Details

Autor(en) / Beteiligte

• Chief, Karletta
• Young, Michael H
• Shafer, David S

Titel

Changes in Soil Structure and Hydraulic Properties in a Wooded-Shrubland Ecosystem following a Prescribed Fire

Ist Teil von

• Soil Science Society of America journal, 2012-11, Vol.76 (6), p.1965-1977

Ort / Verlag

Madison, WI: Soil Science Society of America

Erscheinungsjahr

2012

Link zum Volltext

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• Pre- and post-fire measurements were made for a low-intensity prescribed fire in a semiarid, shrub-woodland transition zone, and objectives were to: (i) determine changes in near-saturated hydraulic conductivity (K(f) measured with a tension infiltrometer), air permeability (k(a) measured with an air permeameter), and soil physical properties at shrub undercanopy and interspace microsites immediately before and after a fall burn and for a 13-mo period; and (ii) quantify the importance and effect of post-fire soil structure on hydraulic properties using pre- and post-fire measurements. At undercanopy microsites, structure deteriorated from a moderate to a weak subangular blocky structure after the fire that broke down to a structureless soil 10 mo later. At interspace microsites, post-fire soil structure deteriorated from a moderate-strong subangular blocky structure with hard dry consistency to a weak subangular blocky structure with soft dry consistency. After 10 mo, the intercanopy maintained a weak-moderate soil structure that became structureless-weak after 13 mo. Immediately after the fire, at both microsites, there was incomplete organic combustion, a decrease in bulk density, and an increase in ka; however, at undercanopy microsites, there was no significant change in K(f) even though there was a slight to moderate hydrophobicity, whereas at interspace microsites where no water repellency existed, K(f) increased. These changes may be a result of expansion of vaporized water through soil pores that broke up aggregates, deteriorating soil structure. Thus, mechanisms that contributed to changes immediately and after the first year post-fire were different for low-intensity burns than for higher intensity burns.