~ By Satvik Parashar
Can improving household living standards help control forest degradation? Interdisciplinary researchers from Universities across India and the USA (Columbia University, Ashoka University, University of Delaware, Azim Premji University and Johns Hopkins University) answer this question in their recent study. In the study, researchers quantify the role of improved living standards, such as durable housing, and alternatives to fuelwood for cooking, in alleviating pressure on forests and reducing degradation in the Central India Highlands.
The study region covers ~25 million hectares (7.6% of the total land area of India) across the states of Madhya Pradesh, Chhattisgarh and Maharashtra. Five thousand households were surveyed in 500 forest fringe villages (10 surveys per village) within 8 km of forest. The survey questions targeted two aspects of household living standards: 1) alternate energy for cooking, primarily the use of LPG or fuelwood for cooking, and 2) durability of house material i.e. kutcha or pucca house.
Location of study region and surveyed villages with value for Bare Ground Index (BGI). Higher value for BGI indicates higher forest degradation
The land cover classification was done using GIS and forest areas were defined as ones with greater than 10% tree cover. Bare Ground Index (BGI), which is a normalised ratio of Bare Ground and Tree Cover, was calculated for these forest areas. Higher BGI means a higher amount of bare ground in an area, with values ranging from -1(full tree cover) to +0.8 (all bare ground aside from 10 % tree cover). Additionally, the distances of the fringes from the forest were derived to analyse the variability of forest degradation with proximity.
The study considered two treatment variables – alternate cooking fuel (Whether the household uses LPG for cooking or not) and durable house material (whether the house was pucca or kutcha). BGI along the buffer distances of 1km, 2km and 5km from villages were analysed for each treatment variable. Three different statistical models were run so that the results were consistent. Combined results of all three statistical models state that households adopting alternative cooking energy rather than fuelwood were significantly associated with less forest degradation around 1km, 2km and 5km buffer distances from villages. As far as durable housing material is concerned, the association was significant in the 1 km buffer, but not so in the other two ranges (2km and 5km).
Mean values from causal forests for Average Treatment Effects (ATE) for two treatments with outcome as Bare Ground Index in 1 km, 2 km, and 5 km buffers around village. Negative values of mean ATE indicate less forest degradation with treatment. Error bars are 95% confidence intervals
Causal forest method was used to determine significant variables. It is a form of non-parametric supervised machine learning classification. Although it has less predictive capabilities than other supervised classification approaches such as decision trees and random forests, it is more beneficial for determining factors that actually cause an event. This can aid in determining areas of interventions with the help of results that are practicable and suitable for decision support. The most important variables identified using the causal forest method were i) the percentage of forest per household, ii) the percentage of forest in buffers around villages, and iii) the distance of the village from towns and roads. Targeting interventions in these areas will significantly alleviate forest degradation. Other variables were found to be less relevant.
Credits: Amrita Neelakantan – NCCI Coordinator
With the increase in household living standards leading to less pressure on forests, the study illustrates how human development and environment conservation can go hand-in-hand. Solely environment-focused conservation measures, such as reforestation, could lead to increased competition for land needed for food and other uses, or bring clashes in land tenure. A limitation of the study is that displaced environmental impacts are not accounted for. LPG is expensive and requires import and transportation, which has its own environmental footprint. Construction with concrete causes greenhouse gas emissions. Also, it retains heat and does not have the airflow of traditional houses made of mud. Even with these limitations, the study highlights the positive impacts of improved living standards in retaining the local environment and paves way for further research that suggests sustainable ways of achieving them without displaced environmental impacts. The people-centric approach to conservation is one that is easily accepted and sustainable in the long run.
Original Paper: DeFries, R., Agarwala, M., Baquie, S., Choksi, P., Khanwilkar, S., Mondal, P., … & Uperlainen, J. (2021). Improved household living standards can restore dry tropical forests. Biotropica. DOI: 10.1111/btp.12978