Group picture taken at one of the Dipterocarp forest in XTBG.
This last summer, I spent a very exciting month participating in a training course in China, titled “The Ecology of Climate Change in the Tropics and Sub-Tropics”. The course was a result of the collaboration between the Xishuangbanna Tropical Botanic Garden (XTBG) and the Organization of Tropical Studies (OTS). It was hosted by XTBG, the largest botanical garden in China and also a research center affiliated with the Chinese Academy of Sciences (CAS). XTBG has around 30 research groups, and many research labs are focused on national strategic needs (Key Laboratories, http://english.xtbg.cas.cn/rh/rd/).
XTBG (1125 ha) is embedded in a remote, rural town in China. Access to XTBG from the town of Menglun is shown by the green line, and it leads to the location of the research center. The yellow line shows the trail to the green stone forest platform, overlooking the area in white. XTBG looks like a peninsula encircled by the LuoSuo River, a tributary of the Mekong Delta.
The course was designed for graduate students and young professionals from the New and Old-world tropics. The diversity of the participants was one of the highlights of my experience in the course. Students were from 16 different countries, and including the instructors there were 20 nationalities participating in the course (see the map below). The atmosphere in the classroom was very unique and enjoyable, as everybody was really interested in learning about each other’s research, but also about each other’s culture.
Distribution map created by Alice C. Hughes showing the original countries of students and instructors.
One of the aspects of the course that I really enjoyed was the opportunity to interact and learn from the scientists teaching the course (see list here). Instructors from OTS came to China and offered us a combination of field exercises, lectures and discussion sessions in biomass estimation, atmospheric science and climate change oral history. XTBG scientists presented a mix of lectures regarding different aspects of climate change ecology, some accompanied with practical exercises to demonstrate cutting-edge techniques and research technologies. Additionally, researchers from international organizations and local NGOs provided the group with study cases from nearby areas like the Hindu Kush Himalayan (HKH) region to discuss issues related to conservation and sustainable development. Last, but certainly not least, plenty of postdocs and graduate students donated their time to show us their laboratories and own experiments.
Group visit to the CTFS, 1-ha plot, close to XTBG.
In the third week of the course, we had to carry out our own projects. We visited two biological research stations hosted by XTBG, Yuanjiang Hot Dry Valley Ecological Station and Ailaoshan Mountain Range. The research projects conducted by students in the course were: 1) Invasive flora along an elevation gradient and implications of climate change: A case study from Ailaoshan Mountain Range, Yunnan, China; 2) Potential influence of climate change on plant-pollinator interactions – Preliminary study from Yuanjiang subtropical forest; 3) Woody plant diversity and leaf morphology along an altitudinal gradient in the hot dry valley; and 4) Coloration of butterflies along an elevation gradient (the project of my group).
Picture taken from the top of the dry savanna at Yuanjiang Hot Dry Valley Ecological Station. At the bottom of the slope is possible to see the Red River (Yuanjiang River).
Developing the group project was the most enjoyable part of the course. The seven people in my group made the unanimous decision to follow one member’s interest on butterflies. We hypothesized that we would see an increase of dark winged butterflies with increasing elevation. As temperature decreases with elevation, ectothermic species with the ability to raise body temperature may be at an advantage at higher elevations. In butterflies, this ability could be achieved through increased melanization of the wings. We found the perfect scenario to test our hypothesis at the Ailaoshan Mountain Range (~1km elevational gradient, 1374 – 2480 m asl), an area covered by montane evergreen broad-leafed forest. In 17 sampling hours, we were able to count 460 butterflies (2 teams & 2 days). Later, we used photographic analysis conducted on the wings of each individual morphospecies to validate the color data registered during the field work.
The highest proportions of dark butterflies were found at high elevations, whereas light colored butterflies were found all along the gradient. These results suggest there is a constraint for dark butterflies to move into open/lower elevation areas. The team wished to include more variables in the project such as butterfly behavior or land use cover, but we only had a few days to collect data. Our findings suggested that darker butterflies may be more susceptible to climate change but the mechanisms (for example: increased ability to heat up, limitation in their dispersal, etc.) are still not clear.
An exciting part of the project –although not so easy- was the thermal analysis of the wings. Using a Flir® brand infrared camera, and exposing the wings to sunlight, we observed that dark-colored wings indeed heat up faster than light-colored wings. On the left, picture of one of the dark specimens collected in the field.
Our project was chosen as the best student project from the course by the panel. Very special thanks have to go to the instructors and course coordinators that encouraged and helped with our project (Alice C. Hughes, Brett Scheffers, Kyle Tomlinson, Pierre Honoré, Richard Corlett and Jingxin Liu). As I said earlier, it was a lot of fun, we worked hard, and we were able to put into practice several techniques we learned during the course.
Finally, I would like to say that this training course was an outstanding experience. I encourage the organizers and funders to work on developing more courses like the XTBG-OTS course for other students and other locations.