Part 0: Why is the Lantana invasion of Indian forests a problem?


By Sanjana Alex, Navya Itty, Anjana Balakrishnan and Anu Sridharan

As you know, the Lantana series documents the journey of CSEI’s Invasive Species Initiative. As we got on with it, we realised that there was a need to first spell out the answer to the question, ‘why is Lantana bad?’. Therefore, today’s post is Part 0 — a prequel that delves into the basics of Lantana invasion.

If you would like to collaborate with us, please reach out to the initiative lead, Sandeep Hanchanale:

Lantana camara flowers (Picture Credit: PumpkinSky)

Don’t be deceived by these brightly-coloured flowers. Lantana is one of the ten worst invasive species in the world.

Native to South America, Lantana was introduced in India by the British in the 1800s as an ornamental plant. Its true dangers as an invasive species were only realised later in the 1920s.

Lantana camara is a highly adaptable and tolerant thorny shrub that has invaded over 40% of the ecologically-sensitive Western Ghats, a total of 13 million hectares. Particularly concerning is its ability to spread rapidly and overpower the native species of the landscape it is introduced in.

This aggressiveness affects biodiversity, livelihoods, and human and animal health. Here, we summarise how this innocuous-looking shrub is causing widespread impacts on the natural environment and the indigenous communities who depend on it.

Lantana spread in India (Picture Credit: Ninad Mungi)

Lantana camara is dangerous because it displaces native plants which then force wildlife to migrate and/or starve.

ATREE researchers found that almost 90% of the Soliga tribes in the Biligiriranga Hills believe that grass and bamboo declined due to the Lantana invasion. Lantana’s chemical properties hinder the growth of other plants in its vicinity, thus suppressing native vegetation. Ticktin et al’s (2012) 10-year study showed that the expansion of Lantana has caused the population of native Amla trees to reduce significantly (by 16%).

A 2013 study conducted in the Mudumalai Tiger Reserve in the Nilgiris highlights the larger ecological implications of the Lantana. Its results indicate a dire future — as native vegetation dies, the herbivores that feed on it dwindle, thus causing apex predators like the tiger and leopard to starve.

Lantana camara is dangerous because it increases human-wildlife conflict

The decline of native fauna has forced some animals like wild pigs to migrate. They venture into human settlements and raid crops for food. As the carnivores follow herbivores, this increases the incidence of animals like tigers coming into contact with humans.

Additionally, due to the reduced visibility through the dense Lantana thickets, forest communities are encountering dangerous animals such as elephants and bears much more today than in the past.

ATREE researcher Madhura Niphadkar in her account from the field — ‘The Green Barrier’ — writes about the difficulty of spotting a grey, 7-foot-tall elephant weighing 3000 kgs in the Lantana thicket!

Lantana restricts the movement of wildlife (Picture Credit: Peggy Bright)

Lantana camara and other exotic weeds are dangerous because they inflict huge economic losses on the Indian agriculture sector (~$11B USD over the past decade)

As the Lantana forces herbivores into neighbouring farms to forage for food, farmers incur significant economic losses. These crop yield losses range from about 13.8% (in transplanted rice) to over 35% (in groundnut). Since more than 70% of farmers in India have less than two hectares of land, these invasive weeds have an adverse impact on these smallholder farmers. Moreover, grazing on Lantana can cause illness and death in livestock due to toxins in the leaves.

Lantana camara and other exotic weeds are bad because they reduce tribal livelihood opportunities

The farming communities are not the only ones who have been impacted by the Lantana invasion. Crucially, the decrease in native species directly affects the forest-dependent communities who rely on non-timber forest products (NTFPs) for their livelihood.

A 2012 study found that the dense growth of Lantana was affecting the lifestyle and livelihood of the Soliga community. It was becoming exceedingly difficult for them to access the forest to forage for edible tubers and collect firewood. The Soligas had also greatly minimised their efforts at maintaining forest paths overrun by Lantana; handling the plant may cause skin irritation or an allergic reaction.

A path created through the dense thicket (Picture credits: Madhura Niphadkar)

Using lantana to create tribal livelihoods is the win-win way forward

ATREE’s social enterprise — Lantana Craft Centre — and its interventions with the Lantana menace in the Western Ghats are well-documented. Using Lantana craft, ATREE has co-opted the local community into its forest restoration efforts while providing them a source of livelihood. Building on ATREE’s work, the shift in focus we hope to achieve is to put equal emphasis on Lantana removal, use and restoration.

At CSEI, we have set an ambitious goal for ourselves: By 2030 we will create livelihoods for 10,000 people through the removal of 500,000 hectares of invasive plant species from Indian landscapes.

We plan to achieve this goal by setting up a Lantana collective that supports multiple MSMEs. While continuing to encourage Lantana crafts, the collective will also co-create Lantana-based innovations like particleboards, wood plastic composites, cretes and Lantana biochar that use up mined Lantana. Once an area is cleared of Lantana, we will also collaborate with partners like Junglescapes, SayTrees and GrowTrees to restore forests.

Read more | Part 1: Connecting Lantana crafts to the furniture market

If you are interested in buying Lantana products, you will find them on the Lantana Collective website. If you would like to collaborate with us on Lantana innovations, reach out to the initiative lead, Sandeep Hanchanale:

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