A reintroduced ecosystem engineer provides a germination niche for native plant species
Date
2020
Authors
Ross, Catherine
McIntyre, Sue
Barton, Philip
Evans, Maldwyn
Cunningham, Saul
Manning, Adrian
Journal Title
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Volume Title
Publisher
Springer Verlag
Abstract
Grasslands and grassy woodlands worldwide have experienced declines in extent and condition, with substantial changes to their ground-layer biodiversity. In Australia, this decline
has coincided with the extinction of many digging mammals that may have once created
regeneration niches for native ground layer plants. These digging mammals are widely
recognised as ‘ecosystem engineers’, due to their infuence on biopedturbation and resultant soil functions. Yet there is uncertainty as to the benefts of digging in restoring grassland diversity with current levels of modifcation and the presence of exotic plants. We
investigated the efect of digging by the reintroduced eastern bettong (Bettongia gaimardi) on seedling germination in a temperate grassy woodland in south-eastern Australia.
We marked fresh bettong foraging pits and undisturbed control plots in dense and open
grassland. We added seeds of seven native forb species and monitored germination and
establishment over 2 years. We found signifcantly more seedlings in bettong pits than controls, particularly in dense grassland. This efect persisted beyond 1 year, suggesting that
pits may have increased seedling survival in dry conditions. Surprisingly, native species
displayed a stronger positive response to pits than exotic species, particularly in a wet year.
There was an initial reduction in exotic species, but this was followed by their increase in
1-year-old pits, suggesting that the disturbance created by digging could eventually lead
to an increase in weed abundance. Our results demonstrate that while bettong pits provide
a germination niche for native forbs, reintroducing digging animals will not necessarily
result in the desired restoration outcomes. Ongoing persistence of exotic species is to be
expected, and seed addition may be required for species that are seed-limited.
Description
Keywords
Bettongia gaimardi, Eastern bettong, Digging, Disturbance, Grassland, Grassy woodland, Restoration
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Source
Biodiversity and Conservation
Type
Journal article
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Restricted until
2099-12-31
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