Multiple stressors on biotic interactions: how climate change and alien species interact to affect pollination

Abstract

Global change may substantially affect biodiversity and ecosystem functioning but little is known about its effects on essential biotic interactions. Since different environmental drivers rarely act in isolation it is important to consider interactive effects. Here, we focus on how two key drivers of anthropogenic environmental change, climate change and the introduction of alien species, affect plant-pollinator interactions. Based on a literature survey we identify climatically sensitive aspects of species interactions, assess potential effects of climate change on these mechanisms, and derive hypotheses that may form the basis of future research. We find that both climate change and alien species will ultimately lead to the creation of novel communities. In these communities certain interactions may no longer occur while there will also be potential for the emergence of new relationships. Alien species can both partly compensate for the often negative effects of climate change but also amplify them in some cases. Since potential positive effects are often restricted to generalist interactions among species, climate change and alien species in combination can result in significant threats to more specialist interactions involving native species.

Global pollinator declines: trends, impacts and drivers

“…In this case alien plants can buffer against potential shortages in nectar (and pollen) supply under environmental change [41]. For instance, the alien plant Impatiens glandulifera facilitated the survival of native bumblebees when native nectar sources were scarce [22].…”

“…Interactive, non-additive effects, where one sub-lethal driver increases the severity of another driver, can help explain ongoing declines in wild and managed pollinators (Box 3; [17,31,40]). However, while awareness of the importance of interacting drivers is increasing [32], most studies have analysed the impacts of specific drivers in isolation, and therefore evidence of interactive effects is scant (but see [41]). Among the most important drivers are land-use change with the consequent loss and fragmentation of habitats [15,21,42,43]; increasing pesticide application and environmental pollution [44,45]; decreased resource diversity [18]; alien species [46,47]; the spread of pathogens [48,49]; and climate change [50,51].…”

“…Infection of colonies by multiple pathogens, and the resultant interactions between pathogens and other environmental stressors, is proposed as one of the reasons for the recently observed honeybee colony collapse disorder [48,80,81], a phenomenon which the authors expect new studies to support. Climate change can affect the spread and virulence of pests and pathogens [31,41], whereas other factors such as land-use change, pesticide load, or decreased resource availability might increase bee susceptibility to pests and pathogens or vice versa (see Box 3).…”

Biodiversität

“…Generalisten mit einer breiteren Klimanische und einem größeren Potenzial zu Interaktionen werden seltener relevante Interaktionen verlieren (a, b), wohingegen Spezialisten mit enger Nische und geringem Potenzial zu Interaktionen diese ganz verlieren können (c, d). (Verändert nach Schweiger et al 2010Schweiger et al , 2013 Anpassungen an den Klimawandel können Invasionen begünstigen. Hierzu zählt besonders der Anbau von fremdländi-schen Energiepflanzen, z.…”

Protecting an Ecosystem Service

“…suggest that a combination of stressors may be sufficient to trigger failure of social bee 359 colonies (Bryden et al, 2013;Perry et al, 2015), yet empirical studies looking at interactive 360 effects are typically limited to two (or few) factors (Baron et al, 2014;Becher et al, 2013;361 Doublet et al, 2015;Fauser-Misslin et al, 2014;Gill et al, 2012;Gonzalez-Varo et al, 2013;362 Hoover et al, 2012;Kennedy et al, 2013;Kleijn and van Langevelde, 2006;Oliver et al, 363 2012;Pettis et al, 2013;Schweiger et al, 2010;Vanbergen et al, 2013). Land-use change 364 and management is seen as one of the leading drivers of insect pollinator declines (Garibaldi 365 et al, 2014;Ollerton et al, 2014;Vanbergen, 2014).…”