Progress 08/01/09 to 07/31/10
Outputs
OUTPUTS: Activities: 1. Completion of post-treatment ecological sampling. Harvest took place over two summers, so data collections was also spread among two summers to avoid complicating findings with the time available for recovery. Sampling in 2010 was required on one of the four treatment blocks. We established five transects, separated by 20 m, in each of the eight treatment units per block. Five sample points, 20 m apart, were arrayed along these transects yielding a network of 25 sample points in each unit. Sample points were used for all data collection. (1) Four of the 25 points were randomly selected in each sample unit for stand assessment. We used variable-radius plots to sample canopy tree species composition and size; and we used fixed-radius plots to sample young individuals of the same species in the understory. (2) We sampled understory species composition and biomass at each sample point (and species composition at additional points) using 0.25 m x 0.25 m nested-frequency plots. (3) We collected a soil core to a depth of 15 cm at each sample point. Soil cores are currently being analyzed for bulk density, and carbon and nitrogen content. 2. Sampling of aspen regeneration along each transect was repeated. This activity began in 2009 as an undergraduate project. We decided to repeat this procedure each summer. Here, we simply walk each transect and record the number of aspen suckers that appear within 1 m of the transect line. 3. Sampling of all study blocks for change in genotype frequency. The staggered harvesting of the study blocks would have little influence on genetic composition so all sample collection took place in the summer of 2010. This timing had allowed for nearly two years of recovery in three of the blocks and one year of recovery in the remaining block. The majority of resprouting would have taken place the spring following harvest. Consequently all blocks would have had an opportunity to resprout. Genetic sampling was accomplished along the transects described in (1). These samples, however, were only collected with the control and full-harvest units. Each aspen stem within 1 m of the transect was sampled (leaves collected for genetic analysis). 4. Processing of ecological samples (plants and soils) for the blocks sampled in summer 2009 was completed. Processing of samples from 2010 is on-going. 5. Analysis of genetic samples collected during summer 2007 was completed. Genotypes were based on eight loci. Not all samples were analyzed; in many cases, relatively few samples were necessary to describe the boundary of genetically identical stems. Analysis of samples collected in 2010 is now beginning, and additional samples from 2008 may be analyzed to assess clonal boundary shifts, as necessary. PARTICIPANTS: Individuals: Ron Ryel - PD, general project management, treatment/experimental design. Josh Leffler - CO/PD, field project management, data handling and analysis, personnel management. Karen Mock - CO/PD, genetic data collection and analysis. Jim Long - CO/PD, forest ecology and timber harvest planning and management. Andres Liedolf - wildlife ecology. Cody Mittanck - graduate student. Carol Rowe - genetics laboratory technician. Spencer Weston - field technician, summer 2010. Daren Boren - field technician, summer 2010. Konrad Hafen - field technician, summer 2010. John Rentschler - field technician, summer 2010. Partner Organizations: Deseret Land and Livestock - in-kind support with housing, land for experiments, and timber harvest. Collaborators: Tom Monaco - USDA/ARS scientist, provided botanical expertise and field botany crews to aid in data collection during summer 2010. Helga Van Miegroet - Professor, Utah State University, provided analyses of soils collected in summer 2007. Training: 1. Data collection during summer 2010 involved contributions from several undergraduate and graduate students. These included: Ritchie Gardner, Cody Mittanck, Spencer Weston, Daren Boren, Konrad Hafen, and John Rentschler. 2. One undergraduate student employed during summer 2009 completed an independent project and presented her findings at the Wildlife Society Student Conclave in March 2010. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: 1. No agreements regarding a burn experiment have been made. Given the limited duration of the grant at this time, agreements will no longer be pursued.
Impacts
Change in Knowledge: 1. Further genetic analysis has confirmed preliminary findings. We have identified 27 unique genotypes. The study block that was nearly pure aspen in composition was lowest in diversity; only two genotypes have been identified in the stand. Stands that are mixed aspen/conifer, or heavily conifer dominated have up to seven different genotypes present. These preliminary data suggest large expanses of aspen may be clones, but that scattered individuals within other forest types may be the result of sexual reproduction and establishment from seed. 2. Aspen sucker data from summer 2010 largely support our findings from summer 2009. Aspen regeneration is most closely associated with the amount of aspen present prior to the harvest. Although harvest types did differ sucker response, these differences were minor compared to preceeding aspen composition. We observed more suckers in the control plots in 2010 suggesting that suckering is an episodic event.
Publications
- St. Clair SB, Mock KE, LaMalfa EM, Campbell RB, Ryel RJ (2010) Genetic contributions to phenotypic variation in physiology, growth and vigor of aspen (Populus tremuloides) clones. Forest Science 56:222-230.
- Rogers P, Bartos DB, Ryel RJ (2010) Historical patterns influencing lichen communities and aspen forests of the southern Rocky Mountains. in: Lichen: Symbionts, Ecology and Economic Uses. Nova Science Publishers (in press).
- Oukrop CM, Evans DM, Bartos DL, Ramsey RD, Ryel RJ (2010) Moderate-scale mapping methods of aspen stand types: a case study for Cedar Mountain in southern Utah. USDA Forest Service Proceedings (in press).
- Ryel RJ (2010). Resource pools: Some new perspectives on plant-plant interactions. Centro de Estudos Florestais and Centro Ecologia Aplicada, Instituto Superior de Agronomia, Lisbon, Portugal. 19-Oct-2010.
- Ryel RJ (2010). Aspen decline: Climate change, management, or just bad luck Dept. of Plant, Soils and Climate, Utah State University, Logan, UT. 16-Feb-2010.
- Evans D, Ryel R, Ramsey RD, Bartos D, Oukrop C. (2010) Using remote sensing to understand spatiotemporal landscape dynamics of aspen decline in southern Utah. Annual Meetings of the Society of Range Management and Weed Science Society of America, Denver, CO, USA. 7-11-Feb-2010.
- Ducas L, Jones S, Leffler AJ, Ryel R. (2010) Understory phenotypic plasticity and functional diversity may buffer inter-annual variations in overstory soil resource uptake. Ecological Society of America 95th meeting, Pittsburg, PA, USA. 2-6-Aug-2010.
- Leffler, A.J., Ryel, R.J., Monaco, T.A. (2010). Long-Term Changes in Community Composition Following Harvest of a Mixed Aspen/Conifer Forest in Northern Utah. Society of Range Management Annual Meeting, Denver, CO. February 2010.
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Progress 08/01/08 to 07/31/09
Outputs
OUTPUTS: Activities 1. Completion of harvest. Harvest began in summer 2008 and took place until late-October 2008. Harvest operations were halted by snowfall, but were approximately 90% complete in 2008. Harvest was completed in July 2009. 2. Post-treatment Data Collection. Post-treatment sampling was conducted on three of the four study blocks - those that were harvested in 2008. The remaining block will be sampled in 2010. We established five transects, separated by 20 m, in each of the eight treatment units per block. Five sample points, 20 m apart, were arrayed along these transects yielding a network of 25 sample points in each unit. Sample points were used for all data collection. (1) Four of the 25 points were randomly selected in each sample unit for stand assessment. We used variable-radius plots to sample canopy tree species composition and size; and we used fixed-radius plots to sample young individuals of the same species in the understory. (2) We sampled understory species composition and biomass at each sample point (and species composition at additional points) using 0.25 m x 0.25 m nested-frequency plots. (3) We collected a soil core to a depth of 15 cm at each sample point. Soil cores are currently being analyzed for bulk density, and carbon and nitrogen content. 3. Large-animal exclusion fence. A fence was constructed to exclude domestic animals (sheep and cattle) and elk from a portion of each study block. The fence was constructed to evaluate the influence of browsing on aspen regeneration. Each fence consists of three lines of high-tension electric polyrope and encloses a 1-ha area divided between control and clear-felling treatment units. The fence was constructed in late July 2009 and will be in place during summer and early fall when animal use will be greatest. 4. Bird community sampling took place following a late spring frost event that caused widespread defoliation. Sampling was designed to determine if bird utilization of aspen was influenced by this disturbance. Previous sample points were distributed among aspen stands that we unaffected by the frost, received moderate frost damage, and received severe frost damage. Sampling consisted of bird point-counts in each of these areas. Number of individuals of various species were recorded for fixed time intervals at each point. Bird response to frost damage is used as a surrogate to understand how birds might respond to harvest of aspen stands and how birds respond to phenological differences in aspen leaf emergence associated with different aspen genotypes. 5. Analysis of genetic samples collected during summer 2007 continues. At this point, 603 samples have been processed, many at eight loci. A complete analysis will consist of all samples processed at eight loci. Events 1. The Utah State University student chapter of the Society of American Foresters conducted field safety training for the 2009 sampling and fence building crew. 2. The Utah State University student chapter of the Society of American Foresters performed a stand assessment at Deseret Land & Livestock as an opportunity to gain experience in forest inventory sampling. PARTICIPANTS: Individuals Ron Ryel - PD, general project management, treatment/experimental design. Josh Leffler - CO/PD, field project management, data handling and analysis, personnel management. Karen Mock - CO/PD, genetic data collection and analysis. Jim Long - CO/PD, forest ecology and timber harvest planning and management. Andres Liedolf - wildlife ecology. Cody Mittanck - graduate student Carol Rowe - genetics laboratory technician. Spencer Weston - field technician, summer 2009. Elizabeth Goss - field technician, summer 2009. Tony Kusbach - field technician, summer 2009. Sara Hunt - field technician, summer 2009. Dan Howell - field technician, summer 2009. Partner Organizations Deseret Land and Livestock - in-kind support with housing, land for experiments, and timber harvest. Collaborators Tom Monaco - USDA/ARS scientist, provided botanical expertise and field botany crews to aid in data collection during summer 2009. Helga Van Miegroet - Professor, Utah State University, provided analyses of soils collected in summer 2007. Training 1. Data collection during summer 2009 involved contributions from several undergraduate students in Natural Resources. These included: Spencer Weston, Elizabeth Goss, Tony Kusbach, Sara Hunt, and Dan Howell. 2. One undergraduate student (Goss) is currently pursuing an independent study; she plans to present findings of an examination of browsing on aspen regeneration at the annual Wildlife Society Student Conclave. 3. Provided opportunities to the Student Chapter of the Society of American Foresters including training of field technicians in field safety, and experience with timber inventory. 4. A new graduate student, Cody Mittank, joined the project in August 2009. The graduate student will be responsible for some project management, but will also develop his own research direction. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Major Changes 1. Harvests were approximately 90% completed at the end of the 2008 season. Unfortunately, snowfall prevented the completion of the harvest in one season. An extremely wet spring also prevented access to the stand until early summer 2009 (to prevent soil damage). Consequently, harvest was not completed until late July. Since harvest on the last block primarily took place in the fall of 2008 and summer 2009, we did not think it appropriate to sample for a response to harvest in 2009. Rather, we have postponed post-treatment data collection for the final block until summer 2010. This change will allow more appropriate comparison among blocks. 2. Post-treatment collection of genetic data for all blocks was postponed until summer 2010. This decision was made to ensure that genetic sampling was performed on all aspen regeneration in the study blocks; some studies suggest aspen may respond to disturbance over multiple years. An extension to the grant has been requested and granted to allow for completion of the work. 3. New agreements regarding the completion of the burn treatment are not yet in place. Plans for the burn treatment continue to be developed.
Impacts
Change in Knowledge 1. We have identified sixty five different species in the understory of aspen, conifer and mixed aspen/conifer communities. Analyses indicate that unique communities are associated with the different treatment blocks and that understory species composition depends on aspen and conifer canopy composition. Moreover, a stand with a recent harvest had an understory species composition that different from those without a history of harvest. The previously harvested stand had a higher grass content and the grass flora was more dominated by a C4 species. Current analyses suggest that understory communities in aspen stands are not more diverse than those in conifer stands, a finding counter to expectations from other publications. 2. Aspen regeneration data suggest harvest stimulates regeneration, but that harvest types differ; the greatest response was observed in the clear-felled units. Additionally, aspen regeneration was reduced in the mixed and conifer stands relative to regeneration in the pure aspen stand. 3. Analyses of soils suggest lower bulk density in aspen stands compared to mixed and conifer stands. Soil carbon content increases from aspen-dominated to conifer-dominated forest while soil nitrogen content does not differ between forest types. Soils in a stand harvested previously contained less carbon and nitrogen than soils in stands with no recent harvest history. 4. Analysis of genetic diversity in aspen has identified 27 unique genotypes. Interestingly, the study block that was nearly pure aspen in composition was lowest in diversity; only two genotypes have been identified in the stand. Stands that are mixed aspen/conifer, or heavily conifer dominated have up to seven different genotypes present. These preliminary data suggest large expanses of aspen may be clones, but that scattered individuals within other forest types may be the result of sexual reproduction and establishment from seed. 5. Phenotypic differences in leaf emergence among aspen clones result in a mosaic of damage response (low to high) in crowns to early season frost. ˇThese differences in frost damage were found to significantly affect bird community distributions and suggest the importance of maintaining aspen genetic diversity among stands at the landscape scale.
Publications
- Leffler, A.J., Ryel, R.J., and Monaco, T.A. 2009. Long-term changes in community composition following harvest of a mixed aspen/conifer forest in northern Utah. Restoration Ecology, pending.
- Leffler, A.J., Rogers, P.C., Ryel, R.J. 2009. A tale of two landscapes: Assessing aspen in northern and southern Utah with ecological indicators. Ecological Society of America Annual Meeting, Albuquerque, NM. August 2009.
- Leidolf, A., Ryel, R.J. 2009. Bird community response to frost damaged aspen. Western North American Naturalist, pending.
- Rogers, P., Ryel R.J., Bartos, D. 2009. The Western Aspen Alliance: Promoting sustainable aspen ecosystems in the Western North America. 7th Western North America Forestry Ecology Workshop. Logan, UT. June 2009.
- Ryel, R.J., Leffler, A.J., Hultine, K.R. 2009. Plants as drivers of ecohydrological processes: a vegetation perspective on global change. Ecological Society of America Annual Meeting, Albuquerque, NM. August 2009.
- Ryel R.J. 2009. Perspectives on future directions for management and restoration in the West. Restoring the West: Conference 2009 -- Peaks to Valleys: Innovative Land Management for the Great Basin, Utah State University, Logan, UT. October 2009.
- Ryel, R.J., Beyschlag W. A unifying perspective for plant coexistence. Lehrstuhl fuer Experimentelle Oekologie und Oekosystembiologie, Universitaet Bielefeld, Germany. 23 Apr. 2009.
- Ryel, R.J. Cooperation versus Competition in Plant Communities. Annual BEHAVE Meeting: Behavior-Based Management, Embracing Change from Genes to Landscapes. Park City, UT 28-30 Oct. 2008.
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Progress 08/01/07 to 07/31/08
Outputs
OUTPUTS: Activities 1. Study Site Establishment. During summer 2007 we selected locations for four experimental blocks that would receive treatments. Three hillslopes were selected for uniformity in slope, aspect, and elevation. Four blocks, spanning a range of tree species composition from conifer-dominated to aspen-dominated, were situated on the hillside. Blocks measure 200 m x 400 m (smaller than originally planned, but better designed for the landscape). Each block was divided into eight treatment units (including controls). 2. Pre-treatment Data Collection. Following site selection, a data collection protocol was designed that was used before treatment and will be used for subsequent monitoring. We established five transects, separated by 20 m, in each of the eight treatment units per block. Five sample points, 20 m apart, were arrayed along these transects yielding a network of 25 sample points in each unit. Sample points were used for all data collection except genetic samples. (1) Four of the 25 points were randomly selected in each sample unit for stand assessment. We used variable-radius plots to sample canopy tree species composition and size; and we used fixed-radius plots to sample young individuals of the same species in the understory. (2) We sampled understory species composition and biomass at each sample point (and species composition at additional points) using 0.25 m x 0.25 m nested-frequency plots. (3) We selected four of the five points per transect and collected a soil core to a depth of 15 cm at these points. Soil cores were analyzed for bulk density, and carbon and nitrogen content. 3. Pre-treatment Genetics Data. Genetic data for each treatment block were collected at two scales. (1) Coarse-scale data were collected on a 50-m grid overlaid on the stand to be treated. These data describe the clonal diversity of aspen on the hillside. (2) Fine-scale data were collected along transects in control and full-harvest units. Each aspen individual within 1 m of the transect was samples. These data will be used to assess genetic changed in response to treatment. 4. Conducting treatments. Mechanical treatments were conducted in summer 2008. Treatments were originally planned for summer 2007, but it was not possible to conduct all the mechanical treatments in one season. We decided to postpone harvest until 2008 to ensure all treatments would take place in one year. We conducted three mechanical treatments (each on two units/block): (1) harvest of all timber in the unit, (2) harvest of only the merchantable timber in the unit, and (3) felling of all timber, but no removal of felled trees. We intend to conduct a burning treatment associated with one of each mechanical treatment units in each block. These will take place in 2009. Events 1. The Utah State University junior-class field trip visited the experimental blocks in September 2008. Students were told about the goals, treatments, and measurements of the experiment. PARTICIPANTS: Individuals Ron Ryel - PD, general project management, treatment/experimental design Josh Leffler - CO/PD, field project management, data handling and analysis, personnel management Karen Mock - CO/PD, genetic data collection and analysis Jim Long - CO/PD, forest ecology and timber harvest planning and management Andres Liedolf - wildlife ecology Carol Rowe - genetics laboratory technician Christo Morris - manager of field crews during summer 2007 data collection Sean Kelly - field technician, summer 2007 Ben Hudson - field technician, summer 2007 Brian Tooley - field technician, summer 2008 David Dinwiddie - field technician, summer 2008 Partner Organizations Deseret Land and Livestock - in-kind support with housing, land for experiments, and timber harvest Collaborators Tom Monaco - USDA/ARS scientist, provided botanical expertise and field botany crews to aid in data collection during summer 2007 Helga Van Miegrote - Professor, Utah State University, provided analyses of soils collected in summer 2007 Training 1. The Utah State University junior-class field trip visited the experimental blocks in September 2008. Students were told about the goals, treatments, and measurements of the experiment. 2. Data collection during summer 2007 involved contributions from several undergraduate and graduate students. These included: Ritchie Gardner, Mical Woldeselassie, Nickoli Hamblin, and Travis Taylor. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Major Changes 1. We experienced a delay in implementing forest harvest treatments. We initially planned for harvest in fall 2007. However, the harvest operation is an in-kind contribution from Deseret Land and Livestock and arrangement were made with their timber contractor. The contractor was delayed with other jobs in summer 2007. Instead, forest harvest treatments began in summer 2008 and are ca. 90% complete at the time of this report. Delays in harvest have also necessitated a delay in the construction of the exclusion fence. We have addressed this delay by reducing spending on the project during summer 2008. We plan a full season of data collection in 2009 (post-harvest) and fence construction in 2009. 2. We initially had State of Utah support for experimental burning. The State of Utah has decided not to participate in this project over the next several years. The state was responsible for an in-kind contribution of fire prescription, ignition, and fire management. At this time, we are pursuing other options for experimental burning. 3. We initially planned for treatment blocks of 200 m x 400 m. These blocks were simply too large for hillslopes within the study site so the size was reduced to better match landscape conditions. Hillslopes were also decided to be too variable to be true replicates of canopy species composition. Instead, we specifically selected hillslopes that spanned a range of conifer encroachment from nearly pure aspen to nearly pure conifer. 4. The State of Utah was also responsible for contribution of funds to perform a mastication treatment. Since the state is no longer a cooperator on this project, the mastication treatment will not happen. We have replaced this treatment with a felling of timber, but this timber will be left in place.
Impacts
Change in Knowledge 1. We have identified over seventy different species in the understory of aspen, conifer and mixed aspen/conifer communities. Of these species, only eight are considered invasive and only one is found commonly throughout the study sites. Analyses indicate that unique communities are associated with the different treatment blocks and that understory species composition depends on aspen and conifer canopy composition. Current analyses suggest that understory communities in aspen stands are not more diverse than those in conifer stands, a finding counter to expectations from other publications. 2. Understory biomass was highly variable among treatment units. Although there were no differences in total biomass between aspen and conifer stands, a trend of declining woody biomass and increasing non-woody biomass with increasing cover of aspen was observed. 3. Stand assessment data suggest aspen regeneration is vigorous in treatment units with considerable aspen already present. 4. Early results from course-scale genetic sampling suggest at least twelve genotypes are found in the single block analyzed at this time. 5. Preliminary analyses of soils suggest lower bulk density in aspen stands compared to mixed and conifer stands. Also, aspen and conifer soils had similar C:N ratio, but soils from mixed stands were considerably higher in C:N.
Publications
- Leffler, A.J., Miegroet, H.V., Monaco, T.A., Long, J.N., and Ryel, R.J. 2008. Efficacy and Consequences of Aspen Treatments: The USU/Deseret Land & Livestock Manipulation Project. Restoring the West: Conference 2008 - Aspen Restoration, Utah State University, Logan, UT. September 2008.
- Leidolf, A. and Ryel, R.J. 2008. Avian responses to frost-damaged aspen in the Wasatch Mountains of Northern Utah. Restoring the West: Conference 2008 - Aspen Restoration, Utah State University, Logan, UT. September 2008.
- Ryel, R.J. and Bartos, D. 2008. Aspen classification. Restoring the West: Conference 2008 - Aspen Restoration, Utah State University, Logan, UT. September 2008.
- Ryel, R.J. and Leffler, A.J. 2008. Plant responses to water stress in arid and semi-arid environments. Ecological Society of America Annual Meeting, Milwaukee, WI. August 2008.
- Leffler, A.J., Woldeselassie, M.W., Miegroet, H.V., Monaco, T.A., Long, J.N., and Ryel, R.J. 2008. Forest treatments to regenerate aspen in northern Utah: Pre-treatment findings. Ecological Society of America Annual Meeting, Milwaukee, WI. August 2008.
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