Modelling

Modelling peatland Carbon and Water dynamics and associated processes

Overall focus:

There are clear linkages between conservation strategies and ecosystem services (see Eigenbrod et al., 2009, 2010), particularly in relation to land management (Moilanen et al., 2011). Moreover, ecosystem services between terrestrial and fresh water systems are tightly linked (Holland et al., 2011). This project will specifically include an assessment of the impact of treatments on stream flow and water budgets alongside predictions of changes in carbon stocks and dynamics. However, we suggest also specifically investigating the link between water and carbon making use of several GIS layers collected as part of this project. This will be assisted by experienced York staff (Dr. Collin McClean). Therefore, we will include an analysis of both carbon stocks and GHG fluxes based on measurements and model approaches.

Although the focus of the project is on experimental manipulation and subsequent data analysis, we shall also deploy the latest peatland model (MILLENNIA; Heinemeyer et al., 2010) to predict management effects on long-term C storage, C fluxes and hydrology. Albeit simple in its nature (which is an advantage in many respects as pointed out by Baird et al., 2011), this model is unique in that it includes a realistic peat accumulation algorithm based on a dynamic water table with feedbacks on vegetation dynamics and also considers measured slope and aspect effects on peat hydrology (see a peat model inter-comparison by Clark et al., 2010). Crucially, this will enable us to model the soil moisture in the peat profile, allowing predictions on food abundance (e.g. craneflies) linked to several upland bird populations (Pearce-Higgins, 2010).

We recently worked with M. Carroll (Carroll et al., 2011; RSPB co-funded UKPopNet PhD) on predicting cranefly abundance across four UK peat sites based on MILLENNIA predicted water table/soil moisture effects (see Figure for an example of predicted (blue) vs. CEH measured (green) monthly water tables and topographic WTD levels and SOC densities at Moor House). This puts us in a unique position to extend the value of the experimental and monitoring work within this project through this modelling platform.


Moreover, we will attempt to model management change impacts on blanket bogs (see O'Brian et al., 2007 for a review) based on literature evidence and the findings from this project. This will include impacts on plant species, carbon and water dynamics.
  At the global scale, we certainly need to include biotic carbon feedbacks (Cox et al., 2000; Milcu et al., 2012), particularly, peat soils have the potential to considerably affect atmospheric greenhouse gas concentration with associated feedbacks on global temperatures (see Heinemeyer et al., 2010).



Millennia model application at Moor House NNR (Pennines UK)
Figure
: MILLENNIA peat model output: (left) comparison of monthly modeled (blue) versus measured (green; CEH; thanks to the Centre for Ecology and Hydrology and the Environmental Change Network [ECN] for data access) water table depth (WTD) at Moor House NNR over 6 years 1999-2004 and, (right) model output of predicted WTD (deep blue = near surface) and soil carbon densities (light grey = high SOC; deeper peat) over a sub-catchment area at Moor House. Also shown is the annual peat cohort structure of the model with root growth and a variable WTD.

For the first MILLENNIA paper (including main description of annual model) and the second paper (including main description of monthly model ) please click below:

MILLENNIA papers