 USA;(2)US Geol Survey, Moab, UT 84532 USA |
推荐引用方式 GB/T 7714 | Evans, RD,Rimer, R,Sperry, L,et al. Exotic plant invasion alters nitrogen dynamics in an arid grassland[J]. United States Geological Survey,2001,11(5):1301-1310. |
APA | Evans, RD,Rimer, R,Sperry, L,&Belnap, J.(2001).Exotic plant invasion alters nitrogen dynamics in an arid grassland.ECOLOGICAL APPLICATIONS,11(5),1301-1310. |
MLA | Evans, RD,et al."Exotic plant invasion alters nitrogen dynamics in an arid grassland".ECOLOGICAL APPLICATIONS 11.5(2001):1301-1310. |
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