What defines an invasive species in ecological terms?

An invasive species is defined as a non-native species that causes harm to local ecosystems and native species. This definition is rooted in the significant consequences that these organisms have on their new environments, which may include ecological disruption, competition with native species for resources, and the potential decline or extinction of indigenous organisms.

Invasive species often thrive in their new environments due to a lack of natural predators, allowing them to outcompete and displace native species. This can lead to a loss of biodiversity, as the introduced species may alter habitats, affect food webs, and disrupt ecosystem functions. The pervasive impact of invasive species necessitates management and control efforts to protect native wildlife and preserve ecological integrity.

The other definitions mentioned do not accurately capture the essence of what it means to be an invasive species. For instance, native plants or animals enhancing ecosystems or existing in high abundance are not inherently harmful. Additionally, species that promote biodiversity in their introduced locations are often beneficial and do not fit the definition of invasiveness, which highlights detrimental effects. Thus, the focus of an invasive species is specifically on the harm they inflict on local ecosystems and native species.