Environmental service rendered by Neem
Neem in Indian culture has been ranked higher than 'Kalpavriksha', the mythological
wish-fulfilling tree. In 'Sharh-e-Mufridat Al-Qanoon, neem has been named
as 'Shajar-e-Mubarak', 'the blessed tree', because of its highly beneficial
Although scientific studies are wanting, neem is reputed to purify air and
the environment of noxious elements. Its shade not only cools but prevents
the occurrence of many diseases.
During hot summer months in northern parts of the subcontinent, the temperature
under the neem tree is ~10° C less than the surrounding temperature;
10 air conditioners operated together may not do the job as efficiently
and economically as a full grown neem.
Restoration of the health of degraded soils and ultimate use of such reclaimed
wastelands lands through neem is another example of its value to humans.
About a decade ago, some 50,000 neem trees were planted over 10 km2 on the
Plains of Arafat to provide shade for Muslim pilgrims during hajj.
The neem plantation has had a marked impact on the area's microclimate,
microflora, microfauna, sand soil properties, and when full grown could
provide shade to 2 million pilgrims (Ahmed 1995).
It is an ancient belief that neem growing inside the house can keep the
surrounding air clean of impurities and thereby control environmental pollution.
Also, hanging neem twigs on the door of a house is said to offer protection
The tree is not only beautiful to look at, providing grandeur and serenity,
but also serves as a refugia to many beneficial organisms, bats, birds,
honey bees, spiders, etc.
Honey-combs established on the neem tree are singularly free from the galleria
wax moth infestation. Many species of birds and fruit-eating bats subsist
on the sweet flesh of ripe fruits, while certain rodents selectively feed
on the kernel, confirming neem's safety to warm-blooded animals.
The litter of falling leaves improves soil fertility and the organic content.
Presently, little is known about the mycorrhizal associations between neem
and bacterial and fungal endophytes, but the tree seems to be a living microcosm.
The evergreen, perennial tree can survive up to from 200 to 300 years,
if not cut down. Even a highly conservative estimate of the 'environmental
service' rendered by the tree @ US $ 10 per month, would give an astonishing
value of US $ 24,000 to 36,000 in its life time. Other economic uses of
neem and the benefits derived, such as biomass production, timber, seed
and honey are more tangible and quantifiable.