Data from: Dispersal barriers and climate determine the geographic distribution of the helicopter damselfly Mecistogaster modesta

This habitat specialist spends its larval development exclusively in tank bromeliads, where it acts as a keystone predator within the aquatic food web. Although tank-forming bromeliads occur from the southern United States throughout most of South America, M. modesta is absent from the Caribbean islands and South America south-east of the Andes mountain chain. We employed species distribution models to explore the relative importance of physical barriers (Andes mountain range and oceanic barriers), climate (mean annual temperature and annual precipitation) and biotic interactions (competition from other bromeliad-dwelling odonates) in limiting the geographic distribution of M. modesta.

We found that dispersal barriers strongly limit the geographic distribution of M. modesta. In addition, its range is restricted by low temperatures and low precipitation. Competition from other bromeliad-dwelling odonates was not important in limiting the damselfly's range.

Because of the physical barriers to dispersal, M. modesta does not occupy its full potential geographic range. Specifically, our model predicted suitable habitat on the Caribbean islands and throughout most of South America, where the species is currently absent. These findings have important conservation implications, particularly as the aridification of rainforests and subsequent localised extinctions due to climate change continue.

On the other hand, the species may respond to warming temperatures by tracking climate to higher elevations, with subsequent effects on naïve high-elevation bromeliad food webs. An upwards migration could also increase the probability of M. modesta overcoming the dispersal barrier presented by the Andes, enabling the damselfly to invade large areas of suitable habitat in South America.

Usage notes

Mmodesta_records_FWB This file contains a comma-delimited dataset of M. modesta presence and absence records, as well as the physical, climatic, and biotic predictor layers used to model the geographic distribution of M. modesta. In addition, it includes information on the data source and the current land cover. Mmodesta_FB.csv Mmodesta_records_FWB_variables This comma-delimited file contains metadata regarding all the variables in "Mmodesta_records_FWB".

Mmodesta_FB_variables.csv