Drivers of post-fire Nothofagus antarctica forest recovery in Tierra del Fuego, Argentina

Introduction Large wildfires were historically absent in the forests of Tierra del Fuego, southern Argentina. This has changed in recent decades as humans have increased ignition sources, and warmer, drier periods have fueled large, severe wildfires. As a result of its location at an extreme southern latitude, Tierra del Fuego has very low tree species diversity. One of the region's dominant tree species, Nothofagus antarctica, is believed to have traits that may make it resilient to wildfire (e.g., the ability to resprout prolifically). Methods This study examined post-fire N. antarctica regeneration across an environmental and time-since-fire gradient. Plots were established in burned areas (n = 160) and unburned controls (n = 32) in and around two wildfires that occurred circa 1940 and in 2019. Seedling/resprout and sapling regeneration densities, as well as site characteristics (e.g., slope) and fire-impacted variables (e.g., distance to mature live trees), were measured. Results Seedling and resprout densities were lower in burned plots than in controls, with this trend being exacerbated in the 2019 fire with increasing distance from mature live trees. Regeneration generally occurs in clumps and principally through sprouting from live and top-killed trees, with not all top-killed trees having resprouted. Seedling and resprout densities were most strongly impacted by time since fire, distance to mature live trees and post-fire canopy cover. Sapling densities were modulated by slope, time since fire, and distance to mature live trees. Discussion Despite lower regeneration densities in recently burned plots and less live basal area and canopy cover in older burned plots compared to unburned controls, burned stands may be on a trajectory to recover pre-fire characteristics, although this recovery is spatially variable. However, full recovery has not occurred 80 years after the 1940's fire. Currently, these burned areas resemble grasslands or savannas. They do not provide the habitat or ecosystem services that denser forests do and may require active restoration to fully recover their pre-fire characteristics.

[1]  María Vanessa Lencinas,et al.  Understory Plant Dynamics Following a Wildfire in Southern Patagonia , 2023, SSRN Electronic Journal.

[2]  E. C. Iranzo,et al.  Patterns of guanaco distribution and microhabitat use in Tierra del Fuego: From protected to sheep ranching areas , 2022, Acta Oecologica.

[3]  Lei Wang,et al.  Global Trends of Forest Loss Due to Fire From 2001 to 2019 , 2022, Frontiers in Remote Sensing.

[4]  S. Bajocco,et al.  Continuous observations of forest canopy structure using low-cost digital camera traps , 2021 .

[5]  B. Pinno,et al.  Relationships between Overstory and Understory Components of Young Natural and Reconstructed Boreal Aspen Stands , 2021, Ecological Restoration.

[6]  A. Cutini,et al.  A comparison of ground-based count methods for quantifying seed production in temperate broadleaved tree species , 2021, Annals of Forest Science.

[7]  M. Ducey,et al.  Topography and fire legacies drive variable post-fire juvenile conifer regeneration in eastern Oregon, USA , 2020 .

[8]  K. Moffett,et al.  High‐severity and short‐interval wildfires limit forest recovery in the Central Cascade Range , 2020 .

[9]  Charles B. Halpern,et al.  Long-Term Effects of Fuels Treatments, Overstory Structure, and Wildfire on Tree Regeneration in Dry Forests of Central Washington , 2020, Forests.

[10]  Jamie L. Peeler,et al.  Seed source pattern and terrain have scale-dependent effects on post-fire tree recovery , 2020, Landscape Ecology.

[11]  F. Chapin,et al.  Factors shaping alternate successional trajectories in burned black spruce forests of Alaska , 2020, Ecosphere.

[12]  J. Pausas,et al.  Fire as a Selective Agent for both Serotiny and Nonserotiny Over Space and Time , 2020, Critical Reviews in Plant Sciences.

[13]  M. Flannigan,et al.  Post-fire regeneration of endangered limber pine (Pinus flexilis) at the northern extent of its range , 2020 .

[14]  Chang-Seok Lee,et al.  Regeneration of pitch pine (Pinus rigida) stands inhibited by fire suppression in Albany Pine Bush Preserve, New York , 2019, Journal of Forestry Research.

[15]  G. M. Pastur,et al.  Atributos de la regeneración natural de ñire (Nothofagus antarctica) en Tierra del Fuego: beneficios y perjuicios que genera el uso silvopastoril , 2018 .

[16]  Lisa M. Holsinger,et al.  Analog‐based fire regime and vegetation shifts in mountainous regions of the western US , 2018 .

[17]  Paula J. Fornwalt,et al.  Spatial patterns of ponderosa pine regeneration in high-severity burn patches , 2017 .

[18]  M. Ritchie,et al.  Resilience of California Black Oak Experiencing Frequent Fire: Regeneration Following Two Large Wildfires 12 Years Apart , 2017 .

[19]  María Vanessa Lencinas,et al.  Ten years of seed production and establishment of regeneration measurements in Nothofagus antarctica forests under different crown cover and quality sites, in Southern Patagonia , 2016, Agroforestry Systems.

[20]  María Vanessa Lencinas,et al.  A review of silvopastoral systems in native forests of Nothofagus antarctica in southern Patagonia, Argentina , 2016, Agroforestry Systems.

[21]  Sam W. Wood,et al.  Effects of high‐severity fire drove the population collapse of the subalpine Tasmanian endemic conifer Athrotaxis cupressoides , 2015, Global change biology.

[22]  K. Mock,et al.  Aspen Seedling Establishment and Growth after Wildfire in Central Arizona: An Instructive Case History , 2014 .

[23]  Jiaojun Zhu,et al.  Effects of gaps on regeneration of woody plants: a meta-analysis , 2014, Journal of Forestry Research.

[24]  D. Renison,et al.  Post‐fire recovery occurs overwhelmingly by resprouting in the Chaco Serrano forest of Central Argentina , 2014 .

[25]  F. Moreira,et al.  Post-fire survival and regeneration of Eucalyptus globulus in forest plantations in Portugal , 2013 .

[26]  Horacio Ivancich.  Relaciones entre la estructura forestal y el crecimiento del bosque de Nothofagus antarctica en gradientes de edad y calidad de sitio , 2013 .

[27]  María Vanessa Lencinas,et al.  Are silvopastoral systems compatible with forest regeneration? An integrative approach in southern Patagonia , 2013, Agroforestry Systems.

[28]  G. M. Pastur,et al.  Regeneración por semillas en bosques nativos de Nothofagus antarctica bajo uso silvopastoril en Patagonia Sur, Argentina , 2013 .

[29]  D. Tinker,et al.  Fire-induced shifts in overstory tree species composition and associated understory plant composition in Glacier National Park, Montana , 2012, Plant Ecology.

[30]  Juli G Pausas,et al.  Fire as an evolutionary pressure shaping plant traits. , 2011, Trends in plant science.

[31]  E. Raffaele,et al.  Synergistic influences of introduced herbivores and fire on vegetation change in northern Patagonia, Argentina , 2011 .

[32]  L. Collado,et al.  Phytoclimatic characterization and cartography of subantarctic native forests in Isla Grande de Tierra del Fuego (Patagonia, Argentina) , 2010 .

[33]  A. Schoettle,et al.  Subalpine vegetation pattern three decades after stand-replacing fire: Effects of landscape context and topography on plant community composition, tree regeneration, and diversity , 2010 .

[34]  J. Keeley.  Fire intensity, fire severity and burn severity: a brief review and suggested usage , 2009 .

[35]  Daniel C. Donato,et al.  Vegetation response to a short interval between high‐severity wildfires in a mixed‐evergreen forest , 2009 .

[36]  F. Pulido,et al.  Incidencia del ramoneo del guanaco (Lama guanicoe Müller) sobre la regeneración temprana en bosques de lenga [Nothofagus pumilio (Poepp et Endl) Krasser] de Tierra del Fuego, Argentina , 2008 .

[37]  A. Premoli,et al.  Genetics of sprouting: effects of long‐term persistence in fire‐prone ecosystems , 2008, Molecular ecology.

[38]  F. López‐Serrano,et al.  Tree density and site quality influence on Pinus halepensis Mill. reproductive characteristics after large fires , 2007, Annals of Forest Science.

[39]  J. H. Bock,et al.  Effects of Fire Frequency and Intensity on Velvet Mesquite in an Arizona Grassland , 2007 .

[40]  Douglas Belz.  Severing Red Alder: Timing the Cut to Achieve the Best Mortality , 2003 .

[41]  S. Pyne,et al.  Fire, Native Peoples, and the Natural Landscape , 2003 .

[42]  J. Peñuelas,et al.  Seedling survival of Mediterranean shrubland species in relation to root:shoot ratio, seed size and water and nitrogen use , 1999 .

[43]  T. T. Veblen,et al.  FIRE HISTORY IN NORTHERN PATAGONIA: THE ROLES OF HUMANS AND CLIMATIC VARIATION , 1999 .

[44]  Aaron M.Ellison.  PC‐ORD: Multivariate Analysis of Ecological Data , 1998, The Bulletin of the Ecological Society of America.

[45]  B. Burns.  Fire-induced dynamics of Araucaria araucana-Nothofagus antarctica forest in the southern Andes. , 1993 .

[46]  D. C. Lorenz,et al.  Recent Vegetation Changes along the Forest/Steppe Ecotone of Northern Patagonia , 1988 .

[47]  S. K. Lothrop.  The Indians of Tierra Del Fuego , 1976 .

[48]  M. Reilly,et al.  Early seral pathways of vegetation change following repeated short-interval, high-severity wildfire in a low-elevation, mixed conifer – hardwood forest landscape of the Klamath Mountains, California , 2020 .

[49]  J. Abatzoglou,et al.  Climate will increasingly determine post‐fire tree regeneration success in low‐elevation forests, Northern Rockies, USA , 2019, Ecosphere.

[50]  A. Müller,et al.  Efecto del ramoneo bovino en renovales de Nothofagus antarctica en Chubut, Argentina, en relación con la carga ganadera y la altura de la plantas , 2014 .

[51]  H. Fischer,et al.  Canopy effects on vegetation caused by harvesting and regeneration treatments , 2010, European Journal of Forest Research.

[52]  A. Premoli,et al.  Adaptive and neutral variation of the resprouter Nothofagus antarctica growing in distinct habitats in north-western Patagonia , 2008 .

[53]  J. Clark,et al.  Interpreting recruitment limitation in forests. , 1999, American journal of botany.

[54]  C. Heusser.  Paleoindians and fire during the late quaternary in southern south america , 1994 .

[55]  E. Bridges,et al.  Uttermost part of the earth , 1950 .