Emerging conflict between conservation programmes: when a threatened vertebrate facilitates the dispersal of exotic species in a rare plant community

Abstract

As an ever-increasing variety of conservation programmes are applied in human-altered environments, there is a growing risk that different conservation actions with conflicting objectives may impede one another. Preventing and resolving the negative impacts of such conflicting conservation programmes could become a key challenge for conservationists. To date, however, the issue of conflicting conservation programmes has been largely overlooked. We explored a potential conflict between the preservation of threatened free-ranging plains bison Bison bison bison and the conservation in a National Park of a rare plant communitynative rough fescue Festuca hallii grasslands. We investigated the dispersal of exotic seeds by examining 283 samples of bison faeces and the spatial distribution of exotic plant species in relation to bison behaviour. We showed that bison facilitated the longdistance dispersal of exotic plant species into the park by transporting seeds. Our analysis indicated there was a high probability (>75%) of occurrence of clover Trifolium spp. and timothy Phleum pratense on bison trails across 38% and 27%, respectively, of fescue grassland area. There was also a high probability of occurrence of timothy on bison wallows across 20% of fescue grasslands area. Furthermore, we demonstrated that exotic plant species were most likely to occur within 3 km of potential introduction points, and identified specific grassland patches most at risk of exotic plant species introduction by bison. By revealing the ecological mechanism underlying the emergence of a potential conflict, we were able to delineate spatial variation in the relative threat that bison might pose to the integrity of native fescue plant communities, allowing managers to optimize the allocation of conservation effort. Our study highlights the value of understanding the ecological mechanisms driving conflict between conservation programmes in order to set evidence-based priorities for guiding future conservation decision-making.

Quantitative Spatial Ecology to Promote Human-Wildlife Coexistence: A Tool for Integrated Landscape Management

“…Human-wildlife conflict generally stems from negative interactions between humans and wildlife. Conflicts can involve a range of outcomes of human-animal interactions, such as human deaths (e.g., predation, wildlife vehicle collision), disease spread, impacts on vegetation, dissemination of exotic plants into protected areas, livestock depredation, crop-raiding, and property damage (Ujvári et al, 1998;Packer et al, 2005;Ripple et al, 2014;Hadidian, 2015;Sigaud et al, 2020;Simon and Fortin, 2020). For example, from 2005-2016, 21 727 cases of crop raiding, 6,768 of livestock depredation, and 1,152 of property damage were reported in Kenya (Long et al, 2020).…”

“…For example, from 2005-2016, 21 727 cases of crop raiding, 6,768 of livestock depredation, and 1,152 of property damage were reported in Kenya (Long et al, 2020). Human-wildlife interactions can thus occur at high frequencies, with even multiple conflict types happening concurrently over a given area (Jordán and Báldi, 2013;Sigaud et al, 2020). HWC should be assessed while considering that people's degree of tolerance for wildlife can be fundamental to finding solutions to promote human coexistence with dangerous or damage-causing species (Treves and Bruskotter, 2014;Struebig et al, 2018).…”

“…For example, multiple species may be simultaneously impacted by local interventions. Monitoring is required to ensure that mitigation measures aimed at reducing a given HWC does not jeopardize other conservation or management objectives (Jordán and Báldi, 2013;Sigaud et al, 2020). Also, wildlife management is often driven by the immediate need to solve a problem (Blackwell et al, 2016), such actions may have to precede the development of a mitigation plan based on an exhaustive understanding the behaviors resulting in HWC.…”

“…This can be due, for example, to seasonal variations in animal-habitat relationships. In Canada bison typically only leave the safety of a national park (i.e., Prince Albert National Park) between mid-summer and mid-fall, when highly profitable vegetation is abundant in agricultural fields (Sigaud et al, 2017(Sigaud et al, , 2020. Wild boar (Sus scrofa) in Alta Murgia National Park, Italy, thrive on natural vegetation during much of the year, and only switch to cultivated crops during summer (Ficetola et al, 2014).…”

“…Here we propose an adaptive management framework (Walters and Hilborn, 1978;Richardson et al, 2020) that can be used to identify cost-effective solutions, while also minimizing constraints (e.g., avoid fencing off entire areas) on animal movement and distribution. We focus on conflicts involving animals for which conflict zones occupy only a portion of their home-range-a common situation for many species (e.g., Ripple et al, 2014;Soulsbury and White, 2015;Soliku and Schraml, 2018;Sigaud et al, 2020). The underlying idea is to use quantitative ecology to develop a species-specific predictive model of space-use dynamics, and then use this information to organize management actions over the landscape to divert animals away from conflict zones.…”