Gran-chaco

The Gran Chaco has seen unprecedented levels of deforestation since 2004, putting this area at risk of extreme habitat destruction

Co$ting Nature version 2.43 was applied at 1km resolution to the ran Chaco area of Paraguay and Argentina. The impact of recent (2004-2012) deforestation on the conservation priority and ecosystem services of this area are analysed.

Baseline ecosystem services, biodiversity and losses so far:

Relative total potential bundled services index (Total potential services including water, carbon, nature based tourism and hazard mitigation services) for this area shows high levels of service provision. Examining areas deforested since 2004 according to terra-i, we see that some areas with significant potential ecosystem service provision have already been lost. Indeed a number of areas lost to deforestation since 2004 were in the top 10% for bundled ecosystem service provision in this area.

The Relative total realised bundled services index (Total realised services including water, carbon, nature based tourism and hazard mitigation services) shows that deforested areas to the west of Filadelfia are those with the highest (now lost) realised ecosystem service provision.

These areas are particularly important for water provisioning services but also for carbon sequestration and storage services, indeed deforestation in this region since 2004 is estimated by Co$ting Nature to have cost 65 million tonnes of carbon stock and 338 000 tonnes of carbon sequestration per year. The deforested areas include areas considered important by 3/5 and 5/5 major global conservation prioritisation schemes (overlap of EBAs (Birdlife), Global200 Ecoregions (WWF), Hotspots (CI), Last of the Wild (WCS,CIESIN), Important Bird Areas (Birdlife) and Key Biodiversity areas (IUCN, BI, PI,CI)) and areas with globally important levels of species richness and endemism amongst threatened amphibians, reptiles, mammals and birds, especially in newly deforested areas to the south and west of Filadelfia. The deforested areas contained on average 390 and up to 450 threatened species on the IUCN redlist in these groups. For biodiversity and realised ecosystem services combined the deforested the areas around Filadelfia provided the greatest service of all of the deforested areas.

Human pressure (Current pressure according to population, wildfire frequency, grazing intensity, agricultural intensity, dam density, infrastructure (dams,mines,oil and gas, urban) density) is very high on many of these landscapes and the threat of increased pressure in the future is also high because of oil and gas concessions, population growth and proximity to existing deforestation fronts.

Projecting losses into the future:

The following scenario was run through the ecoengine land use change model, essentially carrying on existing deforestation rates for the next 50 years and allocating the deforestation according to accessibility and planned or likely transport routes, with effective protected areas and thus no deforestation within their boundaries:

to yield the following scenario for land use change over the next 50 years.

Such a scenario would lead to significant losses of ecosystem services as shown by the bundled ecosystem service index here. Losses would be particularly for areas deforested in the montane forests of Argentina, and these would propagate downstream. Losses would include some 110 million tonnes of carbon storage and some 620 000 tonnes per year of carbon sequestration. A significant loss of endemism richness especially in the Argentinian montane forests and of species richness of already globally threatened species (especially in the Chaco lowlands) would occur.