Weed out the invasive lantana

Forests cover almost one-third of the earth; they are a source of livelihood, food, and fuel and help fight climate change by acting as carbon sinks. Forests purify our air and water and help conserve biodiversity; this includes all life forms found within forests: trees, plants, animals, and micro-organisms.

According to the UN’s Food and Agriculture Organisation’s (FAO) data, forests provide 86 million green jobs and support the livelihoods of many more around the world. The FAO states that since 1990, some 420 hectares of forest have been lost to conversion into other land uses. However, this came down from 16 million hectares per year in the 1990s to 10 million hectares per year. 

A reason to celebrate? Not really, as deforestation and degradation continue, contributing to nearly 40 per cent of losses between 2000 and 2010 because of commercial expansion of agriculture, cattle grazing, logging, and the encroachment of roads into forest land, among other reasons. Additionally, the spread of invasive weeds. The International Union for Conservation of Nature (IUCN) has listed 100 such species of invasive weeds in its Global Invasive Species Database (GISD) as posing “a major threat to biodiversity” and “to agriculture and other human interests.”

Interestingly, some of these invasive weeds, like the toxic ornamental plant Lantana camara (common lantana), were introduced to ecosystems or were accidents that grew to become a threat to biodiversity, changing whole habitats, travelling across the world, and thriving in new geographies. The Lantana camara, with around 650 varieties in 60 countries, has spread through Australia, Asia, Africa, South America, North America, and other regions. In many native forests, the lantana has “become the dominant understorey species, disrupting succession and decreasing biodiversity. At some sites, infestations have been so persistent that they have completely stalled the regeneration of rainforest for three decades.”

Historically, the lantana has existed since the 1800s and originated in tropical America. Introduced in many countries as ornamental plants, this invasive weed can take over vacuums created by intensive logging or forest fires. What makes its eradication difficult is that underlying seeds can germinate even after a forest fire, for the lantana can survive in drought and in almost any climatic condition. 

According to reports, the invasive lantana weed has taken over 40% of India’s forests and can be found almost everywhere—on roadsides, railway lines, fields, on plains and hills—and is found across the country, including the Andaman and Nicobar Islands. 

In their search for ways to control the spread of the lantana, conservationists have been working with tribal communities to help them monetize the lantana, from making wicker baskets and ornamental crafts to furniture. In the past five years, conservationists have trained about 150 Adivasis from South India to make exquisite life-size lantana elephants at The Real Elephant Collective (TREC). These efforts not only provide livelihoods for the tribals; they also help raise funds and awareness about coexistence with nature. 

The Coexistence Consortium, a collective of several organisations promoting co-existence, has brought 100 life-sized lantana elephants to Bengaluru. The lantana elephants are later to be auctioned off, with proceeds going towards continued conservation work.

Although these conservation efforts are commendable, they are still not enough, given the spread of the weed across the country and the world. Conservationists have been looking at mass-scale commercial utilisation of the weed, and towards this, ongoing research has found that the lantana can be used in oil-based insecticides, as biomass energy, and as a raw material in the pulp and paper industry. In a double-edged sword, what might help eradicate the lantana is its large-scale commercialization. As conservationists reiterate, commercialization should remain the secondary goal; the primary goal should be the eradication of the invasive weed and regeneration of the forest ground lost to the weed.  

As the IUCN puts it, with invasive alien species being a major focus of international cooperative conservation efforts, growing awareness will allow people and their communities to “make informed choices that will have lasting effects on their descendants.”

(The writer is a journalist and author)