Problems of Invasive Plants and Animals

Abstract

Alien invasive species are considered the most important threat to biodiversity and ecosystem services in many countries of the world. At the same time, they have a very significant impact on the standard of living of the population (IPBES 2018). Very often, they are the main reason for the extinction of local species (Bellard et al. 2015) and cause major changes in natural ecosystems (Cacabelos et al. 2020; Liu et al. 2020), influencing the services provided by nature. Over the past hundred years, the number of cases of intentional and unintentional introductions of alien species has sharply increased worldwide (Seebens et al. 2017). Naturally, a very large number of alien species were introduced intentionally for economic benefit or to improve the living conditions of the population, possibly for cultural or educational purposes (Liu et al. 2012; Pipek et al. 2020; Pyšek et al. 2020). Many other alien species have been introduced unintentionally, for example, with ballast waters, transport, soil, and forage material or food (Saul et al. 2017). It has been shown that the pathways by which alien species have been transported to new regions have changed over time (Hulme 2009; Essl et al. 2015). In addition, it is clear that many of the most problematic species found their way to their new home in several ways and, most likely, more than once (Wilson et al. 2009; Essl et al. 2015; Saul et al. 2017). As a result of many years of research on alien invasive plant species in Armenia, we have accumulated diverse material on their distribution throughout the territory of the republic and the impact on natural ecosystems. It has to be noticed that work with invasive animals started only recently.