Canals as invasion pathways in tropical dry forest and the need for monitoring and management

Abstract

1. Linear infrastructure intrusions are common around the world to meet the needs of a growing and interconnected human population. The implementation of linear infrastructures involves numerous forms and mechanisms of land-use transformation that can facilitate and serve as pathways to the spread of invasive non-native species. However, the type and intensity of land transformations change over time and this can affect the frequency and intensity in which linear infrastructures route the spread of invasive species.2. Here, we present results collected over 5 years of monitoring surveys (2015)(2016)(2017)(2018)(2019) to assess the relationship between the construction of one of the largest canals to date in Brazil and the spread of non-native species. We studied the Integration Project of the São Francisco River (PISF), a canal fully inserted in the Caatinga biome, a tropical dry forest ecosystem for which information on invasion dynamics are little known. 3. Our results confirmed PISF canals served as habitat and dispersal corridors for non-native plant species. Monitoring surveys recorded 26 non-native species established along the 83.2 km 2 PISF deployment area. Eleven years after the canal deployment area was completely cleared of vegetation, 92.3% of its extension had non-native plant populations. Of the 10 species assessed for their population status, 8 had invasive populations. 4. The time immediately after construction work finished was the critical stage for the spread of non-native woody plants, which increased their distributions with reduced levels of construction intervention, whereas most of the herbaceous species reduced their distributions. When human intervention was drastically reduced, many populations of non-native plants rapidly formed at the deployment area. 5. Policy implications. Man-made linear infrastructures can remove biogeographical barriers and serve as pathways for the spread of invasive species over long distances and across ecosystems. Thus, the planning, construction and management of such infrastructures should include measures and funding for risk assessment, prevention, monitoring and control of biological invasions. Agencies responsible for environmental licensing should mandate invasive species management as part of the installation and operation licensing conditions.

Status e tendências sobre espécies exóticas invasoras no Brasil

“…Algumas das plantas exóticas invasoras com mais ocorrências de invasão biológica conhecidas são jaqueira (Artocarpus heterophyllus) e lírio-do-brejo (Hedychium (Medeiros & Focht 2007, Asth et al 2021. Já a algaroba invadiu mais de um milhão de hectares de Caatinga (Andrade et al 2010), especialmente sítios de elevada importância biológica, como matas ciliares (Andrade et al 2009).…”

“…Para o Cerrado, atualmente amplamente invadido por gramíneas exóticas, têm se feito registros recentes de invasões biológicas incipientes por pinheiros-americanos(Cazetta & Zenni 2020). Para a Caatinga, a expansão de projetos de infraestrutura lineares também representa um importante vetor de introdução e dispersão de espécies exóticas invasoras no bioma e dezenas de espécies exóticas invasoras já ocupam a área de influência direta do projeto de integração do rio São Francisco(Asth et al 2021). A tendência é que a expansão de estruturas viárias esteja diretamente relacionada à dispersão de espécies exóticas invasoras.Um risco futuro e ainda incipiente na região do Cerrado é o santuário de elefantes, uma propriedade de aproximadamente 1.000 hectares no oeste do Brasil com o objetivo de recolocar na natureza elefantes que atualmente vivem em cativeiro.A organização responsável pelo projeto estima que 50 elefantes poderiam viver no santuário em algum momento devido a um número crescente de leis que proíbem os circos de manter animais em cativeiro.…”

Zooplankton in the Technogenic Aquatic Ecosystem of the North Crimean Canal, the Longest in Europe

“…Every canal system is recognized worldwide as a corridor for invasive species distribution [29][30][31][32][33]. As an example, 443 multicellular alien species were introduced into the Mediterranean Sea through the Suez Canal in total [34].…”

Knowledge needs in economic costs of invasive species facilitated by canalisation

“…One of the most important pathways that allow the spread of IAS are canals connecting geographically-isolated aquatic systems (e.g. Asth et al 2021), such as the trans-isthmian Suez and Panama Canals, and the cross continental North Sea-to-Black Sea Rhine-Main-Danube Canal. These highly trafficked strategic canals connect transport networks of critical economic and socio-political value, mainstays of global trade and globalisation (Amato 2020).…”