Elevated atmospheric carbon dioxide and leaf litter chemistry: Influences on microbial respiration and net nitrogen mineralization

Journal Article · Sun Sep 01 04:00:00 EDT 1996 · Soil Science Society of America Journal

DOI:https://doi.org/10.2136/sssaj1996.03615995006000050041x· OSTI ID:420856

Randlett, D L; Zak, D R ^[1]; Pregitzer, K S ^[2]; Curtis, P S ^[3]

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1. Univ. of Michigan, Ann Arbor, MI (United States)
2. Michigan Technical Univ., Houghton, MI (United States)
3. Ohio State Univ., Columbus, OH (United States)

Elevated atmospheric CO{sub 2} has the potential to influence rates of C and N cycling in terrestrial ecosystems by altering plant litter chemistry and slowing rates of organic matter decomposition. We tested the hypothesis that the chemistry of leaf litter produced at elevated CO{sub 2} would slow C and N transformations in soil. Soils were amended with Populus leaf produced under two levels of atmospheric CO{sub 2} (ambient and twice-ambient) and soil N availability (low and high). Kinetic parameters for microbial respiration and net N mineralization were determined on soil with and without litter during a 32-wk lab incubation. Product accumulation curves for CO{sub 2}-C and inorganic N were fit to a first order rate equation [y=A(1-e{sup -kt})] using nonlinear regression analyses. Although CO{sub 2} treatment affected soluble sugar concentration in leaf litter (ambient =120 g kg{sup -1}, elevated =130 g kg{sup -1}), it did not affect starch concentration or C/N ratio. Microbial respiration, microbial biomass, and leaf litter C/N ratio were affected by soil N availability but not by atmospheric CO{sub 2}. Net N mineralization was a linear function of time and was not significantly different for leaves grown at ambient (50 mg N kg{sup -1}) and elevated CO{sub 2} (35 mg N kg{sup -1}). Consequently, we found no evidence for the hypothesis that leaf litter produced at elevated atmospheric CO{sub 2} will dampen the rates of C and N cycling in soil. 35 refs., 1 fig., 4 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 420856
• Journal Information: Soil Science Society of America Journal, Journal Name: Soil Science Society of America Journal Journal Issue: 5 Vol. 60; ISSN 0361-5995; ISSN SSSJD4
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
54 ENVIRONMENTAL SCIENCES
55 BIOLOGY AND MEDICINE
BASIC STUDIES
58 GEOSCIENCES
CARBON CYCLE
CARBON DIOXIDE
CHEMISTRY
ECOSYSTEMS
EXPERIMENTAL DATA
FOREST LITTER
FORESTS
MINERALIZATION
NITROGEN
RESPIRATION