Unchecked rubber spread in northeast India threat to native forests: Study

As the growing demand for natural rubber transforms Southeast Asia’s landscapes, scientists in India have warned against the unregulated expansion of rubber monocultures in seven northeastern states that together make up the second largest area of rubber (Hevea brasiliensis) planted in the country.

Tripura considered as the ‘second rubber capital of India’—after Kerala—has emerged as the frontrunner among the non-traditional rubber growing regions. Meghalaya, Mizoram, Assam, Nagaland and Manipur, the other rubber producing states in the region, have also witnessed notable growth in production. The study likened the rubber boom in northeast India to the spread in southeast Asia.

Culling satellite data, scientists from North Eastern Space Applications Centre (NESAC), Meghalaya, mapped and analysed the extent of rubber plantation in selected sub-watersheds straddling Mizoram, Tripura and Assam.

They observed a five-fold increase in rubber plantations in the study area over a 15 year period (1997 to 2013), with the expansion being more rapid during recent times, i.e. between 2010 to 2013.

“Rubber plantations increased from 4.47 sq. km to 28.42 sq. km in various parts of the study area. The plantations took place in dense forest, open forest and degraded forest areas. The spread of the plantations was also observed in one reserved forest located within the study area,” said author Kasturi Chakraborty.

The study stresses on the issue of rubber plantations spreading at the cost of natural forests, often being “overlooked” because rubber trees look like forests.

The area in focus in the study is bordered by two sub-watersheds, Singla and Longai that cover small parts of Mizoram and north Tripura. The major portion of the sub-watershed, comprises of the Karimganj district of Assam, one of the largest rubber growing areas in southern Assam. The study area chosen to observe the expansion was selected as it is adjacent to Tripura.

Noting that there are several instances of negative impacts of rubber plantation expansion in Southeast Asia, the assessment underscores the importance of sustainable land use.

“Similar expansion of rubber plantation has been observed in northeast India as well. Further spread of rubber plantations in the region needs to be regulated to avoid conversion of dense and reserved forest areas by fostering the use of mixed cropping methods instead of rubber monocultures, and by adopting more sustainable land use and management practices.”

Mixed cropping is desirable not only from the point of strengthening biodiversity but also from the economics angle, asserts developmental economist Indraneel Bhowmik from Tripura University, who was not associated with the study.

“Rubber monoculture exposes the small growers (farmers) to the vagaries of the international market, and the situation can be really grim during the recession as the natural rubber economy of the world is facing since 2012. Having a mixed cropping system can help in absorbing the shocks in a better way,” Bhowmik told Mongabay-India.

The northeastern states of India account for a fourth of India’s forest cover. Experts say that a key factor for the mushrooming of rubber monocultures is the agro-climatic similarity of the northeast region to that found in the south-west coastal region (Kerala) of India.

A tale of two states

About 74,335 hectares (743.35 square km) of area is under rubber in Tripura as compared to under 700 hectares during the mid-1970s. It is estimated that about 100,000 hectares (1000 square km) are to be brought under rubber plantation in the state.

Rubber plantation was introduced in Tripura in 1963 by the forest department, as a means to manage and stabilise shifting cultivation (locally known as ‘jhum’), rehabilitate shifting cultivators and to restore degraded land affected by repeated shifting, informs Ajoy Debbarma of the Tripura-based Centre for Forest-based Livelihoods and Extension (CFLE). The Rubber Board of India provided technical support to the endeavour.

This apart, said Bhowmik, rubber monoculture ensured a steady supply of the essential industrial raw material.

“In Kerala, rubber plantation monoculture has mostly grown at private initiatives during the colonial period in response to market demand. The foremost similarity has been the dominance of smallholdings in both the areas. Moreover, assured market returns for a long period have ensured that the rubber farmers have had considerable economic benefits,” Bhowmik adds.

Also, the success of rubber production in Kerala may have prompted officials to replicate it in Tripura, feels Debbarma.

Acknowledging rubber’s success story in positively impacting livelihoods, Debbarma contends although rubber monocultures may seem superficially similar to a forest, they are less efficient in terms of nutrient recycling, soil conservation and regeneration of forests affecting natural succession.

Moreover, differences in productivity owing to agro-climatic factors and plantation management system have been noticed in the two regions, Bhowmik said. “The issue of food security also needs exploration as the jhum economy ensured production of food crops also,” Bhowmik explained.

Social, legal implications

Tapping of rubber trees starts in the fifth to seventh year after planting and then continues for 25 to 30 years. After 30 years a decline in latex production makes further tapping of the trees uneconomic. Then it becomes very difficult to manage these monoculture plantation areas, remarks Debbarma.

In addition, preparation of the land for rubber plantation takes a toll on Non-Timber Forest Products (NTFPs) such as medicinal plants that are indispensable to the indigenous communities, said Debbarma.

Given that forest-dwelling communities have a right to cultivate any crop for livelihood in accordance with the provisions of the Recognition of Forest Rights Act, 2006, implementation of the Act subsequently has indirectly pushed the cause of rubber.

“Considering the provision of the act, they have the right to cultivate rubber and they see rubber as profitable. But marginal farmers suffer the most as they have less land area and they can’t diversify in that limited area already occupied by rubber monoculture,” Debbarma said.

Stressing that indigenous communities in Tripura who constitute about 31 percent of the total population of the state depend on forests for daily sustenance (including sourcing medicinal plants), Debbarma believes diversification is important.

Rubber plantations in forest lands also appear to be a breach of  the provisions of the Forest Conservation Act 1980 (with amendments made in 1988) that has regulations on use of forest land for non-forest purpose such as rubber plantation amongst other crops like tea, coffee, spices, horticultural crops, medicinal and oil-bearing plants, said Debbarma.

Drawing attention to the latest India State of Forest (ISFR) data concerning Tripura which links a decrease in forest area as well as a positive change (due to extension of area under rubber plantation) to rubber plantation, Debbarma said it is “evident that rubber a non-forestry crop had been and is being aggressively promoted for cultivation in forest areas.”

Restoration of ecology by replacing shifting cultivation?

Arunabha Majumdar, assistant development officer, Rubber Board, contested the notion of rubber plantation as a monoculture.  “Rubber cultivation cannot be regarded as monoculture as genetic variations always remain in different clones that generally get planted in a given area.  Any tree, be it rubber or any other crop, never spoils the environment,” Majumdar said.

Rubber has brought about spectacular socio-economic changes in rural NER, maintained Majumdar.

“In Tripura, private land holdings were worst hit by continuous practice of shifting cultivation by tribal communities who have a major share in rubber area in the state. Rubber has restored the soil status of that kind of land. Land use pattern got redefined with the introduction of rubber in this region,” he said.

Rubber sector, not only in northeast India, but across the entire rubber growing belt of the country, is dominated by small growers, who grow rubber in their own land outside forest areas only, Majumdar emphasised.

“It also has a role in carbon sequestration. One hectare of rubber plantation can sequester 7.82 ton carbon in a year,” he added.