Simulating the spread and establishment of alien species along aquatic and terrestrial transport networks

A multi-pathway and high-resolution approach

authored by

Maurizio Bagnara, Larissa Nowak, Hans Juergen Boehmer, Franz Schöll, Frank M. Schurr, Hanno Seebens

Abstract

The introduction and further spread of many alien species have been a result of trade and transport. Consequently, alien species are often found close to traffic infrastructure and urban areas. To contain and manage the spread of alien species, it is essential to identify and predict major routes of spread, which cannot be obtained by applying common modelling approaches such as species distribution models. Here, we present a new model called CASPIAN to simulate the dispersal of alien species along traffic infrastructure and the establishment of populations along these routes. The model simulates simultaneous spread of species of up to eight different modes of transport along roads, railways and waterways. We calibrated and validated the model using two species that spread within Germany as case studies: the terrestrial plant Senecio inaequidens and the freshwater clam Corbicula fluminea, and performed a shortest path analysis to quantify the relative importance of individual routes for spread. The application of the model yielded detailed predictions of dispersal and establishment for >600,000 segments of the traffic network throughout Germany. Once calibrated, the model captured the general spread dynamics of the two species with higher accuracy for the freshwater environment due to the higher quality of data available for the aquatic species. The quantification of spread routes using the shortest path analysis revealed a clear backbone of major routes of spread, which varied depending on the type of traffic network and the starting points considered. Major routes of spread aligned with high traffic intensities, but high traffic per se did not necessarily result in high spread intensities. Synthesis and application. By simulating the spreading dynamics of alien species along transport networks across multiple pathways, CASPIAN enables the identification of major spread routes along different dispersal pathways and quantification of their relative importance, which helps prioritising pathways of introduction as required by international biodiversity goals such as the CBD Aichi targets.

External Organisation(s)

LOEWE Biodiversity and Climate Research Centre
Spanish National Research Council (CSIC)
University of the South Pacific
Friedrich Schiller University Jena
German Federal Institute of Hydrology (BfG)
University of Hohenheim

Type

Article

Journal

Journal of Applied Ecology

Volume

59

Pages

1769-1780

No. of pages

12

ISSN

0021-8901

Publication date

07.07.2022

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Ecology

Sustainable Development Goals

SDG 15 - Life on Land

Electronic version(s)

https://doi.org/10.1111/1365-2664.14184 (Access: Open)