Prof. Tim Fahey, natural resources, first took interest in forests on family hiking trips in New England. He went on to formally study forest systems, earning degrees in biology and botany.
Since coming to Cornell, Fahey has devoted much of his time outside of the classroom to conducting research at two sites: the Armando Bermudez National Park in the Dominican Republic and the Hubbard Brook Experimental Forest in New Hampshire. Currently, Fahey is writing a paper on his research findings in the Dominican Republic.
Fahey first traveled to the Dominican Republic while on vacation. “I got interested in ecology just from hiking and looking at the landscapes and trying to understand why it would look the way it does,” Fahey said. There was something intriguing about the landscape of one picturesque mountain in Armando Bermudez National Park, which is located within the tropical mountain range Cordillera Central.
At lower elevations on the mountain is a montane “cloud” forest, which looks like a scene out of the Lord of the Rings movies, “everything is covered with mosses, and they’re all odd shapes,” Fahey said. At a point higher up in elevation, there is a sudden change to pine forest. Naturally, changes in elevation cause variations in environmental factors, like temperature and precipitation. Yet, the clear demarcation between the cloud forest and the pine forest caught Fahey’s attention.
Their interactions with each other could be envisioned “as being a war for the side of the mountain” because “they wouldn’t coexist; it’s like night and day.” Trees in the cloud forest are about 20 feet tall and consist of dozens of species, so it has the biodiversity typical of tropical forests. The pine trees, on the other hand, stand about 80 feet tall and are all of a single species unique to the Dominican Republic and for mountain top habitat.
Fahey’s group determined that the split pattern along the mountain slope was due to forest fires. Once every 30 or 50 years, lightening strikes a pine tree and starts a fire destructive enough to burn through the entire pine forest. Afterwards, seeds germinate, and the pine trees repopulate the forest. The researchers hypothesized that the fire would also burn through the trees of the cloud forest and that pine trees would grow in their place. However, after a natural fire, Fahey’s group observed that the cloud forest was largely fireproof, and the predicted conversion was only true on a small scale.
Aside from satisfying his ecological curiosity, Fahey realized that understanding the discontinuity was essential for grasping the complexity of the forest system on this mountain. This knowledge, in turn, is useful for determining the effects of climate change on tropical forests. The preservation of this tropical forest was particularly important because logging giants had eaten bare the forests of all neighboring mountains, and this forest was salvaged only through the creation of the Armando Bermudez National Park in the 1950s.
Fahey has been conducting research in the Dominican Republic for about 20 years and at the Hubbard Brook site in New Hampshire for about 25 years. Hubbard Brook is part of a network of long-term ecological research sites supported by the National Science Foundation. The work of an ecologist is never to be hastened.
Most scientists are given grants to conduct research experiments on a time scale of a few years, but “those sorts of time scales aren’t appropriate for the questions that are often asked in ecology,” Fahey said. Nature is subject to a multitude of variations in the environment and the organisms that cannot be controlled the way variables can be held constant in laboratory experiments. Only when scientists have access to decades worth of data can they tease out the natural variations and see statistically significant patterns.
The temperate forests of New England are also interesting from a climate change perspective not because of biodiversity but because of carbon sequestration. Burning fossil fuels releases carbon dioxide into the atmosphere. Through photosynthesis, trees fix carbon from the atmosphere and use it to build different tissues, which sequesters the carbon. Researchers are interested in how plants’ carbon sequestration can offset humans’ carbon emissions.
Ideally in the real world, emitters could pay for trees to be planted or not to be cut down at all; however, there is not yet a way to make this exchange profitable. At present, measuring the carbon costs more than the carbon itself is worth. What Fahey proposes is a remote automated system that would make measurements on the ground using satellite information and other computer models. Such a cost-effective system would invite investment and add transparency to the entire process.
Although there is no denying the pertinence of Fahey’s research to climate change, he admits that he is always been skeptical of environmentalists’ reactions to changes in forest systems. “Trees die all the time,” because of the stressful environment they inhabit, Fahey said. The death of a tree or even an entire forest is not evidence enough of human activity inducing climate change. However, in time the findings of his own research have erased all his skepticism. “There’re some things we’ve done that seemed rather subtle [but] were big enough to cause forests to die. I think the evidence now is quite conclusive,” Fahey said.
Fahey says he still does not have an environmental agenda. He is simply someone, who after decades of hiking and working in forests, continues to look at landscapes new and old with fresh wonder. As a researcher and naturalist, he finds forests infinitely complex and always intriguing.
Original Author: Jing Jin