More than 200 years in the past, an innocuous-looking decorative shrub was delivered to India from Central America to adorn the gardens of its British colonial rulers. It was deceptively lovely, its flowers modified color with age, turning white, yellow, orange and pink. But inside 50 years of its introduction, one thing menacing began taking place: the plant unfold from hedgerows and gardens and began killing native vegetation in its neighborhood.

Lantana camara is now thought of one of many worst invasive vegetation on the earth – thousands and thousands of hectares of forest throughout the globe have been taken over by this flowering shrub. In India, a 2020 examine discovered that 44 per cent of forests have been experiencing lantana invasion, contributating to the deterioration of forest ecosystems and threatening the habitat of the nation’s majestic apex predator – the tiger.

India is that this month marking the fiftieth anniversary of Project Tiger, the initiative to offer protected havens for a species hunted to the brink of extinction. This weekend, the most recent tiger census figures are anticipated to point out numbers have leapt from 2,967 in 2018 to greater than 3,500 people throughout 53 reserves.

Tigers are extremely territorial and a person can declare as much as 150 sq. km wherein to hunt, making habitat loss as a consequence of invasive species like lantana a critical risk to the longer term enlargement of tiger numbers in India. Ninad Avinash Mungi who has extensively studied lantana camara and is the lead writer of the 2020 examine, connects the dots. “These invasions are an important and fragile part of the tiger conservation story” in India, he says.

“It [the invasion of lantanain forests] has dire consequences. They outcompete native plants and grasses that herbivores like spotted deer and barking deer usually eat. These are the plants that are severely impacted by invasive plants.”

Mungi explains that the leaves and roots of lantana have a chemical that kills different vegetation in its neighborhood as soon as it is available in contact with the bottom, resulting in the depletion of plant range within the forest. Deer won’t eat the lantana themselves, delay by its strong-smelling flowers and tough, jagged leaves.

Aslantana takes over a forest and the deer’s most well-liked forage vegetation disappear, these herbivores are compelled to look elsewhere for meals. Official stories have warned of this decline, corresponding to one recording losses of cheetal [spotted deer] in Bandipur Tiger Reserve in Karnataka as a consequence of a “paucity of quality forage and abundance of lantana camara”.

These deer are the first prey animals for tigers – in order that they observe go well with and transfer away too. This dynamic is being seen throughout India and might occur rapidly: consultants say that if the lantana invasion isn’t tackled quickly, then throughout the subsequent few a long time tiger numbers will plateau and finally begin to fall.

Rajat Rastogi, a researcher who has studied the invasion of lantana in Kanha Tiger Reserve in Madhya Pradesh, central India, says that the issue is urgent. In a examine printed in January this yr within the journal Forest Ecology and Management by the Wildlife Institute of India, he says that invasive species threaten to “cause a future decline of herbivores, which are an important food resource for charismatic carnivores in these ecosystems”.

Rastogi tells The Independent that the issue is extra advanced than it appears, and that the presence of lantana within the forest may very well briefly make life simpler for tigers earlier than it impacts populations negatively.

He explains that in forests dense with lantana shrubs, deer and different herbivores have to speculate extra time foraging for vegetation they will really eat. “When they’re searching for food, there’s less time that they can be vigilant for other animals,” he says, making them straightforward prey for tigers.

“On a tiger reserve level, we’ll see that the carnivore’s health will become better because they are getting food easily. And the herbivores’ health will decline,” Rastogi says.

It is simply within the medium time period, over the following 10 to twenty years, that tiger numbers can even decline “because now there is no food available [for them]”, Rastogi explains. This imaginative and prescient of the longer term for India’s tiger reserves will grow to be irreversible, he emphasises, if lantana isn’t actively faraway from forests and changed with native plant species.

Some scientists outdoors the sector of tiger dialog rejoice the contributions of lantana to forests’ inexperienced cowl and say the flowering shrubs are a boon to the variety of each chicken and butterfly species.

However, consultants like Dr Geetha Ramaswami, who has studied lantana at Mudumalai Tiger Reserve in Tamil Nadu in south India and is at present leads the SeasonWatch venture on the Nature Conservation Foundation, says her analysis suggests in any other case.

She was intrigued by these invasive vegetation as a result of “they have become successful at places where they don’t have an evolutionary history”. She tells The Independent that her analysis discovered how lantana doesn’t simply enhance inexperienced cowl, however “fundamentally” replaces native species with a monoculture of shrubs.

“Our conclusion was that years down the line, the lantana invasion fundamentally changes how a forest will look,” she warns.

Forest officers are conscious of the issue, and each state governments and the central administration in Delhi allocate funds for the elimination of lantana and different invasive species from nationwide parks yearly.

But the work is labour-intensive and expensive: in keeping with tough estimates, the central authorities spends between Rs 80,000 to 120,000 (about £800 to £1,200) to clear a single hectare of dense shrubbery. To forestall lantana springing again, these interventions need to be repeated frequently over a minimum of a three-year interval.

And, for a lot of consultants, these efforts barely scratch the floor of the issue. Tarsh Thekaekara has mapped lantana invasion in forests throughout south India, and says the quantity that state governments within the area spend on the elimination of invasive species is “absolutely useless”.

He says that the elimination of lantana from 30,000 hectares in Mudumalai National Park alone would price an estimated Rs 3bn (about £30m). “But the [Tamil Nadu] government gives Rs 5m (about £50,000),” he says.

What little effort is made can be not finished in a sustainable means, he says. Cleared forests usually are not then monitored, which means lantana merely grows again. It’s a problem that has left many conservationists annoyed with the federal government’s method, which generally entails manually reducing and burning lantana shrubs or, in excessive instances, sending in JCB diggers to uproot total swathes of forest.

But there may be one other means, one prioneered over 15 years in the past by Delhi University’s Professor CR Babu. He and a crew of scholars had outstanding success in a pilot on the Corbett Tiger Reserve in Uttarakhand utilizing the “cut rootstock” technique. It requires merely making a small lower slightly below the soil degree after which uprooting the plant and leaving it the wrong way up.

“We did the experiment back then in the buffer area of Jhirna, Lal Dhang and Dhikala zones [in Corbett Tiger Reserve] that had been invaded by massive lantana growth,” says Prof Babu. Restoring the forest space additionally led to the return of wealthy wildlife – and in flip, higher tiger sightings.

Today, a number of state governments make use of Prof Babu’s “cut rootstock method” to sort out the issue in forests and tiger reserves. In Bandipur Tiger Reserve in Karnataka, southern India, an ecological restoration non-profit known as Junglescapes has cleared lantana from greater than 1,200 hectares of forest utilizing Prof Babu’s technique.

Junglescapes’ Ramesh Venkataraman says lantana isn’t solely an issue that “can hasten the depletion of animal species”, however one that may additionally depart the forest extra weak to wildfires. He says that a large hearth in 2019 at Bandipur destroyed greater than 15,400 acres of forests and was later attributed to the world’s huge invasion of the shrub.

The Independent contacted a number of members of the National Tiger Conservation Authority [NTCA] with questions in regards to the deterioration of tiger habitat and any remedial measures being taken by the federal government, however didn’t obtain a response.

The drawback is pressing, many imagine. Mungi says that since his final examine, the unfold of lantana has solely elevated and he estimates that greater than 60 per cent of forests might now be impacted.

Rastogi additionally sounds the alarm, and says that lantana isn’t the one invasive species of concern. He says that whereas there may be extra deal with lantana, different invasive shrub species like Ageratum conyzoides and Pogostemon benghalensis have began wreaking havoc on the biodiversity of tiger habitats.

Over the years, efforts have been made throughout the nation to search out makes use of for the lantana plant. The Ashoka Trust for Research in Ecology and the Environment [ATREE] runs “Lantana Craft Centres”, the place they practice native artisans to create furnishings and different merchandise from the eliminated shrubs. Another group, the Shola Trust in southern India, creates sculptures of elephants from eliminated lantana shrubs and takes them round as artwork reveals.

Thekaekara believes this might be the important thing to fixing the disaster – it’s only when there are financial makes use of for the plant that its elimination will grow to be a precedence. He criticises the NTCA for not giving clear directions in regards to the elimination of lantana for industrial functions by most people – strictly talking, this might be a breach of the Wildlife Protection Law, which bans any type of industrial exercise inside a tiger reserve.

Venkataraman says that finally the problem of beating lantana “needs a very strategic and holistic approach, with coordination across state boundaries”.

“We are dealing with a very smart adversary,” he provides.