Rodent population dynamics affect seedling recruitment in alpine habitats

Abstract

Questions: How do rodents with cyclic population dynamics affect seedling recruitment in alpine habitats? Does disturbance from rodents have larger implications on seedling recruitment in some plant communities than in others?Location: Snowbeds and sheltered heaths in the low-alpine zone in areas of Børgefjell and Dovrefjell, Norway. Methods:We recorded seedling emergence, rodent activity and cover of mosses, lichens, litter and bare ground in 270 plots in snowbeds and sheltered heaths in a rodent population peak year and in the following low-density year.Results: Seedling recruitment was positively correlated with disturbances from lemmings and voles in both years. More seedlings emerged in the low-density year than in the year of the population peak. Snowbeds had higher seedling recruitment than the sheltered heaths, but both habitats were equally affected by disturbances from rodents.Conclusions: Rodent activity created gaps and increased seedling emergence in these alpine plant communities, particularly in the year after the rodent peak, both in snowbeds and sheltered heath habitats. Our study therefore suggests that regeneration patterns in alpine vegetation are tightly linked to the population cycles of lemmings and voles, which peak in density at 3-to 5-yr intervals.

Microsite conditions in retrogressive thaw slumps may facilitate increased seedling recruitment in the Alaskan Low Arctic

“…Age effects on in situ seedling counts and greenhouse germination trials demonstrate that the source of recruitment in some RTS is likely from the seedbank. Our results suggest that recent RTS can be potential hotspots of seedling recruitment and recruitment rates appear to be comparable to other types of tundra disturbance (Nystuen et al, ; Sutton et al, ).…”

“…Recruitment thus depends on seasonally short windows of suitable microsites and viable seed (Eriksson & Fröborg, 1996). The relationship of increased seedling success in Arctic tundra to disturbance and high-quality microsites has been supported in other research (Gough, 2006;Graae et al, 2011;Milbau, Shevtsova, Olser, Mooshammer, & Graae, 2013;Munier, Hermanutz, Jacobs, & Lewis, 2010;Nystuen et al, 2014;Sutton et al, 2018). Increased recruitment can lead to populations with novel combinations of genes that could help plant species adapt to rapid change (Petit, 2004).…”

“…Seedling recruitment in tundra communities is considered infrequent compared to clonal growth of established individuals (Eriksson, 1989;Rowe, 1983), due to short growing seasons and lack of suitable microsites. Disturbances such as tundra fires (Bret-Harte et al, 2013), frost boils (Sutton, Hermanutz, & Jacobs, 2018), and rodent activity (Nystuen, Evju, Rusch, Graae, & Eide, 2014) can stimulate seedling recruitment by reducing competition and altering microsites and may ultimately influence the structure of vegetation communities (Chambers, 1995).…”

Interacting effects of grazing and habitat conditions on seedling recruitment and establishment

“…Grazing animals create gaps in sward by trampling and biomass removal (Nystuen et al. ) and by excrement deposition, which leads to an increase in the nutrient content of the stands (Malo & Suarez ). Grazing thus increases the number of suitable microsites for seed germination and subsequent seedling recruitment (e.g., Rusch ; Watt & Gibson ; Silvertown et al.…”

Patterns of multiannual changes in the spatial structure of a bank vole (Myodes glareolus) population in hornbeam-oak forest

“…Існують підстави вважати, що під час циклічних коливань чисельності популяція здійснює переходи з одного стану в інший, змінюючи свої кількісні та якісні параметри (Krebs, 2013;Nystuen et al, 2014;Bian et al, 2015;Fauteux et al, 2015). Просторова структура також зазнає пульсуючих перетворень, у процесі яких відбувається стиснення та розширення простору, що використовується для забезпечення існування популяції (Mezhzherin and Semenjuk, 2001).…”