1. Reflection on Summer Bridge’s study trips to El Yunque Tropical Forest and Guánica’s
Dry Forest.
By: Angélica M. González Sánchez
After visiting El Yunque National Pluvial Forest and the Guánica Dry Forest we can
determine that the differences between these two ecosystems are drastically evident. According
to our inquire and as shown by the soil’s condition as well as by the organisms’ adaptations,
while El Yunque receives about 200 inches of water per year, the Guánica Dry Forest remains
with less than 30 inches.We can conclude that this is caused by their different geographical
locations and altitude. By our experience on both ecosystems, we can determine that the
humidity in El Yunque is a lot higher than in Guánica, while the temperature is lower in the
Pluvial Forest; unfortunately we didn’t have quantitative data from Guánicaon these topics to
compare. Because of the qualitative evidence shown by the adaptations of plants on both forests,
we can also deliberate that evolutionary variations result from adjustments of the organisms to
their environmental requirements. We could observe the evident differences between the
variations of the vegetation that have resulted from natural selection: in El Yunque, most of the
plants were taller, leafier and had bigger leaves, while in Guánica Dry Forest the plants had
smaller, fewer leaves and were lower. As we can see, the survival conditions of the organisms
are directly related to the conditions of their habitat. According to our observations, some other
factors, such as the pH, the wind velocity, the competition of other organisms in the area, the
different reproduction cycles, between others also seem to affect the organisms’ variations
according. While comparing the data collecting methods used on both expeditions we can
conclude that they are very different from each other, but that they both reached their inquire
objectives very well. As a group, we would recommend to use the same research techniques on
both forests because that way it would be easier and more effective to compare the obtained
facts. In conclusion, we would say that this trips were enriching experiences because they
allowed us to see some of the natural resources of our Island form both a tourist and a scientific
perspective.
From my point of view, our trip to El Yunque Tropical Forest was a remarkable
experience to our lives. Just the fact that we walked so much to go to the top of the mountain and
the view at the top of it was something outstanding. By taking samples of the soil and making
measurements we learned new techniques on how to take nature samples such as the pH of the
soil, the humidity, the velocity of the wind in that area and many other things. Our objective was
to experiment the feeling of going to a tropical forest and introducing ourselves to sampling, and
we certainly reached them. We were also capable of observing the great multiplicity of creatures
that live in this huge forest, as well as their exceptional adaptations and how, mostly because of
men, these adaptations haven’t been enough to make them survive, making them become

2. endangered species. Because of all these, this trip was a unique experience for our scientific
lives.
In our trip to Guánica’s Dry Forest was a very particular trip. Since we got on the bus, we
started learning a lot about the forest, for what I can say that we filled ourselves with knowledge
about it. Once in the forest, we started getting a tour in it and learning about all the plants,
especially about the mellow cactucs and the agave. The most interesting thing that I learned
about these plants was the special adaptations that they have to survive in this arid ecosystem,
such as their thorns. After our tour through the forest, we started making two types of sampling
which resulted innovative to me. These were line transect and line transect. Both of these
samples resulted quite appealing because the allowed us to concretely observe the organisms of
the forest. It really amazed me all the diversity found in the forest despite its hard survival
conditions.
These two fieldtrips were amazing and unforgettable. Acknowledging that all these things
that we did and learned will be useful and constructive for a near future it’s even a bigger
satisfaction that we get from these trips. Also, the techniques learned will be very helpful for
future studies. From these trips we were able to realize, once again, that the beauty and wonders
of our island are beyond description and how unfortunate it is that people are damaging and
destroying them.