Perran sands Investigation
The Percentage of marram grass decrease as the species diversity increases.
To investigate the species diversity and the percentage of marram grass, we used a belt transect to the collect the data. A belt transect was laid from the beach/dune interface to the dune meadow. Quadrates were laid along on the 000ht side with the left hand bottom corner at the start of each interval along the belt transect. The belt transect was measured every two metres until similarly findings were recorded of each species, of which then we increased the intervals of every 5 metres and finally every 10 metres.
The area within each quadrate was examined for different species of which then was recorded. At the same time the percentage of marram grass was recorded from the area within the quadrates. This data was put into a raw data table. Anomalous sets of data were excluded such as paths which were present on the sand dunes, this is because this could influence an error in patterns that may be seen on the graph.
Taking the data on the same day, which meant that this was a controlled variable.
The time of year is a variable that could have an effect on the species diversity, such as in winter there is more likely to be lower species diversity than in the summer months, due to the harsher temperatures and weather conditions.
The amount of time spent on each quadrat, needed to be the same, as if looking at a quadrat for a longer amount of time this could effect the results as you are more likely to find more species.
There was one belt transect which narrow the amount of data that we could collect.
There was the risk of touching poisonous plants, i.e. Foxglove and Ragwort so we had to make sure we washed our hands when we finished.
When examining the species within the quadrats we took care not to damage any of the species, such as we didn’t pull any of the plants up to get a closer look, so we could identify them. We didn’t leave any litter around which could interfere with the growth of the plants or damage them in anyway.
From my results that I obtained from the sand dunes the scatter diagram illustrated that there may have been a slight positive correlation.
From the Spearman rank test it showed that the results had no significant correlation as the value was lower than the level which was needed to support the that there was a relationship.
On the kite diagram of the marram grass against the distance from the beach/dune interface it shows that there is steady increase in the amount of marram grass, as the distance increases. Then between the 20 metres and 30 metres there are a few sharp decreases and increases in the percentage of marram grass. Theses could indicate that there were paths that were running through the belt transect. Also at 80 metres there is a o percentage of marram grass this could also represent a path.
In the investigation I would have expected the results to indicate a clearer pattern of how the percentage of marram grass increases over the distance. This because marram grass is a species that can survive where the environment offers little water supply and protection. The marram grass forms tuberous roots under the surface of the sand, where they can spread out to form a underground web that helps to hold the sand in place. As the distance increase you would expect the percentage to increase as most other species cannot with stand the environment, therefore there would be less species of which there would be more area for the marram grass to take up.
There were some limitations to this investigation as there we only used one belt transect to collect our data from, therefore it would have been better if we did a number of belt transects. This would enable us to obtain a larger amount of data. As with some of the results that we got there were very few species this was because there was a path running through our belt transect. The seasonal impact is also a limitation as we only took recordings in the summer months, where as in the other seasons there may have been a different of species and also different percentages of marram grass. As in the winter season the environment conditions tend to be not as compactable to some species and this may lead to a decrease in the amount of species that could be found.
Overall I feel that there are some mixed results and to obtain a clearer picture and therefore more data is needed to show a better findings.