Plant species mediate changes in soil microbial N in response to elevated CO{sub 2}

Journal Article · Sun Dec 01 04:00:00 EST 1996 · Ecology

DOI:https://doi.org/10.2307/2265749· OSTI ID:443437

Hungate, B A; Canadell, J; Chapin, III, F S ^[1]

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1. Univ. of California, Berkeley, CA (United States)

The effect of elevated CO{sub 2} on plant-microbial interactions and nitrogen (N) cycling is critical to predicting plant growth responses to elevated CO{sub 2}, because plant growth is often N-limited. We investigated whether the effects of elevated CO{sub 2} on plant-microbial N dynamics differed among six annual plant species: three European grasses that have invaded California grasslands, and one grass and two forbs native to California serpentine grassland. Elevated CO{sub 2} altered plant N pools and {sup 15}NH{sub 4}{sup +} uptake, but the direction and magnitude of the changes were species dependent. The introduced grasses showed increased plant N pools and {sup 15}NH{sub 4}{sup +} uptake, whereas the native species showed smaller increases or even decreases in plant N pools and {sup 15}NH{sub 4}{sup +} uptake. Under nutrient enrichment, soil microbial N and {sup 15}NH{sub 4}{sup +} uptake differed among soils with different plant species, but they were not affected by elevated CO{sub 2}. At low nutrients, elevated CO{sub 2} altered soil microbial N and {sup 15}NH{sub 4}{sup +} uptake differed among soils with different plant species, but they were not affected by elevated CO{sub 2}. At low nutrients, elevated CO{sub 2} altered soil microbial N and {sup 15}NH{sub 4}{sup +} uptake, but the direction and magnitude of the changes were species dependent. The changes in soil microbial N were positively correlated with changes were species dependent. The changes in soil microbial N were positively correlated with changes in the plant N pool, suggesting that there was no trade-off in N uptake between plants and microbes. These results also suggest that plant species composition will partly determine the direction of changes in coil N cycling in response to elevated CO{sub 2}. 38 refs., 4 figs., 5 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 443437
• Journal Information: Ecology, Journal Name: Ecology Journal Issue: 8 Vol. 77; ISSN 0012-9658; ISSN ECOLAR
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BIOLOGICAL EFFECTS
CARBON DIOXIDE
MICROORGANISMS
NITROGEN CYCLE
PLANTS
RESPONSE MODIFYING FACTORS
SOILS