Welcome all to this blog, which similar to a post a few months ago, will focus on a work experience that I was lucky enough to have the opportunity to attend. This was situated at Silwood Park campus, which is Imperial College's second campus, and is described to be 'a leading international centre for research and teaching in ecology, evolution, and conservation'. Here, I spent a few days working with an ecological analyst and several Masters Students in certain structured experiments, which I will outline in detail below. The main experiment that was undertaken throughout my time here was essentially measuring several plant traits, plant height, specific leaf area (SLA) and leaf dry matter content (LDMC), to characterise the plant communities present. These traits are known to be associated with two major axes of plant functional variation: the size of plants and their parts, and the resource economics spectrum. An image of the fields where this particular experiment was undertaken is below.
Five random individuals per species (around 11 were to be investigated) were selected, measured by height, and bagged in labelled plastic bags while kept hydrated (by being smothered by wet tissue). Individuals were aimed to have more than 5 leaves, with as little damage symptoms as possible, and to be at least 5m from each other when picked. An image of the bags that a particular species was kept in, specifically bramble is below.
The next step was to rehydrate the fresh leaves overnight after bringing them back from the field, by placing the stems of the individual plants into water upon arrival and storing the samples in a cool, dark place overnight. An image of the plants prepared to spend the night rehydrated is shown below. Note the plastic bags kept on top of the plants, to limit the loss of water via transpiration from the leaves of the plant, and evaporation from the beakers of water that the plant (stems) are kept in.
To calculate the SLA, five (undamaged) leaves were taken from each individual, and after each leaf was dried to remove any excess water and weighed to obtain the fresh leaf weight, the leaves were scanned on a flatbed scanner (i.e. most normal printers/scanners are capable of this), in which scanned images were used for SLA calculation. When scanning the leaves, all the leaves sat flat on the scanner and did not overlap. Once the scans were made, leaves were transferred to an envelope for future use to calculate LDMC. Next, to calculate SLA, a program 'ImageJ' was used - surprisingly, this took more effort than I previously thought would be required, showing me the effort needed for extra orders of precision to be calculated, as an estimate could easily be made in a few seconds.
Unfortunately, I was not able to stay to calculate the LDMC, however, I knew this could be completed by the following steps. Firstly, the envelopes that contained the leaves previously scanned should be placed in a drying oven at 70 degrees Celsius for 3 days to allow them to fully dry out. Once removed from the oven, the leaves are placed in a silica gel, so as to not any moisture from being absorbed while cooling from the oven. Then, the leaves are weighed in their respective groups.
To calculate the SLA, the equation SLA = one-sided leave surface area (mm>2) / dry leaf mass (mg) is used.
To calculate the LDMC, the equation LDMC = dry leaf mass (mg) / Water-saturated fresh mass (g) is used.
Although this was the main experiment that I had the opportunity to help in throughout my time at ICL, I also went on a long tour of the campus' temperate forests with my supervisor, in order to check each bird nest that had been set in place the year before. This was to remove any chicks that had died without leaving the nest, mainly due to malnutrition, or not being fed by their mother because they were too small, and conversely to note down the number of birds that did leave the nests. Thankfully, the majority of chicks, bar from two, hatched accordingly and left the nest. I captured many pictures of the beautiful scenery of the forest that we hiked through, which houses a large array of different species. This campus was overall extremely rich in its biodiversity, which provides conservationist and ecologist researchers with a lot of resources to work with / research. The images I captured are below.
Thank you for reading this blog, and keep posted for the next!
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