Region versus site variation in the population dynamics of three short‐lived perennials

Abstract

Summary1. When range shifts or invasions of plant species are studied, it is important to know whether large-scale spatial variation in a species' demography can be ignored or approximated by variation observed over smaller spatial scales. 2. Here, we studied the population dynamics of three similar (as shown by elasticity analysis) shortlived perennial plant species in multiple sites in different European countries over 2 years. We constructed a total of 40 transition matrices and analysed the spatio-temporal variation in the projected population growth rate (k) with spatially nested life table response experiments (LTRE). 3. All species (Carlina vulgaris, Tragopogon pratensis and Hypochaeris radicata) showed considerable life-history variation among regions on top of variation among sites within regions. 4. Net variance contributions (NVC), a novel LTRE statistic, revealed that in each species, variation in one group of vital rates contributed most to variation in k among regions as well as among sites. However, that most important type of vital rates differed between species: plant growth in C. vulgaris, flower head production in T. pratensis and establishment probability of seedlings in H. radicata. The rankings of the NVCs of other vital rates varied between site and region effects, suggesting that buffering through negative vital rate correlations varies over different spatial scales, while the identity of the main contributor to k variation is more constant. 5. Temporal effects were smaller than spatial effects, but the LTREs showed strong interactions between time and space (region or site), suggesting that the effect of, e.g. climate fluctuations are not synchronized throughout the distribution of a species. 6. Synthesis. This study shows that the life histories of plant species are distinguishable even when mean elasticity values show only small differences, and that life histories vary over the distribution range of a species. Demographic differences over large spatial scales can therefore only be partly substituted by small scale spatial variation in modelling studies on the population dynamics of a species across its entire distribution.

Comparative Population Dynamics of Two Closely Related Species Differing in Ploidy Level

“…While it would be ideal to observe population dynamics after transplanting individuals between the environments [31], this is only feasible in short-lived species. Thus, most studies exploring plant population dynamics in different environments indeed work with local populations only (e.g., [34], [35], [36], [37], [15], [39], [40], [41], [42], [43]). …”

“…As for different ploidy levels, many studies have compared single life history traits between populations from different habitats (e.g., [32], [33]). Recently, various authors started to compare the whole life cycle of populations of the same species occurring in different habitat types (e.g., [34], [35], [36], [37], [38], [15], [39], [40], [41], [42], [43]). …”

Small‐scale spatial and temporal variation in the demographic processes underlying the large‐scale decline of eiders in the Baltic Sea

“…However, with the advent of sophisticated demographic methods to compare and partition the Electronic supplementary material The online version of this article (doi:10.1007/s10144-015-0517-y) contains supplementary material, which is available to authorized users. contributions of demographic processes to differences in local population dynamics (e.g., life table response experiment analyses ;Caswell 2001), it is possible to better incorporate such spatial heterogeneity into conservation schemes (Cowlishaw et al 2009;Jongejans et al 2010). Stochastic demographic analyses further increase realism, enabling the inclusion of temporally variable vital rates in projections of population dynamics (e.g., Wilson et al 2012).…”

Explaining variability in the production of seed and allergenic pollen by invasive Ambrosia artemisiifolia across Europe

“…Different environmental factors may act at different spatial scales (Jongejans et al 2010), and assessing the relative importance of these scales will inform whether general management strategies are applicable or if a case-by-case approach is needed (Pauchard and Shea 2006). Invader performance is therefore ideally assessed at multiple spatial scales and in various invaded habitat types within a broad distributional range, but this has only occasionally been done (Pauchard and Shea 2006;Traveset et al 2008).…”