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DOI	10.1002/lno.11081
	Scoured or suffocated: Urban stream ecosystems oscillate between hydrologic and dissolved oxygen extremes
	Blaszczak, Joanna R.1,2; Delesantro, Joseph M.3; Urban, Dean L.2; Doyle, Martin W.2; Bernhardt, Emily S.1
通讯作者	Blaszczak, Joanna R.
来源期刊	LIMNOLOGY AND OCEANOGRAPHY
ISSN	0024-3590
EISSN	1939-5590
出版年	2019
卷号	64 期号:3 页码:877-894
英文摘要	Headwater streams draining urbanized watersheds are subject to frequent and intense storm flows. These floods can disrupt metabolic processes occurring in benthic biofilms via the removal of biomass (i.e., scouring flows, bed mobilization) or light attenuation due to turbidity. Furthermore, channel incision caused by frequent hydraulic disturbance alters the geomorphology of streams, indirectly changing the flow and light regimes experienced by benthic biofilms. We measured dissolved oxygen (DO) and modeled whole-stream metabolism for 18 months in six urban headwater streams in the North Carolina Piedmont, U.S.A. All streams were heterotrophic and had low rates of productivity despite relatively high streamwater nutrient concentrations. Light availability at the channel surface explained more of the day to day variation in gross primary productivity within each stream than did hydrologic disturbance. Yet among streams, the explanatory power of light declined with increasing hydrologic flashiness. We found a surprisingly wide range in DO regimes, which ranged from frequent hypoxia to near constant saturation. Hypoxia was more common in streams with lower channel gradients where bedrock outcroppings and culverts create rapid slope transitions between pools. We hypothesize this geomorphic change increases the susceptibility of benthic biota to perturbation during storms and the mean water residence time during baseflow. Increased water residence times together with elevated organic matter and nutrient inputs can set up ideal conditions for hypoxia at baseflows punctuated by frequent scouring storm flows. As a result, benthic biota are caught between hydrologic and chemical extremes that constrain their productivity.
类型	Article
语种	英语
国家	USA
开放获取类型	hybrid
收录类别	SCI-E
WOS记录号	WOS:000467593600004
WOS关键词	TEMPORAL VARIABILITY ; DESERT STREAM ; LAND-USE ; METABOLISM ; URBANIZATION ; RIVER ; DISTURBANCE ; PERIPHYTON ; ECOLOGY ; REGIMES
WOS类目	Limnology ; Oceanography
WOS研究方向	Marine & Freshwater Biology ; Oceanography
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/217507
作者单位	1.Duke Univ, Dept Biol, Durham, NC 27708 USA; 2.Duke Univ, Nicholas Sch Environm, Durham, NC 27708 USA; 3.Univ N Carolina, Dept Geog, Chapel Hill, NC 27515 USA
推荐引用方式 GB/T 7714	Blaszczak, Joanna R.,Delesantro, Joseph M.,Urban, Dean L.,et al. Scoured or suffocated: Urban stream ecosystems oscillate between hydrologic and dissolved oxygen extremes[J],2019,64(3):877-894.
APA	Blaszczak, Joanna R.,Delesantro, Joseph M.,Urban, Dean L.,Doyle, Martin W.,&Bernhardt, Emily S..(2019).Scoured or suffocated: Urban stream ecosystems oscillate between hydrologic and dissolved oxygen extremes.LIMNOLOGY AND OCEANOGRAPHY,64(3),877-894.
MLA	Blaszczak, Joanna R.,et al."Scoured or suffocated: Urban stream ecosystems oscillate between hydrologic and dissolved oxygen extremes".LIMNOLOGY AND OCEANOGRAPHY 64.3(2019):877-894.