Kolkata: City based ecologists feel that the state Forest department, as well as the Parks and Squares department of Kolkata Municipal Corporation, should strictly adhere to some basic theories of urban plantation when they go for planting trees in the city. The observation comes in the wake of nearly 150 trees toppling in the city on Tuesday evening.”Rapid urbanisation in the city is emerging as a bane for the trees. Work for underground sewerage, underground telephone cables and underground electric wires are taking place on a regular basis, which is often destroying the roots of the trees, making them vulnerable to storms and squalls,” feels noted ecologist Nandadulal Parui. Also Read – Heavy rain hits traffic, flightsAccording to Parui, trees that usually follow a lateral growth pattern can withstand greater wind velocity than those that have a vertical growth pattern. “Trees like Bakul, Jarul, Gulmohar and Shirish have a lateral growth pattern. They grow to a medium height and have the capacity to withstand high wind velocity, which trees with vertical growth pattern cannot. In urban areas, taking care of the nature of trees before plantation is of utmost importance. There are trees whose wood is tough enough to withstand the velocity of wind,” he maintained. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedSoumitra Paul, Assistant Professor of the Botany department of Calcutta University, however, feels that the state Forest department and KMC plants trees in a much more scientific manner than what was done ten-twelve years ago. “Trees are not getting proper space to expand because of rapid urbanisation. The soil is losing its strength to hold the trees, resulting in their felling,” Paul said. He feels that putting concrete, cement or any sort of barrier at the bottom of the tree allows it to absorb rain water or precipitation of similar nature in a better way and is favourable factor for its growth. “If a tree is situated at an upward or sloping level, the water flows downwards and the trees fail to absorb water properly. We should remember that a tree uproots because of problems in its roots that lie below the ground. It has nothing to do with cement or concrete surrounding the tree above the ground,” Paul said.It may be mentioned that in well-planned cities, especially in Europe, a minimum of 50 cubic feet of soil is provided for a tree’s root system to expand. However, in the city, hardly 10 cubic feet of soil is available on an average for a tree’s root system to grow and therefore, toppling of trees during squalls and thunderstorms is becoming a common phenomenon every year, according to the environmental experts.