Biological control of invasive plant species: a reassessment for theAnthropocene

Abstract

Contents 490I.490II.491III.492IV.494V.497VI.498499References499 Summary The science of finding, testing and releasing herbivores and pathogens to control invasive plant species has achieved a level of maturity and success that argues for continued and expanded use of this program. The practice, however, remains unpopular with some conservationists, invasion biologists, and stakeholders. The ecological and economic benefits of controlling densities of problematic plant species using biological control agents can be quantified, but the risks and net benefits of biological control programs are often derived from social or cultural rather than scientific criteria. Management of invasive plants is a ‘wicked problem’, and local outcomes to wicked problems have both positive and negative consequences differentially affecting various groups of stakeholders. The program has inherent uncertainties; inserting species into communities that are experiencing directional or even transformational changes can produce multiple outcomes due to context‐specific factors that are further confounded by environmental change drivers. Despite these uncertainties, biological control could play a larger role in mitigation and adaptation strategies used to maintain biological diversity as well as contribute to human well‐being by protecting food and fiber resources.

Do Wildfires Promote Woody Species Invasion in a Fire-Adapted Ecosystem? Post-fire Resprouting of Native and Non-native Woody Plants in Central Argentina

“…Also, we did not find higher growth rates in the native species. Possibly, the presumed advantage of native species due to their adaptations for resprouting after fires was compensated by the equally good advantage of non-native species gained at their new range by having less or no specific predators, less competition, or having a climate better suited to the species than the climate at the native range (Mack et al 2000;Seastedt 2014). Supporting this explanation studies in the Chaco Serrano of the functional traits of non-native tree species have shown higher growth rates than native tree species Zeballos et al 2014).…”

Defoliation of common ragweed byOphraella communabeetle does not affect pollen allergenicity in controlled conditions

“…Plants assigned to the Ophraella treatment received a centrifuge tube near their stem before the tissue was closed, and which contained six male beetles and three unhatched egg batches each containing a minimum of 10 eggs on pieces of leaves, natural enemies from the native range are introduced to control the plant in the invaded range (Müller-Schärer & Schaffner 2008). This method has proven to be permanent, environmentally friendly and a cost-effective control of several invasive plants (Seastedt 2015). In 2013, the leaf beetle Ophraella communa LaSage (Coleoptera: Chrysomelidae), already used as a biocontrol agent of ragweed in China (Zhou et al 2011) and also effective against ragweed in Australia (Palmer et al 2010), was unexpectedly found to have established in Northwestern Italy and southern Switzerland (Boriani et al 2013;Müller-Schärer et al 2014).…”

Confronting the wicked problem of managing biological invasions

“…As the human-mediated biogeographic processes that characterize the Anthropocene continue to intensify, there is a growing recognition of wicked problems in conservation management around the world (Game et al 2014, Seastedt 2014. As anthropogenic dispersal of organisms continues to grow and conservation budgets remain constrained in a volatile global economy, the management of invasive species will increasingly require novel approaches, including heuristic assessments of the ecological risk associated with proposed interventions, and adaptive, stakeholder-conscious management through structured engagement initiatives, to enable positive outcomes for ecosystem integrity.…”

“…The term was used by Evans et al (2008), citing difficulties encountered when managing aquatic pests in the Crystal River, Florida; by McNeely (2013) when describing the management of plant introductions in conservation areas; and by Seastedt (2014) when describing the socio-political and ethical issues surrounding biocontrol. The management of biological invasions is particularly susceptible to wickedness in the form of conflicting social pressures.…”