Fallopia japonica and Impatiens glandulifera have a negative impact on terrestrial invertebrates
River banks are complex, dynamic habitats which form the interface between aquatic and terrestrial habitats and can harbour a high diversity of terrestrial invertebrate species. These habitats are prone to invasion by non-native plant species which can use riparian systems as corridors for spread. Fallopia japonica (Polygonaceae) and Impatiens glandulifera (Balsaminaceae) are both on the EPPO List of Invasive Alien Plants and are two species which are associated with riparian systems in the EPPO region. To evaluate the impact of these two invasive plant species, terrestrial invertebrates were sampled next to small narrow rivers in southern Scotland (United Kingdom). For each river, control sites (uninvaded) were located upstream from a pair of invaded sites containing either I. glandulifera or F. japonica. Invertebrates were collected at each site using 12 pitfall traps in June and August 2016 and total invertebrate abundance was recorded for each site at each sampling date along with diversity measurements based on morphospecies identification. Land-use was recorded at each site along with soil properties, percentage cover of the alien plant species and overall plant species richness. The results showed that with a greater percentage cover of either F. japonica or I. glandulifera invertebrate abundance and morphospecies diversity was lower, and that the two invasive plants affected abundance and morphospecies diversity more than environmental conditions. The results support managing invasive plant species along rivers to restore terrestrial diversity.
Sources
Seeney A, Eastwood S, Pattison Z, Willby NJ, Bull CD (2019) All change at the water’s edge: invasivion by non-native riparian plants negatively impacts terrestrial invertebrates. Biological Invasions. https://doi.org/10.1007/s10530-019-01947-5.