Heterogeneity of soil organic matter following death of individual plants in shortgrass steppe

Publication Type:

Journal Article

Source:

ECOLOGY, ECOLOGICAL SOC AMER, Volume 78, Number 4, 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036, p.1256-1261 (1997)

Keywords:

litterfall vs. decomposition, Northern Colorado (USA) shortgrass steppe, plant microsite, resource gap, semiarid ecosystems, shortgrass steppe soils, soil heterogeneity, soil organic matter

Abstract:

The shortgrass steppe of northern Colorado is characterized by patchy plant cover and associated spatial heterogeneity of soil resources. Zones of relatively high soil organic matter (SOM) under plants are maintained by direct litter inputs and physical stabilization of aeolian material. We studied the duration of plant-associated soil enrichment following plant death. We sampled soils between plants, under live plants, and under plants dead for 1, 9, and 36 mo. Live- and dead-plant soils were more enriched in total C and N than bare soils. We found a general pattern following plant death of initial active and total SOM increase due to greater litterfall than decomposition. Next, SOM decreased as substrate supplies declined, and decomposition continued. The temporal pattern depended upon SOM turnover. Though decomposition initially provided resources to maintain enriched plant-associated zones, our results suggest that enriched nutrient-supply zones under dead plants do not persist beyond several months.