Lucas O. Bianchi
Lucas O. Bianchi
Researcher
Researcher
About Me
My research interests are focused in paleoclimatology and climate variability studies. I am also attracted to climate-plant relationships, stand dynamics and disturbances ecology, with particular emphasis in the Andean Patagonian forests and Southern Hemisphere.
My research mainly applies dendrochronological methods combined with glaciological, radiocarbon, cosmogenic, lake sediment and other dating methods. I also enjoy working with Remote Sensing data and performing GIS and spatial analysis.
At present, I divide my time studying the climate variability during the last 2000 years and the forests dynamics in Patagonia in response to climate and natural disturbances.
Recent publications
Complete list of publications on my CV
2021
Dinámica forestal pos-incendio en el gradiente de
precipitaciones del río de las Vueltas, Santa Cruz.DOI - Download
Few studies have evaluated post-fire forest dynamics. Our objective was to compare the fire history and post-fire dynamics in Nothofagus pumilio forests at two contrasting sites within the precipitation gradient in Las Vueltas river basin, Santa Cruz, Argentina. Our results show differences in fire histories and post-fire forest dynamics. While in the dry sector a single event of high severity and large spatial extension was recorded, three small-size fires with reduced intensities occurred in the humid sector. The post-fire dynamics reflect differences in both fire histories and N. pumilio sensitivity to water deficit. Retrospective studies of forest dynamics combining fire history reconstruction and establishment are of great value for improving our understanding of landscape dynamics over time.
2020
Six hundred years of South American tree rings
reveal an increase in severe hydroclimatic events since mid-20th century.The number and quality of SA climate-sensitive tree ring chronologies have significantly increased in recent decades, now providing a robust network of 286 records for characterizing hydroclimate variability since 1400 CE. We combine this network with a self-calibrated Palmer Drought Severity Index (scPDSI) dataset to derive the South American Drought Atlas (SADA) over the continent south of 12°S. Relating the SADA to the Australia–New Zealand Drought Atlas, sea surface temperatures and atmospheric pressure fields, we determine that the El Niño–Southern Oscillation (ENSO) and the Southern Annular Mode (SAM) are strongly associated with spatially extended droughts and pluvials over the SADA domain during the past several centuries. The SADA provides a long-term context for observed hydroclimatic changes and for 21st-century Intergovernmental Panel on Climate Change (IPCC) projections that suggest SA will experience more frequent/severe droughts and rainfall events as a consequence of increasing greenhouse gas emissions.
2019
Climate-growth relationships of deciduous and evergreen species of Nothofagus in Southern Patagonia, Argentina.
Differences in growth patterns between a deciduous species, Nothofagus pumilio, and an evergreen species, N. betuloides, were analyzed in southern Patagonia, Argentina (49°01' S –17 72°52' W). The relationships between the growth rate of these two species and variations in temperature, precipitation, and the Southern Annular Mode (SAM) were also evaluated. Our study provides the first chronologies of N. pumilio and N. betuloides in the area and increases knowledge about the relationships between tree-ring growth and climate.
A nonlinear mixed‐effects modeling approach for ecological data: Using temporal dynamics of vegetation moisture as an example
Our work covers a poorly addressed topic in ecology: illustrate the statistical modeling process using a nonlinear mixed‐effects framework. Similar to many other ecological variables, time series of vegetation moisture do not fit into classical statistical methods. We applied a nonlinear approach to model vegetation moisture dynamics proposing a logistic‐type function based on ideas about the dynamics of the system. Our model had greater support than alternative (and less complex) models. Parameter interpretation can be linked to vegetation features and environmental conditions showing how nonlinear mixed‐effects models could be used to advance ecological theory and practice. We encourage researchers to propose statistical models based on conceptual ideas rather than adjusting data to standard models that many times involve data transformation to meet model assumptions. Our approach can be useful to researchers addressing different ecological problems.
Ongoing projects
Climate reconstruction
Using tree-rings and other dating techniques (radiocarbon, cosmogenic, etc.) we aim to reconstruct climate variability of the past 1000-2000 years in Patagonia Argentina. The general objective is to improve our understanding of Southern Hemisphere cryospheric and climate change, variability, and sensitivity during the Holocene.
Climate Change in Northern Patagonia: Influence of environmental conditions on Fitzroya cupressoides (alerce patagónico) growth patterns
The endangered Fitzroya cupressoides is a millennial, emblematic species from the rainy Patagonian forest suitable for tree-ring analyses. The aim of this project is to conduct a multi-year study intended to determine the F. cupressoides growth responses to variations in the hydroclimate (precipitation, temperature, soil moisture) at different temporal scales (daily to seasonal). This information will facilitate the evaluation of potential impacts on the growth of F. cupressoides associated with future scenarios of climate change .
The project in Researchgate.
Climate, landscape and human drivers of spatiotemporal fire regimes across a southern Andes basin
Fire regime is regulated by the interaction among bioclimatic, environmental and human factors. Understanding this interaction allows to adapt fire management to changes in climate and land use. In Andean Patagonia there are numerous fire reconstructions, although none include the Río de las Vueltas basin, Santa Cruz, Argentina. This basin presents a marked precipitation gradient in a northwest-southeast direction, from ~1,000 to 320 mm per year, which allows studying the relationships among these factors on a landscape scale.
The main objective of the project is to reconstruct the fire history, describe its space-time variation, evaluate the influence of bioclimatic and anthropic variables, and develop a fire probability model for the basin landscape.Using tree-rings for Silvopasture management and Forest and shrubland structure estimation
Using dendro I collaborate with projects for: 1)Establishing management principles for silvopasture in mixed forests (Austrocedrus chilensis and Nothofagus dombeyi) in north-western Patagonia, Argentina, and 2) calibrating techniques of estimation of forest and shrubland structure from satellite images and Unmanned Aerial Vehicles (UAV).
Outreach activities
Dissemination through the media of our work
The value of Llancanelo in the western dry region.
Dissemination article explaining the results presented in the publication A regional water balance indicator inferred from satellite images of an Andean endorheic basin in central-western Argentina (Bianchi et al. 2016) in the journal Hydrological Sciences.
Patagonian moraines
Documentary Video filmed by CONICET Documental. It presents the work done in the field and in the lab to reconstruct glacial advances and retreats and their relationship with climate.
CV
For more detail about my Publications and Projects, take a look at my CV