Agricultural expansion and the ecological marginalization of forest-dependent people

Abstract

Agricultural expansion into subtropical and tropical forests causes major environmental damage, but its wider social impacts often remain hidden. Forest-dependent smallholders are particularly strongly impacted, as they crucially rely on forest resources, are typically poor, and often lack institutional support. Our goal was to assess forest-smallholder dynamics in relation to expanding commodity agriculture. Using high-resolution satellite images across the entire South American Gran Chaco, a global deforestation hotspot, we digitize individual forest-smallholder homesteads (n = 23,954) and track their dynamics between 1985 and 2015. Using a Bayesian model, we estimate 28,125 homesteads in 1985 and show that forest smallholders occupy much larger forest areas (>45% of all Chaco forests) than commonly appreciated and increasingly come into conflict with expanding commodity agriculture (18% of homesteads disappeared; n = 5,053). Importantly, we demonstrate an increasing ecological marginalization of forest smallholders, including a substantial forest resource base loss in all Chaco countries and an increasing confinement to drier regions (Argentina and Bolivia) and less accessible regions (Bolivia). Our transferable and scalable methodology puts forest smallholders on the map and can help to uncover the land-use conflicts at play in many deforestation frontiers across the globe. Such knowledge is essential to inform policies aimed at sustainable land use and supply chains.

Agents of Forest Disturbance in the Argentine Dry Chaco

“…We also found marked effects of smallholder homesteads in relation to disturbance prevalence. The decreasing partial clearing closer to smallholder homesteads likely indicates that homesteads persist only if they have sizeable forests in the surrounding, with many homesteads abandoned as industrialized agriculture expands around them [62]. Fire occurrence was lower closer to homesteads; on the one hand, because of higher fire control; on the other hand, likely because livestock reduces woody cover and herbaceous fuel loads in the close surroundings of homesteads [51,52].…”

“…Second, much logging is linked to charcoal production, a common economic activity of poorer rural people [49,61]. Third, the Chaco harbors many forest smallholders, locally referred to as 'puesteros' or 'criollos', who live inside the forest and use the surroundings of their homesteads for sustenance (e.g., fuelwood collection, timber for construction) [62]. The livestock of these smallholders typically roam freely around homesteads and have a considerable impact on forest structure [63].…”

“…Third, we compared our disturbance agent map to a dataset of locations of forest smallholder homesteads (Table 2), obtained by screen-digitalizing about 24,000 individual homesteads from Landsat and Google Earth with very-high-resolution imagery for our entire study region [62]. This database includes temporal information, specifically on which homesteads were persistent over the time period 1985-2015, and which homesteads disappeared or emerged (and when).…”

Frontier metrics for a process-based understanding of deforestation dynamics

“…Historically, land use in the Chaco was dominated by small-scale producers, such as the Eastern European colonies in the Chaco province, or forest smallholders who used a few hectares of land for subsistence cropping to sell on local markets, and the surrounding woodlands to gather firewood and material for rural construction, as well as forest grazing of roaming livestock (Fatecha 1989, Bucher andHuszar 1999). While smallholders continue to be important in parts of the Chaco (Levers et al 2021), the emergence and rapid expansion of large-scale agribusinesses has happened over wide areas since the 1990s. These actors have substantial capital and knowledge on the existence and the amount of expected land rent, allowing them to quickly and efficiently capitalize on opportunities that frontier situations entail (le Polain de Waroux 2019).…”

“…Increasing access to satellite images along with new processing capabilities offer new opportunities for understanding frontier dynamics at unprecedented temporal and spatial resolution (Gorelick et al 2017, Wulder et al 2019, Woodcock et al 2020, yet these opportunities have so far not been explored. Prior work on assessing frontiers has mostly focused on mapping deforestation (Hansen et al 2013, Müller et al 2016, Griffiths et al 2018, Vancutsem et al 2021, what follows deforestation (Zalles et al 2019, 2021, Souza et al 2020, Song et al 2021 or, most recently, who drives deforestation frontiers (Curtis et al 2018. The question of how frontier dynamics unfold, beyond identifying hotspots of deforestation (Harris et al 2017, Tyukavina et al 2018, Potapov et al 2019, remains largely unexplored.…”