Chapter 24 - Species invasion and ecological risk

Abstract

In modern times, the biodiversity is suffering from different factors across the world. Ecological invasion (EI) is a potential threat to biodiversity, which is yet to be acknowledged and explored properly throughout the world. The impact of invasive species (IS) is very much severe as it causes irreplaceable damage to the ecosystem. EI may also have transboundary impact across the globe leading to habitat degeneration. The major problem by invasive biota includes understanding the learning of species from individual point of view rather ecosystem point of view. Most of the impact was studied in relation to particular species. Few studies on EI have reported the impact on biodiversity, ecological services, and on natural resources. Under the era of technology and development, the earth’s environment is gradually becoming hostile for IAS in comparison to indigenous species. The biggest challenge seems to be change in indigenous species composition by IAS species. In global context, it was observed that indigenous species is gradually being replaced by IAS leading to change in the nature of ecosystem both in developed and developing world. This issue of invasion is very much severe under tropical conditions as the medium of dispersal of spores of various weeds are very much active to promote EI in the tropics. The EI varied between 10% and 70% in the area of tropical America, Africa, and Neo-tropical region. From Indian perspective, colonial rule played active part for dispersal of IAS. It has been found that 1/4th of the exotic species often acts as IS in India. Such huge amount of invasion often imposes problems on soil, biodiversity, ecosystem services, human health, forest ecosystem, economy, socioeconomic conditions, food security, agroecosystem, and many other aspects of ecological instability. The major cause behind such event includes changes in land-use practices, habitat conditions, loss of indigenous biodiversity, biotic interferences and above all lack of research, development, and awareness and subsequent management in relation to EI. Considering the problem of EI proper strategy formulation and risk assessment needs to be done for effective management of floral invasion. Integrated weed management, restriction of weed invasion, awareness regarding early perception of weed infestation are some of the major scientific approaches which needs to be implemented through research and developmental activities to combat against this negative event.