Sand Dune Plant succession Task: annotate your diagram to explain what plant succession is.

Salt Marsh Plant succession Task: annotate your diagram to explain what plant succession is.

Plant succession field work Method of data collection The quadrant is a 50cm x 50cm square. From the shoreline, place the quadrant at regular intervals, e.g. every 5m. Count the number of different plant species that are within the quadrant (you may count the number of sub-squares that each species takes up within the quadrant). Record the results in table. Results This is a KITE DIAGRAM which show the species found and their richness along the transect from the shoreline at each site. Analysis Chi squared can be sued to test

Distance from the high water mark 10m 20m 30m 40m 50m 60m 70m 80m total Number of plants observed within a plant quadrant (O) 1 11 15 14 9 5 56 This table shows the number of Marram grass plants at various points in an area of sand dunes. This data is known as observed (O), or actual numbers that exist when doing a Chi-squared test. At first glance, it would seem as if the distance from the water mark is important in determining the number of marram grass plants present. But how important? The Chi-squared test shows how clustered distributions are - it compares how clustered a distribution is with how it might be if everything was evenly distributed. 1. Establish a hypothesis: There is no difference in the distribution of marram grass plants with increasing distance from the high-water mark. 2. Decide what the hypothesis means. A total of 56 plants would be evenly distributed with 7 plants at each of the 8 sampling sites. This is the expected (E) or theoretical numbers, which would exist if the marram grass were evenly distrubuted to match the hypothesis. 3. Now compare the observed values (O) with the expected Values (E) and calculate the value known as Chi-squared. 4. Chi squared or x2 is the final figure in the table. This figure means nothing by itself. It has to be referred to significance tables. 5. degrees of freedom are arrived at by subtracting 1 from the number of categories tested, in this case 8.