Once celebrated as the ‘Garden City’ for its lush greenery and rich biodiversity, Bengaluru is grappling with the realities of urbanisation. Now, residents struggle to find a spot of shade amidst the onslaught of concretisation. An Indian Institute of Science (IISc) study suggests that Bengaluru has lost a staggering 80% of its forest cover since the 1970s. Trees are the first casualties of the rapid development and mega-construction projects of Bengaluru.
That’s why conducting a tree census in the city is crucial. Such an exercise regulates tree felling and helps monitor tree health, assess species diversity, and inform resilient urban planning. However, a closer look at the ongoing tree census in Bengaluru reveals glaring inaccuracies and inconsistencies while raising doubts about its reliability and effectiveness.
Decades of delay
The Karnataka Protection of Trees Act was passed in 1976 to restrict and regulate the felling of trees. The Act lists carrying out a census of the existing trees in the State as one of the duties of the Tree Authority — a five-member committee including the Forest Officer in charge, a representative of the BBMP commissioner, and a botanist or ecologist nominated by the State government.
Decades after the Act was passed, in June 2019, the Karnataka High Court directed the Tree Authority to conduct a tree census as per Section 7(b) of the Act. After several delays and court orders, BBMP was able to count only 18,144 trees in 2022. The census process sped up in February 2024 and was expected to be finished by October. But only 4,16,888 trees have been enumerated till January 2025. According to a 2014 IISc study, Bengaluru had 14.79 lakh trees, while a recent news report citing the BBMP estimates the count to be around 20 lakh.
At this pace, Bengaluru may finish counting its trees long after they have disappeared.
Read more: It’s been a long and difficult struggle to preserve Bengaluru’s trees
Quality gaps in the tree census data
The real question is — why does it take years, multiple court orders, and relentless public pressure for the administration to simply count trees, let alone protect them? Is the city serious about saving what’s left of its once-thriving green cover?
Citizens and experts have identified significant quality gaps, including incorrect map positioning, missing and duplicate entries and incorrect species labelling. “I am concerned about the credibility of the survey,” says Anand Ramachandran, a resident of Indiranagar.
Anand has identified several unmarked trees in his locality, including two large trees at the 1st cross and 12th main road intersection. In Domlur, two barks of the same tree are given two different numbers, Dattatraya T Devare, an environment activist, points out.
Improper numbering, such as non-consecutive numbers for adjacent trees, hampers the effectiveness of the census, especially for citizens to find and notify missing trees. According to Devare, data fields such as girth and height of the trees, health condition, economic importance, flowering/fruiting season and flower colour must also be captured.
“What has been done doesn’t give a proper idea of the tree cover in the city. Leaving out some of the parameters results in an incomplete census,” he says. Besides trees on the roadside, BBMP must also count those on private properties, which is not done currently.
Successful tree census in other regions
- While the Bengaluru tree census has so many flaws, the Pune tree census 2019 data included several important data fields, including the girth, height, canopy diameter, health condition, ownership, economic benefits and the flowering season.
- The Ambalipura lake tree census is a citizen-led initiative to protect the trees. A green audit complemented by a tree census helped a group of active citizens maintain their neighbourhood lake and trees. While the data fields are less, the comprehensive census helped understand the importance of the trees in the lake.
Read more: How to do a tree census: Ambalipura Lake volunteers’ experience
A dashboard for flawed data
BBMP also maintains a dashboard to update the geotagging and other data fields from the Bengaluru tree census. However, this database has many flaws. Some trees are inaccurately mapped, certain marked trees are missing from the dashboard, some entries appear twice, and photos are incorrect.
What Anand Ramachandran has identified in his locality
- Unmarked trees: Two large trees at the 1st Cross & 12th Main intersection (well within Ward 80).
- Incorrect map positioning: Some trees are inaccurately mapped.
Example: HOY3141 is off by 20 metres and shown on the wrong side of the road. - Missing entries: Marked trees are not listed on the website. For example, HOY3167 is missing from the website
- Duplicate entries: HOY3145 appears twice.
- Low-utility photos: Images do not capture the girth, height, or shape of the tree, limiting their usefulness for monitoring.
- Incorrect species labelling: HOY3145 is labelled Syzygium cumini but is Mimusops elengi. HOY3168 is listed as Guava but is Pride of India.
Pictures of the trees are supposed to be uploaded in the geotagging, which could help identify physical features. But photos of just the leaves or the tree trunk are of low utility, Anand explains.
Let alone pictures with low utility. In some cases, the images uploaded are not of trees at all. For example, ATT-47, marked as Ficus benghalensis (banyan tree), shows a pen. ATT-37 is not a tree but a watch, and its species is identified as Tabebuia rosea. “This shows that they are not doing the exercise with due diligence,” says Devare.
Misidentification of the species
Bengaluru is highly biodiverse, and the agency conducting the census may lack sufficient knowledge of various species, leading to misidentification.
“Tracking the species accurately is important to understand the region’s biodiversity. Looking at the mistakes in the census, it is clear that the people marking the trees are not experts. Recording the size and shape of the tree is also important to maintain the tree’s health and to ensure that the branches are not being cut,” says Anand.
Increasing number of unidentified trees
As of November 2024, Pongamia pinnata was the most numerous tree species, making up 24% of the total. The category marked as ‘others’ accounted for 13.80%. By January 2025, this ‘others’ category had risen significantly to 38.49%. With a little calculation, we find that 92.92% of trees counted between November 2024 and January 2025 are marked as ‘others’. This raises serious concerns about the credibility of the tree census data and hinders the recognition of Bengaluru’s true diversity.
“The way it is being done now is far from satisfactory,” said Devare. If the tree census is riddled with errors and inconsistencies, it risks becoming a mere bureaucratic exercise. Despite several attempts to contact the BBMP, we did not receive a response.
Accurate data helps track tree health, regulate felling, plan afforestation, and ensure ecological balance in a rapidly urbanising city like Bengaluru. Without a reliable census, authorities lack the necessary insights to protect and expand the green cover, making the process futile. Fixing these flaws is crucial to protect the city’s remaining trees.
Watch this video to understand the problems with the BBMP tree census, and how it can be done right:
What experts suggest
- Ensure that trees next to each other have consecutive numbers. Involve citizens to flag issues, followed by official verification.
- Ensure trees are counted sequentially and photographed clearly. Correct the data before finalising the survey.
- Ensure the species are labelled correctly by tree experts.
- More fields of data about each tree must be recorded and trees in private properties must also be covered in the census.
- Avoid delays and complete the exercise soon.
- Make the website (where census data is uploaded) user-friendly.
Have you seen the tree census being conducted in your locality? If you have noticed any discrepancies call BBMP on 1533 or give feedback here: https://kgis.ksrsac.in/test/
Very well researched article. Unfortunately, the BBMP is just not equipped to do such surveys fully and efficiently. The outcome of the survey goes beyond just protection of trees. Trees are our only sources for respiratory Oxygen. And only full grown adult trees contribute significantly over its lifespan. So, if the scientific number of trees required per person is defined – between 4 to 7 trees, then it could be that some areas/wards may not afford to lose a single tree for any development. Or it could compel the BBMP to start Green Belts across Bengaluru to ensure that adequate number of trees are always available.