Vegetation responses to late Holocene climate changes in an Andean forest By Klaas Land (currently studying MSc Biological Sciences (Ecology & Evolution) at the University of Amsterdam.
The discussion during the APC meeting on the 19th of March was on the paper by Schiferl et al. (2018), a very recent study on the climatic shifts in the late Holocene and their effects on the South American tropics. The study had analysed a core going back about 3800 years from Lake Palotoa, which was in the Andean foothills (1370m elevation). They found that subtle changes to the fossil pollen record could be identified around the estimated periods for the Little Ice Age (LIA) and Medieval Climate Anomaly (MCA). The focus in the paper Continue Reading
Huisman, S.N.*, Bush, M.B. & McMichael, C.N.H. (2019) Four centuries of vegetation change in the mid-elevation Andean forests of Ecuador. Vegetation History and Archaeobotany. DOI: 10.1007/s00334-019-00715-8
Cuesta, F., Llambi, L.D., Huggel, C., Drenkhan, F., Gosling, W.D., Muriel, P., Jaramillo, R. & Tovar, C. (2019) New land in the Neotropics: a review of biotic community, ecosystem, and landscape transformations in the face of climate and glacier change. Regional Environmental Change. DOI: 10.1007/s10113-019-01499-3
I am sitting on the shore of Lago Condorcillo in Southern Ecuador, after a long day of travel, trying to control my shivering. At roughly 10,500 ft. above sea level, the lake is very cold, with wind that howls over the barren hills dotted with giant boulders. The lake is also almost always blanketed by thick fog and pelted by driving rain. When you’re surrounded by the thick fog punctuated by lightning bolts, it’s easy to believe that some lost civilization lurks just out of sight. Tonight we are experiencing lightning storms, which is adding to the feeling that some angry, ancient life form must live at Lago Condorcillo.
Tomorrow, I will be out in the cold and rain, balancing on an inflatable boat and fighting frostbite. Mark Bush, who is my Ph.D. advisor, Courtney Shadik, who is my lab partner and tent buddy, and I will be collecting cores of mud from the bottom of Condorcillo. We will create our rig for coring by tying two inflatable boats together, and placing a wooden platform between them. Mark, Courtney, and I will then collect our mud cores from this platform.
As I’m contemplating the hazards of camping in a lightning storm, Mark says, “Tell me everything that went wrong today.” Courtney pulls a sleeping bag closer to her. I begin to describe how Google Maps can’t seem to understand distance in the Andes, and so traveling to Lago Condorcillo took much longer than we anticipated. Courtney laughs beside me and adds, “We don’t have any matches to start a fire.” Despite our troubles, I am grinning from ear to ear, no doubt spoiling the grim mood Mark is attempting to cultivate and Lago Condorcillo is doing its best to enforce.
In the 4th edition of our “Amsterdam Paleoecology Club”(APC), we discussed ‘A 6900-year history of landscape modification by humans in lowland Amazonia’ by Bush et al. (2006)1. The high-resolution record presented in this paper shows impressively that what we might perceive as native rainforest today could rather be a since a long time actively modified landscape.
The chronology from Lake Sauce (Peruvian Andes) suggests a continuously forested landscape under significant anthropogenic impact over the last 6900 years. Indicators of human activity are taken to be the varying presence of crop pollen (Zea mays) throughout the record, combined with the continuous occurrence of charcoal. Two extra-large fire events are dated at c. 6700 and between 4500-4230 cal BP, probably enhanced by the relatively drier climate of the mid-Holocene. However, it is not clear yet if human actions formed a response to climate change or were part of social and cultural changes.
Hagemans, K., Tóth, C.-D., Ormaza, M., Gosling, W.D., Urrego, D.H., León-Yánez, S., Wagner-Cremer, F. & Donders, T.H. (2019) Modern pollen-vegetation relationships along a steep temperature gradient in the Tropical Andes of Ecuador. Quaternary Research online. DOI: 10.1017/qua.2019.4
The International Conference on Past Plant Diversity, Climate Change, and Mountain Conservation was aimed to address this question, with a focus on mountain (montane) species. As climate warms, there are several outcomes for montane species. They can migrate upslope, go extinct, or adapt to the warming conditions. Given these options, we got together to discuss our most recent datasets, and the best strategies for the conservation of montane species. Effective conservation strategies are crucial for the survival of many rare and endemic montane species, because climate is indeed warming, regardless of what Trump or Fox News tries to tell people.