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Summary Evolutionary history plays a key role driving patterns of trait variation across plant species. For scaling and modeling purposes, grass species are typically organized into C3vs C4plant functional types (PFTs). Plant functional type groupings may obscure important functional differences among species. Rather, grouping grasses by evolutionary lineage may better represent grass functional diversity.We measured 11 structural and physiological traitsin situfrom 75 grass species within the North American tallgrass prairie. We tested whether traits differed significantly among photosynthetic pathways or lineages (tribe) in annual and perennial grass species.Critically, we found evidence that grass traits varied among lineages, including independent origins of C4photosynthesis. Using a rigorous model selection approach, tribe was included in the top models for five of nine traits for perennial species. Tribes were separable in a multivariate and phylogenetically controlled analysis of traits, owing to coordination of important structural and ecophysiological characteristics.Our findings suggest grouping grass species by photosynthetic pathway overlooks variation in several functional traits, particularly for C4species. These results indicate that further assessment of lineage‐based differences at other sites and across other grass species distributions may improve representation of C4species in trait comparison analyses and modeling investigations.
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Morphological and physiological traits in relation to carbon balance in a diverse clade of dryland mosses
Abstract Plant functional trait analyses have focused almost exclusively on vascular plants, but bryophytes comprise ancient and diverse plant lineages that have widespread global distributions and important ecological functions in terrestrial ecosystems. We examined a diverse clade of dryland mosses,Syntrichia, and studied carbon balance during a precipitation event (C‐balance), a functional trait related to physiological functioning, desiccation tolerance, survival, and ecosystem carbon and nitrogen cycling. We examined variability in C‐balance among 14 genotypes ofSyntrichiaand measured an additional 10 physiological and 13 morphological traits at the cell, leaf, shoot, and clump level. C‐balance varied 20‐fold among genotypes, and highest C‐balances were associated with long, narrow leaves with awns, and small cells with thick cell walls, traits that may influence water uptake and retention during a precipitation event. Ordination analyses revealed that the axis most strongly correlated with C‐balance included the maximum chlorophyll fluorescence,Fm, indicating the importance of photosystem II health for C exchange. C‐balance represents a key functional trait in bryophytes, but its measurement is time intensive and not feasible to measure on large scales. We propose two models (using physiological and morphological traits) to predict C‐balance, whereby identifying simpler to measure traits for trait databases.
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- PAR ID:
- 10455513
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Plant, Cell & Environment
- Volume:
- 42
- Issue:
- 11
- ISSN:
- 0140-7791
- Page Range / eLocation ID:
- p. 3140-3151
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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