Bengtsson, Jan
- Department of Ecology, Swedish University of Agricultural Sciences
Research article2015Peer reviewedOpen access
Leinaas, Hans Petter; Bengtsson, Jan; Janion, Charlene; Chown, Steven L.
Biological invasions are major threats to biodiversity, with impacts that may be compounded by other forms of environmental change. Observations of high density of the invasive springtail (Collembola), Hypogastrura manubrialis in heavily grazed renosterveld vegetation in the Western Cape, South Africa, raised the question of whether the invasion was favored by changes in plant litter quality associated with habitat disturbance in this vegetation type. To examine the likely mechanisms underlying the high abundance of H.manubrialis, cages with three types of naturally occurring litter with different nutrient content were placed out in the area and collected after different periods of time. Hypogastrura manubrialis was mainly found in the nutrient-rich litter of the yellowbush (Galenia africana), which responds positively to disturbance in the form of overgrazing. This suggests that invasion may have been facilitated by a positive interaction with this grazing resistant plant. By contrast, indigenous Collembola were least abundant in yellowbush litter. Negative correlations between high abundance of H.manubrialis and the abundance and diversity of other species suggest that competitive interactions might underlie low abundance of these other species at the patch level. Group behavior enables H.manubrialis to utilize efficiently this ephemeral, high quality resource, and might improve its competitive ability. The results suggest that interactions among environmental change drivers may lead to unforeseen invasion effects. H.manubrialis is not likely to be very successful in un-grazed renosterveld, but in combination with grazing, favoring the nutrient-rich yellowbush, it may become highly invasive. Field manipulations are required to fully verify these conclusions.
Facilitation; nonadditive effects; renosterveld; resource patchiness; South Africa
Ecology and Evolution
2015, Volume: 5, number: 16, pages: 3462-3471
Publisher: WILEY-BLACKWELL
SDG15 Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss
Ecology
DOI: https://doi.org/10.1002/ece3.1483
https://res.slu.se/id/publ/69467