Knowledge Tree
non-native species
Also known as: nonnative species
Facts (12)
Sources
Compendium Vol. 5 No. 1: The ecological role of native plants bio4climate.org 11 facts
claimIn cases where soil has been stabilized with nonnative species, native species can be added or helped to recover spontaneously while nonnative species are removed to assist the recovery of a native ecosystem.
claimWhile insect conservationists have long recognized the importance of habitat containing appropriate native host plants, the widespread replacement of native host plants with non-native species has not yet been significantly addressed in the literature on insect declines, according to Tallamy (2020).
claimThe displacement of native plant species with non-native species reduces lepidopteran diversity and abundance, which ripples up the food chain to reduce diversity at higher trophic levels, ultimately leading to lower ecosystem productivity and stability.
claimWhen native plants are displaced by non-native species, phytophagous insects often fail to recognize the new plants for feeding or egg-laying, or cannot overcome the novel plant defenses, which can lead to local insect extirpation and altered food web structures.
claimKaren Holl (2020) identifies several pitfalls in tree-planting initiatives: using non-native species (which fails to create a true forest and can deplete groundwater in arid areas), planting trees in historic grasslands or savannas (harming native ecosystems), abandoning trees after planting (leading to high mortality from lack of water, competition, grazing, or clearing), and planting trees on agricultural land (which risks displacing crop production into native forests, causing further deforestation).
claimNumerous studies document that the establishment of non-native species can result in local ecological decline.
claimMany insect species are specialists that can only consume certain plant species; when these specific plants are replaced by non-native species or lost locally, the dependent insects disappear.
claimThe conversion of native plant communities into assemblages dominated by non-native species is one of the most ubiquitous threats to biodiversity today, as habitats are rapidly converted from coevolved ecosystems into novel assemblages.
procedureRestoration plans for degraded sites (such as rangelands or post-mine sites) that have been revegetated with a mix of native and nonnative species can be developed by harvesting nonnative species, replacing them with native species, and taking other actions to assist the system in recovering to its pre-degradation condition.
claimInsect herbivores are often adapted to the self-defensive toxins produced by specific plants, making them vulnerable when those specific plants are replaced by non-native species.
referenceDuring urban conversion, native plants are replaced by non-native species that possess novel chemical, physical, and phenological features, for which native herbivorous arthropods lack sufficient physiological or behavioral adaptations, according to Narango (2017).
Ecologists Study the Interactions of Organisms and Their Environment nature.com 1 fact
claimThe loss of a native species or the introduction of a non-native species can threaten the survival of other organisms.