Almost 1.4 million kilometres of roads not marked in official road maps and often built illegally, known as “ghost roads”, are presenting a grave threat to tropical forests in the Asia-Pacific region, researchers have found.
Research published in the journal Nature has revealed a total of 1.37 mln km of ghost roads across the region, 3-6.6 times more roads than are found in global road datasets.
“Worryingly, our new findings show that the extent and length of roads in the tropical Asia-Pacific is severely underestimated, with many roads being out of government control,” Bill Laurance, co-author of the research paper and professor at James Cook University, said in a statement.
The study was conducted with the help of 200 trained volunteers who examined satellite pictures of 1.42 mln square km in the islands of Borneo, Sumatra, and New Guinea.
Laurance said that informally or illicitly constructed roads can either be bulldozed tracks in logged forests or roads in palm oil plantations, and also other roads that are not accounted for in existing road datasets for various reasons.
“They’re being constructed by a range of people, including legal or illegal agriculturalists, miners, loggers, land grabbers, land speculators, and drug traffickers,” he added.
Meanwhile, Jayden Engert, lead author and a doctoral student at the university, said the research found that building of roads “almost always preceded local forest loss” across the study area.
“Road density was by far the strongest correlate of deforestation out of 38 potential biophysical and socioeconomic variables,” Engert added.
ALL ROADS LEAD TO…
The research stated that such “striking gaps” found in the roadmaps were not surprising, especially in the case of developing nations.
Studies conducted in Brazil, Cameroon, and the Solomon Islands have found similar unmapped roads – ranging from 2.8-9.9 times those recorded by the government, the paper added.
“There are some 25 mln km of new paved roads expected by mid-century and 90% of all road construction is happening in developing nations, including many tropical and subtropical regions with exceptional biodiversity,” Laurance said.
Even the protected areas in the Asia-Pacific region are not completely safe from ghost roads, according to the study.
“However, conservation function of terrestrial protected areas, at least in the Asia-Pacific region, is limiting road incursions and their many associated impacts on forests,” it added.
Even though road databases are improving in quality globally, there are still plenty of gaps and inconsistencies that limit the value of making comparisons with different nations, regions, and ecosystems, the researchers said.
Conservation metrics such as human footprint index and wilderness areas are based on incomplete road data, which often leads to inaccurate indicators.
The researchers added that when they fed the ghost road discoveries in the human footprint index for Borneo and compared the two versions, they found that areas with very high human driven disturbances doubled in size while areas of low disturbances halved.
“Collectively, our findings suggest that burgeoning, poorly studied ghost roads are among the gravest of all direct threats to tropical forests,” the researchers noted.
‘‘In these findings, nature is the big loser,” Laurance added.
By Nikita Pandey – nikita@carbon-pulse.com
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