CRN 2031 – PI: Jobbágy (Universidad de Buenos Aires – ARGENTINA)
Land use change in the Río de la Plata basin: Linking biophysical and human factors to understand trends, assess impacts, and support viable strategies for the future


As the global demand for agricultural commodities grows, following the increasing number and per-capita consumption of humans, societies start to realize that the same land ecosystems that provide goods and income are often the source of vital services such as the provision of fresh water or the regulation of atmospheric gases and climate. How are these social signals changing land use patterns across the globe? What are the trade-offs and synergies between the production of commodities and the provision of ecosystem services? How can we optimize both? These questions pose urgent challenges and unique opportunities to global change scientists, particularly in a region like the Rio de la Plata Basin, where the largest and most productive agricultural systems of the continent are experiencing their fastest expansion in history. Our goals in this project are to A. Characterize patterns and drivers of land use change. B. Assess the consequences of land use change. C. Explore land use change feedbacks & plausible scenarios. D. Couple market and environmental interests for land use planning (Outreach).

We will focus our work on the following land use changes, which have dominated the basin during the last three decades:

Vegetation zone

Humid, forest

Sub-humid, grasssland

semi arid, forest savanna

Mata Atlantica
Pastizal Serrano
Key Land use
Natural →Agriculture
Agriculture shifts
Natural →Agriculture
Agricultural shifts
Natural →Afforestation
Grazing on natural veg.
Natural →Agriculture
Agriculture shifts
Grazing on natural veg.

Working at the regional scale, the project will bridge the gap between a growing, but disperse body of local studies, and the novel perspectives and tools of global change science (satellite imagery, biophysical and social databases, historical documents and statistics, and simulation models). Local studies (biophysical experiments and social interviews/surveys) will cover critical gaps and provide strategic information for an effective regional scaling-up of results.

The activities stated below will include the exploration of land use change (LUC) patterns, drivers, and consequences and their integration into a modeling framework capable of representing their feedbacks. Patterns: Description of LUC throughout the last 25 years merging national databases and remote sensing-based classifications. Development of state & transitions diagrams of LUC changes. Drivers: (a) – Historical socioeconomic context of key land use changes: Across-nation comparative historical reconstruction of political, economic, and technological drivers of key LUC based on census data and economic databases. Political and financial contrast across borders in otherwise similar conditions used to evaluate hypotheses. (b) – Spatial and temporal controls of land use changes: Causes and constrains of LUC explored based on space-time associations between LUCs and human and biophysical drivers. Spatial configuration of changes (e.g. aggregation patterns) assessed.Consequences: (a) – Socioeconomic impacts: Impact on societies at local and national level. Quantification of shifts in income/employment outputs and their distribution among social groups using databases and key interviews. (b) - Carbon uptake, storage & burning: LUC impact on C uptake and its interaction with climatic variation explored based remote sensing information. General mechanisms responsible of soil organic carbon storage shifts in LUC transitions (e.g. plant type change vs. soil disturbance shifts) assessed in ecosystems with clear 13C signature changes. Baseline description of biomass burning patterns in the basin and their interaction of demographic and climatic variables (d) Water balance changes: Effects of LUC on the partition of precipitation inputs into evapotranspiration and water yield (drainage and runoff) assessed experimentally in a network of key study sites. Integration at the regional and basin level merging these studies with hydrological records and remote sensing proxies. Feedbacks: Spatially explicit connection of drivers-LUCs- impacts-ecosystem products/services through interactive modeling. Drivers-LUC represented with a cellular automata (CLUE modeling framework). LUC-impacts using biophysical models (CENTURY, BIOME, VAST). Impacts-ecosystem services based on dimensionless scalars. Representation of plausible biophysical feedbacks based on loops between drivers and impacts. Representation of plausible social feedbacks based on historical experience and explicit hypotheses into CLUE. Outreach: Development of a regional forum for global change science extension oriented to policy makers, stakeholders, and the public in general. The forum will be based on the participation of CRN researchers and other invited scientists presenting science based discussion on LUC issues. The forum will be publicized through regular articles in newspapers at strategic times. Workshops with stakeholders dealing with specific LUCs (e.g. afforestation on rangelands) will be carried on at the national level at different stages of the project.

From a basic science perspective, our team will take advantage of the unique array of experimental situations offered by the land use changes of the basin to gain new insights on broad global change questions. From an applied perspective, the project will meet urgent knowledge needs through the characterization of agriculture and afforestation expansion and natural ecosystem losses at the country & state level; the development of efficient, simple and publicly available methods for the detection of land use changes and the assessment of their biophysical impacts; the projection of land use change impact on private and public income, employment, and commodity outputs; the identification of C sequestration opportunities across land uses and biomes, the assessment of possible trade-offs between C sequestration and commodity production and/or water provision; and the generation of a modeling framework for the exploration of plausible land use change scenarios under different climatic and socioeconomic conditions in Argentina, Southern Brasil, Paraguay, and Uruguay. A team of 18 researchers from 13 institutions and 5 countries will merge their complementary backgrounds generating novel insights on global change theory and land use planning. As it occurred with previous IAI projects granted to the team members, training new scientist and integrating them into an international research network will be a priority.

:: First year Technical Report: PDF

:: Second year Technical Report: PDF

:: Third year Technical Report: PDF

:: Fourth year Technical Report: PDF