Arctic herbivory current knowledge and future directions

AARHUS INSTITUTE OF ADVANCED STUDIES Toke Thomas Høye ABA Congress, Trondheim AU AARHUS UNIVERSITY Senior Researcher 04 December 2014 Why study Arctic insect herbivory?

Aarhus University Toke Thomas Høye ABA Congress, Trondheim AU Senior Researcher 04 December 2014 Why study insect herbivory?

 Spatio-temporal dynamics of herbivory  Latitudinal, altitudinal and within-canopy gradients in levels of herbivory  Outbreak dynamics  Vegetation responses  Vegetation regime shifts  Plant physiological responses  Effects on shrub expansion rates  Forestry in the boreal zone  Herbivore and natural enemy dynamics  Population regulation  Parasitoid, generalist predators and pathogenetic fungi AU Aarhus University Toke Thomas Høye ABA Congress, Trondheim  Broader ecosystem effectsSenior Researcher 04 December 2014  Knock-on effects on e.g. insectivorous birds and saproxylic beetles  Interactions with climate, avian and mammalian herbivores A Latitudinal gradient in herbivory? Moles et al. (2011)Moles al. et Functional

Ecology

Aarhus University Toke Thomas Høye ABA Congress, Trondheim AU Senior Researcher 04 December 2014 What about insect herbivory?

B. pubescens Kozlov (2008) B. pendula Climatic Change

Aarhus University Toke Thomas Høye ABA Congress, Trondheim AU Senior Researcher 04 December 2014 Outbreak dynamics and spatial synchrony in sweden Alpine Research Alpine Young (2014) al. et Arctic , , Antarctic and and

Aarhus University Toke Thomas Høye ABA Congress, Trondheim AU Senior Researcher 04 December 2014 (2011) Global Change ( al. et Jepsen Climate change and Range expansions of geometrid  Winter moving northwards 2008) Journal of

aurantiaria expanding Biology from southern to northern Norway Eclogy ; Jepsen et al. al. et Jepsen ;

Aarhus University Toke Thomas Høye ABA Congress, Trondheim AU Senior Researcher 04 December 2014 Spatial variation in herbivorySouth facing North facing Betula pubescens 0.5 m Tenow 1.5 - 2m (1990) Meddelelser om Gr (1990) Meddelelser

Salix glauca ø nland

Aarhus University Toke Thomas Høye ABA Congress, Trondheim AU Senior Researcher 04 December 2014

Percentage of grazed shoots Regional variation in insect outbreaks

 Well documented in Fennoscandia

 Reports on planted Pinus Halldorsson sylvestris in Iceland  Recent reports of occulta

outbreaks reported in West al. et Greenland in 2004/5 & 2010/11, sporadic older reports. SCI. (2013) AGRIC. ICEL.  Spruce budworm in Canada and recently in Alaska  Sporadic accounts from taiga areas in Russia

Aarhus University Toke Thomas Høye ABA Congress, Trondheim AU Senior Researcher 04 December 2014 press vs pulse insect herbivory  Functional feeding groups

 Galling (e.g. eriophyoid 1981-2000 (2008) al. et Wolf mites)  Sap feeding (e.g aphids)  Leaf-mining  Seed/flower predation

 Leaf defoliation (e.g. Climatic moth larvae) 2071-2090 Change

Aarhus University Toke Thomas Høye ABA Congress, Trondheim AU Senior Researcher 04 December 2014 Vegetation regime shifts Karlsen et al. (2013) al. et Karlsen Oecologia

Aarhus University Toke Thomas Høye ABA Congress, Trondheim AU Senior Researcher 04 December 2014 Interaction with mammalian (2013) al. et (2004) al. et Journal of Herder Applied Den herbivores

 Pikas forage predominantly Biology

in areas Letters affected by invertebrate herbivores  Mammalian herbivores

reduce Ecology invertebrate herbivores (leaf Barrio, beetles and

AUgall-inducingAarhus University Toke Thomas Høye ABA Congress, Trondheim saw flies (den Senior Researcher 04 December 2014 Herder et al. 2004) Future directions

 Spatio-temporal dynamics of herbivory  Extend Fennoscandian ‘outbreak’ studies to other regions (e.g. Greenland)  Establish ‘early warning’ system to allow mapping of spatial extent of outbreaks in new regions  Establish hubs for integrated insect herbivory research (e.g. the herbivory network)  Vegetation responses  Integration of insect herbivory into plant monitoring programs (e.g. for assessments of shrub expansion rates)  Herbivore and natural enemy dynamics  Standard trapping/collection protocols for (e.g. for future DNA-based identification) AU Aarhus University Toke Thomas Høye ABA Congress, Trondheim  Broader ecosystem effectsSenior Researcher 04 December 2014  Exclosures to study interaction with other herbivore groups AU Aarhus University Toke Thomas Høye ABA Congress, Trondheim ThanksSenior for Researcher your04 December attention 2014