Biology Field Trip – Year 13
During October half term, Year 13 biology students travelled to Shropshire to the Preston Montford Field Centre for a busy weekend of ecology practicals. We arrived on Friday afternoon and were greeted by our team leader Vicky. Once we had settled in we had our first lesson; recapping and building upon our knowledge of biodiversity from our Year 12 studies. Using this information, we formed hypotheses about the abundance of invertebrates with differing oxygen requirements in two different ponds; the field pond, a freshwater pond and the middle pond, a eutrophic pond which was a part of the wetland treatment system at the field centre. Our theory was that the invertebrates in the freshwater pond would have higher oxygen requirements than the polluted pond. We then carried out various tests in order to determine if our hypothesis was correct. We examined the abiotic factors of both ponds using instruments such as an oxygen probe, a pH reader, nitrogen test strips and carried out a turbidity test to determine the amount of sediment in the water. Next, we used nets to catch some of the invertebrates in the pond and classified them. Having gathered our results, we headed back to the classroom to analyse them. Using the chi squared test we proved our theory to a significance level of 0.001% allowing us to reject the null hypothesis: there was a significant difference between the types of invertebrate residing in each pond which related directly to the extent of nitrate pollution present.
On our second day, we had an early start, beginning the day with a lesson on the different types of succession. We also learnt about the different seral stages that a lake goes through in its development, from submerged bare rock to developing a climax community of woodland. We travelled to Crosmere Lake near to the research centre to see the differing seral stages for ourselves. Before going we formulated our hypotheses stating that with increasing distance from the lake, the seral stages of plant will require less water. We also thought that with increasing distance from the lake the plant types will increase in seral stage causing the plant biodiversity to change. We set up two different 60 meter long line transects in order to test our hypotheses. Using quadrats, we calculated and classified the different plant species along the line transect at the differing seral stages. We also tested various abiotic factors such as water concentration in the soil, the pH of the soil, light intensity, wind speed and temperature. After gathering our results, we returned to the classroom to do our analysis. We used the Spearman’s rank correlation to analyse our results, enabling us to confirm that our theories were correct. Later that evening we set up small mammal traps, in the hope of catching either a mouse, shrew or a vole. We set our Longworth traps, filling them with hay for bedding and bait for each different type of mammal dependent upon their specific diets.
On our last morning we opened up our traps. Three of us were lucky enough to catch a wood mouse; two males and one female. We were able to scruff them and examine them more closely. In the afternoon we carried out conservation work, surveying hedgerows as part of the National Citizen Science Scheme.
We left Preston Montfort with greater knowledge about ecosystems and biodiversity and a greater appreciation for the wildlife around us. It was a very informative and interactive trip that enabled us to build on our previous ecological knowledge and to gain a better understanding of it which will stand us in good stead for our final exams.