Overview

Project Highlights: 

  • Leveraging the £15m national facility, BIFoR-Free Air Carbon Dioxide Experiment (FACE), and existing carbon budget measurement at BIFoR, this project will determine the nutrient (phosphorus, cations and micronutrients) cycling processes in a temperate forest under elevated carbon dioxide world.
  • This is the first study of its kind in a mature temperate forest, which will constrain earth system models and lead to a step change in our ability to predict climate change.
  • Interdisciplinary team of supervisors existing BIFoR students, and strong supports from BIFoR-FACE technical team

Enhanced plant growth as a result of elevated atmospheric carbon dioxide concentration (eCO2) and nutrient deposition has been estimated to be largely responsible for absorbing more than a quarter of recent anthropogenic CO2 emissions. The present-day global net land sink is located primarily in northern ecosystems, and in particular old-growth forests. Land C responses to eCO2 are potentially the most important, but also the most uncertain C-cycle feedback to climate change. This is primarily because availability of nutrients (macro- and micronutrients) may limit forest C sequestration, with models and empirical data identifying a potentially strong sensitivity of eCO2 response rates to the availability of nitrogen. This would imply that the potential for C uptake by terrestrial ecosystems may have been overestimated, adding tens of ppmv (15 – 150 ppmv) to the predicted 21st-century atmospheric CO2 concentration. If confirmed, a major reduction in allowable emissions of CO2 would be required to achieve the challenging < 2oC target agreed at the UN COP21, which has profound policy and social implications.

Therefore, to predict long-term responses of forest to increase CO2 concentration, it is essential to determine how nutrient cycling processes interact with carbon cycling in forest ecosystems in a high CO2 world. However, this is only possible when the new BIFoR-FACE facility becomes available (2017).

Aim and objectives: The aim of this project is to quantify the nutrient (e.g., P, Mn, Zn, K) cycling processes in a temperate forest under elevated CO2. The specific objectives are:

  • To measure the change in the stocks and fluxes of selected nutrients in soils at BIFoR-FACE site before and after CO2
  • To elucidate the role of nutrients in BIFoR-FACE woodland soil respiration and carbon storage.
BIFoR-FACE facility

Methodology

Microbially mediated nutrient cycling (P, Mn, Zn, and K) will be assessed by analysis of atmospheric deposition, soil and soil water, soil nutrients (using memberances), leaves, and roots. Samples collected by the student, other BIFoR students, or technicians will be analysed for speciated P, Mn, Zn, and K using nurient analyser, IC and ICP-OES to establish the flux and budget of bioavailable nutrients, and the net products of microbial metabolism in soils and soil waters under elevated CO2.

The student will also work closely with Earth System Modellers at Birmingham, Exeter and elsewhere to test and improve their models.

Training and Skills

CENTA students are required to complete 45 days training throughout their PhD including a 10 day placement. In the first year, students will be trained as a single cohort on environmental science, research methods and core skills. Throughout the PhD, training will progress from core skills sets to master classes specific to the student's projects and themes.

The students will be integrated into the science team of BIFoR, including 4 existing PhD students, science and technical team. Full training on BIFoR-FACE facility access, core methods for the project will be provided from the supervisory team. The planned measurements will provide a strong grounding in carbon and nutrient cycling research, generate high-impact publications and a strong PhD thesis. Training at sister FACE experiments (AmazonFACE/EucFACE) will also be arranged.

Timeline

Year 1: Training on soil, soil water, soil nutrients, and plant sampling, nutrient analysis, literature review; general training via CENTA; routine measurement of nutrient monitoring; soil and water sample analysis; analysis of baseline soil respiration and nutrient datasets

Year 2: Continuous soil, soil water, soil nutrient, and plant sampling; nutrient, cation and metal analysis; initial data analysis.

Year 3: Nutrient, cation and metal analysis; data analysis and manuscript drafting

Year 4: Thesis write up and manuscript publishing.

Partners and collaboration (including CASE)

Dr. Iain Hartley from Exeter is leading to the belowground processes in AMAZONFACE, a sister facility in the tropical forests. His involvement will enable a harmonised approach between AmazonFACE and BIFoR-FACE and ensures a bigger impact on the results from this PhD studentship. Dr. Liz Hamilton has initiated the soil water and nutrient baseline measurement at BIFoR-FACE sites so has extensive experience in soil, soil nutrient and plant sampling as well as analyses.  

Further Details

Contact Dr. Zongbo Shi, z.shi@bham.ac.uk for more details.