Understanding the Response of Forest Canopy to Climate Change

Primary Investigator: Brett Scheffers

When you take a walk through the forest, what is most noticeable to you? Maybe it is the hoots and chatter from distance calls on a high branch. Or the slices of light from above that cut between leaves. Perhaps the immense trunks of trees, stretching up - wards to heights that may play host to un - seen creatures and communities. Those who have walked the trails of Ranomafana have certainly spent time looking up at the mys - terious canopies, envisioning what may be hiding there just out of sight.

For our research group, looking up wasn’t enough. Due to the nature of the organisms we study – amphibians and reptiles, or col - lectively called herps – we climb. Many of the herp species found in the eastern rainforests of Madagascar are arboreal, living above the ground, and some may almost never touch the forest floor. To only study the forest communities at ground-level is inherently a flat perspective, and to fully understand the complexity of forests is to appreciate their three-dimensional structure. Armed with harnesses and ropes, we ascend to the cano - py to explore the many layers that make up a rainforest.

Our particular interests lie in understanding how forest canopies, and their inhabitants, will respond to climate change. As the planet warms and becomes more variable, so does the forest, but potentially not at the same rate across the vertical spectrum (from forest floor to canopy). The canopy is more exposed to the sun than the forest floor– perhaps arboreal herps are more tolerant of warm temperatures, and may be more tolerant to climate change than their terrestrial neigh - bors.

Thanks to the laboratory facilities available at CVB, we are able to further explore these relationships ex-situ (outside of the natural environment). After capturing and identify - ing herps, we head to CVB to perform exper - imental trials: we place frogs in an arena that offers a range of temperatures, and observe where each individual relocates to, and therefore the temperatures it prefers. After finishing these trials, we carefully return all organisms back to the exact same tree they were found in. Then it’s off on a deep dive into the data, to find patterns that may match our predictions. What species preferred the warmer temperatures? Which ones were found higher in the canopy? Who will be resilient to climate change, and who needs further attention to ensure they persevere? We’re eager to discover soon, before time runs out on the unique biodiversity of these forests.