PDS in Costa Rica

The students have not quite learned how to use iPads for blogging, so Mr. W has the duties for today. This afternoon we gathered for a few hours for a little team building and to discuss basic ecological concepts and terms on the trip. IF you are not very familiar with ecology, it is the study of the interactions between the community of living things and the non-living environment. Since most of the students on this trip have yet to take high school biology, we spent some time reviewing key terminology needed for our field studies in the Costa Rican rainforests.

First, we discussed the concept of a food chain (who eats who). Then, we read a case study about acorns and the spread of Lyme Disease in the NE USA. Why? Because when you examine ecosystems, you find that there are many interconnected food chains that form what is known as a food web. One of the students diagrammed the connections between species on an iPad and sent me the screenshot below:

A food web

In the case study we read, analyzed and diagrammed, the incidence of Lyme Disease (spread by the ticks) is impacted by the numbers of tick hosts (mice or deer) and/or by the amount of food (moth larva or oak saplings/acorns) available to the hosts. Besides these biotic (living) factors, the amount of oaks is influenced by abiotic (non-living) factors like temperature and rain–or by human activity (clearing land). Hopefully it is clear that everything is connected when we step outside into an ecosystem, and getting rid of Lyme Disease is not as simple as trying to find and eliminate all the ticks!

After this, we discussed tropic (feeding) levels and niches (jobs/roles) that organisms occupy in food webs. Tomorrow, we leave for Costa Rica and get to start putting all this to use! Stay tuned…