A Day in the Mangrove Forest

By Gabrielle Mendelsohn

On our way to Cuerici Biological Station in the Cartago Province of Costa Rica, we stopped at a mangrove forest in Guanacaste for the day. Donned with our long sleeves and high rain boots, we trekked through the mud, struggling along the way to avoid stepping on the hollow and delicate roots of the mangrove trees while trying not to get our feet stuck in the mud or fall over. Upon entering the surrounding layers of the forest, which housed species unrelated to the mangroves, we thought our boots were doing a good job of protecting us. However, once we ventured into the slightly deeper water, the depth of which we learned depends on the tides, we found that it was quite impossible to avoid getting covered in mud. Admiring the beauty of the forest, I quickly embraced the mess and found the challenge of walking the difficult terrain extremely enjoyable.

            Throughout our walk we received a field lecture on the evolutionary history of the mangroves, the ecological processes and features unique to these ecosystems, and the threats that they face. Having the opportunity to learn about an ecosystem while being physically surrounded by it brings a sense of reality to the material, preventing you from disconnecting from what you are hearing. For instance, while discussing the adaptive traits mangrove trees have to survive in high salinity water, we were instructed to lick the salt-coated leaves. After, we learned that one way the mangrove trees filter the salt from the water they use, something necessary because of the scarcity of freshwater in these ecosystems, is by concentrating salt to older leaves and allowing them to fall. Because younger leaves have less salt and are a rare source of fresh water, one of the two primary species of crabs in the area will seek them out by climbing the trunks of the trees.

            Mangrove trees are one of the only plant species adapted to the harsh conditions of tropical coastal ecosystems, resulting in much lower biodiversity than many of the other forests we had visited. Despite this, the mangrove forest was extremely beautiful and interesting. It reminded me that nature is overwhelming and inspiring not only because of its abundance and its diversity, but also because of its resilience. These forests and the other species occupying it are uniquely adapted to their environment, allowing them to survive in conditions most species cannot. They grow roots that have pneumatophores in order to increase gas exchange since the soil is extremely fine as a result of the sedimentation from the tides. They disperse their seeds by water to increase dispersal range. However, all these amazing adaptations that makes mangroves unique also make them rare and vulnerable. It is hard to imagine while sitting among the trees how they could be carelessly destroyed for the sake of water-front development. I think the most valuable part about being able to experience what you are learning about is that you cannot ignore what you are seeing. In my classrooms in New York City, it is easy to forget why you are studying what you are, why it matters, and why you care. In Costa Rica, it is hard to ignore it.