Carbon fluxes from a temperate rainforest site in southern South America reveal a very sensitive sink

Abstract

2018. Carbon fluxes from a temperate rainforest site in southern South America reveal a very sensitive sink. Ecosphere 9(4):

Warming and Drought Weaken the Carbon Sink Capacity of an Endangered Paleoendemic Temperate Rainforest in South America

“…This results in a shorter period of carbon uptake than in a typical temperate evergreen forest in the Northern Hemisphere and consequently lower annual NEE magnitude compared with the global NEE average of temperate evergreen forests (398 ± 42 g C m -2 year -1 ; Luyssaert et al, 2007 ). However, annual GPP and Reco are higher compared to the global average (1762 ± 56 g C m -2 year -1 ; and 1336 ± 57 g C m -2 year -1 , respectively; Luyssaert et al, 2007 ), which agrees with what was reported for an evergreen broadleaved rainforest in southern Chile ( Perez-Quezada et al, 2018 ).…”

“…Even GPP and Reco values were very similar (1,815 ± 70 and 1,557 ± 89 g C m −2 year −1 , respectively) to the Douglas‐fir forest, although R s was much higher compared to their estimation (981 ± 43 g C m −2 year −1 ). Annual NEE was 20% higher than that measured in an old‐growth evergreen broadleaved North‐Patagonian rainforest in southern Chile (−238 ± 31 g C m −2 year −1 ; Perez‐Quezada et al., 2018) and 70% higher than in an open Mediterranean shrubland in central Chile (−82 ± 41 g C m −2 year −1 ; Meza et al., 2018).…”

“…This contrasts with the typical seasonal pattern of carbon uptake of temperate evergreen coniferous forests in the Northern Hemisphere, where net carbon uptake starts in spring, peaks in summer and ends in autumn ( Richardson et al, 2010 ). A broadleaved rainforest located 180 km south of the Alerce Costero site has a similar starting date and peak for carbon uptake, but it ends in late autumn ( Perez-Quezada et al, 2018 ). The distinctive seasonal dynamics of the Fitzroya rainforest shows that it is particularly adapted to cool and wet spring conditions and that it is strongly constrained by summer drought and warmth in the second half of the growing season.…”

“…Therefore, it is necessary to measure and determine how austral temperate forests behave and respond to climate change. A recent study of carbon fluxes in a North‐western Patagonian evergreen forest from southern South America (42°S) showed lower net ecosystem exchange (NEE), but higher biological activity (higher gross primary productivity and ecosystem respiration) compared to rainforests in the Northern Hemisphere (Perez‐Quezada et al., 2018). This same forest was also found to store the largest C stock in the soil among temperate rainforests in the world (Perez‐Quezada et al., 2021).…”

Recent Consequences of Climate Change Have Affected Tree Growth in Distinct Nothofagus macrocarpa (DC.) FM Vaz & Rodr Age Classes in Central Chile

“…Field experiments are necessary to understand how adult trees of different ages and their dynamic processes are responding to the new drier and hotter climate conditions. Only recently a few forest micrometeorological monitoring sites have started to operate in southern Chile and Argentina [66], including measurements of water and carbon exchange, soil respiration, radial stem growth, and the transpiration flow to understand how climate change is affecting temperate forests. In addition, our dendroecological approach could be combined with tomography and growth simulation models to help with decision-support for management and conservation of forest ecosystems [67].…”