Why non-native grasses pose an existential threat to biodiversity conservation and connectivity in multiple-use landscapes

Author:

Godfree, Bob; Firn, Jennifer; Knerr, Nunzio; Stol, Jacqui; Doerr, Veronica

Date of Publication:

2017-05-01

Publication Type:

Journal Article

Journal Title:

Landscape Ecology

Volume:

32

Pages:

1219

Abstract:

Aim There is mounting evidence that a small number of non-native grasses (NNGs) transcend normal spatio-ecological limits and threaten conservation initiatives that seek to generate or protect functional, biodiverse production landscapes. The aim of this paper is to identify the ecological and social mechanisms through which NNGs transform these systems and to consider the broader implications for the future of conservation and connectivity in multiple-use landscapes (MPLs). Location Global multiple use production landscapes, especially pastures and rangelands. Methods We first develop a conceptual model that defines MPLs as comprising four key land use elements (conservation, multi-value, agricultural and degraded) that differ in conservation and agro-economic value. We then use the available literature and a set of core value drivers to determine the impact of eight key Australian perennial NNGs on the socio-ecological trajectories of these land use types and on MPLs in general. Results Despite being a heterogeneous group, all eight NNGs drive landscapes through either what we term ‘co-degrading’ or ‘tradeoff’ transformations. The former are characterised by a joint state of biodiversity and agricultural impoverishment, while tradeoff transformations involve agro-economic gain at the expense of conservation value. Critically, however, both represent a significant shift away from ideal MPLs that contain enhanced biodiversity value and functional connectivity. We also demonstrate that, in Australia, all current and planned major landscape conservation and corridor initiatives contain at least one intractable, landscape-transforming NNG. Similar situations are emerging globally. Main Conclusion Given the rapidly growing focus on landscape-scale planning as central to biodiversity conservation, we argue that there is an urgent need for robust, ecological and policy-level solutions to the management of non-native grasses that have the capacity to transform multiple-use landscapes. So far, these remain elusive.

Publisher:

Springer

Keywords:

Connectivity, fragmentation, invasive grasses, landscape-scale conservation, tradeoff, transformation

Field Of Research:

Ecology not elsewhere classified; Population Ecology

DOI:

https://doi.org/10.1007/s10980-017-0516-9

Funding Sources:

Funding Body Name	Project/Grant ID
Australia. Department of the Environment	LSP-944101-899

Identifier:

EP154830

Publication Sub Type:

Journal article - Refereed

Language:

English

Attribution Statement:

Godfree, Bob; Firn, Jennifer; Knerr, Nunzio; Stol, Jacqui; Doerr, Veronica. Why non-native grasses pose an existential threat to biodiversity conservation and connectivity in multiple-use landscapes. Landscape Ecology. 2017; 32:1219. https://doi.org/10.1007/s10980-017-0516-9