Does origin determine environmental impacts? Not for bamboos

Abstract

Societal Impact Statement Non‐native species can cause considerable negative impacts in natural ecosystems. Such impacts often are directly due to the fact that these species occur in habitats where they did not evolve. We explored this for bamboos and found that, contrary to the situation in many other plant groups, biogeographic origin was not a strong predictor of the type and severity of environmental impacts caused. We argue that impacts from bamboos are a response to land transformation and disturbance of forest habitats by humans. Therefore, the threats posed by bamboos to highly disturbed forest systems should be the same wherever bamboos are present or planted, and management should adopt similar approaches. Summary Negative environmental impacts can result from the human‐mediated breakdown of biogeographic boundaries that historically shaped species distributions leading to rapid population expansions, that is, from biological invasions. However, the alteration of natural ecosystems by humans has created opportunities for both native and non‐native species to become weedy. We assessed whether origin status (native or non‐native) matters for the type and magnitude of environmental impacts caused by bamboos (Poaceae: Bambusoideae). We used a systematic global literature search and the International Union for Conservation of Nature's (IUCN) Environmental Impact Classification of Alien Taxa (EICAT) scheme as the basis for scoring impacts of bamboo species. We found that the type and severity of recorded impacts were similar in the native and non‐native ranges of weedy bamboos, and that the habitats in which impacts are most often reported (i.e., temperate and tropical forests) were also the same. Origin was not a strong predictor of environmental impacts for bamboos. Rather, impacts are likely to be a response to human‐mediated land transformation and disturbance of forests. Further research on the mechanisms whereby bamboos impact other species is needed to guide management strategies in their native ranges and as input to risk assessments for new introductions and plantings.

An Evaluation of the Impacts of Alien Species on Biodiversity in South Africa Using Different Assessment Methods

“…The Environmental Impact Classification for Alien Taxa has been applied to various taxa that are known to occur as alien species in South Africa including grasses (Visser et al 2017;Nkuna et al 2018;Canavan et al 2019), amphibians (Kumschick et al 2017), birds (Evans et al 2016), mammals (Hagen and Kumschick 2018), fish (Marr et al 2017), gastropods (Kesner and Kumschick 2018), and some other invertebrates (Nelufule 2018). Most EICAT assessments performed to date have been done at a global scale, i.e.…”

Global environmental and socio-economic impacts of selected alien grasses as a basis for ranking threats to South Africa

“…More impact studies are still needed for alien grass species, especially when it comes to species with no impact records across all introduced ranges, but with taxonomic characteristics of invaders (such as Bambusa balcooa, Canavan et al 2016). It will be interesting to see if the findings of Canavan et al (2018a), that bamboos have similar impacts in their native and alien ranges are the same for other grasses or perhaps only other tall-statured grasses (Canavan et al 2018b). However, we suspect there are qualitative differences between the impacts in the native and alien ranges, for the grasses studied here, as the impacts observed are not primarily a response to human disturbance.…”

Application of the Socio-Economic Impact Classification for Alien Taxa (SEICAT) to a global assessment of alien bird impacts

“…The impact descriptions are analogous to those used for the IUCN EICAT protocol, which has been used by individual assessors to undertake global assessments of the environmental impacts of alien species (e.g. Canavan et al 2019).…”