IDENTIFYING BIOTIC AND ABIOTIC CONTROLS OF PLANT REGENERATION TO ADVANCE SAGEBRUSH STEPPE CONSERVATION AND RESTORATION

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1012844
• Project Start Date: Jul 1, 2017
• Project End Date: Jun 30, 2022
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UTAH STATE UNIVERSITY
(N/A)
LOGAN,UT 84322

Performing Department
Wildland Resources

Non Technical Summary
The sagebrush steppe covers 120 million acres across 14 western states and 3 Canadian provinces, providing habitat for 357 vertebrate species and many more plants and invertebrates. Iconic western species such as greater and Gunnison sage-grouse, pygmy rabbits, and sage-thrashers are sagebrush obligates, while many others such as mule deer and pronghorn depend heavily on sagebrush habitats. The "sagebrush sea" is used for livestock grazing, oil and gas development, mineral extraction, and recreation. These activities, along with agricultural development, have converted large areas of sagebrush steppe, but invasion by non-native annual grasses and resulting acceleration of the fire cycle is the primary threat to the ecosystem. Loss and degradation of sagebrush vegetation threatens the viability of sagebrush dependent wildlife, triggering numerous petitions to list both species of sage-grouse and pygmy rabbits under the Endangered Species Act. Many additional sagebrush obligate species are identified as species of conservation concern in State Wildlife Action Plans. Consequently, management emphasis across the west has changed from sagebrush eradication to restoration and conservation of sagebrush communities on public and private land. Conserving sagebrush habitat means conserving the dominant native plant species and limiting establishment of invasive plants. However, researchers and managers have demonstrated little ability to accomplish either of these goals. Expensive efforts to reseed native perennials after wildfires fail at shockingly high rates, especially in the driest portions of the sagebrush steppe. Despite considerable and creative effort, we have yet to slow or reverse the increasing dominance of annual invasive grasses such as cheatgrass . In fact, recent research indicates the potential for climate change to exacerbate the cheatgrass invasion, threatening the cooler, wetter portions of the ecosystem that have appeared resistant and resilient to date. Fortunately, improving our ability to restore native species and anticipate and manage the impacts of annual invaders hinges on a limited set of ecological processes: seed production, germination, emergence, and seedling establishment and survival. If we can increase our understanding of the biotic and abiotic factors that limit regeneration, we will be able to advance sagebrush steppe conservation and restoration. The proposed research will combine manipulative field experiments with mathematical models to help us understand and predict 1) the role of soil microbes in mediating the establishment of native perennials, and 2) the role of climate in limiting the establishment of cheatgrass. Although the proposed work is basic, it directly aligns with applied goals of restoring native sagebrush steppe species and predicting future impacts of cheatgrass and fire.

Animal Health Component

15%

Research Effort Categories

Basic

75%

Applied

15%

Developmental

10%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
121	0799	1070	100%

Knowledge Area
121 - Management of Range Resources;

Subject Of Investigation
0799 - Rangelands and grasslands, general;

Field Of Science
1070 - Ecology;

Keywords

bromus tectorum

coexistence

competition

ecological forecasting

germination

population models

seedling establishment

soil microbes

Goals / Objectives
1. Determine how plant-soil feedbacks influence the establishment of native perennials in the sagebrush steppe2. Determine how climate change will alter impacts of the cheatgrass invasion

Project Methods
Objective 1. Our approach will combine a field experiment and population modelling. The field experiment will measure effects of plant-soil microbial feedbacks on plant seedling establishment and survival in situ under field conditions. We can then project the population and community-level consequences of the experimentally described PSFs by incorporating them into our existing population models.Objective 2. We will combine seed collections with DNA sequencing to model the spatial distribution of cheatgrass genotypes. We will conduct common garden experiments with at least 100 cheatgrass genotypes to model the demographic rates as a function of environmental drivers (e.g. temperature, soil moisture) and genotype. We will combine the genotype distribution model with our models of demographic rates to build a population model. Predictions from the population model will be tested by collecting observations of the demographic performance of local ecotypes at dozens of sites across the region. These tests will allow us to quantify uncertainty in projected changes in cheatgrass abundance under climate change.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:The primary target audience is research scientists working in universities and government agencies including the USGS, USDA-ARS, and USFS. A secondary target audience includes federal land managers responsible for long range land-use planning decisions. Changes/Problems:Due to COVID related restrictions, we delayed most of our Bromecast field work and associated hiring one year. As explained under Major Activities, we are using this time to fine tune our experimental design with pilot experiments. Given NSF's generous no cost extension policy, we do not feel that the one year delay will negatively impact the project. What opportunities for training and professional development has the project provided?The combination of this UAES project and my NSF funded Bromecast project has provided training opportunities for seven hourly research assistants. They helped process seed collections, conduct the seed bulking at UN Reno, and helped implement pilot common garden experiments and satellite experiments. The project has also provided partial support for two post-docs working with Bromecast Co-PI Germino in Boise, who helped design and implement the pilot common garden experiments. How have the results been disseminated to communities of interest?PI Adler presented the work on the hierarchical modeling framework in a poster at the ESA 2020 annual meeting, as part of the Leading Ecologists spotlight (details in bibliography). What do you plan to do during the next reporting period to accomplish the goals?For the next year, our priorities for the NSF Bromecast project are 1) DNA sequencing and analysis, 2) implementation of the common garden and satellite experiments, 3) and continued work on developing novel statistical analyses. We will also fully implement the public education program. This UAES project will complement those efforts.

Impacts
What was accomplished under these goals? Objective 1: How do plant-soil feedbacks influence the establishment of native perennials in the sagebrush steppe? Field work for this objective is now complete. Former post-doc Anny Chung and I are working together to disseminate the results. Dr. Chung presented on this work at the 2020 Ecological Society of America annual meeting, and we are now preparing two manuscripts. Objective 2: How will climate change alter impacts of the cheatgrass invasion? Most of our work this year focused on this objective, carried out in coordination with our NSF "Bromecast" award. During spring and summer 2019, before the grant's official start date, we worked with more than 30 Bromecast participants to collect cheatgrass seeds from more than 250 locations in the Intermountain West. We selected 105 genotypes from these collections to grow out seeds in a common, greenhouse environment in Reno, with the help of Bromecast super-participant Dr. Beth Leger. We harvested enough seeds in summer 2020 for the first year of the common garden experiment for 70 genotypes, and enough seeds for both years of the common garden experiment for 60 genotypes. We are now beginning a second seed-bulking round at USU, supervised by Adler. We are working with 30 genotypes that did not produce much seed in the 2020 season, hoping that a vernalization treatment will improve seed production. In addition to collections from the core region of cheatgrass impact in the intermountain West, in 2020 PI Lasky (Penn State) forged new relationships with dozens of collectors and obtained seed collections from ~150 additional sites across the US and Canada, as well as the native Eurasian range. We originally planned to plant the common garden experiments in fall 2020. Due to COVID, we decided to delay the experiments a full year. We have used the time to implement a series of pilot studies to work out a new temperature manipulation treatment: we use aquarium gravel to alter albedo. Black gravel increases soil surface temperatures, white gravel decreases it. We are conducting pilots in Logan, UT, Boise, ID, and Cheyenne, WY, near the planned locations for the full experiments. We are monitoring soil temperatures and soil moisture, and have planted cheatgrass at high and low densities (as planned for the full experiment) to make sure the gravel treatments do not inhibit germination, or create such extreme temperatures that no plants survive. Although we would have preferred to avoid the delay, it may ultimately work in our favor by giving us time to design better experiments. We have recruited volunteers to conduct the distributed, satellite experiments. So far, we have 27 sites planned, involving about 30 Bromecast participants (some sites have more than one volunteer). Most sites will begin work in fall 2021, but six sites were implemented in fall 2020 to fine tune the experimental design and data collection protocol. PI Lasky (PSU) hired a postdoctoral scholar, Diana Gamba, in September 2020 to lead DNA sequencing. Lasky was successful with an application for a New Investigator Project at the Joint Genome Institute, Department of Energy. Through this project, JGI scientists will conduct deep resequencing (~50x Illumina) of 6 natural inbred cheatgrass lines. Plants were sown in September at Penn State and DNA will be extracted and sent to JGI in November. JGI will use the resequencing to estimate the genome size of cheatgrass using the k-mer approach. JGI will also prepare de novo assemblies from these data. Lasky and Gamba have conducted pilot cheatgrass growth chamber growth experiments. In October-November 2020 they organized the hundreds of seed collections that will soon be grown for DNA extraction and sequencing. In September 2020, PIs Lasky, Hooten & Adler submitted a review and perspective manuscript to Proceedings of the Royal Society B. The manuscript, now published, is titled, What processes must we understand to forecast regional scale population dynamics? The focus of the manuscript is the urgent challenge being addressed by this NSF grant: predicting the regional scale population dynamics of species facing environmental change. Biologists suggest that we must move beyond predictions based on phenomenological models and instead base predictions on underlying processes. For example, population biologists, evolutionary biologists, community ecologists, and ecophysiologists all argue that the respective processes they study are essential. Our manuscript asks whether our models include processes from all of these fields? We argue that answering this critical question is ultimately an empirical exercise requiring a substantial amount of data. To motivate and facilitate the necessary data collection and integration, we first review the potential importance of each mechanism for skillful prediction. We then develop a conceptual framework based on reaction norms, and propose a hierarchical Bayesian statistical framework to integrate processes affecting reaction norms at different scales. Adler also published a paper in Ecography titled, Matching the forecast horizon with the relevant spatial and temporal processes and data sources.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Adler, P., White, E., & Cortez, M. (2020). Matching the forecast horizon with the relevant spatial and temporal processes and data sources. Ecography, 43(11), 1729--1739.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Kulmatiski, A., Adler, P., & Foley, K. M. (2020). Hydrologic niches explain species coexistence and abundance in a shrubsteppe system. Journal of Ecology, 108(3), 998--1008.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Lasky, J. R., Hooten, M. B., & Adler, P. (2020, December). What processes must we understand to forecast regional-scale population dynamics? Proceedings of the Royal Society B: Biological Sciences, 287(1940), 20202219.
• Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Presentations Adler, P., Western Drought Resilience Workshop, "Ranching, rangelands, and resilience: ensuring adaptive capacity in an increasingly variable climate," USDA Southwest Climate Science Hub. (2020 - Present)
• Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Presentations Chung, A. (Author Only), Monaco, T. (Author Only), Taylor, J. B. (Author Only), Adler, P., Ecological Society of America Annual Meeting, "From phenomenon to mechanism: Are plant-soil feedbacks maintaining coexistence in the sagebrush steppe?," Ecological Society of America, Salt Lake City. (2020)
• Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Presentations Adler, P., Lasky, J. (Author Only), Hooten, M. (Author Only), Ecological Society of America Annual Meeting, "What processes must we understand to forecast the impact of global change on species distribution and abundance?," Ecological Society of America, Salt Lake City, UT. (2020)

Progress 10/01/18 to 09/30/19

Outputs
Target Audience:The primary target audience is research scientists working in universities and government agencies including the USGS, USDA-ARS, and USFS. A secondary target audience includes federal land managers responsible for long range land-use planning decisions. Changes/Problems:No problems to report. The biggest change is the NSF award to greatly expand our cheatgrass work (Objective 2). What opportunities for training and professional development has the project provided?Post-doc Chung has been mentored by PI Adler. She began an Assistant Professor position at the University of Georgia in August, 2019. Chung and Adler trained two undergraduates field technicians in summer, 2019. The students were trained in plant species identification, plant species composition monitoring, sampling and processing of biomass samples and soil samples, data entry, spatial data digitization, and some simple computer programming. How have the results been disseminated to communities of interest?Chung presented results of the plant-soil feedback experiment at the 2019 annual meeting of the Ecological Society of America. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: Finish data analysis and write and submit papers. Objective 2: The BromeCast project will be my first priority for the next four years. In 2020, our focus will be on hiring staff and implementing the field experiments.

Impacts
What was accomplished under these goals? Objective 1: How do plant-soil feedbacks influence the establishment of native perennials in the sagebrush steppe? With the help of Dr. Tom Monaco and his staff at the USDA-ARS Forest and Range Lab here in Logan, and an undergraduate assistant, post-doc Anny Chung successfully collected the second and final year of data from her field experiment at the USDA-ARS Sheep Experiment Station. In addition, she completed a complementary seedling competition experiments in the greenhouse. She has processed all field samples, entered all data, and has almost completed data analysis. The preliminary results show that soil microbes limit plant establishment more than root competition. However, evidence for species-species plant-soil feedbacks or even species-specific competitive effects was extremely weak. This result is surprising in light of our analyses of long-term observational data which show that intraspecific competition limits recruitment much more than does interspecific competition. The implication is that field experiments and observational studies can return quite different estimates of species interactions, a conclusion consistent with a recent removal experiment we conducted, and with studies by other ecologists as well. Comparison of the field and greenhouse soil-feedback experiments shows similar inconsistency, with evidence of positive microbial effects emerging in the greenhouse. Again, this result add to accumulating evidence that field and greenhouse soil feedback experiments measure very different things. Our discipline clearly has challenges to tackle in improving our methods for estimating the effects of species interactions. I am interested in developing new methods based on integration of experiments, observations, and advanced statistical methods. Objective 2: How will climate change alter impacts of the cheatgrass invasion? In 2019, the $1.8 million BromeCast project that I am leading was funded by the National Science Foundation. Our goal is to learn how to predict the effect of climate change on the population dynamics of cheatgrass (Bromus tectorum) across its range in western North America. To make accurate predictions about population growth, do we need to account for local genetic variation? Do we need to account for intra- and interspecific interactions with other plants? Will information about phenology and physiology improve predictions? Or do we need to integrate all these sources of information? With support from the National Science Foundation, and help from a network of volunteer participants, we will answer these questions with a combination of common garden experiments, distributed demographic observations, and dynamic models, all designed to provide independent tests of model predictions. Although the grant does not officially begin until 2020, we have already begun work. In summer 2019, BromeCast participants collected B. tectorum seeds from more than 200 locations in western North America. This winter, will select 100 genotypes from these collections to grow out for common garden experiments. We will also sequence more than 200 genotypes from across the range. We are now finalizing experimental protocols for the common garden and distributed satellite experiments. We are also preparing to hire technicians and post-docs.

Publications

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:The primary target audience is research scientists working in universities and government agencies including the USGS, USDA-ARS, and USFS. A secondary target audience includes federal land managers responsible for long range land-use planning decisions. Changes/Problems:Nothing to report. What opportunities for training and professional development has the project provided?Post-doc Chung is mentored by PI Adler. As evidence that our professional development work was successful, I am happy to report that Chung has accepted a tenure-track Assistant Professor position at the University of Georgia, which she will begin in August, 2019. Chung trained one undergraduate research assistant in basic laboratory methods including: plant propagation, design of experimental apparatus, and soil sampling and processing. Chung and Adler also worked with an NSF REU summer student, Sam Willard from the University of Minnesota. He conducted a project on relationships between plant functional traits and plant-soil feedbacks. How have the results been disseminated to communities of interest?Nothing to report yet. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: Chung will complete the field work on the field experiment in spring-summer 2019. Much of her time between now and her August end-date will be devoted to analyzing data and writing manuscripts. Objective 2: I will lead revision of our cheatgrass proposal and will submit it to NSF Rules of Life in February. I will also explore the potential for a scaled-down version of this proposal focused primarily on forecasting fire fuels.

Impacts
What was accomplished under these goals? Objective 1: How do plant-soil feedbacks influence the establishment of native perennials in the sagebrush steppe? With the help of Dr. Tom Monaco and his staff at the USDA-ARS Forest and Range Lab here in Logan, and 1undergraduate assistant, post-doc Anny Chung successfully collected the first year of data from her field experiment at the USDA-ARS Sheep Experiment Station, and planted seedlings for year 2 of the experiment. In addition, she completed a complementary greenhouse experiment, and mentored an NSF REU student working in a related project over the summer. She has begun analyzing the experimental data and expects to begin writing manuscripts soon. We also collected another year of monitoring data on our permanent plots at the USDA-ARS Sheep Experiment, data which will complement the field experiment. Objective 2: How will climate change alter impacts of the cheatgrass invasion? In 2017, Adler led a multi-institutional effort to write a $1.7 million NSF Macrosystems Biology proposal focused on predicted the future trajectory of the cheatgrass invasion under climate change. The proposal was rejected in spring 2018. Since then we have looked into a number of programs where we might propose this research. After talking to a number of program offices, we have decided to try again through the NSF Rules of Life program this winter, with proposal submission planned in February 2019.

Publications

• Type: Journal Articles Status: Published Year Published: 2018 Citation: Adler, P., Kleinhesselink, A. R., Hooker, G., Taylor, J. B., Teller, B., & Ellner, S. (2018). Weak interspecific interactions in a sagebrush steppe: evidence from observations, models, and experiments. Ecology, 99, 1621-1632.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Anderson, T. M., al, e., & Adler, P. (2018). Herbivory and eutrophication mediate grassland plant nutrient responses across a global climatic gradient. Ecology, 99, 822-831.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Hautier, Y., al, e., & Adler, P. (2018). Local loss and spatial homogenization of plant diversity reduce ecosystem multifunctionality. Nature Ecology and Evolution, 2, 50-56.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Hodapp, D., al, e., & Adler, P. (2018). Spatial heterogeneity in species composition constrains plant community responses to herbivory and fertilisation. Ecology Letters, 21, 1364-1371.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Kleinhesselink, A. R., & Adler, P. (2018). The response of big sagebrush (Artemisia tridentata) to interannual climate variation changes across its range. Ecology, 99, 1139-1149.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Laughlin, D., Strahan, R., Adler, P., & Moore, M. (2018). Survival rates indicate that correlations between community-weighted mean traits and environments are unreliable estimates of the adaptive value of traits. Ecology Letters, 21, 411-421.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Renwick, K., Curtis, C., Kleinhesselink, A. R., Schlaepfer, D., Bradley, B., Aldridge, C., Poulter, B., & Adler, P. (2018). Multi-model comparison highlights consistency in predicted effect of warming on a semi-arid shrub. Global Change Biology, 24, 424-438.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Tredennick, A., Kleinhesselink, A. R., Taylor, J. B., & Adler, P. (2018). Ecosystem functional response across precipitation extremes in a sagebrush steppe. PeerJ, 6, e4485.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Tredennick, A., Adler, P., Hooker, G., & Ellner, S. (2018). Size-by-environment interactions: a neglected dimension of species responses to environmental variation. Ecology Letters, 21, 17571770.

Progress 07/01/17 to 09/30/17

Outputs
Target Audience:Researchers. Changes/Problems:Nothing to report. What opportunities for training and professional development has the project provided?Post-doc Chung is mentored by PI Adler. So far, our professional development training has focused on preparing application materials for faculty jobs. Chung submitted two job applications this fall and interviewed for one faculty position in Taiwan. Chung trained two undergraduate research assistants in basic laboratory methods including: plant propagation, design of experimental apparatus, and soil sampling and processing. How have the results been disseminated to communities of interest?No results to report yet. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: We will continue working on the plant-soil feedback as outlined in our NSF award. Spring will be a busy time for field work, and Chung will also implement a greenhouse experiment. In mid-summer and fall, we will repeat the preparations for another year of the seed and seedling experiments. Objective 2: We expect a decision on the Macrosystems award by April, 2018. That decision will determine our plan of work under this objective.

Impacts
What was accomplished under these goals? Objective 1: How do plant-soil feedbacks influence the establishment of native perennials in the sagebrush steppe? Post-doc Anny Chung began her USU position in August, 2017. During the fall, she successfully implemented the field experiment proposed in our NSF award. This required a tremendous effort in a short time to 1) count and clean tens of thousands of seeds, 2) germinate and grow thousands of plants, 3) identify experimental sites at the USDA-ARS Sheep Experiment Station, and 4) transplant seedlings and seeds into the field. Anny also instrumented the experimental site to monitor soil moisture and temperature. She managed to complete all this work with the help of Dr. Tom Monaco and his staff at the USDA-ARS Forest and Range Lab here in Logan, and 2 part-time undergraduate assistants. In December, Chung and Adler submitted a proposal for supplemental NSF funding as part of the Research Experiences for Undergraduates (REU) program. If funded, we will be able to hire an undergraduate researcher to join, and extend, the project this spring and summer. Objective 2: How will climate change alter impacts of the cheatgrass invasion? Adler led a multi-institutional effort to write a $1.7 million NSF Macrosystems Biology proposal focused on predicted the future trajectory of the cheatgrass invasion under climate change. We submitted the proposal in October.

Publications