Rachel M Mitchell

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Journals/Publications

• Mitchell, R. M. (2025). Phenotypic plasticity in six species of native and exotic Asteraceae.
• Mitchell, R. M. (2025). The spice of life: Quantifying intraspecific functional trait variation.
• Mitchell, R. M., Bakker, J. D., Vincent, J. B., & Davies, G. M. (2025). Received Date: 20-Apr-2016 Revised Date: 11-Oct-2016 Accepted Date: 02-Nov-2016 Article type.
• Klein, Z., & Mitchell, R. M. (2024). Seed source environment predicts response to water availability in Plantago patagonica. Restoration Ecology, 32(2), e14002.
• Klein, Z., & Mitchell, R. M. (2024). Seed source environment predicts response to water availability in Plantago patagonica. Restoration Ecology, 32(Issue 2). doi:10.1111/rec.14002
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  The intensity, duration, and severity of drought increasing across the American Southwest. Plant restoration efforts are often thwarted by drought-induced effects (i.e. drought-induced mortality or failure to reproduce). Careful selection of plant materials to match future environmental conditions could improve restoration success under climate change. Here, we focus on Plantago patagonica, a priority arid land restoration species in the southwestern US. Using experimental drought in a greenhouse and supplemental watering in a common garden experiment, we quantified how the seed-collection site environment influenced plant growth, performance, phenotypic plasticity, and evidence of local adaptation in 12 populations of P. patagonica. In the greenhouse, we found plants from hotter and drier environments had higher root:shoot ratios, while those from more variable precipitation regimes had greater total biomass in response to drought. Populations sourced from warmer environments exhibited sevenfold greater plasticity in root:shoot ratio compared to those from cooler environments, and there was strong evidence for local adaptation in phenology, as populations sourced from geographic locations nearer the common garden exhibited five times more flowering individuals than those sourced furthest from that garden. In the common garden, we found that plants sourced from wetter locations and those with more consistent precipitation regimes had lower mortality and higher specific leaf area, a proxy for growth, under unwatered ambient conditions. These results suggest plant performance of P. patagonica under reduced water availability is strongly shaped by the seed-collection site environment and may be a useful tool for improving restoration outcomes in a changing world.
• Klein, Z., & Mitchell, R. M. (2024). Seed source environment predicts response to water availability in Plantago patagonica. Restoration Ecology, e14002.
• MacDougall, A. S., Esch, E., Chen, Q., Carroll, O., Bonner, C., Ohlert, T., Siewert, M., Sulik, J., Schweiger, A. K., Borer, E. T., & others, . (2024). Author Correction: Widening global variability in grassland biomass since the 1980s. Nature ecology \& evolution, 8(10), 2003--2003.
• MacDougall, A. S., Esch, E., Chen, Q., Carroll, O., Bonner, C., Ohlert, T., Siewert, M., Sulik, J., Schweiger, A. K., Borer, E. T., & others, . (2024). Widening global variability in grassland biomass since the 1980s. Nature ecology \& evolution, 8(10), 1877--1888.
• MacDougall, A., Esch, E., Chen, Q., Carroll, O., Bonner, C., Ohlert, T., Siewert, M., Sulik, J., Schweiger, A., Borer, E., Naidu, D., Bagchi, S., Hautier, Y., Wilfahrt, P., Larson, K., Olofsson, J., Cleland, E., Muthukrishnan, R., Alberti, J., , Anderson, T., et al. (2024). Widening global variability in grassland biomass since the 1980s. Nature Ecology and Evolution, 8(10). doi:10.1038/s41559-024-02500-x
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  Global change is associated with variable shifts in the annual production of aboveground plant biomass, suggesting localized sensitivities with unclear causal origins. Combining remotely sensed normalized difference vegetation index data since the 1980s with contemporary field data from 84 grasslands on 6 continents, we show a widening divergence in site-level biomass ranging from +51% to −34% globally. Biomass generally increased in warmer, wetter and species-rich sites with longer growing seasons and declined in species-poor arid areas. Phenological changes were widespread, revealing substantive transitions in grassland seasonal cycling. Grazing, nitrogen deposition and plant invasion were prevalent in some regions but did not predict overall trends. Grasslands are undergoing sizable changes in production, with implications for food security, biodiversity and carbon storage especially in arid regions where declines are accelerating.
• MacDougall, A., Esch, E., Chen, Q., Carroll, O., Bonner, C., Ohlert, T., Siewert, M., Sulik, J., Schweiger, A., Borer, E., Naidu, D., Bagchi, S., Hautier, Y., Wilfahrt, P., Larson, K., Olofsson, J., Cleland, E., Muthukrishnan, R., O'Halloran, L., , Alberti, J., et al. (2024). Erratum: Author Correction: Widening global variability in grassland biomass since the 1980s (Nature ecology & evolution (2024) 8 10 DOI: 10.1038/s41559-024-02500-x). Nature ecology & evolution, 8(10). doi:10.1038/s41559-024-02538-x
• Mitchell, R. M., & Martin, A. R. (2024). Fire, flammability and functional traits at the forefront of global change ecology (vol 37, pg 2767, 2023). FUNCTIONAL ECOLOGY, 38(1), 272--272.
• Samuel, E. M., Mitchell, R. M., Winkler, D. E., Davidson, Z. M., Lencioni, S. J., & Massatti, R. (2024). Intraspecific trait variability in wild populations predicts neither variability nor performance in a common garden. Restoration Ecology.
• Samuel, E. M., Mitchell, R. M., Winkler, D. E., Davidson, Z. M., Lencioni, S., & Massatti, R. (2024). Intraspecific trait variability in wild plant populations predicts neither variability nor performance in a common garden. Restoration Ecology, e14322.
• Samuel, E., Mitchell, R., Winkler, D., Davidson, Z., Lencioni, S., & Massatti, R. (2024). Intraspecific trait variability in wild plant populations predicts neither variability nor performance in a common garden. Restoration Ecology, 33(Issue). doi:10.1111/rec.14322
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  Dryland restoration requires plant materials capable of performing well despite difficult growing conditions. Selecting plant materials with higher intraspecific trait variability (ITV) may support successful outcomes by enhancing the performance of those materials in restoration settings. However, maintaining ITV from wild populations is not well understood and requires further investigation if ITV is to be incorporated into native plant materials, which are often developed from wild-collected seed grown in agricultural settings. We used two perennial plant species to explore whether (1) ITV measured at field sites predicts ITV in a common garden, (2) rankings of ITV among populations remain stable over time, and (3) higher levels of ITV promote survival and reproductive effort in a common garden. We measured ITV in specific leaf area and height for Bouteloua curtipendula and Heterotheca villosa at field sites and over 2 years in a common garden, as well as survival and flower production in the common garden. We also calculated climate distance between field sites, where seeds were originally sourced, and the common garden to account for the impact of climatic differences on ITV. We found that (1) ITV measured at field sites did not predict ITV in the common garden, (2) rankings of ITV across populations were inconsistent, and (3) relationships between ITV and performance were rare and differed by species. Our findings indicate that the utility of ITV in wild populations as a predictive tool may be limited.
• Taber, E. M., & Mitchell, R. M. (2024). Experimental warming has limited impacts on post-fire succession across a burn severity gradient. Journal of Vegetation Science, 35(2), e13248.
• Waters, S. M., Mitchell, R. M., Brown, E. R., & Taber, E. M. (2024). Prescribed fire increases plant--pollinator network robustness to losses of rare native forbs. Ecological Applications, 34(2), e2928.
• Bakker, J. D., Price, J. N., Henning, J. A., Batzer, E. E., Ohlert, T. J., Wainwright, C. E., Adler, P. B., Alberti, J., Arnillas, C. A., Biederman, L. A., & others, . (2023). Compositional variation in grassland plant communities. Ecosphere, 14(6), e4542.
• Gornish, E. S., Campbell, C., Svejcar, L., Munson, S. M., Vaughn, K., Spaeth, M. K., Yelenik, S. G., Wolf, A., & Mitchell, R. (2023). Functional traits are used in restoration practice: a response to Merchant et al.(2022). Restoration Ecology, 31(7), e13880.
• Gornish, E. S., Campbell, C., Svejcar, L., Munson, S. M., Vaughn, K., Spaeth, M. K., Yelenik, S. G., Wolf, A., & Mitchell, R. (2023). Functional traits are used in restoration practice: a response to Merchant et al.(2022). Restoration Ecology, e13880.
• Klein, Z. M., & Mitchell, R. M. (2023). Phenotypic plasticity in six species of native and exotic Asteraceae. Restoration Ecology.
• Mitchell, R. M., & Martin, A. R. (2023). Fire, flammability and functional traits at the forefront of global change ecology. Functional Ecology, 37(11), 2767--2769.
• Samuel, E. M., Mitchell, R. M., & Winkler, D. E. (2023). Perspectives on challenges and opportunities at the restoration-policy interface in the USA. Restoration Ecology, 31(4), e13823.
• Taber, E. M., & Mitchell, R. M. (2023). Rapid changes in functional trait expression and decomposition following high severity fire and experimental warming. Forest Ecology and Management, 541, 121019.
• Ve\v{c}e\v{r}a, M., Axmanov\'a, I., Chytr\`y, M., Div\'\i\v{s}ek, J., Ndiribe, C., Velasco, M. G., \v{C}eplov\'a, N., A\'ci\'c, S., Bahn, M., Bergamini, A., & others, . (2023). Decoupled phylogenetic and functional diversity in European grasslands. Preslia, 95(4), 413--445.
• Waters, S. M., Mitchell, R. M., Brown, E. R., & Taber, E. M. (2023). Prescribed fire increases plant--pollinator network robustness to losses of rare native forbs. Ecological Applications, e2928.
• Mitchell, R. M., Brudvig, L. A., Murphy, S. M., & Wimp, G. M. (2022). COVID resilience inside the research ecosystem. Frontiers in Ecology and the Environment, 20(4), 203.
• Mitchell, R. M., Samuel, E. M., & Winkler, D. E. (2022). Perspectives on challenges and opportunities at the restoration‐policy interface in the U.S.A.. Restoration Ecology. doi:10.1111/rec.13823
• Mitchell, R. M., Ames, G. M., & Wright, J. P. (2021). Intraspecific trait variability shapes leaf trait response to altered fire regimes. Annals of botany, 127(4), 543--552.
• Wolf, A., & Mitchell, R. M. (2021). Leveraging Historic Cattle Exclosures to Detect Evidence of State Change in an Arid Rangeland. Rangeland Ecology \& Management, 78, 26--35.
• Firn, J., McGree, J. M., Harvey, E., Flores-Moreno, H., Sch\"utz, M., Buckley, Y. M., Borer, E. T., Seabloom, E. W., La, P., MacDougall, A. M., & others, . (2020). Author Correction: Leaf nutrients, not specific leaf area, are consistent indicators of elevated nutrient inputs. Nature Ecology \& Evolution, 4(6), 886--891.
• Laughlin, D. C., Gremer, J. R., Adler, P. B., Mitchell, R. M., & Moore, M. M. (2020). The net effect of functional traits on fitness. Trends in Ecology \& Evolution, 35(11), 1037--1047.
• Wainwright, C. E., Mitchell, R. M., & Bakker, J. D. (2020). Spatial Sampling Grain Shapes Conclusions about Community Structure and Dynamics. Natural Areas Journal, 40(1), 51--61.
• Firn, J., McGree, J. M., Harvey, E., Flores-Moreno, H., Sch\"utz, M., Buckley, Y. M., Borer, E. T., Seabloom, E. W., La, P., MacDougall, A. M., & others, . (2019). Leaf nutrients, not specific leaf area, are consistent indicators of elevated nutrient inputs. Nature Ecology \& Evolution, 3(3), 400--406.
• Keil, P., Chase, J. M., Firn, J., McGree, J. M., Harvey, E., Flores-Moreno, H., Sch\"utz, M., Buckley, Y. M., Borer, E. T., Seabloom, E. W., & others, . (2019). Leaf nutrients, not specific leaf area, are consistent indicators of elevated nutrient inputs..
• Mitchell, R. M., Wright, J. P., & Ames, G. M. (2018). Species??? traits do not converge on optimum values in preferred habitats. Oecologia, 186, 719--729.
• Schliep, E. M., Gelfand, A. E., Mitchell, R. M., Aiello-Lammens, M. E., & Silander Jr, ,. J. (2018). Assessing the joint behaviour of species traits as filtered by environment. Methods in Ecology and Evolution, 9(3), 716--727.
• Mitchell, R. M., Bakker, J. D., Vincent, J. B., & Davies, G. M. (2017). Relative importance of abiotic, biotic, and disturbance drivers of plant community structure in the sagebrush steppe. Ecological Applications, 27(3), 756--768.
• Mitchell, R. M., Bakker, J. D., Vincent, J. B., & Davies, G. M. (2017). Relative importance of abiotic, biotic, and disturbance drivers of plant community structure in the sagebrush steppe. Ecological Applications, 27(Issue 3). doi:10.1002/eap.1479
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  Abiotic conditions, biotic factors, and disturbances can act as filters that control community structure and composition. Understanding the relative importance of these drivers would allow us to understand and predict the causes and consequences of changes in community structure. We used long-term data (1989-2002) from the sagebrush steppe in the state of Washington, USA, to ask three questions: (1) What are the key drivers of community-level metrics of community structure? (2) Do community-level metrics and functional groups differ in magnitude or direction of response to drivers of community structure? (3) What is the relative importance of drivers of community structure? The vegetation in 2002 was expressed as seven response variables: three community-level metrics (species richness, total cover, compositional change from 1989 to 2002) and the relative abundances of four functional groups. We used a multi-model inference framework to identify a set of top models for each response metric beginning from a global model that included two abiotic drivers, six disturbances, a biotic driver (initial plant community), and interactions between the disturbance and biotic drivers. We also used a permutational relative variable importance metric to rank the influence of drivers. Moisture availability was the most important driver of species richness and of native forb cover. Fire was the most important driver of shrub cover and training area usage was important for compositional change, but disturbances, including grazing, were of secondary importance for most other variables. Biotic drivers, as represented by the initial plant communities, were the most important driver for total cover and for the relative covers of exotics and native grasses. Our results indicate that the relative importance of drivers is dependent on the choice of metric, and that drivers such as disturbance and initial plant community can interact.
• Mitchell, R. M., Wright, J. P., & Ames, G. M. (2017). Intraspecific variability improves environmental matching, but does not increase ecological breadth along a wet-to-dry ecotone. Oikos, 126(7), 988--995.
• Mitchell, R. M., & Bakker, J. D. (2016). Grass abundance shapes trait distributions of forbs in an experimental grassland. Journal of Vegetation Science, 27(3), 557--567.
• Wright, J. P., Ames, G. M., & Mitchell, R. M. (2016). The more things change, the more they stay the same? When is trait variability important for stability of ecosystem function in a changing environment. Philosophical Transactions of the Royal Society B: Biological Sciences, 371(1694), 20150272.
• Wright, J. P., Ames, G. M., & Mitchell, R. M. (2016). The more things change, the more they stay the same? When is trait variability important for stability of ecosystem function in a changing environment. Philosophical Transactions of the Royal Society B: Biological Sciences, 371(Issue 1694). doi:10.1098/rstb.2015.0272
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  The importance of intraspecific trait variability for community dynamics and ecosystem functioning has been underappreciated. There are theoretical reasons for predicting that species that differ in intraspecific trait variability will also differ in their effects on ecosystem functioning, particularly in variable environments. We discuss whether species with greater trait variability are likely to exhibit greater temporal stability in their population dynamics, and under which conditions this might lead to stability in ecosystem functioning. Resolving this requires us to consider several questions. First, are species with high levels of variation for one trait equally variable in others? In particular, is variability in response and effects traits typically correlated? Second, what is the relative contribution of local adaptation and phenotypic plasticity to trait variability? If local adaptation dominates, then stability in function requires one of two conditions: (i) individuals of appropriate phenotypes present in the environment at high enough frequencies to allow for populations to respond rapidly to the changing environment, and (ii) high levels of dispersal and gene flow. while we currently lack sufficient information on the causes and distribution of variability in functional traits, filling in these key data gaps should increase our ability to predict how changing biodiversity will alter ecosystem functioning.
• Mitchell, R. M., & Bakker, J. D. (2014). Intraspecific Trait Variation Driven by Plasticity and Ontogeny in Hypochaeris radicata. PloS one, 9(10), e109870.
• Mitchell, R. M., & Bakker, J. D. (2014). Quantifying and comparing intraspecific functional trait variability: a case study with Hypochaeris radicata. Functional Ecology, 28(1), 258--269.
• Mitchell, R. M., & Bakker, J. D. (2011). Carbon addition as a technique for controlling exotic species in Pacific Northwest prairies. Northwest Science, 85(2), 247--254.

Proceedings Publications

• Annetts, T., Mitchell, R. M., Moore, M. M., Laughlin, D., Leonard, J. M., & Grady, K. C. (2019). Assessing the magnitude of compositional change in two arid ecosystems over 80 years. In 2019 ESA Annual Meeting (August 11--16).
• Mitchell, R. M., Wright, J. P., & Ames, G. M. (2018). Are more variable species closer to ???optimum??? across an environmental gradient?. In 2018 ESA Annual Meeting (August 5--10).
• Wright, J. P., Mitchell, R. M., & Ames, G. M. (2016). Implications of trait variability for biodiversity-ecosystem function relationships in a changing environment. In 101st ESA Annual Meeting (August 7--12, 2016).
• Mitchell, R., Hilton, E., & Rosenfield, P. (2012). Engage: The Science Speaker Series-A novel approach to improving science outreach and communication. In AGU Fall Meeting Abstracts, 2012.
• Linden, J., Hilton, E., Mitchell, R., & Rosenfield, P. (2011). Engage: The Science Speaker Series-A novel approach to improving science outreach and communication. In APS Division of Plasma Physics Meeting Abstracts, 53.
• Mitchell, R. M., & Bakker, J. D. (2010). COS 72-6: Phenotypic plasticity in six species of native and exotic Asteraceae. In The 95th ESA Annual Meeting.

Presentations

• Mitchell, R. M. (2024). 2024. Native Plant Materials and the UN Decade on Ecological Restoration: A Sustainability Challenge and Opportunity. National Sustainability Society Meeting. Seattle, Washington.
• Mitchell, R. M. (2024). Leaf area predicts ignitability better than fuel moisture content in live herbaceous fuels. . Southwest Fire Ecology Conference.
• Mitchell, R. M. (2024, Summer). Stinknet. Annual meeting of Arizona Conservation Districts.
• Winnick, I. A., & Mitchell, R. M. (2024). Processes of deterministic community assembly change along a burn severity gradient.. Ecological Society of America meeting.
• Atkins, D., Gremer, J., Laughlin, D., Mitchell, R. M., & Moore, M. (2023). Functional traits predict demographic fitness in perennial graminoid species.. Ecological Society of America Meeting..
• Mitchell, R. M. (2023). Negative demographic response to climate in two dominant grasses over the last 60 years.. Ecological Society of America Meeting..
• Mitchell, R. M., & Maddie, W. (2023). Seed origin and drough affect offspring life history traits in Plantago patagonica.. Society for Ecological Restoration Southwest Chapter Meeting..
• Mitchell, R. M., Laughlin, D., Gremer, J., Bakker, J., Atkins, D., Stears, A., & Moore, M. (2023). Negative demographic response to climate in two dominant grasses over the last 60 years.. Society for Ecological Restoration Southwest Chapter meeting..
• Mitchell, R. M., Waters, S. M., Taber, E. M., & Browth, E. R. (2023). Prescribed fire increases plant-pollinator network robustness to losses of rare native forbs.. Ecological Society of America Meeting..
• Taber, E., & Mitchell, R. M. (2023). Interannual weather extremes drive post-fire succession more than constant experimental warming.. Ecological Society of America Meeting..
• Winick, I., & Mitchell, R. M. (2023). High severity fire alters community assembly in a ponderosa pine forest.. Society for Ecological Restoration Southwest Chapter Meeting.
• Mitchell, R. M. (2022, December). Restoration in a New Fire Landscape. Society for Ecological Restoration Southwest.
• Mitchell, R. M. (2022, November). Hot, Dry, and On Fire: Understanding Compounding Stressors in Semiarid Ecosystems. Research Institutes in Semiarid Ecosystems (RISE).
• Mitchell, R. M. (2022, October). Hot, Dry, and On Fire: Understanding compounding stressors in arid landscapes.. SNRE Departmental Seminar.
• Taber, E., & Mitchell, R. M. (2022, August). Transient effects of experimental warming on trait expression and ecosystem function along a burn severity gradient northern Arizona. Ecological Society of America.

Poster Presentations

• Goolsby, D., Mitchell, R. M., Jones, S. A., & Lien, A. (2024). Predicting Perils: Unraveling buffelgrass and stinknet invasions on the Santa Rita Experimental Range using Random Forest Models.. RISE Symposium.
• Javier, V., Wallace, M., & Mitchell, R. M. (2024). Understanding stinknet (Oncosiphon pilulifer) response to drought in populations across the southwestern USA. . Ecological Society of America Meeting.
• Wallace, M., & Mitchell, R. M. (2024). Transgenerational plasticity in response to drought affects functional traits of Plantago patagonica, a priority restoration species.. ALVCES Annual Research Poster Showcase..
• Wallace, M., & Mitchell, R. M. (2024). Transgenerational plasticity in response to drought affects functional traits of Plantago patagonica, a priority restoration species.. SNRE 50th Anniversary Symposium..
• Wallace, M., & Mitchell, R. M. (2024). Transgenerational plasticity in response to drought affects functional traits of Plantago patagonica. . Ecological Society of America Meeting.
• Winick, I., & Mitchell, R. M. (2024). The assembly of post-fire forest communities changes as fire becomes more severe. . ALVSCES Annual Research Poster Showcase.
• Sacoman, K., Mitchell, R. M., & Bogan, M. (2023). Decrease in Native Species Cover in Relation to Change in Flow Permanence and Depth to Groundwater.. Society for Ecological Restoration Southwest Chapter Meeting..
• Sacoman, K., Mitchell, R. M., & Bogan, M. (2023). Decrease in Native Species Cover in Relation to Change in Flow Permanence.. Society for Advancement of Chicanos/Hispanics and Native Americans in Science meeting.

Others

• Firn, J., McGree, J. M., Harvey, E., Flores-Moreno, H., Sch\"utz, M., Buckley, Y. M., Borer, E. T., Seabloom, E. W., La Pierre, K. J., MacDougall, A. M., & others, . (2019). Leaf nutrients, not specific leaf area, are consistent indicators of elevated nutrient inputs. Nat Ecol Evol 3: 400--406.
• Mitchell, R. (2013). The Extent, Drivers, and Consequences of Intraspecific Variation in Plant Functional Traits.