Deposition of sand over a cyanobacterial soil crust increases nitrogen bioavailability in a semi–arid woodland

Williams, Wendy J. and Eldridge, David J. (2011) Deposition of sand over a cyanobacterial soil crust increases nitrogen bioavailability in a semi–arid woodland. Applied Soil Ecology, 49 1: 26-31. doi:10.1016/j.apsoil.2011.07.005


Author Williams, Wendy J.
Eldridge, David J.
Title Deposition of sand over a cyanobacterial soil crust increases nitrogen bioavailability in a semi–arid woodland
Journal name Applied Soil Ecology   Check publisher's open access policy
ISSN 0929-1393
1873-0272
Publication date 2011-09
Sub-type Article (original research)
DOI 10.1016/j.apsoil.2011.07.005
Volume 49
Issue 1
Start page 26
End page 31
Total pages 6
Place of publication Amsterdam, Netherlands
Publisher Elsevier BV
Collection year 2012
Language eng
Formatted abstract
The movement of sand by erosion is a common feature of drylands during droughts and periods of sparse vascular plant cover. We examined the effects of sand deposition on the bioavailability of N in cyanobacterial-dominant soil crusts during and after a severe drought. Crusts were sampled from two depths on stony and stone-free surfaces with and without sandy deposits. All sites supported an extensive cover (up to 51%) of N-fixing cyanobacteria and cyanolichens. During drought, sand-covered crusts had up to three-times more mineral N (NH4+ and NO3) and twice the mineralisable N, at both depths, than sand-free samples. Mineralisable N was always greater in the surface soil layer both during and after drought. During the drought, two common N-fixing cyanobacteria (Scytonema cf. hofman-bangii, Stigonema ocellatum) were significantly more abundant on uncovered than sand-covered surfaces. Increased N bioavailability likely results from autolysis and subsequent breakdown of N-enriched cyanobacterial cell material mediated by changes in the soil surface microenvironment. Our work suggests that landscape-level processes of sand deposition have a marked effect on soil nutrient pools by enhancing the accumulation of plant-available N on cyanobacterial crusted surfaces. Inappropriate land management or the loss of cyanobacterial soil crusts during drought would compromise the long-term bioavailability of soil N.
Keyword Microbiotic soil crusts
Cyanobacterial soil crusts
Drylands
Cyanolichens
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2012 Collection
School of Agriculture and Food Sciences
 
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Created: Wed, 28 Dec 2011, 09:49:32 EST by Wendy Williams on behalf of School of Agriculture and Food Sciences