Results and Discussion

Results:

With the use of the two different sampling techniques we were able to create two individual population estimates. This helped us to generate a range of possible population sizes. Using the transect method we estimated the eucalyptus population to be 3,229 individuals. The average count in our transects was 43 individuals. The area of the transects were 795m^2 and our total study area was 58,869.42m^2. By dividing the total area by the area of one transect and then multiplying by the average transect count we were able to create a population estimate.

The next sampling method we used was the point count method. Using this we estimated the population size at 3,457. To calculate this we divided the total study area by 706.858m^2 (the area of a single point count) and then multiplied by 41 which was our average count. To our delight these two independent population estimates were in a relatively tight range. This leads us to believe that our estimates were at least precise if not accurate.

Discussion:

The reason that we were interested in the population size of the eucalyptus trees was because it was a unique sampling opportunity. We were curious how difficult it would be to estimate the total number of trees within a forest. On top of that, there are good reasons to be aware of this information for the MDO groves. For example, some people find the eucalyptus trees in MDO to be a pest and an invasive species that prevents the growth of native plants through their allelopathic qualities (Chu et al. 2014). Perhaps these people would be curious of the population size because they would want to know how much it would cost to remove them. Others find the trees to be a crucial part of the state park's look and would want to preserve this grove. Additionally there have been studies that suggest eucalyptus plantations are actually hosts to quite substantial species richness (Timo et al. 2014). They may be interested in if the population size is fluctuating through time. Whatever the case may be, it was an interesting study to tackle and it was a good exercise to sample in such a large study area.

If we were to sample again, using the point count method would probably be our best option. It was not labor intensive and it was easier to be accurate with our counts in this manner. To further refine it, we would use an accurate GPS unit to pinpoint location. We also would find a way to better delineate the outlines of our point counts just to insure that we are 100% accurate in our counts. Regardless, the estimates that we came up with are remarkably close to one another.

Thank you so much for joining us on this adventure. It was a blast and we learned a lot. This is the Eucalyptus Team signing out.

Sources:

Chu, Chaojun, et al. "Allelopathic effects of Eucalyptus on native and introduced tree species." 

     Elsevier: Forest Ecology and Management 323 (2014): 79-84. Print.

Timo, Thiago, Maria Carolina Lyra-Jorge, and Carla Gheler-Costa. "Effect of the plantation age on 
     the use of Eucalyptus stands by medium to large-sized wild mammals in south-eastern Brazil." 
     Biogeosciences and Forestry 8 (2014): 108-33. Print.