BIFoR FACE

The Birmingham Institute of Forest Research (BIFoR)

The BIFoR FACE (Birmingham Institute for Forest Research Free Air Carbon Dioxide Enrichment) facility, located in a Staffordshire woodland, is one of the world’s largest climate change experiments.

Since 2017, it has been simulating the predicted 2050 atmosphere by pumping carbon dioxide (CO₂) around mature oak trees. Here’s how it works:

  1. Elevated CO₂: BIFoR FACE increases CO₂ levels to 550 ppm (parts per million), mimicking the future environment. This helps researchers understand how woodlands respond—do trees grow faster, sequestering more carbon? Or do soil and insect changes pose problems?
  2. Real-world Experiment: Unlike previous experiments with young forests, BIFoR FACE focuses on mature, complex ecosystems. It’s one of only three such facilities globally and the sole one in the Northern Hemisphere.
  3. Research Questions: Scientists study how elevated CO₂ affects carbon flows, nutrient cycles, water use, biodiversity, and ecosystem structure. The goal? Improve climate projections and ensure resilient woodlands for the future.

BIFoR FACE represents a significant advancement in forest research, being the second generation of forest Free-Air Carbon dioxide Enrichment (FACE) sites. It focuses on mature oak forests, scaling up from earlier experiments on young plantations to understand the impact of increased atmospheric CO2. Operational since April 2017, it's one of only three such facilities globally and has been celebrated for its eco-friendly design. As of 2024, it's in its eighth year of simulating a 38% CO2 increase, providing invaluable insights into future forest responses to climate change.

Research projects in BiFoR FACE

Below we have tried to map research projects into different research themes but as the research is related to whole forest ecosystems, there is naturally overlap between the areas.

The information to follow regarding measurements at BIFoR FACE is separated into:

  1. Core measurements - these measurements have been taken continuously over a long period and are made in most cases by the Research Technician staff at the FACE Facility
  2. Project specific measurements - these might have been taken just for a shorter undergraduate/postgraduate research project

Above ground vegetation processes

Core measurements

  • Vegetation indices - Phenocameras
  • Phenology and biodiversity observations, including bryophyte, deadwood surveys
  • Tree stem growth – LIDAR surveys (includes tree height), dendrometers (manual and automated)
  • Tissue samples of green leaves taken from the top/middle/bottom of canopy for oak trees and also tissue samples from the other 3 key species of tree (hazel, hawthorn & sycamore) biobanked for future research
  • Tissue samples of buds & catkins bio banked for future research
  • Leaf Area measurements of green leaves sampled from top/middle/bottom of canopy for the four key species of tree (oak, hazel, hawthorn & sycamore)
  • Leaf litter trap samples - matter is separated into different categories including a 'woody material' archive and 'reproductive output' archive
  • Leaf Area Index – both hemispherical and direct method
  • Each tree is identified and has its own ID number and is mapped.

Projects specific measurements

  • Leaf temperature
  • Leaf-level gas exchange
  • Tree stem respiration
  • Canopy spread
  • Tree stem xylem sap flux
  • Stem wood characteristics from core and slice samples
  • Physiological performance in naturally regenerated trees
  • Carbon isotope analysis of tree cores
  • Sulphur measurements from tree discs
  • Poplar seedlings under elevated CO2
  • Wood compositional analysis
  • Dry and wet deposition fluxes
  • Sub-canopy Photosynthetically Active Radiation (PAR)
  • Imaging of leaves from leaf litter traps for leaf area
  • Acorn collection and some hazel nuts

Examples of research projects

to add

Below ground vegetation, litter and soil processes

Core measurements

  • Fine Root development
  • Soil CO2, H20 and CH4 fluxes
  • N mineralization and N2O source partitioning
  • Soil sampling and lab analysis for nutrients (cations, anions), particle size distribution at least three times a year
  • pH, soil type, organic matter content, CEC, bulk density
  • Leaf litter
  • Hyphal growth and turnover

Project specific measurements

  • CH4 and N20
  • Leaf litter decomposition
  • Fine root production and chemistry:
  • Hyphal growth and turnover
  • Root and hyphal control over decomposition rates, microbial functional activity and nutrient availability
  • Production and turnover of extra-radical mycelium of symbiotic mycorrhizal fungi
  • Dissolved Organic Matter (DOM).

Examples of research projects

to add

Animals (especially invertebrates)

Core measurements

Camera traps are installed through the woodland - take a look at some images in our "Gallery" 

Project specific measurements

  • Invertebrate sampling including the following trapping:
    Malaise, pitfall, pan, funnel, beating (canopy, field layers), Robinson trap
  • Image analysis of green leaves and senesced leaves for herbivory
  • Leaf mines
  • Winter active lepidoptera specific study
  • Saproxylic activity and wood decay

Example of projects

to add

Forest Hydrology

Core measurements

  • Throughfall precipitation (ground level)
  • Groundwater levels
  • Field precipitation (ground level)
  • Soil moisture
  • Soil pore water

Project specific measurements

  • Tree stem xylem sap flux
  • Isotopic composition of branches
  • Soil water isotopic composition
  • Soil pore water samples
  • Soil temperature profile
  • Leaf water potential
  • Leaf transpiration and water vapour exchange

Across site project specific measurements

  • Resarzurin-resorufin(Raz/Rru)
  • Dissolved Oxygen
  • Conductivity Temperature and Depth (CTD)
  • Stream Stage
  • pH/electrical conductivity/dissolved oxygen/turbidity/temp/chromophoric dissolved organic matter/Tryptophan
  • NO3, NO2, Chemical Oxygen Demand (COD), Total Organic Carbon (TOC)
  • Stream pore water samples
  • Stream surface water samples
  • Precipitation
  • Air pressure

Examples of research projects

to add

Microbial Processes & Biomarkers

Project specific measurements

  • soil fungal metagenomics
  • macrofungi surveys
  • n-alkanes

Examples of projects

to add

Plant health and plant diseases

Visit our Forest Health Research page for further information. 

Examples of projects

Vegetation and Land Surface Modelling

This team is expanding, check back soon for some updates.

Get involved

The BIFoR FACE facility is a versatile research platform open to global researchers, not limited to the University of Birmingham team. It supports a broad spectrum of studies, including but not limited to elevated carbon dioxide effects. With comprehensive support infrastructure, it invites academics and students to conduct forest research, offering on-site technicians, welfare amenities, data archives, and robust technological support.