Temporal variation and its drivers in the elemental traits of four boreal plant species

Abstract

Aims Intraspecific variation in plant traits has important consequences for individual fitness and herbivore foraging. For plants, trait variability across spatial dimensions is well documented. However, temporal dimensions of trait variability are less well known, and may be influenced by seasonal differences in growing degree days, temperature, and precipitation. Here, we aim to quantify intraspecific temporal variation in traits and the underlying drivers for four commonly occurring boreal plant species. Methods We sampled the elemental and stoichiometric traits (%C, %N, %P, C:N, C:P, N:P) of four common browse species’ foliage across two years. Using a two-step approach, we first fitted generalized linear models (GzLM, n = 24) to the species’ elemental and stoichiometric traits, and tested if they varied across years. When we observed evidence for temporal variability, we fitted a second set of GzLMs (n = 8) with temperature, productivity, and moisture as explanatory variables. Important Findings We found no evidence of temporal variation for most of the elemental and stoichiometric traits of our four boreal plants, with two exceptions. Year was an important predictor for percent carbon across all four species (R 2 = 0.47 to 0.67) and for multiple elemental and stoichiometric traits in balsam fir (5/8, R 2 = 0.29 to 0.67). Thus, variation in percent carbon was related to interannual differences, more so than nitrogen and phosphorus, which are limiting nutrients in the boreal forest. These results also indicate that year may explain more variation in conifers’ stoichiometry than for deciduous plants due to life history differences. Growing degree days (GDD) was the most frequently occurring variable in the second round of models (8/8 times, R 2 = 0.21 to 0.41), suggesting that temperature is an important driver of temporal variation in these traits.

Ecoregion and community structure influences on the foliar elemental niche of balsam fir (Abies balsamea (L.) Mill.) and white birch (Betula papyrifera Marshall)

“…Thus, we are unable to rely on PERMANOVA results (see Appendix S8 : Figure S6 for PCA; Appendix S9 : Figure S7 for spherical niche hypervolumes; Appendix S10 : Figure S8 for scatter plot kernel density comparisons; and Appendices S11–S13 : Table S3–S5 for niche hypervolume sample size, statistical summary, and PERMANOVA results, respectively). Overall, given our temporal comparisons, we suspect the effect observed in this study is likely due to biogeographical differences (for temporal comparisons of foliar stoichiometric traits see Richmond et al, 2021 ).…”

“…First, although we collected data/foliar samples in a similar way between these two projects, there are differences in terms of the spatial distribution of sample plots that may have influenced the spatial autocorrelation of samples and thus our interpretation of the findings. However, the two projects do target similar forest units: coniferous, deciduous, and mixedwood for- due to biogeographical differences (for temporal comparisons of foliar stoichiometric traits see Richmond et al, 2021).…”

Spatiotemporal variations in the growth status of declining wild apple trees in a narrow valley in the western Tianshan Mountains, China

“…S3 and S5). Elevational variations in the growth vigor and leaf traits of declining wild apple trees in different years are apparently related to the interannual difference in meteorological factors (Wang and Wang, 2015;Du et al, 2021;Richmond et al, 2021).…”

“…Soil variables are correlated to plant nutrients at different elevations, but the interpretation of soils to variations in plant physiological traits is usually lower than that of temperature and precipitation (Gong et al, 2020). In addition to elevation, plant traits in natural ecosystems usually exhibit obvious interannual variation, which is mainly related to the interannual fluctuation of climate (e.g., precipitation, air temperature, and sunshine hours (Pérez-Camacho et al, 2012;Du et al, 2021;Richmond et al, 2021), and different plant species and various plant traits are likely to present differential interannual variation patterns (Mendes et al, 2014). Climatic characteristics and vegetation composition generally differ among regions, so the elevational and interannual variation patterns of plant traits are inconsistent to a large extent, and the influencing factors are complex and diverse.…”