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Climate Change 2016
October 27-29, 2016
Volume 7, Issue 9(Suppl) J Earth Sci Clim Change
ISSN: 2157-7617 JESCC, an open access journal
conferenceseries .com
October 24-26, 2016 Valencia, Spain
World Conference onClimate Change
Carbon stocks and fluxes in the Andean tree line of Polylepis reticulata in Ecuador: Present balance
and projected values for the 21st century
Carlos A Gracia1,2
1University of Barcelona, Spain
2University of Cuenca, Ecuador
Trees in the tropical and subtropical mountains of South America are able to develop at high elevation, with some species
forming the highest tree-line in the world at 5200m. Under these unique environmental conditions, only evergreen trees of
the genus Polylepis are able to subsist. Polylepis reticulata is a very slow growth tree. The strategy of these trees to survive in such
unfavorable conditions has been analyzed in the Cajas National Park (Azuay, Ecuador). In this work we measure for the first
time, the carbon stocks and fluxes, particularly GPP, NPP, respiration and carbon allocation of Polylepis reticulata growing over
4000 m of altitude. From dendrometric measurements we have estimated the age of some trees (around 30 cm in diameter) to
be more than 400 years. The temperature increase and changes in the rainfall pattern in these areas of the Andean cordillera
can modify substantially the carbon fluxes between the forest and the atmosphere. From the 1151gC.m-2 year-1 uptake as GPP,
888gC.m-2 year-1 is returned to the atmosphere as growth and maintenance respiration. Most of the carbon retained as NPP
is allocated to the leaves (194 from the 263 gCm-2 year-1). To produce one kg of dry biomass these trees transpire 5m3 of
water. The physiological response of P. reticulata under different RCP scenarios (IPCC, 2013) has been simulated using the
GOTILWA+ model. The results show drastic changes in all the scenarios. For example growing under the RCP 2.6, at the end
of the present century the NPP is projected to increase up to 362 gCm-2 year-1 but, at the same time, the carbon allocated to
leaves increase up to 325 gCm-2 year-1 or 90 per cent of the NPP. In that scenario the water used to grow 1 kg of dry matter is
projected to increase up to 20 m3. The exploration of other climate scenarios shows more drastic changes that put at risk the
survival of this emblematic species endemic of the Andean cordillera.
Biography
Carlos A Gracia is the Professor at the Department of Ecology, University of Barcelona. The ecophysiological responses of forest ecosystems to climate change,
primary production, water and carbon balance are the core of his research work. He is the author of GOTILWA+, a process-based forest growth simulation model
under different climate change scenarios. He has been the Vice-President of the Spanish Society of Terrestrial Ecology (AEET) and Member of the Directory Board
of the Spanish Society of Forest Science (SECF), Member of the Scientific Advisory Board of the European Forest Institute (EFI). Since January 2014, he has
joined the Prometeo fellowship from the SENESCYT (Secretaría Nacional de Educación Superior, Ciencia, Tecnología e Innovación) of Ecuador at the University
of Cuenca (Azuay, Ecuador).
Carlos A Gracia, J Earth Sci Clim Change 2016, 7:9(Suppl)