气候变化领域集成服务门户(CCPortal): The biotic contribution to the benthic stream sediment phosphorus buffer

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DOI	10.1007/s10533-020-00709-z
	The biotic contribution to the benthic stream sediment phosphorus buffer
	Simpson Z.P.; McDowell R.W.; Condron L.M.
发表日期	2020
ISSN	0168-2563
起始页码	63
结束页码	79
卷号	151 期号:1
英文摘要	Benthic stream sediments interact strongly with phosphorus (P) and can buffer dissolved reactive P (DRP) concentrations. The sediment P buffer can be measured with the sediment equilibrium phosphate concentration at net zero sorption (EPC0), which often correlates well with DRP. Yet, it is unclear how much of this P affinity in sediments is attributable to biotic (microbial P demand) or abiotic (sorption) processes. To clarify the role of biotic processes on EPC0, we used two experiments with benthic sediment from 12 streams. First, sediments sterilized by γ-irradiation increased in EPC0 compared to fresh sediments by a median of 83%. This increase in EPC0 was likely a result of cell lysis, where microbial biomass P (2.4 to 22.6 mg P kg−1) was re-adsorbed to sediment surfaces. This data also shows that the sediment microbial biomass is a significant, yet under-reported biotic stock of P in streams compared to their photic zone counterpart (i.e., periphyton). In a second experiment, fresh sediment EPC0 was measured after alleviating potential limitation of carbon (C) and nitrogen (N) for microbial growth. Sediment EPC0 did not change with C addition and decreased slightly (0.5 µg P L−1 or ~ 5% decrease) with N addition, suggesting these sediments strongly buffered DRP towards the EPC0 in spite of biotic demand. Together, these experiments suggest that sediment EPC0 was primarily abiotic in nature but that sediments may subsidize biotic P requirements through desorption. Further work is needed on whether this relation holds for streams with different substrate, geology, and nutrient inputs. © 2020, Springer Nature Switzerland AG.
英文关键词	Buffer; EPC0; Microbial biomass; Phosphorus; Sediment; Streams
语种	英语
scopus关键词	biomass; buffering; cell; equilibrium; experimental study; microbial activity; nutrient limitation; phosphate; sediment chemistry; stream
来源期刊	Biogeochemistry
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/153097
作者单位	Department of Soil and Physical Sciences, Lincoln University, Lincoln, New Zealand; AgResearch, Lincoln Science Centre, Lincoln, New Zealand
推荐引用方式 GB/T 7714	Simpson Z.P.,McDowell R.W.,Condron L.M.. The biotic contribution to the benthic stream sediment phosphorus buffer[J],2020,151(1).
APA	Simpson Z.P.,McDowell R.W.,&Condron L.M..(2020).The biotic contribution to the benthic stream sediment phosphorus buffer.Biogeochemistry,151(1).
MLA	Simpson Z.P.,et al."The biotic contribution to the benthic stream sediment phosphorus buffer".Biogeochemistry 151.1(2020).