Nutrients control reproductive traits of hygrophytic bryophytes

Abstract

Nutrient economy and plant nutrient concentrations have been suggested as important selective pressures of reproductive traits in vascular plants. However, evidence supporting that the reproduction of bryophytes and their reproductive traits have also been conditioned by nutrient availability is lacking. We here analysed the nutrient (N, P, K, and Fe) concentration of 35 aquatic and semi‐aquatic bryophytes and the chemistry of the spring water in which they lived to determine whether bryophyte nutrient concentrations were correlated with the frequency of sexual reproduction, main reproductive mode (sexual vs. asexual), dioicy, and spore diameter, while controlling for climate and nutrient concentrations in the spring water. Water nutrient concentrations, except for K, had a small but positive influence on bryophyte nutrient concentrations. P‐rich and K‐poor species produced sporophytes more often and were more likely to reproduce sexually and be monoicous. Spore diameter was smaller in P‐ and Fe‐rich mosses but larger in N‐rich mosses living in humid climates. P‐rich species thus produced more and smaller spores and were able to propagate more extensively. Overall, our results suggest that nutrient economy, especially P economy, has played an important role in shaping the reproductive traits of bryophytes.

Tree species with conservative foliar nutrient status and strong phosphorus homeostasis are regionally abundant in subtropical forests

“…By contrast, it is not necessary to decouple foliar N levels from soil N through N stoichiometric homeostasis for plant species when N limiting is not severe for plant growth (Sterner & Elser, 2002). In line with the biogeochemical niche hypothesis (Peñuelas et al, 2019), such distinct stoichiometric strategies of woody plants suggest that species abundance distribution is jointly determined by soil chemical filters and elemental composition related evolutionary history of species (Fernández-Martínez et al, 2021;Sardans et al, 2021).…”

Do Bryophyte Elemental Concentrations Explain Their Morphological Traits?

“…On the other hand, the elemental composition of mosses was not as strongly related to cell traits as to macroscopic traits (Figure 2), and only four elements appeared as important predictors of cell traits. These results suggest that differences in the elemental composition amongst species may be more important for whole-organism processes of moss functioning, fitness, and adaptation or evolution (e.g., overall growth rate, photosynthesis, drought tolerance, reproduction [19,31]) than for processes occurring at the cellular level. Nonetheless, cell traits were good predictors of moss macroscopic morphological traits, which actually indicates a good correspondence between cell and macroscopic traits (Figure 3).…”

“…We used previously published data in which we analysed the elemental composition of moss samples [30,31] from a large collection used in a previous study [25] for which their morphological traits were already estimated, including 29 different hygrophytic moss species. From the total collection of 100 samples with morphological traits, 80 samples had enough mass to analyse their elemental composition.…”

“…In the subset of springs used here, water pH ranged from 5.17 to 8.34 (median: 7.20) and water conductivity ranged from 24 to 2094 (median: 498) µS cm −1 . A detailed analysis of the water chemical composition can be found in the online material from references [25,30,31]. All mosses collected were in direct contact with the water of the springs throughout the year, with only occasional interruptions in water flow during winter and summer (when water freezes or during intense drought events, respectively).…”

“…Nonetheless, our results do not disregard the direct or indirect effect of abiotic factors on either the elemental composition of bryophytes or their morphological traits. Previous research has shown that water chemistry has an important impact on bryophyte elemental concentrations [9,30], and their functional and morphological traits [25,31]. Additionally, the evolutionary history of bryophytes has also been shown to be a relevant predictor of their elemental concentration and their functional traits [25,30].…”