TitleInvasive alien trees and their management in India

Abstract: Invasive alien species (IAS) are non-native plants, animals and microbes whose introduction into new environments will cause economic or ecological harm and/or harm to human health. Globally, they have been identified as one of the biggest threats to biodiversity. Invasive alien plants are known to invade a variety of ecosystems, spread quickly, displace native plants, monopolize resources and upset ecological equilibrium of the invaded area. Economic damage due to IAS is estimated to be 1.4 trillion dollars globally which equals 5% of the global economy. As in other parts of the world, a wide spectrum of alien plants has been introduced into India either intentionally or inadvertently – the latter mainly promoted byinternational trade and travel. However, our knowledge on introduced trees which have become invasive in the country is patchy. Of these, Acacia mearnsii, Prosopsisjuliflora andLeucaenaleucocephala deserve special mention since they are already widespread and managing them would be a challenge.And, socio-economic relevance of some of these treeswill have to be considered before control methods are attempted. However, management of a few species such as Sennaspectabilisand Maesopsiseminii, natives of tropical America, may still be possible since invasiveness of these trees has been noticed only recently and their spread is currently limited.Attention should also be focused to prevent invasion by any new tree species through risk analysis and adoption of proper quarantine methods. Success of managing plant invasions (through physical, chemical and biological methods) is dependent on several factors including proper implementation of methods. However, a lack of tools, information and expertisefrustratesthis.It is also necessary to raise awareness on the damages due to invasive species among all concerned. The paper will discuss these concerns and highlight the need of a Govt. policy to deal with IAS in the country.