Non‐target impacts of weed control on birds, mammals, and reptiles

David B Lindenmayer,Jane A Catford,Richard J Hobbs,Jeff Wood,Christopher Macgregor

doi:10.1002/ecs2.1804

David B Lindenmayer, Jane A Catford + Show 3 more

Open Access

https://doi.org/10.1002/ecs2.1804

Copy DOI

Abstract

AbstractThe impacts of invasive plant control on native animals are rarely evaluated. Using data from an eight‐year study in southeastern Australia, we quantified the effects on native bird, mammal, and reptile species of (1) the abundance of the invasive Bitou Bush, Chrysanthemoides monilifera ssp. rotundata, and (2) a Bitou Bush control program, which involved repeated herbicide spraying interspersed with prescribed burning. We found that overall species richness of birds, mammals, and reptiles and the majority of individual vertebrate species were unresponsive to Bitou Bush cover and the number of plants. Two species including the nationally endangered Eastern Bristlebird (Dasyurus brachypterus) responded positively to measures of native vegetation cover following the control of Bitou Bush. Analyses of the effects of different components of the treatment protocol employed to control Bitou Bush revealed (1) no negative effects of spraying on vertebrate species richness; (2) negative effects of spraying on only one individual species (Scarlet Honeyeater); and (3) lower bird species richness but higher reptile species richness after fire. The occupancy of most individual vertebrates species was unaffected by burning; four species responded negatively and one positively to fire. Our study indicated that actions to remove Bitou Bush generally have few negative impacts on native vertebrates. We therefore suggest that controlling this highly invasive exotic plant species has only very limited negative impacts on vertebrate biota.

Highlights

Invasive plants are a major threat to biodiversity worldwide (Sala et al 2000), and there is considerable annual expenditure on their control (e.g., McNeely et al 2003, Simberloff 2013)
Using data from an eight-year study in southeastern Australia, we quantified the effects on native bird, mammal, and reptile species of (1) the abundance of the invasive Bitou Bush, Chrysanthemoides monilifera ssp. rotundata, and (2) a Bitou Bush control program, which involved repeated herbicide spraying interspersed with prescribed burning
We found that overall species richness of birds, mammals, and reptiles and the majority of individual vertebrate species were unresponsive to Bitou Bush cover and the number of plants

Summary

Introduction

Invasive plants are a major threat to biodiversity worldwide (Sala et al 2000), and there is considerable annual expenditure on their control (e.g., McNeely et al 2003, Simberloff 2013). In the USA, environmental impacts of alien species are estimated to cost approximately US$120 billion per year (Pimentel et al 2005). Was spent directly on controlling invasive alien plants in 2004, the annual economic costs of such plants was estimated to be AUD 3.5–4.5 billion (Sinden et al 2004). Despite a desire for vegetation dominated by native plants, there are often complex issues associated with alien species control, including the cost vs efficacy of control (Lindenmayer et al 2015b) and non-target impacts on other species. The effects of the weed control procedure itself can directly harm native species (Matarczyk et al 2002, Crone et al 2009, Firn et al 2010), such as herbicide impacts on pollinators (e.g., herbicide effects on pollinators; Potts et al 2010)

Methods

Results

Discussion

Conclusion