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ARS Home » Pacific West Area » Burns, Oregon » Range and Meadow Forage Management Research » Research » Publications at this Location » Publication #222741
Title: MICROSITE AND HERBACEOUS VEGETATION HETEROGENEITY AFTER BURNING ARTEMISIA TRIDENTATA STEPPE

Author
item Davies, Kirk
item Bates, Jonathan - Jon
item James, Jeremy

Submitted to: Oecologia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2008
Publication Date: 2/17/2009
Citation: Davies, K.W., Bates, J.D., James, J.J. 2009. MICROSITE AND HERBACEOUS VEGETATION HETEROGENEITY AFTER BURNING ARTEMISIA TRIDENTATA STEPPE. Oecologia 159:597-606

Interpretive Summary: Wyoming big sagebrush can create distinct underneath (subcanopy) and between shrub canopies (interspace) zones in plant communities. However, information detailing the impact of prescribed burning on zonal characteristics is lacking. The purpose of this study was to determine the influence of prescribed burning on subcanopy and interspace zones. Burned and unburned zones were compared at six locations at the Northern Great Basin Experimental Range. Zonal and former (burned) zonal herbaceous and microsite characteristics were measured the two years post-burn. Prescribed burning resulted in microsite and herbaceous vegetation differences between zones and former zones, while former subcanopies and former interspaces appear to be relatively similar. The similarity in former zonal microsite characteristics probably explains the lack of differences in herbaceous vegetation cover and biomass production. However, some microsite and herbaceous vegetation characteristics differed between former zones. Our results demonstrate that zones and former zones are dissimilar and former subcanopy and interspaces zone are similar in microsite and herbaceous vegetation characteristics. This suggests that prescribed burning reduces the microsite and herbaceous vegetation heterogeneity created by Wyoming big sagebrush. Our results also suggest that the effects of prescribed burning on herbaceous vegetation vary by zonal location. The results of this study are of interest to land managers and scientists.

Technical Abstract: Woody vegetation can create distinct subcanopy and interspace microsites, which often results in resource islands in subcanopies compared to interspaces. This heterogeneity in soil resources contributes to herbaceous vegetation heterogeneity in plant communities. However, information detailing the impact of disturbance, such as fire, that removes the woody vegetation on microsites and herbaceous vegetation heterogeneity is limited. The purpose of this study was to determine the influence of burning on microsites and herbaceous vegetation in subcanopies and interspaces. Six study sites (blocks) were located at the Northern Great Basin Experimental Range (NGBER) in shrub (Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh)-bunchgrass plant communities and one half of each block was burned to remove A. tridentata. Herbaceous vegetation and microsite characteristics were measured two years post-fire in intact and burned subcanopies and interspaces. Burning resulted in microsite and herbaceous vegetation differences between intact and burned subcanopies and intact and burned interspaces. However, burned subcanopies and burned interspaces appeared to be relatively similar. The similarity in microsite characteristics probably explains the lack of differences in herbaceous vegetation cover and biomass production between burned subcanopies and burned interspaces (P > 0.05). However, some microsite and herbaceous vegetation characteristics differed between burned subcanopies and burned interspaces. Our results suggest that disturbances that remove woody vegetation reduced microsite and herbaceous vegetation heterogeneity within plant communities, but do not completely remove the resource island effect. This suggests soil resource heterogeneity may influence post-fire community assembly and contribute to diversity maintenance.