- From 1991 to 2014, 12 percent of the forests inside Papikonda National Park were degraded compared with 32 percent around its surrounding unprotected buffers, as per a landscape-level satellite analysis.
- But zooming in on village-level forest degradation revealed that it was higher inside the park compared with the outside buffer forests.
- Local communities were able to accurately gauge the extent of degradation. They identified the main drivers as shifting cultivation, logging and over-extraction of non-timber forest produce.
- The researchers suggest that existing roads in the buffer forests should not be widened. They also recommend greater monitoring of the Godavari river as well as education among the local communities to curb further degradation.
The forests of the northern Eastern Ghats have been experiencing rapid degradation over the past two and a half decades, with degradation levels higher around the villages inside Papikonda National Park—the largest protected area in the region—compared with those located in the surrounding unprotected buffer forests, reports a new study by researchers at Bengaluru’s Ashoka Trust For Research in Ecology and The Environment (ATREE). It also reveals that local communities in the forests have a solid grasp of both the extent and the causes of forest degradation around their villages.
While a landscape level satellite-based analysis showed that forest degradation was greater outside the park, looking at forest degradation at a finer scale on the village level revealed that the impact around villages inside the park was infact higher. Focusing only at landscape level can mask nuanced changes taking place inside the protected areas, the researchers point out.
The Eastern Ghats, a 1600-km stretch of rich, biodiverse forests on discontinuous hills lying parallel to the Bay of Bengal have largely remained neglected from conservation efforts compared with other regions in India. In fact, only 3.53 percent of their total area is protected. Home to various indigenous tribes as well as several rare and endemic species, they are facing threats from large infrastructural projects such as dams.
Using satellite imagery, the team quantified the changes in vegetation density from 1991 to 2014 at the landscape level in Papikonda National Park (PNP), which occupies an area of 1012 square kilometers, along with five km around its forested buffers. They then zoomed in on vegetation changes within a one-km buffer around 212 villages of which 51 were inside the park. Specifically, they used the Normalized Difference Vegetation Index (NDVI), which is an index of ‘greenness’ or vegetation density.
They then compared the satellite-detected forest changes at the village-level to community perceptions of forest change and drivers of the changes by surveying 138 residents from 33 randomly chosen villages from 2014 to 2015. Most of the respondents belonged to the indigenous tribes Konda Reddis (81) and Koyas (35). The Konda Reddis mostly inhabit the hills and are largely dependent on forests whereas the Koyas are found mainly on the plains and are engaged in cultivation.
Degradation in protected versus unprotected areas: Scale of analysis matters
In the first estimate of forest degradation in the northern Eastern Ghats, the researchers found that a quarter of forests in PNP and its unprotected buffers were degraded over the course of 24 years until 2014, with greater levels seen in the lower foothills where roads and rivers were easily accessible. The landscape level analysis revealed that while degradation inside the park was 12 percent, it was higher for the surrounding unprotected buffer regions at 32 percent.
As the buffer forests are lost, this leads to isolation of the forests inside PNP from the larger Eastern Ghats. Isolation can “have implications on wildlife populations and their dispersal ability within the landscape,” said Vikram Aditya, a Ph.D. scholar at ATREE and lead author of the study. What’s worse, although PNP has contiguous forested buffers in the north and east, “being the southern extremity of the NEG it is completely isolated southwards,” he explained. “Therefore, the loss of the existing buffer forests which are in the north and east can lead to total isolation of PNP forests.”
“Aside from isolation of course, loss of the buffers would also expose PNP to higher conversion pressures, edge effects (forest edges get progressively degraded) higher hunting pressures etc.,” added Aditya.
But the case was the opposite when looking at forest degradation at the village-level: it was higher around villages inside the park compared with those outside. Consequently, the researchers concluded that the protected area was effective in reducing degradation at the landscape level but not at the village level inside the protected area.
The researchers believed this was because communities outside PNP have better access to roads and are closer to towns giving them a wider range of options for livelihood such as trading and transport. In contrast, those living inside the parks are relatively isolated making them largely dependent on the forests through non-timber forest produce (NTFP) collection, broomstick grass harvesting and podu cultivation—a form of shifting cultivation practiced in the region. While the park offered protection against mining and dams, it did not prevent degradation at the village level such as from over-extraction of forest resources.
The main drivers of forest degradation identified by the villagers were podu cultivation, logging, over-extraction of NTFP and plantations. Residents of the buffer villages reported that bamboo cutting and population growth were additional factors driving forest loss.
“The findings of the study are interesting,” said P.K. Joshi, professor of environmental sciences at Jawaharlal Nehru University. “If one plots a gradient of change from the settlements to their surrounding, we will see a pattern of higher changes near to settlements, lesser changes as we move away from the settlement and it will be very true for protected areas. And then may be higher changes [in] the locations where protection is missing or least, buffer and outside protected areas,” he pointed out. “This pattern prevails in all tropical forests.”
According to him, one of the major limitations of the study is that it relies on NDVI values. “This biophysical parameter is highly sensitive to and dependent on rainfall (even a slight shower before the date of data acquisition changes the entire values), dryness and soil moisture,” he explained. For this reason, he suggested carrying out actual mapping where NDVI is used along with other band information to provide a better representation.
Satellite mapping versus community perceptions
The local communities had an intimate understanding of the extent and the drivers of forest degradation. Their observations on the extent of degradation around their villages both inside PNP and its forested buffers corresponded well with satellite-derived patterns of forest loss, with those inside PNP noting greater changes.
As a result, the researchers advocate the strengthening of village-based forest management committees as well as greater environmental education in schools stressing the need to conserve the last remaining forests of the Eastern Ghats.
Joshi found the correspondence between the community responses and the satellite interpretation interesting. He felt that “community information corroborated with satellite remote sensing interpretation provides much better and authentic information on the dynamics in the forested landscapes.”
Curbing forest degradation
While roads are essential for the local communities as they provide them with greater sources of alternate livelihoods, they also end up affecting the forests, said Aditya. “If the existing roads are not widened (there’s very little vehicular movement anyway) that could prevent any further degradation from them,” he suggested.
He also recommends that forested buffer without any villages and with low human activity should be incorporated into PNP, “which will afford them higher protection legally.”
“The Godavari river bisecting PNP serves as a conduit for transport of illicitly felled timber, and therefore greater monitoring along the river could greatly contribute to arresting deforestation,” he added.
In the wake of the ongoing construction of the Polavaram dam to the southeast of PNP, which according to Aditya, would perhaps be the largest in the country with respect to reservoir size, land area that it will submerge and displacement of villagers, conservation of unprotected forests in the region need to be stepped up to ensure habitat connectivity for fauna.
CITATION:
Aditya, V. & Ganesh, T. (2018). Deciphering forest change: Linking satellite-based forest cover change and community perceptions in a threatened landscape in India. Ambio, doi.org/10.1007/s13280-018-1108-x