Forest Ecophysiologist and Tropical Biologist Dr. Sybil Gotsch: ‘Epiphytes are a small collection of plants, but they have an outsized importance in the ecosystem.’
A familiar face to the Monteverde community and its luscious forest canopies, Sybil Gotsch’s research on epiphytes reveals the secrets of the often overlooked yet crucial members of cloud forest ecosystems. Epiphytes (from epi- ‘in addition’ and Greek phuton ‘plant’) are organisms that grow on the surface of other plants, taking moisture and nutrients not from roots in the soil, but from air and rainfall. These ‘air plants’ include mosses, orchids, and bromeliads and are found in their highest densities in cloud forests. Trunks and branches are covered in this dense mat of additional, often wet vegetation, providing not just the characteristic look of the cloud forest, but also a crucial role in the water cycle. As Dr. Gotsch explains, “it’s a small collection of plants, but they have an outsized importance in the ecosystem. There’s evidence that suggests that having epiphytes in the trees influences the microclimate, and we know that microclimate affects tree performance.” With climate change pushing clouds further up into the sky, a question is formed: how will the epiphytes respond?
As clouds retreat, a key variable in the equation, vapor pressure deficit (i.e., the deficit between the amount of moisture in the air and its maximum potential of saturation), increases, driving with it the moisture that escapes plant tissues. Plants in drier environments have evolved ways to deal with high vapor pressure deficit, but do cloud forest epiphytes share the same flexibility? “Something interesting that’s come out of the work that we’ve been doing is that we’re finding a wide range of responses. Succulent plants have a built-in savings account of water in the form of hydrenchymal cells --you can think of them as balloons-- they swell and shrink as water becomes available. On the other side of the spectrum, we have plants that don't have that water storage layer but are really good at absorbing water from the clouds through their stomata, or even through cracks in the cuticle on the surfaces of leaves.” These variable responses to high vapor pressure deficit indicate a hidden resilience of some but not all cloud forest epiphytes. As Dr. Gotsch explains, the water-absorbing specialists are more likely to suffer as cloud layers move up, yielding changes in the epiphyte community. How will this change affect cloud forest tree performance and the cloud forest water cycle?
To find out, the Gotsch lab initiated the first large scale experimental removal of epiphytes from 20 cloud forest trees in Monteverde. Stripped of their mighty epiphytes but not entirely naked, these trees now sport a number of microclimate sensors, sap flow sensors, dendrometers, throughfall gauges, and stem flow gauges that will keep a record of the effects of epiphyte loss. At the same time and for the purpose of outreach to local schools, Dr. Gotsch and her team grow and care for epiphytes near the Monteverde Institute, facilitating the transfer of knowledge and engagement with the local community. A third, world-weary question peaks its jaded head: if climate change is bound to negatively impact most cloud forest epiphytes and trees, why all this effort? Dr. Gotsch replies: “It’s hard to get out of bed in the morning if your mindset is that you’re studying a dying ecosystem – we can still focus on the things we can change. Where is climate change taking us? Where and how can we promote cloud forests in the future?” In other words, instead of resigning to the inevitability of climate change, we can choose the mindset of adaptation. Let’s learn how to protect vulnerable ecosystems by investigating how they already respond to environmental stress, and let’s not forget the importance of education outreach!
Dr. Gotsch is one of many researchers that have found a second home in Monteverde. For her, what makes Monteverde special is abundantly clear: “I really love working in Monteverde specifically because it is a community, and what I think is particularly inspiring about that community is that we all gain inspiration and drive from the mountain, from the ecosystem. This is the case if you are the owner of Taco Taco, or Monteverde Stones, or The Butterfly Garden, or the scientists that are on the mountain. We all have this common inspiration that creates a community that's really close knit and powerful. It feels like an extreme privilege to be able to work in that kind of context.”
Dr. Gotsch is a recent hire at the University of Kentucky and plans to continue her work in Monteverde while also exploring new frontiers. If you are curious about her work and potential opportunities with her lab, you can learn more here: https://www.sybilgotsch.com/cloud-forest-environmental-physiology.html. Moreover, click the following hyperlinks for informative videos on the Gotstch lab (i) experimental design, (ii) microclimate installation, and (iii) sap flow installation.
We thank Dr. Gotsch for her time, insight, and for being a valued member of the Monteverde community.
Author: Luis Beltrán | Postdoctoral Researcher & Biologist | lcbeltran92@gmail.com