Long term productivity and diversity in high altitude peatlands of Northern Chile

Background/Question/Methods

Peatlands, called bofedales by the local population, are typical features found above 3.500 masl in the Andes of Northern Chile. These peatlands are dominated by cushion plants from Juncaceae (Oxychloe andina, Patosia clandestina) and Cyperaceae; they are fed mainly by groundwater and are located in foothills of mountain slopes, ravines and the margins of salt lakes. During the last twelve years we studied formation, plant productivity and diversity in peatlands of the Atacama Region in Chile (29°S, between 3.500 and 4.000 masl).

Results/Conclusions

Modern peatlands in the region started to expand about 1200 years ago, and have accumulated to form peats of an average of 2 m in depth. Hydrogeology data show that peatlands are connected with the regional aquifer, but that also local flow systems are important water sources. Interannual changes in the peatlands' summer water level are consistent with the influence of precipitation from the previous winter; these changes, however, are less dramatic than those observed in the regional aquifer. Average annual plant productivity varies between 1000 and 1200 gr m^-2, with a recorded minimum of approximately 700 gr m^-2 (2004 and 2005) and maximum of ca. 2400 gr m^-2 (2011-12). While dominant species did not change during the studied period, the relative contributions of less abundant plant species affected the Shannon-Wiener (H’) diversity, which ranged between 1.4 and 2.6.

Financed by Compañía Minera Nevada, Chilean Millennium Initiative (ICM P05-002) and CONICYT (PFB-23) grants