Do some trees really harm our environment?!

Well, unfortunately on a long term basis.. Yes!

The tree to be selected for plantation in a locality must be able to adapt to the area's climate, soil, topography and plant & animal life. But there are number of species of trees around us. Every species has its own way of performing various activities like getting their nutrition & water, growing, rooting, pollinating, multiplying, competing with other species & surviving..

There are trees which are useful to us. Some also have unique medicinal properties. Some trees are also preferred in farmlands as they are beneficial to the crops. On the other hand, there are trees which are troublesome, weedy or poisonous too.. That's the variety of Nature!! So which one should be selected for plantation and which one must be avoided?

And when we search the web for useful & multipurpose trees, we get more than 70% of trees that are not native to India. All of these claiming to be very useful even in Agroforestry in foreign countries. But this doesn't mean that we can also use & apply them in India while expecting the same returns. The foreign authors of the agroforestry articles/presentations are right at their place because they are studying and using their native trees. But for us, the case is different. Don't we have our own native agroforestry trees? Of course We do.. Remember, India has the second largest tree treasuries in the world. We just need to know about them :)

But before knowing what to plant, let us know what not to plant and why?!

One has to keep in mind that the introduced trees do not support our ecosystem. According to experts, these trees are driving away our wildlife. As these trees do not host birds or insects, they can not participate effectively in the food chain. Food chains or Food webs are the representatives of the relationships of living organisms in nature and are very essential for the balance of nature. Imagine, if we keep planting these non-native trees, our food chain is definitely going to disturb, so as our balance of nature. And if there will be no or very less native trees, where our birds, butterflies, insects will go then?

Its ridiculous to know that many of our native trees are much more high priced in nurseries than the non-native ones. And its not a proud thing at all. It simply suggests that in our region, the non-native & introduced trees are much more common than our own trees! Biggest misfortune is what I call it!!

Some also argue that we need these non-native trees to fight the ever-increasing global warming as they are fast growing and if we plant our native slow growing trees, then it will be difficult for us to fight back. Few days back, I met this interesting fellow who has spent his entire life serving the Forest Department. He also dared to compare Gulmohar & Banyan tree saying that after 5 years, which one will be big? After listening to him, I just asked, "And after 25 years, which one will be more useful to humans as well as wildlife?" My question was enough for him to change the topic! People tend to cuddle the immediate benefits and simply ignore the huge future loss..

Here are some trees which must not be included in tree planting campaigns..

Royal Poinciana or Gulmohar (Delonix Regia/गुलमोहर) is very common everywhere in India. You will not have any problem if you want to see the tree. It is native of Madagascar & Zambia.

It is a tree as good as plastic for wildlife. It has superficial roots and competes successfully with neighbouring plants. It is the tree which tend to fall easily during storms.

Copperpod (Peltophorum Pterocarpum/सोनमोहर) is not different from Royal Poinciana. It is native of Sri Lanka, Malesia & Australia. It is also native to Andaman islands of India. Thats the reason it is introduced to you as if its native to India. But actually, the atmosphere and flora & fauna of Andaman is quite different from India.

It has densely spreading canopy which retards the growth of other neighbouring plants.

Leucaena or White Babool (Leucaena Leucocephala/सुबाभूळ) is native of Mexico and Central America. Though it was introduced in India as a fodder & afforesting species, now it is considered unsuitable for urban plantation because of its tendency to get uprooted in rain & wind. Its foliage contains mimosine, toxic to ruminants if consumed in excessive amounts.

The tree has the potential to become a pest or rather, it has become one in India. It is considered one of the 100 worst invasive species Invasive Species Specialist Group of IUCN Species Survival Commission. Though locally known as Subabhul (Good Babool) due to no thorns, its actually a Kubabhul (Worst Babool).

Eucalyptus group or Gum trees (Eucalyptus spp./निलगिरी) are native of Australia. It is a widespread invasive water-sucker.

Many communities in India, Asia, Central America, the Caribbean and Africa are suffering from the long term damage caused by massive eucalyptus plantings. At first, most communities were content with having a tree. But the root system, barely under the surface of the soil, continued to widen into fields where farmers once grew crops. Farmers quickly discovered that eucalyptus trees are causing problems with their roots, taking all available water and nutrients from neighboring trees and crops. And their leaves are blanketing the ground inhibiting new growth. Eucalyptus trees inhibit the growth of other vegetation exposing soils to erosion, and cause lakes & ground water to disappear.

African Tulip (Spathodea Campanulata/रगतुरा) is native to Africa. It has the potential to become invasive.

It is not useful for avian-wildlife in India, nor is browsed by domestic animals. I have seen mass plantation of this tree even in a tourist place like Lonavala, as if we don't have our native ornamental trees. Or do we want our foreign tourists to know that We have bravely planted the trees which are not preferred for plantation near residential societies in its native countries also. It is said that African hunters make use of its nuts by boiling the centres and thus obtaining a poisonous liquid.

Silky Oak or Silver Oak (Grevillea Robusta/सिल्वर ओक) is native of eastern coastal Australia.

It is not resistant to persistent strong winds. This tree can become weedy or invasive according to the authoritative source USDI Geological survey. It is reported to become a pest in several countries. Its leaves produce an allelopathic substance which inhibits the establishment and development of other species. Also is a 'plastic tree' for birds.

Mexican Lilac or Gliricidia (Gliricidia Sepium/उंदीरमार) is one of the easily toppled species in strong wind. It is native to Mexico and Central America.

The tree is reported to lower the ground water level markedly. It also inhibit the new growth due to a thick cover of its leaves on the ground. The roots, bark & seeds are proven to be poisonous.

Rain Tree (Samanea Saman/पर्जन्य वृक्ष, गुलाबी सरस) is native to South and Central America.

It has umbrella-like wide spreading canopy and massive branching. It, therefore, inhibits development and growth of neighbouring plants. It has an extensive surface root system, which may interfere with agricultural activities or landscape maintenance. The seeds have been found to contain a toxic alkaloid, which may account for the occasional deaths of cattle which graze near the tree.

Blue Jacaranda (Jacaranda Mimosifolia/नीलमोहर) is same as Royal Poinciana. It is native of South America.

It is considered as an invasive species in many countries. It too acts as a plastic tree for Indian avi-fauna.

Australian wattle (Acacia Auriculiformis), as the name suggests, is native of Australia.

It is very weak tree as strong wind easily breaks its branches. It is considered as a threat to indigenous flora. Its fallen leaves make a thick carpet on the ground preventing development of other species. 

Sausage Tree (Kigelia Africana) is native of Africa.

This tree has a rather invasive root system. It has a big fruit and the falling fruit can cause serious injury to people and damage vehicles parked under the trees.

Finally, one has to accept that No tree is perfect. So decision is yours now. If you plant and grow trees, its a good thing! But planting Native Indigenous trees is bestest!!!  The tree species that has been living in India from many centuries and endowing benefits not only to humans but also to wildlife & our ecosystem deserves the priority.

We do have many of beautiful, fast-growing, unique & multi-purpose trees that can be used in plantation campaigns.

Get ready to be acquainted with them...