Plant functional type effects on trace gas fluxes in the shortgrass steppe

• Published in: Biogeochemistry 1998-08, Vol.42 (1-2), p.145-168
• Main Authors: Epstein, H.E. (Colorado State Univ., Fort Collins, CO (USA). Dept. of Forest Science), Burke, I.C, Mosier, A.R, Hutchinson, G.L
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Animal and plant ecology; Animal, plant and microbial ecology; Atmosphere; Biogeochemistry; Biological and medical sciences; C3 PLANTS; C4 PLANTS; Chemical, physicochemical, biochemical and biological properties; Clay loam; COMMUNAUTE VEGETALE; Community composition; Community structure; COMUNIDADES VEGETALES; DENITRIFICACION; DENITRIFICATION; ECHANGE GAZEUX; Environmental conditions; Fundamental and applied biological sciences. Psychology; GAS EXCHANGE; Gases; Grasses; Grassland soils; GRASSLANDS; Growing season; HERBAGE; INTERCAMBIO DE GASES; Loam soils; METANO; METHANE; NITRIC OXIDE; NITRIFICACION; NITRIFICATION; NITROUS OXIDE; Organic matter; OXIDO NITRICO; OXIDO NITROSO; OXYDE NITREUX; OXYDE NITRIQUE; Physics, chemistry, biochemistry and biology of agricultural and forest soils; PLANT COMMUNITIES; Plant ecology; PLANTAS C3; PLANTAS C4; PLANTE EN C3; PLANTE EN C4; Plants; PRADERAS; Soil air; Soil ecology; Soil science; Soil temperature; Soil water; Steppes; Synecology; Terrestrial ecosystems
• ISSN: 0168-2563; 1573-515X
• DOI: 10.1023/A:1005959001235

Plant community structure is expected to regulate the microbial processes of nitrification and denitrification by controlling the availability of inorganic N substrates. Thus it could also be a factor in the concomitant release of NO and N2O from soils as a result of these processes. C3 and C4 plants differ in several attributes related to the cycling of nitrogen and were hypothesized to yield differences in trace gas exchange between soil and atmosphere. In this study we estimated fluxes of NO, N2O and CH4 from soils of shortgrass steppe communities dominated by either C3 plants, C4 plants or mixtures of the two types. We collected gas samples weekly from two sites, a sandy clay loam and a clay, throughout the growing seasons of 1995 and 1996 Plant functional type effects on gas fluxes at the clay site were not apparent, however we found several differences among plant communities on the sandy clay loam. CH4 uptake from atmosphere to soil was significantly greater on C4 plots than C3 plots in both years. NO fluxes were significantly greater from C4 plots than from C3 plots in 1995. NO fluxes from C3 and mixed plots were not significantly different between 1995 and 1996, however fluxes from C4 plots were significantly greater in 1995 compared to 1996. Results indicate that under certain environmental conditions, particularly when factors such as moisture and temperature are not limiting, plant community composition can play an important role in regulating trace gas exchange.