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ABSTRACT Plant functional traits are vital tools in ecological restoration and biodiversity conservation. While functional traits and functional diversity are increasingly being used to inform restoration efforts, challenges remain in the characterization of trait variation in many systems, including within‐species. Likewise, understanding axes of trait variation describing trade‐offs in plant function is important for trait‐based restoration frameworks, yet the degree of coordination between above‐ground functional traits and their below‐ ground counterparts is often unknown. Here, we investigate intraspecific trait variation among five populations ofSchizachyrium scoparium(little bluestem), a species commonly used for restoration, from different habitat types across a gradient from southern Wisconsin to Northern Illinois. We asked (1) how regional populations ofS. scopariumdiffer in their functional traits, (2) how functional trait variation inS. scopariumis structured among and within populations, and (3) how above‐ and below‐ground functional traits ofS. scopariumcoordinate and describe axes of functional trade‐offs. We found that populations differed in multivariate trait space, but evidence for differences in individual traits among populations was mixed. Trait relationships with habitat types were idiosyncratic and often misaligned with expectations of plant economic spectra. Variation within populations was as high, or higher, than between populations across traits. We found evidence for weak coordination in several trait pairs, including two above‐ and below‐ground trait combinations, while others appeared to be uncoordinated. Our findings support previous research that trait differentiation can occur at multiple scales, both between and within populations. Extensive within‐population trait variability could be leveraged in trait‐based restoration frameworks targeting intraspecific functional diversity. The lack of strong signals of coordination between above‐ and below‐ground functional traits suggest that sourcing decisions meant to match below‐ground functional traits to recipient restored communities should rely on direct measurement of root traits associated with desired functions rather than above‐ground proxies.
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How woody plants adjust above‐ and below‐ground traits in response to sustained drought
Summary Future increases in drought severity and frequency are predicted to have substantial impacts on plant function and survival. However, there is considerable uncertainty concerning what drought adjustment is and whether plants can adjust to sustained drought. This review focuses on woody plants and synthesises the evidence for drought adjustment in a selection of key above‐ground and below‐ground plant traits. We assess whether evaluating the drought adjustment of single traits, or selections of traits that operate on the same plant functional axis (e.g. photosynthetic traits) is sufficient, or whether a multi‐trait approach, integrating across multiple axes, is required. We conclude that studies on drought adjustments in woody plants might overestimate the capacity for adjustment to drier environments if spatial studies along gradients are used, without complementary experimental approaches. We provide evidence that drought adjustment is common in above‐ground and below‐ground traits; however, whether this is adaptive and sufficient to respond to future droughts remains uncertain for most species. To address this uncertainty, we must move towards studying trait integration within and across multiple axes of plant function (e.g. above‐ground and below‐ground) to gain a holistic view of drought adjustments at the whole‐plant scale and how these influence plant survival.
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- Award ID(s):
- 1655499
- PAR ID:
- 10506703
- Publisher / Repository:
- Tansley Reviews
- Date Published:
- Journal Name:
- New Phytologist
- Volume:
- 239
- Issue:
- 4
- ISSN:
- 0028-646X
- Page Range / eLocation ID:
- 1173 to 1189
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1111/nph.19000
