Abundance, Activity and Community Structure of Denitrifiers in Drainage Ditches in Relation to Sediment Characteristics, Vegetation and Land-Use

Abundance, Activity and Community Structure of Denitrifiers in Drainage Ditches in Relation to... Drainage ditches are ubiquitous yet understudied features of the agricultural landscape. Nitrogen pollution disrupts the nutrient balance of drainage ditch ecosystems, as well as the waterbodies in which they drain. Denitrification can help ameliorate the impact of N-fertilization by converting reactive nitrogen into dinitrogen gas. However, factors affecting denitrification in drainage ditches are still poorly understood. In this study, we tested how within-ditch and regional environmental conditions affect denitrifier activity, abundance, and community structure, to understand controls on denitrification at multiple scales. To this end, we quantified in situ denitrification rates and denitrifier abundance in 13 drainage ditches characterized by different types of sediment, vegetation and land-use. We determined how denitrification rates relate to denitrifier abundance and community structure, using the presence of nirS, nirK and nosZ genes as a proxy. Denitrification rates varied widely between the ditches, ranging from 0.006 to 24 mmol N m−2 h−1. Ditches covered by duckweed, which contained high nitrate concentrations and had fine, sandy sediments, were denitrification hotspots. We found highest rates in ditches next to arable land, followed by those in grasslands; lowest rates were observed in peatlands and nature reserves. Denitrification correlated to nitrate concentrations, but not to nirK, nirS and nosZ abundance, whereas denitrifier-gene abundance correlated to organic matter content of the sediment, but not to nitrate concentrations. Our results show a mismatch in denitrification regulators at its different organizational scales. Denitrifier abundance is mostly regulated at within-ditch scales, whereas N-loads, regulated by landscape factors, are most important determinants of instantaneous denitrification rates. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Ecosystems Springer Journals

Abundance, Activity and Community Structure of Denitrifiers in Drainage Ditches in Relation to Sediment Characteristics, Vegetation and Land-Use

Loading next page...
 
/lp/springer_journal/abundance-activity-and-community-structure-of-denitrifiers-in-drainage-i9TegE8KAM
Publisher
Springer US
Copyright
Copyright © 2016 by The Author(s)
Subject
Life Sciences; Ecology; Plant Sciences; Zoology; Environmental Management; Geoecology/Natural Processes; Hydrology/Water Resources
ISSN
1432-9840
eISSN
1435-0629
D.O.I.
10.1007/s10021-016-0083-y
Publisher site
See Article on Publisher Site

Abstract

Drainage ditches are ubiquitous yet understudied features of the agricultural landscape. Nitrogen pollution disrupts the nutrient balance of drainage ditch ecosystems, as well as the waterbodies in which they drain. Denitrification can help ameliorate the impact of N-fertilization by converting reactive nitrogen into dinitrogen gas. However, factors affecting denitrification in drainage ditches are still poorly understood. In this study, we tested how within-ditch and regional environmental conditions affect denitrifier activity, abundance, and community structure, to understand controls on denitrification at multiple scales. To this end, we quantified in situ denitrification rates and denitrifier abundance in 13 drainage ditches characterized by different types of sediment, vegetation and land-use. We determined how denitrification rates relate to denitrifier abundance and community structure, using the presence of nirS, nirK and nosZ genes as a proxy. Denitrification rates varied widely between the ditches, ranging from 0.006 to 24 mmol N m−2 h−1. Ditches covered by duckweed, which contained high nitrate concentrations and had fine, sandy sediments, were denitrification hotspots. We found highest rates in ditches next to arable land, followed by those in grasslands; lowest rates were observed in peatlands and nature reserves. Denitrification correlated to nitrate concentrations, but not to nirK, nirS and nosZ abundance, whereas denitrifier-gene abundance correlated to organic matter content of the sediment, but not to nitrate concentrations. Our results show a mismatch in denitrification regulators at its different organizational scales. Denitrifier abundance is mostly regulated at within-ditch scales, whereas N-loads, regulated by landscape factors, are most important determinants of instantaneous denitrification rates.

Journal

EcosystemsSpringer Journals

Published: Nov 23, 2016

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off