Abstract

To understand how the environment drives spatial variation in population dynamics, we need to assess the effects of a large number of potential drivers on vital rates (survival, growth, and reproduction) and explore these relationships over large geographical areas and broad environmental gradients. In this study, we examined the effects of a wide variety of abiotic and biotic environmental factors on the demography of the forest understory herb Actaea spicata between 2017 and 2019 at 40 sites across Sweden, including the northern range margin of its distribution. We assessed the effects of potential environmental drivers on vital rates using generalized linear mixed models (GLMMs) and then quantified the impact of each important driver on population growth rate (lambda) using integral projection models (IPMs). Population dynamics of A. spicata were mostly driven by environmental factors affecting survival and growth, such as air humidity, soil depth, and forest tree species composition, and thus, those drivers jointly determined the realized niche of the species. Soil pH had a strong effect on the flowering probability, while the effect on lambda was relatively small. In addition to identifying specific drivers for A. spicata's population dynamics, our study illustrates the impact that spatial variation in environmental conditions can have on lambda. Assessing the effects of a broad range of potential drivers, as done in this study, is important not only to quantify the relative importance of different drivers for population dynamics but also to understand species distributions and abundance patterns.

Keywords

environmental drivers; integral projection model; perennial herb; plant demography; population dynamics; population growth rate; spatial variation

Published in

Ecosphere
2021, Volume: 12, number: 1, article number: e03356
Publisher: WILEY

SLU Authors

• Merinero, Sonia

  • Department of Ecology, Swedish University of Agricultural Sciences
    
  • Stockholm University

UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1002/ecs2.3356

Permanent link to this page (URI)

https://res.slu.se/id/publ/110895