Respiratory C fluxes and root exudation differ in two full-sib clones of Pinus taeda (L.) under contrasting fertilizer regimes in a greenhouse

• Published in: Plant and soil Vol. 363; no. 1/2; pp. 257 - 271
• Main Authors: Stovall, Jeremy P., Seiler, John R., Fox, Thomas R.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01-02-2013; Springer Netherlands; Springer Nature B.V
• Subjects: Acid soils; Agricultural site preparation; Agrology; Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Biological and medical sciences; Biomedical and Life Sciences; Carbon dioxide; Ecology; Environmental aspects; Exudation; Fertilizer application; Fertilizers; Forest soils; Forestry; Forestry research; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Genotype & phenotype; Genotypes; Greenhouses; Growth rate; Life Sciences; Pine; Pine trees; Pinus taeda; Plant growth; Plant Physiology; Plant roots; Plant Sciences; Plant-soil relationships; Regular Article; Root exudates; Seedlings; Soil fertility; Soil respiration; Soil science; Soil Science & Conservation; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; United States; efflux; Intensive silviculture; Soil CO; Varietal forestry; Carbon allocation; Gas emission; Full sib; Silviculture; Carbon dioxide; Pinus taeda; Allocation; Softwood forest tree; Gymnospermae; Clone; Root; Flux; Carbon; Fertilizers; Soils; Vegetative apparatus; Forestry; Coniferales; Spermatophyta; Exudation; Greenhouse; Soil plant relation; Respiration; Variety
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-012-1319-z

Aims We investigated whether changes in respiratory C fluxes, soil CO₂ efflux, or root exúdate quantity or quality explained differences in growth rates between closely related clones of Pinus taeda (L.). Methods A factorial design with two clones, fertilized and control treatments, and four sequential harvests was installed in a greenhouse for 121 days. Results The two clones did show significant differences in respiratory C fluxes, soil CO₂ efflux, and root exudation quantity and quality. While the clones also differed in growth rates, the C fluxes assessed in this paper did not explain how seedlings were able to allocate more C to stem growth in the months following fertilizer application. Changes in root exudation were not consistent with reduced heterotrophic soil CO₂ efflux, which does not appear to be a plant-mediated process. Conclusions These results indicate that if single genotypes are deployed over large land areas in plantations, dramatic differences between clonal plant-soil interactions may require consideration in ecosystem C budgets. Further, the range of belowground fluxes observed implies that genotype-specific C allocation may make some clones better able to exploit a given resource environment than others.