Progress 10/01/20 to 09/30/21
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Substantive research experiences for: - two graduate (M.S.) students (1 completed thesis, 1 thesis in progress) - 1 post-graduate reseach technician - 2 undergraduate student research assistants How have the results been disseminated to communities of interest?Changes in knowledge: We developed new methodology for propagating pinyon pine seedlings with high success. Our protocols have been adopted by the Washoe Tribe of Nevada & California. The first paper from Georgia Vasey's thesis work will soon be submitted to a peer-reviewed journal (by March 2022). This study assesses geographical patterns of intraspecific trait variation across range-wide environmental gradients, improving our understanding of potential climate change response of P. monophylla at the level of individuals and populations. Results allow us to identify particular source populations, and associated reproductive and foliar traits, that can be expected to perform better (establish more reliably from seed or planted seedlings) given differing conditions of water availability and seasonality (for example, given climate change driven drought events). Changes in action: In collaboration with RMRS, we have continued to donate seeds and seedlings from our greenhouse trials to the Washoe Tribe, who have planted them in burned areas for restoration purposes. Collaborations between RMRS and UNR, beginning with this project, have expanded to the HTNF as well as Tribal entities. We have developed and submitted proposals together (led by RMRS) that have the potential to lead to new or refined approaches for management of pinyon-juniper woodland in the region. What do you plan to do during the next reporting period to accomplish the goals?We will implement watering treatments and continue measurements for the remaining greenhouse experiment, continue field measurements for the field experiments, submit two completed M.S. thesis chapters for publication, and see the second M.S. student's thesis through to completion by December.
Impacts
What was accomplished under these goals?
Five experiments have been set up (2 completed, 3 in progress), all addressing climate resilience in singleleaf pinyon pine using a common-garden approach: Observational study of intraspecific variation in maternal tree traits (completed) Greenhouse experiment at Nevada Agricultural Experiment Station's Valley Road Field Lab: Seedling trait variation and plasticity in response to water limitation (completed) Field common garden experiment with sown seeds on Humboldt-Toiyabe National Forest lands just south of Carson City (at the Plymouth Work Center): Pinus monophylla seedling trait variation and performance under various seasonal precipitation regimes (in progress). Field experiment with planted seedlings at the USFS Rocky Mountain Research Station (RMRS) Underdown Canyon Demonstration Project area, Shoshone Mountains, central Nevada (in progress). Greenhouse experiment at the USDA-ARS greenhouse on Valley Road: Pinus monophylla seedling trait variation and ecophysiological responses to pulse events in a greenhouse common garden (in progress) Observational study of intraspecific variation in maternal tree traits (completed; part of Georgia Vasey's M.S. thesis) Questions: How is intraspecific trait variation in P. monophylla structured across four ecological scales: between mountain ranges, among sites elevationally distributed within mountain ranges, among individual trees, and for foliar traits, among growth years? Is the structure of this variation arranged along broad-scale environmental gradients that reflect the amount and seasonality of water availability? Methods: We measured foliar and reproductive traits for trees at 23 sites in nine mountain ranges. Mountain ranges were selected based on gradients of total amount and seasonality of precipitation. *The provenances sampled for this study form the basis of all studies in this project. Results: Most trait variation was explained at the scale of individual trees (18-46%), with smaller contributions at the scale of sites (8-25%) and mountain ranges (0-15%). Covariance between trait syndromes and environmental variables was explained by two major axes of variation: (1) the drought-stress gradient covarying with reproductive traits, and (2) the seasonality of precipitation covarying with foliar morphology. Seedling trait variation and plasticity in response to water limitation (completed; part of Georgia Vasey's M.S. thesis) Questions: How do seedling trait values and biomass allocation ratios of different source provenances, associated with distinct environmental parameters, respond to a gradient of water availability? Does population-level phenotypic trait plasticity, as indicated by response to water availability, relate to environmental characteristics of the provenances? Methods: We used a randomized block design to plant a total of 3,740 seedlings from 137 maternal trees in a greenhouse experiment. Watering treatments (Wettest, Wet, Dry, and Driest) were assigned based on known gravimetric water contents. Aboveground and belowground phenotypic traits were measured at the end of the experiment. Biomass allocation ratios and plasticity were calculated from trait measurements. Results: Seedlings under all treatments from the hotter and drier climates, which are also characterized by greater summer precipitation, grew larger aboveground and belowground biomass compared to seedlings from more mesic environments with winter-dominated precipitation regimes. Additionally, trait plasticity in response to watering treatments was greatest for seedlings from more water-limited environments and from sites with more summer precipitation. Field common garden experiment with sown seeds on Humboldt-Toiyabe National Forest lands just south of Carson City (at the Plymouth Work Center): Pinus monophylla seedling trait variation and performance under various seasonal precipitation regimes (in progress) (part of Jeremy Adkins M.S. thesis) Question: Does the seed source environment affect pinyon seedlings' functional trait variation and performance in response to different seasonal precipitation regimes? Study design: Location: Plymouth site on Humboldt-Toiyabe NF (hotter/drier than pinyon occurs) Randomized block design: randomized seed grids planted under nurse sagebrush shrubs Two seed cohorts: 6600 planted in fall of 2019; 2700 planted in fall of 2020 Four watering treatments were based on the seasonality of precipitation regimes at the seed source environments Seedling performance was evaluated by measuring emergence, survival, growth and morphology Field experiment with planted seedlings at the USFS Rocky Mountain Research Station (RMRS) Underdown Canyon Demonstration Project area, Shoshone Mountains, central Nevada. (in progress) Questions: What is the role of seed source and first-year growing conditions on seedling performance across an environmental/elevational gradient? How long do first-year effects persist? Study design: Fully randomized design: 3 first-year greenhouse watering treatments; 20 seed sources; 3 outplanting sites (Underdown Canyon - Austin; Plymouth - Carson) Planted 968 seedlings in fall 2020: 358 in PUD-H and PUD-L (Underdown Canyon), 252 in PUD-PL (Plymouth) Preliminary results: 792 seedlings (82%) alive in March 2021; 624 (65%) alive in August 2021 2021 survival (Mar-Aug): 88% in PUD-H; 90% in PUD-L; 24% in PUD-PL Wetter first-year greenhouse conditions had lower survival, esp. in the driest site *Continuing to track seedling growth, needle & stem mortality, signs of herbivory, morphology. Greenhouse experiment at the USDA-ARS greenhouse on Valley Road: Pinus monophylla seedling trait variation and ecophysiological responses to pulse events in a greenhouse common garden (in progress) (part of Jeremy Adkins M.S. thesis) Question: How does the seed source environment affect pinyon seedlings' functional trait variation and ecophysiological response to different precipitation pulse regimes? How does the seed source environment and variation in P. monophylla seedlings' functional traits and ecophysiological responses to precipitation pulses contribute to overall performance? Study design: We will conduct a greenhouse common garden that simulates multiple pulse precipitation regimes for four populations of P. monophylla seedlings. The target populations represent various extremes of cumulative water deficit and summer precipitation at the seed source. Only lower elevation sites were used to ensure that the cohorts come from similar ecological and hydrological environments and they are trailing edge populations. The four sites are at Mount Charleston (high summer precipitation and high CWD), San Bernardino mountains (low summer precipitation and high CWD), Schell Creek (high summer precipitation and lower CWD), and Desatoya Mountains (low summer precipitation and lower CWD). The seeds were collected in September of 2019 and were stored in a refrigerator for 2 years at approximately 4 degrees Celsius. In December of 2021, the seeds were flushed, imbibed, and cold stratified In December of 2021 and January of 2022, a greenhouse common garden was established. There will be 4 populations * 3 watering treatments * 4 replicates per treatment = 48 seedlings to be sampled destructively on each of 6 sampling days, for a total of 288 seedlings. The watering treatments simulate pulses of differing magnitude and interval. Water status variables to be measured will include relative leaf water content, stomatal conductance, and transpiration. Carbon dynamics will include maximum photosynthetic rate, specific leaf area, root to shoot ratio, root architecture, and delta 13 C. Performance measurements will include survival, height, total biomass, and trunk diameter.
Publications
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Progress 10/01/19 to 09/30/20
Outputs
Target Audience:
Nothing Reported
Changes/Problems: For the Common Garden experiment (Experiment 1), lizards and rodents preyed upon a significant number of the seeds and germinating seedlings in our experimental grids, but we retain sufficient replication that the overall study outcome should not be affected. Due to the UNR hiring freeze, resulting from anticipated budget cuts associated with the pandemic, we are having a difficult time hiring a critical employee as field technician. As a result, experimental setup was slightly delayed and we planted fewer seedlings than we had hoped. The overall study outcomes should not be greatly affected, as long as our anticipated hire is approved in the near future. What opportunities for training and professional development has the project provided?The project has thus far contributed to training of one M.S. student in the Department of Natural Resources and Environmental Science, whose M.S. thesis is dedicated to this work; one postdoctoral researcher who has contributed to the project; one undergraduate researcher who has developed valuable research skills assisting with our field and greenhouse experiments; one postgraduate research technician who has played a huge role in keeping the project going; and two recent UNR graduateswho have volunteered on an occasional basis to help with both field and greenhouse experiments. How have the results been disseminated to communities of interest?An informal PlantTalk seminar on the study was presented at UNR by graduate student, Georgia Vasey. What do you plan to do during the next reporting period to accomplish the goals?We will complete the experiment, analyze results, the graduate student will complete her M.S. thesis, we will submit publications to journals, give talks at conferences, etc.
Impacts
What was accomplished under these goals?
Three major experiments have been set up: Common garden experiment with sown seeds on Humboldt-Toiyabe National Forest lands just south of Carson City (at the Plymouth Work Center). Greenhouse experiment at Nevada Agricultural Experiment Station's Valley Road Field Lab Field experiment with planted seedlings at the USFS Rocky Mountain Research Station (RMRS) Underdown Canyon Demonstration Project area, Shoshone Mountains, central Nevada. Experiment 1: Common garden experiment with seeds sown in field trials: In Fall 2019 we planted a total of 288 seed grids under sagebrush shrubs (4 watering treatments * 3 blocks * 24 replicates), for a total of 6,912 seeds planted (1 seed from each site in each randomized grid of 24 seeds under each nurse shrub). The 24 sites from which seeds were collected were selected from 10 mountain ranges ("populations") located largely in Nevada and in parts of western Utah and southern California, covering P. monophylla's species distribution. At each population where possible, three sites were selected along an elevational gradient. Sites range in elevation from 1,515 to 2,611 meters. Four watering treatments have been implemented throughout the 2020 growing season: Unwatered (simulating winter-dominated precip regime with growing season drought) Early-season (April-May) watering (simulating spring-dominated precipication regime) Late-season (July-Sept) watering (simulating late-summer-domiated precipitation regime) Moderate watering across the growing season (April-Sept; simulating winter-dominated precip regime with continuing growing season moisture) The germination and survival of planted seeds were monitored continuously at approximately 2-week intervals from April through November 2020. Out of nearly 7000 seeds planted, approximately 1600 remained living by the most recent tally on November 15. The experiment will continue to be monitored through the next growing season, and a second year of seed sowing will be completed in the late fall of 2020 in 192 additional seed grids. Experiment 2: Greenhouse experiment with seedlings grown from seed in pots: In December 2019, seeds from 23 sites were flushed for 36 hours to imbibe seeds and rinse pathogens, then stratified for 65 days in a fridge that was on average 41° F In February 2020, up to two stratified seeds per container were planted, with a total of 3,740 planted containers For the experimental design, there were four watering treatments, with three replicate blocks in each treatment, for a total of 12 treatment blocks. In total, each block had two to three maternal trees, with up to nine replicates per maternal tree represented in each block. We developed a soil water release curve using a W4PC water potential meter for six fine soil (0.065 mm) subsamples across a range of known gravimetric water content that represent how functionally dry, or the relative amount of water available for the plant, before triggering irrigation. The blocks included a high watering treatment (34-40%), moderate watering treatment (22-28%), low watering treatment (10-16%), and control (no added water following seedling emergence). Seedlings were watered at the high treatment for the first 1.5 months until most seedlings had emergerd, and treatments were implemented for four months until August 2020. We weighed test pots daily to turn on irrigation and rotated trays on table before each treatment. Measurements happened monthly, at the beginning, and at the end depending on the trait from April through August. Measured seedling traits (for all): height (monthly), crown diameter (beginning and end), average juvenile root mass (beginning), number of branches (end) Measured seedling traits (1/3 subset): length of 3 needles (beginning and end), stem diameter (end), scanned root architecture (end), dried root mass (end), dried aboveground biomass (end) Seedling survivorship results: 3320 survived, 91 died, and 329 did not emerge. All of the treatments had roughly the same amount of deaths by the end of the experiment. Experiment 3: Field experiment with planted seedlings: A third of the seedlings from the greenhouse experiment (Experiment 2) were destructively sampled for measurement of traits (n = 1,140. A large portion of the remaining seedlings were used for this field experiment. Seedlings from 20 seed collection sites from 7 mountain ranges were planted under sagebrush shrubs at the Underdown Canyon Demonstration Area, with approx. 350 seedlings planted at each of two sites: an upper-elevation site (elevation = 2380 m) and a lower-elevation site (elevation = 1980 m), representing the upper and lower treelines of the pinyon-juniper woodland in the central Great Basin. For a third site, representing the "future lower treeline" environment of pinyon-juniper woodland given climate change scenarios, 250 additional seedlings were planted at the Plymouth common garden site (elevation = 1435 m) described above. Seedlings in this experiment will thus allow us to compare the effects of: (a) different source populations from throughout the range of singleleaf pinyon pine; (b) different watering treatments during their first year of life (i.e. first-year drought conditions); and (c) different site climate conditions (elevational bands). Beginning in 2021, we will measure seedling survival and growth on a monthly frequency, and will measure key functional traits of seedlings using destructive methods upon seedling death. Analysis of trait variation in maternal trees (from which seeds were collected): For Chapter 1 of her MS Thesis, graduate research assistant Georgia Vasey is analyzing how the functional trait variation of singleleaf pinyon pine trees varies across four ecological levels or spatial scales (Population = mountain range, Site = elevation zone within mountain range, Tree, and Tree Growth Year). Trait information was measured for the maternal trees from which seeds were collected for the purposes of the three experiments previously described. Functional morphological traits that were measured include both vegetative (foliar) traits (specific leaf area, needle length, needle width, and needle weight) and reproductive traits (cone length, cone dry weight, number of ovules per cone, seed projected area, seed weight). Random effects regression models were used to quantify the proportion of variation explained at each of the four levels of ecological organization (Population, Site, Tree, Tree Growth Year). We addressed the research question, "Are patterns of trait variation among sites correlated with geographic variation in climate variables?" The 2B-PLS multivariate analysis method was used to correlate site-level patterns of trait dissimilarity with dissimilarity in climate variables.
Publications
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Progress 07/01/19 to 09/30/19
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?We have hired one graduate research assistant (Georgia Vasey, a new NRES M.S. student), one undergraduate research assistant (Spencer Cortright, a Forest Management and Ecology major), and one postgraduate research assistant (Erica Sullivan, a recent UNR graduate who was a Forest Management and Ecology major). This project will frame the M.S. thesis of Georgia Vasey. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
To obtain seeds for our common garden experiment, we have collected green cones (≥ 60 cones from each of six trees per population) from 24 populations throughout the geographic range of P. monophylla, where populations refer to elevationally stratified zones in 10 sites scattered across Nevada, California, Idaho and Utah (but mostly in Nevada), located in the following mountain ranges or geographical areas: Pine Nut Mountains, Desatoyas, Schell Creek Mountains, Pequop Mountains, East Tintic Mountains, Mount Irish, Mount Charleston, Beaver Dam Mountains, San Bernardino Mountains, Rock Creek (Sierra Nevada between Bishop and Bridgeport). Populations and sites were selected following a GIS analysis of the climate variability within the range of the species, such that the full range of climate and geographical variation was represented within our sample (as well as possible given the sample size that was feasible). This resulted in collection of 7,500 cones from 144 maternal trees. Seeds have been removed from all cones, and predated or obviously inviable seeds have been tallied and discarded. A total of 1,440 cones have been measured for the following: cone length (mm), two cone diameter measurements (mm) when closed, dry weight (g), total seeds per cone, total predated seeds per cone Over 28,000 seeds have been tested for viability A site has been identified for our common garden experiment on Humboldt-Toiyabe National Forest lands just south of Carson City (at the Plymouth Work Center). This is co-located with several other common garden experiments sponsored by the Humboldt-Toiyabe NF, and is well protected from vandalism and destructive land uses, with ready access to water for our irrigation experiments. We have completed approx. 70% of the planting in the common garden. We are sowing seeds beneath protective wire mesh cages under sagebrush nurse shrubs (n=288 shrubs = 24 tree populations * 3 spatial replicates * 4 watering treatments). When completed this will be a total of 6,912 seeds planted (1 seed from each population in each randomized grid of 24 seeds under each nurse shrub). Watering treatments will include an unwatered treatment, an early-season watering treatment simulating snowmelt-driven water availability, and a treatment that includes both early-season and late-season supplemental water (simulating increased availability of monsoonal precipitation). We have designed a greenhouse experiment using 56 seeds per tree per population (total n = 8,064 seeds), representing four drought stress treatments in a randomized block design (three blocks). We have purchased trays, pots, and other infrastructure for the greenhouse experiment and are currently designing our greenhouse infrastructure with the help of Scott Huber. To accomplish the above objectives, we have hired one graduate research assistant (Georgia Vasey, a new NRES M.S. student), one undergraduate research assistant (Spencer Cortright, a Forest Management and Ecology major), and one postgraduate research assistant (Erica Sullivan, a recent UNR graduate who was a Forest Management and Ecology major). This project will frame the M.S. thesis of Georgia Vasey. Our Forest Service project partners have been contributing vehicles, lab and greenhouse space, field technician time, and their own time and expertise to the overall effort. We have given one informal presentation about the project to the "PlantTalk" seminar series at UNR.
Publications
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