Premium
Sagebrush Wildfire Effects on Surface Soil Nutrient Availability: A Temporal and Spatial Study
Author(s) -
Blank Robert R.,
ClementsTye Charlie,
Harmon MorganDan
Publication year - 2017
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2017.02.0039
Subject(s) - shrub , microsite , environmental science , nutrient , ecosystem , agronomy , ecology , biology , seedling
Core Ideas In sagebrush ecosystems, wildfire effects on surface soil nutrient availability varied spatially. Wildfire increased surface soil nutrient availability long‐term, mostly in shrub canopies. Soil nutrients of greatest increase with long‐lasting elevated levels included mineral N and Mn. Wildfires occurring in Artemisia (sagebrush) ecosystems can temporarily increase soil nutrient availability in surface soil. Less is known, however, on how soil nutrient availability changes over time and microsite post‐wildfire. In October 2013 a wildfire approximately 30 km north of Reno, Nevada, occurred in an Artemisia tridentata ssp. vaseyana (mountain big sagebrush) community. We quantified soil nutrient availability of surface soil (0–10 cm) by microsite (shrub interspace and shrub canopy), treatment (burned and unburned), and temporally (monthly from November 2013 through May 2015). Changes in nutrient availability, due to wildfire, largely occurred in shrub canopy microsites. For most months and relative to unburned shrub canopies, burned shrub canopies had elevated availability of mineral N (dominantly NH 4 + ‐N), bicarbonate‐extractable P, DTPA‐extractable Mn, and solution‐phase Ca +2 , Mg +2 , SO 4 –2 , K + , and ortho‐P. Burned shrub canopies also had, for most months, far less N mineralization potentials than unburned shrub canopies. The large increase in Mn availability in burned shrub canopies significantly correlates with mineral N and solution‐phase Ca +2 and SO 4 –2 , suggesting release via pyrolysis of soil organic matter. Except for a slight increase in solution‐phase Mg +2 , SO 4 –2 , and ortho‐P for particular months, there is little evidence for nutrient translocation from burned canopies to adjacent interspaces during the study. Density of the exotic annual grass Bromus tectorum increased from 5 to 10% cover pre‐wildfire to about 60% in the post‐wildfire growing season attesting to the importance of elevated soil nutrient availability to its growth.