Tackling the Lantana Menace at Scale
Commodity products and a living labs approach.
Lantana camara is an invasive weed, whose spread is strangling India’s forests. Introduced by the British, as an ornamental species, lantana reproduces aggressively and hinders the regeneration of native plants and grass species. Because lantana is unpalatable, its spread reduces forage for wild herbivores. Lantana also impacts the livelihood of indigenous communities, who depend on the forests for non-timber forest produce, which is also displaced by lantana invasion. So widespread and aggressive is lantana that it has been described as a ‘monster weed’.
Prior efforts to eliminate lantana at scale have largely been unsuccessful. Lantana removal is expensive as there is a large seed bank in most forest soils. It has been argued that the only way of addressing the lantana crisis is by promoting the use of the abundantly available lantana. This could significantly enhance the livelihoods of the forest-dwelling indigenous communities.
Toward this end, a decade ago, ATREE introduced lantana crafts to indigenous forest-dwelling communities in MM Hills in southern India. The aim was to substitute their loss of income from the forest as well as act as a substitute for traditional bamboo resources, that were beginning to decline because of overuse for commercial purposes. While the use of lantana for artisanal furniture did improve tribal incomes, it did not make a significant dent in lantana density, except in the immediate vicinity of the hamlets.
There are several reasons for this. First, the tribal communities harvest the lantana sticks manually. Second, only a small fraction of the lantana plant biomass, is suitable for artisanal purposes — specifically mature stems of a certain thickness. Third, the ‘artisanal’ approach of building a few high-value handicrafts is inherently limited by market demand for artisanal furniture products and the supply of highly skilled master craftsmen.
One way of utilising a large fraction of the lantana biomass is to transition to low-value commodity products such as plywood, bioenergy, or bio-brick manufacturing. The advantage of this approach is that all of the biomass can be utilised and the market size is considerable.
But the problem is the cost of lantana as a fraction of the overall product is significant. Unlike artisanal furniture where the lantana stems themselves only contribute about 10% of the cost of the finished product, with commodity products, the cost of the lantana biomass can be as high as 50–70% of the total cost of the product. But while lantana furniture is marketed and potentially sold for its rustic ‘look and feel’ and conservation backstory, commodity uses are simply based on economics. In other words, lantana biomass must be competitive with other locally-available biomass such as acacia plantations or even agro-waste.
Most lantana is found in protected areas. By definition, this occurs far away from sites where the biomass can be used. As a result, making lantana utilisation economically competitive involves a careful optimisation between transporting lantana to more distant locations (thereby increasing its cost and reducing its competitiveness) and using lantana closer to the point of harvest for a variety of purposes and in a way that boosts rural economies (where the demand for the volumes of biomass being generated does not exist).
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Then there is the problem of how far we should go in getting rid of lantana. Ultimately, it may not be possible/desirable to have constant human management of protected areas. Ecologists with divergent opinions on the long-term effects of removal and/or restoration, arguing natural processes of species co-evolution, render the prospects of success uncertain. Further, ecologists remain divided on whether simply thinning out lantana by pruning it for commercial use or engaging in full-scale restoration by complete uprooting followed by replanting is the best way forward.
Nonetheless, we have got to start somewhere. We cannot stay content with writing articles on the threat lantana poses to Indian forests and their biodiversity. We also cannot confine our research to plot-scale experiments and hope to settle the science — given that the uncertainties involve disagreements about what will happen over larger spatial and temporal scales. The only way forward is a “living labs” approach starting with the least risky lantana-invaded sites (perhaps on private lands), embedding rigorous scientific data collection within the scope of large-scale implementation programmes from the very inception.
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