Controls on the Plant-Soil Stoichiometry of Dryland Agroecosystems: A Sabbatical Strengthening Grant
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Controls on the Plant-Soil Stoichiometry of Dryland Agroecosystems: A Sabbatical Strengthening Grant (Grant #2013-67020-21354) Rebecca L. McCulley, Dept. of Plant & Soil Sciences, Univ. of Kentucky, USA Catarina Moura, Centre for Functional Ecology, Dept. of Life Sciences, Univ. of Coimbra, Coimbra, PT Maria Caldeira, Centro de Estudos Florestais, Instituto Superior de Agronomia, Lisbon, PT Obj. 1: Quantify how human management of cork oak savannas impacts plant and soil C:N:P Figure 2. Conceptual diagram illustrating how human use alters the ecosystem services of cork oak savanna (from Bugalho et al. 2011). PES – payment for ecosystem services. References: • Bugalho, MN, MC Caldeira, JS Pereira, J Aronson, and JG Pausas. 2011. Meditteranean cork oak savannas require human use to sustain biodiversity and ecosystem services. Frontiers in Ecology & the Environment 9(5):278- 286. • Parisi A.V., P. Schouten, N.J. Downs, J. Turner. 2010. Solar UV exposures measured simultaneously to all arbitrarily oriented leaves on a plant. Journal of Photochemistry and Photobiology B: Biology 99:87-92. Obj. 2: Assess interactive effects of woody plant encroachment and ultraviolet (UV) radiation on litter decomposition in cork oak savannas. Acknowledgements: Future Work - Obj. 3: Evaluate the ability of a process-based model to capture the effects of these controlling parameters on dryland biogeochemical cycling. Figure 3. Photos of Cistus ladanifer shrub encroachment (left) and Sown Biodiverse Pasture (right) in central and eastern Portugal field sites. What has been achieved? • Plant & soil samples from two sites in central and eastern Portugal with adjacent, paired land uses have been sampled (Vila Viçosa – shrub encroachment and Herdade Machoqueria do Grou – sown biodiverse pasture). • Samples have been received in my lab and are in various stages of processing. • We will obtain δ 15 N data on the plant and soil material associated with the sown biodiverse pasture project – to assess N-fixation from the legumes. HMG VV Contact: [email protected] What has been achieved? • We have completed a 2-yr litter decomposition experiment at Vila Viçosa, which included: 3 litter types (oak, Cistus, herbaceous); 3 incubation locations (oak canopy, Cistus invaded, and herbaceous); 2 UV treatments (full and no UV); and 4 replicates. • Samples are in various stages of processing. • We also measured the UV environment of each location using polyphenylene oxide films (Parisi et al. 2010). Photos of litter decomposition plots, and a graph of estimated daily UV doses measured in the three incubation locations. The sun illustrates the UV dose measured in full sun conditions at the site.
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Transcript of Controls on the Plant-Soil Stoichiometry of Dryland Agroecosystems: A Sabbatical Strengthening Grant
Controls on the Plant-Soil Stoichiometry of Dryland Agroecosystems: A Sabbatical Strengthening Grant (Grant #2013-67020-21354)
Rebecca L. McCulley, Dept. of Plant & Soil Sciences, Univ. of Kentucky, USACatarina Moura, Centre for Functional Ecology, Dept. of Life Sciences, Univ. of Coimbra, Coimbra, PTMaria Caldeira, Centro de Estudos Florestais, Instituto Superior de Agronomia, Lisbon, PT
Obj. 1: Quantify how human management of cork oak savannas impacts plant and soil C:N:P
Figure 2. Conceptual diagram illustrating how human use alters the ecosystem services of cork oak savanna (from Bugalho et al. 2011). PES – payment for ecosystem services.
References:• Bugalho, MN, MC Caldeira, JS Pereira, J Aronson, and JG Pausas. 2011.
Meditteranean cork oak savannas require human use to sustain biodiversity and ecosystem services. Frontiers in Ecology & the Environment 9(5):278-286.
• Parisi A.V., P. Schouten, N.J. Downs, J. Turner. 2010. Solar UV exposures measured simultaneously to all arbitrarily oriented leaves on a plant. Journal of Photochemistry and Photobiology B: Biology 99:87-92.
Obj. 2: Assess interactive effects of woody plant encroachment and ultraviolet (UV) radiation on litter decomposition in cork oak savannas.
Acknowledgements:
Future Work - Obj. 3: Evaluate the ability of a process-based model to capture the effects of these controlling parameters on dryland biogeochemical cycling.
Figure 3. Photos of Cistus ladanifer shrub encroachment (left) and Sown Biodiverse Pasture (right) in central and eastern Portugal field sites.
What has been achieved?• Plant & soil samples from two sites in central and eastern Portugal with adjacent,
paired land uses have been sampled (Vila Viçosa – shrub encroachment and Herdade Machoqueria do Grou – sown biodiverse pasture).
• Samples have been received in my lab and are in various stages of processing.• We will obtain δ15N data on the plant and soil material associated with the sown
biodiverse pasture project – to assess N-fixation from the legumes.
HMGVV
Contact:
What has been achieved?• We have completed a 2-yr litter decomposition experiment
at Vila Viçosa, which included: 3 litter types (oak, Cistus, herbaceous); 3 incubation locations (oak canopy, Cistusinvaded, and herbaceous); 2 UV treatments (full and no UV); and 4 replicates.
• Samples are in various stages of processing.• We also measured the UV environment of each location
using polyphenylene oxide films (Parisi et al. 2010).
Photos of litter decomposition plots, and a graph of estimated daily UV doses measured in the three incubation locations. The sun illustrates the UV dose measured in full sun conditions at the site.
