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

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. Here, we present results collected over five years of monitoring
surveys (2015 to 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. 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 km2 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 ten species assessed for their population
status, eight had invasive populations. 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. 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.