Jacintha Ellers

Mapping the economic loss of ecosystem services caused by the invasive plant species Antigonon leptopus on the Dutch Caribbean Island of St. Eustatius

Abstract
Invasive species are a worldwide threat to biodiversity, especially on Caribbean islands.
Through their impact on the structure and functioning of ecosystems, they also affect
ecosystem services. Therefore, invasive species can have profound socio-economic
effects. On the Dutch Caribbean Island of St. Eustatius, the invasive perennial vine Coralita
is present on roughly 33% of the Island. While ecological damage is evident, effective
management strategies are still lacking. This study links the ecological, cultural and
societal effects of the invasion to the economy of the Island by estimating the ecosystem
service losses due to Coralita in monetary value. We have spatially assessed the
economic value of five main ecosystem services (tourism, non-use value, carbon
sequestration, archaeology and local cultural and recreational value) to the different
habitats on the Island and estimated the loss of these values under three scenarios of
Coralita cover: 0%, 3% and 36% dominant cover. The baseline scenario of 0%
demonstrated a total ecosystem service value of $2.7 million per year, concentrated on the Quill volcano. The 3% and 36% scenario showed a yearly loss of $39,804 and $576,704, respectively, with the largest losses located on the northern and eastern slopes of the Quill.
These areas should be prioritised for management and the known potential gain per area
enables choice of strategy, based on cost-benefit considerations. To reduce further
economic loss by Coralita, we urgently advise an immediate management strategy and
ongoing research into eradication and restoration methods.

Keywords
BES Islands, Coralita, economic value, invasive species, spatial assessment, scenario
mapping

Date
2021
Data type
Scientific article
Theme
Education and outreach
Research and monitoring
Journal
Geographic location
St. Eustatius

Disentangling the effects of plant species invasion and urban development on arthropod community composition

Abstract
Urban development and species invasion are two major global threats to biodiversity. These threats often co-occur, as developed areas are more prone to species invasion. However, few empirical studies have tested if both factors affect biodiversity in similar ways. Here we study the individual and combined effects of urban development and plant invasion on the composition of arthropod communities. We assessed 36 paired invaded and non-invaded sample plots, invaded by the plant Antigonon leptopus, with half of these pairs located in natural and the other half in developed land-use types on the Caribbean island of St. Eustatius. We used several taxonomic and functional variables to describe community composition and diversity. Our results show that both urban development and A. leptopus invasion affected community composition, albeit in different ways. Development significantly increased species richness and exponential Shannon diversity, while invasion had no effect on these variables. However, invasion significantly increased arthropod abundance and caused biotic homogenization. Specifically, uninvaded arthropod communities were distinctly different in species composition between developed and natural sites, while they became undistinguishable after A. leptopus invasion. Moreover, functional variables were significantly affected by species invasion, but not by urban development. Invaded communities had higher community-weighted mean body size and the feeding guild composition of invaded arthropod communities was characterized by the exceptional numbers of nectarivores, herbivores, and detritivores. With the exception of species richness and exponential Shannon diversity, invasion influenced four out of six response variables to a greater degree than urban development did. Hence, we can conclude that species invasion is not just a passenger of urban development but also a driver of change.

Keywords: Anthropocene, Antigonon leptopus, coralita, exotic species, feeding guilds, functional traits, land use change, multistressor effects

 

Referenced in BioNews 35 article "Drastic effects of coralita on the biodiversity of insects and spiders"

Date
2020
Data type
Scientific article
Theme
Education and outreach
Research and monitoring
Document
Geographic location
St. Eustatius