Scientists' warning on invasive alien species

Abstract

Biological invasions are a global consequence of an increasingly connected world and the rise in human population size. The numbers of invasive alien species – the subset of alien species that spread widely in areas where they are not native, affecting the environment or human livelihoods – are increasing. Synergies with other global changes are exacerbating current invasions and facilitating new ones, thereby escalating the extent and impacts of invaders. Invasions have complex and often immense long‐term direct and indirect impacts. In many cases, such impacts become apparent or problematic only when invaders are well established and have large ranges. Invasive alien species break down biogeographic realms, affect native species richness and abundance, increase the risk of native species extinction, affect the genetic composition of native populations, change native animal behaviour, alter phylogenetic diversity across communities, and modify trophic networks. Many invasive alien species also change ecosystem functioning and the delivery of ecosystem services by altering nutrient and contaminant cycling, hydrology, habitat structure, and disturbance regimes. These biodiversity and ecosystem impacts are accelerating and will increase further in the future. Scientific evidence has identified policy strategies to reduce future invasions, but these strategies are often insufficiently implemented. For some nations, notably Australia and New Zealand, biosecurity has become a national priority. There have been long‐term successes, such as eradication of rats and cats on increasingly large islands and biological control of weeds across continental areas. However, in many countries, invasions receive little attention. Improved international cooperation is crucial to reduce the impacts of invasive alien species on biodiversity, ecosystem services, and human livelihoods. Countries can strengthen their biosecurity regulations to implement and enforce more effective management strategies that should also address other global changes that interact with invasions.

Fundamental research questions in subterranean biology

“…Of these, 10 questions were part of the initial List #1, while two additional questions were suggested by survey participants. Three questions (Q32, Q33, and Q36) highlighted three of the greatest threats to biodiversity worldwide – climate change (Ripple et al ., 2019), pollution (Ripple et al ., 2017), and invasive alien species (Pyšek et al ., 2020) – whose effects are pervasive also underground (Mammola et al ., 2019 b ). Additional questions were centred on the impacts of above‐ground disturbance (Q34) and human activities (Q43) on subterranean habitats.…”

Harmonising the fields of invasion science and forest pathology

“…The term "emerging alien species" is used to describe those that are detected as aliens for the first time, i.e. with no previous invasion history (Seebens et al 2018), consequently, it is challenging to predict their impact and spread (Pyšek et al 2020).…”

“…Invasive alien species (IAS) present a major threat to global biodiversity, ecosystem services, economies and human health. In the present era of globalisation, and with no end in sight to the accumulation of alien species worldwide (Seebens et al 2017), this threat continues to grow (Pyšek et al 2020). The field of invasion science has been established to address the issues arising from the introduction of alien species and resulting biological invasions.…”

Into the great wide open: do alien plants spread from rivers to dry savanna in the Kruger National Park?

“…The majority of protected areas worldwide are vulnerable to invasions, with very few completely free of alien species (Foxcroft et al 2017;Moodley et al 2020) and many suffering various impacts at the species and community levels. These impacts include the alteration of habitats, ecosystem regime shifts and losses to native species abundance, diversity and richness (Foxcroft et al 2013;Hulme et al 2014;Pyšek et al 2020). In a global assessment, De Poorter (2007) found there were 487 protected areas where invasive alien species posed a serious threat to biodiversity.…”