Ponds and pH: Biology in the Field at Mop End

In the modern digital era, our lives seem to be revolving around data of some kind. However, it is rare to actually step back and think about how data is sourced. The new OCR Biology A Level aims to explore this in depth - teaching students how to generate ‘valid’ statistics, as well as understand when data is actually ‘significant’. For instance: how to work out if two results are far enough apart to make a valid conclusion from them.

To give Year 12 biologists the chance to explore this first hand (and complete two essential practicals as part of our A Level), last Friday we travelled to Mop End, near Old Amersham, to enjoy a day of research 'in the field'. Mop End is a purpose built nature reserve for students to explore ecosystems - and then carry out our data readings on them.

Our day started with a pond ecosystem. In groups of four, we went onto the pontoons and compared the environments of the open water, plants, and sediment on the bottom. We used nets to collect a sample of the organisms in each respective area, and then put these into basins of water where we were able to tally all the different organisms we found. As well as the more exciting animals such as newts, it was very interesting to see how the types of organisms varied greatly between environments such a short distance apart.

We then measured the 'abiotic' factors in each area - including temperature, light intensity, pH and even oxygen concentration.

After all this data, we were fairly exhausted and so enjoyed a packed lunch next to a huge (and rather noisy) National Grid 400kV substation the size of Trafalgar Square. Our leader later told us that in the UK we throw away enough rubbish to fill this area up to the top of an electricity pylon - which was shocking to say the least.

After this interlude, we moved on to observing how human trampling affects the plant species growing in an ecosystem. We took samples along a transect, and recorded how the percentage cover of each plant species changed.

Upon our return to classrooms, we then used various biological statistical tests to observe whether the data we had produced a 'significant' enough correlation for us to make any conclusions. Our data successfully proved that the proportion of thin grass decreased further away from the path, but interestingly, despite an apparent trend, did not conclude that the number of daisies increased further away from the path.

Being able to test data in this way is undoubtedly not only far more fun, but also more memorable than we would ever achieve in a normal classroom, and so on behalf of all Year 12 biologists, I’d like to thank Mr Bristow as well as the Mop End staff for organising such a brilliant day.