Survival, growth and vulnerability to drought in fire refuges: implications for the persistence of a fire-sensitive conifer in northern Patagonia
- 237 Downloads
Fire severity and extent are expected to increase in many regions worldwide due to climate change. Therefore, it is crucial to assess the relative importance of deterministic vs. stochastic factors producing remnant vegetation to understand their function in the persistence of fire-sensitive plants. Vegetation remnants (areas within the landscape that have not burned for a considerable amount of time) may occur stochastically or in more predictable locations (fire refuges) where physical conditions decrease fire severity. Our aim was to determine if remnant forests of the fire-sensitive conifer Austrocedrus chilensis are associated with biophysical attributes that allow persistence in a fire-prone Patagonian landscape. We conducted a multi-scale approach, determining attributes of forest remnants and their surroundings (matrices) through remote sensing and field-based biophysical and functional characteristics, and quantifying how tree survival probability relates to microsite conditions. Trees within remnants displayed abundant fire scars, were twofold older and had threefold larger growth rates than matrix trees. Remnants were associated with high rocky cover and elevated topographical positions. Tree survival increased in hilltops, eastern aspects, and with sparse vegetation. Trees within remnants experienced severe reductions in growth during droughts. Our results suggest that A. chilensis remnants are mainly the result of refuges, where environmental conditions increase fire survival, but also increase susceptibility to drought. A trade-off between fire survival and drought vulnerability may imply that under increasing drought and fire severity, locations that in the past have served as refuges may reduce their ability to allow the persistence of fire-sensitive taxa.
KeywordsBasal area increment Forest remnant Climate change Biophysical attributes Austrocedrus chilensis
We thank Juan Manuel Morales for insightful comments on the manuscript and Maria Laura Suarez for her help in the tree chronology and correlation function analysis. We especially thank Jeremy Lichstein (handling editor) and two anonymous reviewers for their comments which greatly improved the quality of the manuscript. This study was funded by grant BIRF 7520 (Sustainable Forests Plantations Component) PIA 10058 and PIA 12055 (Ministerio de Agricultura, Ganadería y Pesca). J.B.L. acknowledges a CONICET fellowship.
Author contribution statement
J.B.L. performed the research, conducted fieldwork, analyzed the data and wrote the manuscript. J.B.L., J.H.G. and T.K. conceived and designed the study. L.A.G. contributed to the data analysis.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest and that the experiments comply with the current laws of Argentina, where the experiments were performed.
- Bran D, Ayesa J, López C, Sbriller D (1996) Evaluación del área afectada por el incendio de enero de 1996 en Co. Catedral. Laboratorio de Teledetección Aplicada, INTA EEA BarilocheGoogle Scholar
- Elmqvist T, Wall M, Berggren AL, Blix L, Fritioff A, Rinman U (2001) Tropical forest reorganization after cyclone and fire disturbance in Samoa: remnant trees as biological legacies. Conserv Ecol 5(2):10Google Scholar
- Kitzberger T, Aráoz E, Gowda JH, Mermoz M, Morales JM (2012) Decreases in fire spread probability with forest age promotes alternative community states, reduced resilience to climate variability and large fire regime shifts. Ecosystems 15(1):97–112. doi: 10.1007/s10021-011-9494-y CrossRefGoogle Scholar
- Monmonier MS (1982) Computer-assisted cartography: principles and prospects. Prentice-Hall, Englewood Cliffs, NJ, pp 76–80Google Scholar
- Newton A et al. (2011) Landscape-scale dynamics and restoration of dryland forest ecosystems. In: Newton A, Tejedor N (eds) Principles and practice of forest landscape restoration: case studies from the drylands of Latin America. International Union for Conservation of Nature, pp 229–272Google Scholar
- Pinheiro J, Bates D, DebRoy S, Sarkar D (2011) R Development Core Team 2010, nlme: linear and nonlinear mixed effects models. R package version 3.1-97. R Foundation for Statistical Computing, ViennaGoogle Scholar
- Salguero J (2000) Informe sobre las consecuencias ecológicas de los incendios forestales. APN, Delegación Regional Patagonia, Ecología del FuegoGoogle Scholar
- Souto C, Gardner M (2013) Austrocedrus chilensis. The IUCN red list of threatened species, version 2014.3Google Scholar
- Szarzynski J (2000) Xeric islands: environmental conditions on inselbergs. In: Porembski S, Barthlott W. (eds) Inselbergs: biotic diversity of isolated rock outcrops in tropical and temperate regions. Springer, Heidelberg, p 37–48Google Scholar
- Tachikawa T, Hato M, Kaku M, Iwasaki A (2011) The characteristics of ASTER GDEM version 2, IGARSS, pp 3657–3660 doi: 10.1109/IGARSS.2011.6050017
- Veblen TT, Kitzberger T, Raffaele E, Lorenz D (2003) Fire history and vegetation changes in northern Patagonia, Argentina. In: Veblen TT, Baker W, Montenegro G, Swetnam TW (eds) fire and climatic change in temperate ecosystems of the western Americas. Ecological studies, vol 160. Springer, Heidelberg, pp 265–295Google Scholar
- Willis B (1914) El Norte de la Patagonia. Dirección de Parques Nacionales, Buenos AiresGoogle Scholar