New study shows the value of natural habitat analysis on transportation infrastructure design and planning

Alberto Villalba (IDB), Louis Reymondin

CIAT and the Terra-i team are pleased to announce the publication of a new study in Paraquaria Natural, the most prestigious journal in Paraguay dedicated to biodiversity and the conservation of nature.

The study shows the potential indirect impact of the road segment San Juan Nepomuceno-Ruta 6 in Paraguay. It is important to note that this study is a joint effort among the environmental nongovernment organization GUYRA based in Paraguay, the International Center for Tropical Agriculture (CIAT) based in Colombia, and the Inter-American Development Bank (IDB) based in Washington, D.C., USA. This work follows a series of successful collaborations between IDB and CIAT on the topic of road impacts on natural habitats.

The first collaborative work between CIAT and IDB was conducted with The Nature Conservancy (TNC) and Conservation Biology Institute (CBI), providing tools to analyze the impact of large-scale road projects on natural habitats. That study analyzed the impact of five road infrastructure projects (Figure 1) in Latin America: (1) the Santa Cruz-Puerto Suárez Corridor in Bolivia; (2) the BR-364 Highway in Brazil; (3) the section of the Pan-American Highway in Darién, Panama; (4) the Trans-Chaco Road in Paraguay; and (5) the IIRSA Integration Corridor in Peru. (Read more about that study here: Road Impact Assessment Using Remote Sensing Methodology for Monitoring Land-Use Change in Latin America: Results of Five Case Studies,

In a similar way, a second collaborative study between CIAT and IDB was prepared to determine the potential impacts of road improvement and construction projects in Guyana until 2022. The study clearly suggests that road infrastructure projects (improvement, pavement, and/or construction) can have substantive impacts on land-use change, thus affecting natural habitat extent and leading to increased greenhouse gas emissions. This work was presented at the Sustainable Mega-Infrastructure and Impact Assessment symposium held in Panama in December 2015, organized by the International Association for Impact Assessment (IAIA). (Read more about that study here: Potential Impact of Road Projects on Habitat Loss and Greenhouse Gas Emissions in Guyana from 2012 to 2022 , ,

Figure 1 map of risk of deforestation

This third and new study analyzes the past, current, and potential future deforestation resulting from the improvement of the road segment between San Juan Nepomuceno and Route 6 (PR-L1080) in southeastern Paraguay. The deforestation baseline in the study area was defined using Landsat imagery from 1987 to 2014. Using this baseline and additional datasets, a map of deforestation risk was developed at the national scale and then applied in the area of influence of the road studied.

The results of the baseline analysis, performed by GUYRA, show that, between 1987 and 2014, about 215,000 hectares of native forest were lost in the direct area of influence of the road, before the improvement of the road that is planned to occur in 2017. From the data produced, it is possible to estimate the impact of the introduction of the “zero deforestation” law in 2004 as the rate of deforestation decreased sharply between 2005 and 2010. However, the deforestation trend increased again between 2010 and 2014.

The analysis of the maps of deforestation risk, performed by CIAT, shows that the road improvement project would potentially increase deforestation in the area by 1.41% by 2023 if no protected area enforcement is implemented, which is equivalent to 15,603 hectares.

In contrast, if good support is provided to protected areas and assuming the deforestation trends are similar to the ones observed between 2010 and 2014, deforestation would potentially increase by only 1.11%.
Nonetheless, a potential low impact of the road improvement, such as the one predicted above, could simply mean that most deforestation already occurred in the past decades and that there is little forest to convert in the study area, which is still under high risk of deforestation because of several other factors (Figure 1).

These findings clearly identify road infrastructure projects (improvement, pavement, and construction) as a deforestation enabler with strong indirect impacts on natural ecosystems. They reconfirm the importance of not only ex ante and detailed environmental impact assessments that should accompany any infrastructure project but also national and local policies aimed at discouraging deforestation and promoting compensation and habitat protection schemes, especially in areas known as important carbon sinks and essential for biodiversity conservation.

In this particular case in Paraguay, IDB strongly supports the implementation of compensation schemes, including the purchase of certificates under the new law of Payment for Environmental Services. IDB will also support the consolidation of protected areas, the restoration of biological corridors, implementation of fauna crossings, and reforestation of headwaters and eroded areas along the right of way in close cooperation with local and national stakeholders. In this way, this initiative will make this road project a first example of sustainable road infrastructure in Paraguay.

For more details, see the full paper here:

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