Cyclically outbreaking geometrid moths in sub-arctic mountain birch forest: the organization and impacts of their interactions with animal communities

• Main Author: Vindstad, Ole Petter Laksforsmo
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: UiT The Arctic University of Norway 2015
• Subjects: VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480::Økologi: 488; VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ecology: 488; Arctic; Hagen; Schott; Vindstad; Fennoscandia
• Online Access: https://hdl.handle.net/10037/7004

Paper I, II and V of this thesis are not available in Munin: I. Vindstad OPL, Hagen SB, Schott T & Ims RA: ‘Spatially patterned guild structure in larval parasitoids of cyclically outbreaking winter moth populations’. Ecological Entomology 35 (4): 456-463, 2010. Available at http://dx.doi.org/10.1111/j.1365-2311.2010.01201.x II. Vindstad OPL, Hagen SB, Jepsen JU, Kapari L, Schott T & Ims RA: ‘Phenological diversity in the interactions between winter moth (Operophtera brumata) larvae and parasitoid wasps in sub-arctic mountain birch forest’. Bulletin of Entomological Research 101 (6): 705-714, 2011. Available at http://dx.doi.org/10.1017/S0007485311000277 V. Vindstad OPL, Jepsen JU & Ims RA: ‘Resistance of a sub-arctic bird community to severe forest damage caused by geometrid moth outbreaks’. (Manuscript) In sub-arctic mountain birch forest in northern Fennoscandia, the 2 geometrid moth species Epirrita autumnata (autumnal moth) and Operophtera brumata (winter moth) show high-amplitude population cycles with regular 10-year periodicity. During some population peaks, moth populations attain outbreak densities and cause region-wide defoliation and mortality of mountain birch. The severity and duration of moth outbreaks presently appears to be increasing, owing to climate-driven range-expansions of both native and novel (see below) moth species in the system. The causal mechanisms of moth population cycles have been widely studied, with research focusing on the role of parasitoids during the last decade. This research has focused on total parasitism rates and has paid little attention to parasitoid community organization and its consequences for the functionality of parasitoid communities. Study I – III of this PhD project addressed this knowledge gap for larval parasitoids, which have received more attention than other parasitoid guilds in the research on parasitism the birch-moth system. Study I explored the possibility of stochastic extinction-recolonization dynamics – induced by fluctuations in ...