Comparisons of photosynthesis‐related traits of 27 abundant or subordinate bryophyte species in a subalpine old‐growth fir forest

Abstract

Bryophyte communities can exhibit similar structural and taxonomic diversity as vascular plant communities, just at a smaller scale. Whether the physiological diversity can be similarly diverse, and whether it can explain local abundance patterns is unknown, due to a lack of community‐wide studies of physiological traits. This study re‐analyzed data on photosynthesis‐related traits (including the nitrogen, phosphorus and chlorophyll concentrations, photosynthetic capacities, and photosynthetic nutrient use efficiencies) of 27 bryophyte species in a subalpine old‐growth fir forest on the eastern Tibetan Plateau. We explored differences between taxonomic groups and hypothesized that the most abundant bryophyte species had physiological advantages relative to other subdominant species. Principal component analysis (PCA) was used to summarize the differences among species and trait values of the most abundant and other co‐occurring subdominant species. Species from the Polytrichaceae were separated out on both PCA axes, indicating their high chlorophyll concentrations and photosynthetic capacities (axis 1) and relatively high‐light requirements (axis 2). Mniaceae species also had relatively high photosynthetic capacities, but their light saturation points were low. In contrast, Racomitrium joseph‐hookeri and Lepidozia reptans, two species with a high shoot mass per area, had high‐light requirements and low nutrient and chlorophyll concentrations and photosynthetic capacities. The nutrient concentrations, photosynthetic capacities, and photosynthetic nutrient use efficiencies of the most abundant bryophyte species did not differ from co‐occurring subdominant species. Our research confirms the links between the photosynthesis‐related traits and adaptation strategies of bryophytes. However, species relative abundance was not related to these traits.

A combination of morphological and photosynthetic functional traits maintains the vertical distribution of bryophytes in a subtropical cloud forest

“…Photosynthetic capacity and light adaptability were greater in P. inflexum , indicating its high irradiance tolerance due to its dense turf life‐form, thicker cell wall, and surface‐wax layers that reduce water loss (Proctor, ). These features are reflected in the wide ecological and geographical distribution of Polytrichaceae mosses (Corradini and Clément, ) and their role as pioneer species in managed open habitats (Bao, ; Wang et al., 2017a). In contrast, the cushion life‐form species, L. juniperoideum , which is known to be well adapted to low‐light environments (Wang et al., ), had higher photosynthetic capacity and larger leaves and cells, indicating greater adaptability to shade conditions, but lower adaptability to intense irradiation conditions.…”

“…Most studies on the role of functional traits in bryophytes have focused on terricolous species (Wang et al., , Wang et al., , b; Coe et al., ) or bole epiphytic species in the understory (Song et al., ; Chen et al., ). To date, only one study has focused on functional traits of bryophytes along vertical gradients in a lowland wet forest and demonstrated correlations between photosynthetic traits and morphological traits (Waite and Sack, ).…”

Seasonal variation of secondary metabolites in nine different bryophytes

“…This is in accordance with the plant strategy theory which explicitly describes transitions between the different life strategies (During, ; Grime, ). According to results of Wang, Bader, Liu, Zhu, and Bao (), the intermediary life strategies of Polytrichum and Plagiomnium may be explained by specialized traits related to photosynthesis and growth forms.…”

Morphological and physiological traits in relation to carbon balance in a diverse clade of dryland mosses

“…Trait‐based studies on bryophytes have illustrated the diversity of morphological and physiological traits across species, clades (Kraichak, ; Waite & Sack, ; Wang, Bader, Liu, Zhu, & Bao, ; Wang, Bao, Feng, & Lin, ), sexes (Shaw & Gaughan, ; Slate, Rosenstiel, & Eppley, ), and within the diverse genus Sphagnum (Rice, Aclander, & Hanson, ). These studies have demonstrated how suites of physiological, morphological, and structural traits in bryophytes can be intercorrelated and also illustrate how variable some traits can be within and among species.…”

“…Also, certain physiological traits (i.e., light‐saturated photosynthetic rate and chlorophyll content) are often correlated with light environment (Marschall & Proctor, ; Waite & Sack, ), but, unlike vascular plants, these physiological traits are not consistently correlated with N content (Rice et al, ; Wang et al, ). To date, no trait‐based analyses have fully explored photosynthetic traits in bryophytes beyond basic light response and C assimilation (e.g., Rice et al, ; Wang et al, ). Examining characteristics of photosynthetic efficiency (e.g., using the chlorophyll fluorescence parameter F v / F m , the maximum quantum yield of photosystem II) and ecologically relevant C fixation traits (e.g., C‐balance) may uncover examples of novel physiological traits.…”