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Aim: Understanding the mechanisms promoting resilience in plant communities is crucial in times of increasing disturbance and global environmental change. Here, we present the first meta‐analysis evaluating the relationship between functional diversity and resilience of plant communities. Specifically, we tested whether the resilience of plant communities is positively correlated with interspecific trait variation (following the niche complementarity hypothesis) and the dominance of acquisitive and small‐size species (following the mass ratio hypothesis), and for the context‐dependent effects of ecological and methodological differences across studies. Location: Global. Time Period: 2004–2021. Major Taxa Studied: Vascular plants. Methods: We compiled a dataset of 69 independent sites from 26 studies that have quantified resilience. For each site, we calculated functional diversity indices based on the floristic composition and functional traits of the plant community (obtained from the TRY database) which we correlated with resilience of biomass and floristic composition. After transforming correlation coefficients to Fisher's Z‐scores, we conducted a hierarchical meta‐analysis, using a multilevel random‐effects model that accounted for the non‐independence of multiple effect sizes and the effects of ecological and methodological moderators. Results: In general, we found no positive functional diversity–resilience relationships of grand mean effect sizes. In contrast to our expectations, we encountered a negative relationship between resilience and trait variety, especially in woody ecosystems, whereas there was a positive relationship between resilience and the dominance of acquisitive species in herbaceous ecosystems. Finally, the functional diversity–resilience relationships were strongly affected by both ecological (biome and disturbance properties) and methodological (temporal scale, study design and resilience metric) characteristics. Main Conclusions: We rejected our hypothesis of a general positive functional diversity–resilience relationship. In addition to strong context dependency, we propose that idiosyncratic effects of single resident species present in the communities before the disturbances and biological legacies could play major roles in the resilience of terrestrial plant communities. [ABSTRACT FROM AUTHOR]

Restoring Midwestern oak savannas and woodlands over the long term requires balancing mortality of large oaks with recruitment of oaks into large size classes. At restoration sites in northwestern Ohio, we tracked survival of large oak trees ([greater than or equal to] 20 cm in stem diameter) and recruitment between 2002 and 2015 after initial tree thinning and prescribed burning treatments. The 24 study sites spanned a gradient of canopy cover from unrestored forests to restored woodlands and savannas. Of 141 large black oak (Quercus velutina) and white oak (Quercus alba) trees alive in 2002, 79% were alive 14 y later. Large oak survival varied among vegetation types, with restored savannas not losing a single tree, compared with 18% mortality in unrestored forests and 28% mortality in restored woodlands. At least some mortality in the woodlands was associated with a tornado that damaged two sites. Diameter distributions changed over the 14 y in all three vegetation types. Unrestored forests shifted toward proportionally greater large and fewer small diameter oaks. Meanwhile, restored woodlands, despite having the highest mortality of large oaks, still exceeded, via recruitment of new large oaks, the reconstructed pre-Euro-American-settlement tree density. Restored woodlands and savannas exhibited four-fold increases in oak recruitment potential (saplings 1 to 10 cm in diameter) between 2002 and 2015. Ecological restoration processes have been compatible with conserving large oaks and sustaining oak recruitment potential., INTRODUCTION Since the early 1900s, oak (Quercus) dominated ecosystems in eastern North America have been transitioning to dominance by other tree species (Lorimer, 1993; Abrams, 2005; Arthur et al, 2012). [...]

Two related concepts in restoration ecology include the relative interchangeability of biotic and abiotic restoration treatments for initiating recovery and bet hedging using multiple restoration approaches to increase the likelihood of favorable restoration outcomes. We used these concepts as a framework to implement a factorial experiment including biotic (outplanting greenhouse‐grown individuals of three perennial species) and abiotic treatments (constructing microtopography or vertical mulch consisting of upright, dead plant material). These treatments were designed to stimulate native plant recruitment and reverse soil degradation at four disturbed sites in the Sonoran Desert, U.S.A. The first growing season after the restoration treatments was the driest of the last 47 years, and 100% of outplants died. While the biotic treatment failed, the vertical mulch abiotic treatment increased native shrub seedling cover at the driest site and reversed soil loss across sites by increasing soil accumulation by 6× to 2 cm/year. Results revealed that (1) inexpensive, minimal‐input abiotic treatments outperformed resource‐intensive biotic treatments; (2) the restoration effort withstood the total failure of a major component (outplanting) to nevertheless achieve key restoration benefits within 2–3 growing seasons; and (3) incorporating multiple treatment types served as a bet‐hedging approach to buffer against treatment failures. Integrating minimal‐input abiotic treatments in restoration warrants consideration given their low cost and bet‐hedging potential. [ABSTRACT FROM AUTHOR]