Increased consumption of fossil fuels such as coal, oil and natural gas has led global
carbon dioxide levels to rise dramatically over the last century and still they continue
to climb.
But what effect could this increase in ambient CO2 concentrations have on our natural environment
and an ecosystem such as this?
Well, we’re here at the University of Birmingham’s Institute of Forestry to find out!
In this vast area of private, unmanaged woodland in rural Staffordshire an experiment of epic
proportions is taking place.
This is BIFoR FACE, the free-air carbon dioxide enrichment experiment.
The BIFoR FACE experiment consists of a series of cylindrical ring structures that reach
as high as the treetop canopy and are over 30m wide.
These towers support pipes that are continually pumping out CO2 in order to artificially raise
ambient CO2 concentrations inside the ring.
The aims of this colossal experiment include examining how carbon storage in mature woodland
is affected by elevated CO2 and also finding out how biodiversity and ecosystems are altered
under conditions that we are likely to face in 50 to 70 years-time.
With all good experiments there should also be a control and so, as well as three test
rings, there are also three control rings that have been built and designed in exactly
the same way but instead of pumping out CO2 these rings pump out normal, ambient air.
How might researchers working here at BIFoR FACE go about investigating the effects of
increased CO2 on biodiversity and species distribution?
They may use techniques very similar or identical to the ones we’re familiar with from A-level
biology classrooms.
For instance, we could use a quadrat to sample areas from within both the control and elevated
CO2 sites to detect changes in the distribution of certain plants or slow moving animals.
It’s important to remember that when using quadrats the sampling areas selected within
both sites should be chosen at random in order to avoid bias.
Another factor that researchers will be analysing is how elevated CO2 affects transpiration
rate.
You might be familiar with using a potometer for this in the classroom but using a potometer
to determine the transpiration rate of an oak tree is, frankly, easier said than done.
What we can do instead is to use a thermal imaging camera to gauge transpiration rate
as evaporation of water from the surface of a leaves requires energy, resulting in a decrease
in leaf temperature.
So, here at BIFoR FACE, a multimillion pound world-leading research experiment, scientists
are still using some of the same, classical sampling techniques that we learn about in
biology classrooms alongside some more expensive and technologically advanced alternatives.
And what has this experiment shown us?
Well, construction of the FACE towers was only completed in 2016 and this experiment
is aiming to run for more than 10 years and during that time scientists will need to gather
and analyse an enormous volume of data, so we may have to wait some time until we get
the answer to that important question.