Its survival instincts make Prosopis juliflora the most hated tree in India—and unfairly so
Lhendup G Bhutia | 12 Jul, 2018
THE LITTLE RANN of Kutch, like the rest of the salt desert, is a bleak and hostile landscape. A punishing sun beats down on a vast and empty expanse. The land is flat, white and barren. Nothing grows except for the odd shrub and some vegetation. The soil has too much salinity and water is scarce. But, invisible to the casual eye, something interesting goes on here. Every year, undeterred by the elements, a particular type of shrub—or rather, tree— gradually expands its reach. And Prosopis juliflora isn’t even a native species.
A study which focused on the nearly 5,000 sq km enclave for Indian wild asses in the Little Rann—the Indian Wild Ass Sanctuary, the only one of its kind for this endangered species—published in the National Academy Science Letters in 2014 found that the tree had been invading territory there at an annual pace of 25 sq km in the 1990s, back when the area was said to be wetter, a clip that has slowed to about 1.95 sq km in recent years. Still, the expansion of this tree’s coverage has been extremely rapid.
How is Prosopis juliflora able to thrive in such conditions? The answer, the researchers of the study found, lay in the excreta of the sanctuary’s residents. The chestnut-brown Indian wild asses, which look like donkeys that have been dunked in a large vat of brown cream, have taken quite a liking to the tree’s seed pods. According to the researchers, the wild asses’ dung, which is damp and nutrient rich and filled with seeds (the endocarp layer that surrounds the seed having been separated in the digestive process), provides the perfect conditions for the tree’s seeds to germinate and grow in the desert. ‘Otherwise, with high salinity and frequent droughts, seedlings of mesquite (another name for Prosopis juliflora) would not [be] able to germinate,’ the authors write.
The expanding coverage of this tree brings trouble with it. It is taking over the grasslands that used to feed the wild asses and other animals of the sanctuary, as the researchers note. The count of Indian wild asses has been increasing. It was 362 in 1960 and over 4,800 now. Since a sanctuary can only sustain so many wild asses, these endangered animals have now begun to extend their stomping ground, very often into human areas, eating crops, getting into direct conflict with them, and in the process, through their droppings, also expanding the coverage of Prosopis juliflora to areas of human habitation. There have even been media reports of wild asses found dead, killed by pesticide consumption. ‘The annual expansion rate of mesquite cover… indicates a significant threat to indigenous biodiversity,’ the authors write. ‘The existing population of wild ass is ever increasing due to legal protection… This growing population… is dispersing into surrounding human dominated landscape.’
The march of Prosopis juliflora isn’t just limited to a sanctuary in Gujarat. Unencumbered with the harshness of salt deserts, its advance is even more pronounced in other parts of India where it is known by various local names: from vilayati kikar or angreji babul in Delhi, baavlia (‘the mad one’, upon translation) in Rajasthan, and gando baval in Gujarat to seemai karuvel (‘foreign black fence’) in Tamil Nadu and Ballaari jaali in Karnataka. And almost everywhere, it is almost unanimously disliked. Governments have set aside budgets to uproot the tree, online and on-ground petitions and campaigns have been launched, citizen groups have been mobilised, the dust and pollution levels in our cities have been blamed on it, and even courts have been pressed into action to extirpate the kikar tree.
This hatred of Prosopis juliflora, referred to as mesquite in the US, is shared by several other countries as well. Originally from South America, over the past half century it has expanded across the world, especially to arid and semi-arid regions in Africa, Asia and Australia. And wherever it has gone, with its deep roots, prodigious seeds, thick branches and ability to grow in dry environments, it has taken over other plant and tree species native to those lands. It is now widely found to be one of the most invasive species of plants in the world (some even consider it a weed). In 2004, it was rated one of the world’s 100 least wanted species (Invasive Species Specialist Group of the IUCN).
In Ethiopia, it’s called the Devil’s Tree.
There is no exact date available of its first arrival in India. Most accounts suggest it was brought to the Subcontinent in the latter half of the 1800s. According to CR Babu, who heads the Centre for Environment Management of Degraded Ecosystems in Delhi (CEMDE), vilayati kikar was first planted in Delhi when the British Raj shifted its capital from Calcutta to Delhi in the early 20th century. “They wanted the city to be more beautiful, greener. They were considering several species, but they zeroed in on the kikar because it was the best candidate to succeed and the quickest to spread. It had already shown great success in other places like the deserts in Rajasthan,” Babu says.
“The ridge used to have 480 bird species once. Now there are some 35. Imagine what other harm the kikar has silently been causing” – CR Babu, head, Centre for Environment Management of Degraded Ecosystems
With none of the accompanying natural controls like bacteria, insects and diseases that could keep an ecological check on the tree’s growth, combined with the fact that it is suited for desert and semi arid conditions, the tree took over large expanses in and around Delhi. About four- fifths of all trees on the Delhi Ridge, the soi-disant lungs of the city, are estimated to be kikar. It also dominates much of the Aravali foothills around Gurugram.
It was a much appreciated species once, though. It had been used to afforest deserts in Rajasthan, for example, and later in the 1960s, to help Tamil Nadu overcome a severe shortage of firewood. According to one account, the Maharajah of Jodhpur scattered bags filled with vilayati kikar seeds from his two-seater Tiger Moth aircraft to turn his desert kingdom green. By 1940, the royal family even bestowed upon it the title of ‘Royal Plant’. But once the plant laid siege to the kingdom, the rose-tinted view of the tree began to change dramatically. In 2006, when the Rao Jodha Desert Rock Park was being built in an area adjoining Jodhpur’s Mehrangarh Fort and an attempt was being made to restore the natural ecology of the area, one of the first things they did was have a go at the kikar. ‘Baavlia is extremely difficult to eradicate,’ reads the website of the Park. ‘After trying several different methods without success, we employed Khandwaliya miners to use time-tested ways of manually chiselling into the hard, volcanic rock. We knew we had to go down at least 45 cm below ground-level to kill the baavlia.’
“Several parts of Rajasthan have tried to remove the baavlia and replace it with a native species. But almost always, within a year or two, the baavlia returns,” says JC Tewari, a forestry scientist formerly with the Jodhpur-based Central Arid Zone Research Institute (CAZRI). “It’s not easy.”
The kikar does have a few established benefits, chief among them being its use as fuelwood and charcoal. But in recent times, its detractors have been conducting a loud campaign, claiming that the negatives far outweigh the benefits. Not only does it muscle out all other native species, but also an entire ecosystem of insects, birds and animals dependent on those trees. Its deep roots, according to some, absorb litres of water, depleting groundwater levels and drying out water bodies. Some even say, strangely, that the trees sometimes poison groundwater and reduce the oxygen in the air, while emitting carbon dioxide and nitrogen.
In Delhi, after years of trying, the government will have another go at clearing the Ridge area of its kikars. Last year, the Delhi government launched its ‘Kikar Hatao’ campaign, setting aside a budget of Rs 50 lakh for it. Babu of CEMDE, who has for years been trying to build a consensus on the ejection of the species from Delhi and who will now oversee the programme, calls the tree a biological nightmare. “It has been nothing but a biological invasion of one species. Do you know, the Ridge used to have 480 bird species once? Now there are some 35. And we are only talking about birds. Imagine what other harm it has silently been causing. Its roots grow 21 metres—so deep. It is like a water pump, pumping out all the water from the soil,” he says. “No insect depends on it, no bird nests on it. And it is a poor dust trapper, with a poor ability to mitigate dust pollution. For a city like Delhi, we need better trees.”
“The false impression has been that this is a horribly invasive and useless species. But no species is useless. We just need to find out their utilities” – JC Tewari, forestry scientist
In the past, several methods have been unsuccessfully attempted to clear Delhi of its kikars. This time, Babu says, a new method will be tried out, a sort of biological warfare, where kikar branches will be cut and several openings created in the foliage cover—so that their capacity to produce food for itself is reduced, while also allowing sunlight and water to pass through the openings and onto the ground, where new saplings of other native species will have been planted. To expedite the process, Babu says, he will also be planting parasitic vines in the area that will cut kikar’s access to sunlight while taking away its nutrients.
“We have learnt you can’t just cut down the tree. It will then just regenerate from its root. Also, this will lead to the green cover getting [depleted],” says Babu, “By reducing its foliage and branches and planting vines, we are allowing kikars to slowly die on their own. And gradually, new native tree species will begin to replace it.”
This exercise will be conducted in phases, about 100 acres at a time. Babu estimates that within three to five years, he will have altered the landscape. “It will be very different. There will be some 700 to 800 different types of tree and plant species, some of the trees over 30 feet tall. Birds will come, maybe even wild animals,” Babu says. “It will be lovely.”
IS THE KIKAR really as harmful as it is made out to be? Last year, Tamil Nadu went about uprooting these trees, known there as seemai karuvel, with exceptional vigour. This was after a Madras High Court bench ordered its removal across the state. Judges and district munsifs began to oversee the eradication, advocate commissioners were appointed to oversee the work, and according to some media reports, judges ventured out to some sites to watch first- hand how their directives were being implemented. “This was so strange,” says Gopal Krishnan, an advocate whose petition against the programme last year resulted in an immediate stay order on the work. “Because, to be honest, there is very little scientific knowledge on whether the tree is harmful or not.”
Krishnan, who often represents cases involving the environment, got interested in this case when he noticed how the seemai karuvel was being removed from the campus of IIT Madras. The campus, about 630 acres in all, is a vast green space, and home not just to students, but also a vast number of blackbucks, spotted deer, star tortoises, and a variety of snakes, birds and other animals. The dreaded trees, however, have sprawled across the expanse. “They were using JCBs to pull out the roots, in some places as deep as 15 feet,” he says.
After it was petitioned, the High Court constituted a committee of experts to study claims against the tree. Most of these have no scientific basis, according to its report, submitted late last year. The tree does not cause depletion of groundwater, its roots do not penetrate to any great depth as believed, and it does not reduce oxygen. Rather, the study found it supports several indigenous plant species like neem and sisso and a good diversity of birds are known to roost and nest in them. However, near water bodies and channels, its dense growth and leaf litter was found to reduce and impede water flow. “The report found many benefits from the tree: it enriches soil nitrogen; it is used as fodder by blackbucks and livestock, gives fuelwood, and is an important source of income in rural economies,” Krishnan says. ‘In spite of its positive role,’ the report states, ‘the extensive spread of the P. juliflora has generated some kind of a hate-psychology among sections of public and some NGOs.’
There is a minority of researchers like Tewari, formerly with CAZRI, who profess a love for this tree. “I know it doesn’t look very attractive,” he says. “But it is very beautiful in the inside. We have not yet tapped all its benefits. So what if it is a foreign species and has invaded [the territory of native species] and impacted biodiversity? It is here now. And there are other birds and animals that are dependent on it. The truth is, even after the British left, various states went about randomly planting the tree. There was nothing planned about it. It was obviously going to spread. Now you can’t just decide it is a bad tree and want the old trees back. You can’t randomly cut it down.”
CAZRI has been working on several projects to make the most of what kikar offers, ranging from products for cattle to those fit for human consumption. For example, it has been using the tree’s pods to develop ‘juli coffee’. It has also been using the pods to create a kind of syrup that can be mixed with fruit juices and milk to be consumed as another type of beverage. Its most successful project, carried out in several villages of Rajasthan between 2009 and 2014, involved grinding kikar pods for use as cattle feed. According to Tewari, a single tree can yields as much as 30 kg of pods a year. The organisation found that these pods could constitute about 30 per cent of the cattle feed mix, saving farmers at least around Rs 140 per 50 kg. According to him, this feed mix has also been found to boost milk production.
“The false impression has been that this is a horribly invasive and useless species in most parts of the world,” observes Tewari, “No species in nature is useless. We just need to find out their utilities.”
T REES OCCUPY different spaces in our mental landscape. To some, a large tree in a concrete forest is an image of beauty. To others, trees are a source of livelihood. In India, some of them are also uniquely living symbols of faith. It would be considered sacrilege, for instance, to chop down a Banyan or Peepal tree. Kikar, despite becoming a part of the livelihood of so many rural households, has somehow remained an ‘outcaste’.
An academic paper presented by Kurt Walter to the Faculty of Agriculture and Forestry of the University of Helsinki in 2011, however, reported that the tree was being prayed to—although less fervently compared to other holy trees—in some parts of Andhra Pradesh. In one instance, outside the town of Tirupathi, Walter discovered a kikar tree being worshipped as the abode of a deity. ‘Every Friday evening,’ he writes, ‘the villagers gathered under the tree to perform a puja in honour of their deity. She was known to have helped many women become pregnant after years of infertility.’ Just the kind of thing that might help the tree overcome its ‘most hated’ tag.