Problems, Errors and Results

Problems:

There were a couple of major problems with obtaining the data for this project.  Half the time the project took was just the data preparation.  It took a surprisingly large amount of time to reprocess the spatial coordinates to a usable form.  Fortunately this was just a time factor and not a major problem.  The second major problem was that there was originally supposed to be 3 years worth of samples available.  However, due to oversight, the spatial coordinates were not recorded for two years worth of data, and so it was unusable.  This left me with only the 1997 data to work with.  Finally, I also had plans to do a comparison between a local temperature and precipitation map and the sample results to determine if there was any correlation, but unfortunately I could not obtain that data in time either.  It appears that data at the scale I am working at is extremely difficult to obtain.


Error Analysis:

The purpose behind using the two metrics to get the results was to see how far the results from a single sample point can be extrapolated without losing to much accuracy in the result.  The 10 kilometer metric is very obviously to large.  The problem with it is that it blocks out a great deal of the geographical diversity that has not been sampled in the Fraser Valley.  For example, if you look at the center of the final maps, there are two clusters of sample sites that make a pair of east-west running lines.  One cluster is north of the Fraser River in the Mission and Hatzic lake area.  The second cluster is on the Sumas Flats in Abbotsford.  Between these two areas is Sumas Mountain which has a very different climate than the floodplain to the north and south.  The 10 kilometer metric overlaps the results from Sumas mountain and thus we loose a great deal of accuracy.  For all we know, none of the species might be found in such a different climatic area.  The five kilometer metric shows a much more accurate result in comparison.  However, it also shows that many more samples will be need to fill in the holes in the map, especially in areas where there are major climatic changes such as Sumas Mountain.  

Results:

Despite the difficulties in obtaining data we can still make several interesting discoveries about the maps.  First of all, samples of Lygus Hesperus are concentrated in two locations.  One population is in the vicinity of Delta and White Rock, and a couple of insects were found out in Agassiz.  If we ignore the sample in Agassiz, this result is consistent with an insect close to the northern end of its range since it is staying close to the shoreline where the temperature is warmer.  I suspect that the insects out in Agassiz were either transported there by human means or they represent a fragment of the population indicating that although they may be capable of surviving in colder areas, they are being out competed by the other two species.  

The relationship between Lygus Elisus and Lygus Hesperus is an interesting one.  There was not a single sample of Lygus Elisus taken alone without Lygus Shulli. First of all, this shows that there is competition between the two species since they are being found during sweeps on the same plants.  There are many samples of Lygus Shulli that occur without any other species.  Lygus Shulli appears to be more common in this region than Lygus Elisus.  Perhaps Lygus Elisus is not as general in the habitats it prefers when compared with Lygus Shulli.  Or maybe Lygus Shulli is just out competing Lygus Elisus for resources in many areas.  

Based on the results of this project, I would conclude that an invasion of Lygus Shulli into a greenhouse operation is most likely in this region.  That is not to say that the other two species will not invade greenhouses.  However, Lygus Hesperus is pretty much only found near the coast and so is most likely to affect greenhouse operations in that area.  Lygus Elisus is less common than Lygus Shulli in the Fraser Valley, and so is less likely to invade purely by a smaller population.  On a personal note, this project shows the difficulties of modeling biological systems.  It is very difficult to map the range of something that can run away when you try to catch and identify it.  It provided good experience with solving a spatial problem.  

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