Disentangling effects of air and soil temperature on C allocation in cold environments: A 14C pulse‐labelling study with two plant species

Autor: Pascal A. Niklaus, Frank Hagedorn, Adele Ferrari
Přispěvatelé: University of Zurich, Niklaus, Pascal Alex
Jazyk: angličtina
Rok vydání: 2018
Předmět:
0106 biological sciences
1403 Business and International Management
Evolution
growth
air‐soil temperature interaction
Photosynthesis
01 natural sciences
Sink (geography)
Carbon cycle
10127 Institute of Evolutionary Biology and Environmental Studies
Leucanthemopsis alpina
Behavior and Systematics
lcsh:QH540-549.5
Ecosystem
1405 Management of Technology and Innovation
Ecology
Evolution
Behavior and Systematics
Nature and Landscape Conservation
Rhizosphere
geography
geography.geographical_feature_category
photosynthesis
Ecology
Pinus mugo
04 agricultural and veterinary sciences
soil and root respiration
Agronomy
Soil water
040103 agronomy & agriculture
0401 agriculture
forestry
and fisheries
Environmental science
570 Life sciences
biology
590 Animals (Zoology)
lcsh:Ecology
Microcosm
Cycling
010606 plant biology & botany
Zdroj: Ecology and Evolution, Vol 8, Iss 16, Pp 7778-7789 (2018)
ISSN: 2045-7758
Popis: Carbon cycling responses of ecosystems to global warming will likely be stronger in cold ecosystems where many processes are temperature‐limited. Predicting these effects is difficult because air and soil temperatures will not change in concert, and will affect above and belowground processes differently. We disentangled above and belowground temperature effects on plant C allocation and deposition of plant C in soils by independently manipulating air and soil temperatures in microcosms planted with either Leucanthemopsis alpina or Pinus mugo seedlings. Daily average temperatures of 4 or 9°C were applied to shoots and independently to roots, and plants pulse‐labelled with 14CO2. We traced soil CO2 and 14CO2 evolution for 4 days, after which microcosms were destructively harvested and 14C quantified in plant and soil fractions. In microcosms with L. alpina, net 14C uptake was higher at 9°C than at 4°C soil temperature, and this difference was independent of air temperature. In warmer soils, more C was allocated to roots at greater soil depth, with no effect of air temperature. In P. mugo microcosms, assimilate partitioning to roots increased with air temperature, but only when soils were at 9°C. Higher soil temperatures also increased the mean soil depth at which 14C was allocated. Our findings highlight the dependence of C uptake, use, and partitioning on both air and soil temperature, with the latter being relatively more important. The strong temperature‐sensitivity of C assimilate use in the roots and rhizosphere supports the hypothesis that cold limitation on C uptake is primarily mediated by reduced sink strength in the roots. We conclude that variations in soil rather than air temperature are going to drive plant responses to warming in cold environments, with potentially large changes in C cycling due to enhanced transfer of plant‐derived C to soils.
Databáze: OpenAIRE
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