| Literature DB >> 34750428 |
Nikolas Kuschnig1, Jesús Crespo Cuaresma2,3,4,5, Tamás Krisztin3, Stefan Giljum2.
Abstract
Deforestation of the Amazon rainforest is a threat to global climate, biodiversity, and many other ecosystem services. In order to address this threat, an understanding of the drivers of deforestation processes is required. Spillover effects and factors that differ across locations and over time play important roles in these processes. They are largely disregarded in applied research and thus in the design of evidence-based policies. In this study, we model connectivity between regions and consider heterogeneous effects to gain more accurate quantitative insights into the inherent complexity of deforestation. We investigate the impacts of agriculture in Mato Grosso, Brazil, for the period 2006-2017 considering spatial spillovers and varying impacts over time and space. Spillovers between municipalities that emanate from croplands in the Amazon appear as the major driver of deforestation, with no direct effects from agriculture in recent years. This suggests a moderate success of the Soy Moratorium and Cattle Agreements, but highlights their inability to address indirect effects. We find that the neglect of the spatial dimension and the assumption of homogeneous impacts lead to distorted inference. Researchers need to be aware of the complex and dynamic processes behind deforestation, in order to facilitate effective policy design.Entities:
Year: 2021 PMID: 34750428 PMCID: PMC8575964 DOI: 10.1038/s41598-021-00861-y
Source DB: PubMed Journal: Sci Rep ISSN: 2045-2322 Impact factor: 4.379
Figure 1Mato Grosso lies at the intersection of the Amazon rainforest, the Cerrado tropical savannah, and the Pantanal wetlands (coloured). The frontier state is located in the centre-west of Brazil (see inset) and is subdivided in 141 municipalities (gray lines). Created using the tmap (version 3.3-2) R (version 4.1.1) package[25,26].
Figure 2Land use cover in Mato Grosso in 2001 and 2017. The clustered expansion of croplands and their appearance in areas previously covered by forest or pasture is noticeable when comparing both years. The area devoted to pasture has also increased considerably, replacing vast amounts of forest. See Fig. 3 for a visualisation of transitions between land use cover. Data is derived from the maps by Câmara et al.[40]; created using the tmap (version 3.3-2) R (version 4.1.1) package[25,26].
Figure 3Direct land use change over selected years from 2001 to 2017. The height of flows represents the amount of yearly incoming/outgoing land use cover, the height of individual bars the maximum thereof. An interactive version of this figure with exact measurements of flows as tool-tip is provided as supplementary material. Also see Fig. 2 for a visualisation of land use cover in 2001 and 2017.
Regression of deforestation on agricultural drivers and control variables.
| Forest change | Direct | Indirect | ||||
|---|---|---|---|---|---|---|
| Mean | (HPDI) | Mean | (HPDI) | |||
| Croplands | 0.941 | (− 0.141 | 2.017) | − 8.083 | (− 11.964 | − 4.24) |
| Soy yields | 0.055 | (− 0.014 | 0.122) | 0.131 | (− 0.159 | 0.411) |
| Pasture | − 0.150 | (− 0.886 | 0.553) | 1.675 | (− 1.116 | 4.583) |
| Cattle | − 0.153 | (− 0.261 | − 0.048) | 0.190 | (− 0.379 | 0.706) |
We report the posterior mean and boundaries of credible intervals (the highest posterior density intervals (HPDI)) covering 95% of the posterior. Effects are divided into direct effects (within a municipality) and indirect effects (affecting other municipalities). Deforestation is measured as change of forest in hectare per total area in km2, croplands and pasture in percent of area, cattle as logged cattle density per pasture, and soy yields in Brazilian Real per harvested area. More information on the model, data, and extended results are provided in the methods section and supplementary material.
Regressions with heterogeneous effects across biomes and over time periods.
| Specification A | Forest change | Direct | Indirect | ||||
|---|---|---|---|---|---|---|---|
| Mean | (HPDI) | Mean | (HPDI) | ||||
| Amazon | Croplands | 1.967 | (0.604 | 3.365) | − 8.443 | (− 13.260 | − 3.754) |
| Soy yields | 0.069 | (− 0.006 | 0.142) | 0.148 | (− 0.151 | 0.449) | |
| Pasture | 0.885 | (− 0.044 | 1.876) | 3.123 | (− 0.887 | 6.882) | |
| Cattle | − 0.243 | (− 0.393 | − 0.093) | 0.063 | (− 0.734 | 0.871) | |
| Other | Croplands | 0.121 | (− 1.305 | 1.608) | − 3.831 | (− 10.811 | 2.957) |
| Soy yields | 0.043 | (− 0.031 | 0.116) | 0.084 | (− 0.192 | 0.376) | |
| Pasture | − 1.111 | (− 2.024 | − 0.198) | − 1.130 | (− 4.920 | 2.144) | |
| Cattle | − 0.089 | (− 0.233 | 0.070) | 0.115 | (− 0.658 | 0.866) | |
Specification A on the top allows effects for the Amazon biome to differ from the rest of the state. Specification B on the bottom allows different effects for the 2006–2011 and 2012–2017 periods. See Table 1 for further information.