DEVELOPING SILVICULTURAL STRATEGIES FOR GUIDING FOREST STRUCTURAL COMPLEXITY TO ACHIEVE DESIRED ECOSYSTEM SERVICES

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: MCINTIRE-STENNIS
• Reporting Frequency: Annual
• Accession No.: 0232193
• Project Start Date: Jan 1, 2013
• Project End Date: Dec 31, 2017
• Program Code: [(N/A)]- (N/A)

Recipient Organization
PENNSYLVANIA STATE UNIVERSITY
208 MUELLER LABORATORY
UNIVERSITY PARK,PA 16802

Performing Department
Ecosystem Science & Management

Non Technical Summary
The focus of this research is on (1) expanding knowledge about the relationship between forest stand structures and the important ecosystem services desired by our society and provided by forested ecosystems and (2) developing tools and strategies to translate that knowledge into management to enhance our natural resource base, facilitate environmental stewardship, and promote economic and social welfare for generations to come. Forest stakeholders in the U.S. have expressed serious concerns about the ability of managed forests to safeguard biodiversity while also supplying products for human needs (Pinchot Institute 2006). Although the forestry profession has a vast store of experience in managing for timber production, it is now widely acknowledged that foresters have often failed to safeguard other ecosystem services of equal or greater importance to society, such as biodiversity. Consequently, silvicultural strategies that expressly aim to bridge the gap between conflicting values are needed. The premise of this proposal is that a more thorough understanding of forest structure and its spatial and temporal variability is the key to developing more successful silvicultural approaches. After all, forest structure, i.e., the 3-dimensional distribution of tree attributes among neighbors in space, which is characterized by the spatial arrangement of trees into more or less heterogeneous clusters of trees (Zenner and Hibbs 2000), is what is directly manipulated via silvicultural interventions (OHara 1998). In addition, forest structure is the outcome of processes that operate in forests across temporal and spatial scales and thus provides many functions expected from forests, such as habitat provision. If we can determine the physical structural conditions that permit biodiversity to flourish within our forested ecosystems, we can develop silvicultural prescriptions that specify the creation of those conditions when and where they are desired. The same approach can be used to achieve any desired forest ecosystem service, from higher growth rates for timber production to specific species compositions and arrangements that maintain water quality. Because forests are slow-growing and long-lived and the outcomes of research may require decades to improve the lives of individuals, silvicultural research is concerned with perpetuity rather than immediacy. However, through the dissemination of research results to private and public land managers, changes in forest management practices can be expected within only a few years and we expect the cost-effective approaches we develop to linking forest structure to biodiversity responses at multiple scales to be applied by managers within this short time frame. Toward that end, we will spend the next five years focusing on three primary projects necessary to the development of silvicultural strategies to achieving desired ecosystem services.

Animal Health Component

50%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
123	0620	1070	100%

Knowledge Area
123 - Management and Sustainability of Forest Resources;

Subject Of Investigation
0620 - Broadleaf forests of the North;

Field Of Science
1070 - Ecology;

Keywords

silviculture

forest structure

structural complexity

lidar

scale

cerulean warbler

ecosystem services

Goals / Objectives
Goals and objectives: Determine, define, and delineate 1-, 2-, and 3-dimensional characteristics of forest stand structural complexity between natural and managed stand structure types, among silvicultural treatments, across natural disturbances and succession, and developmentally over time to improve our understanding of how silvicultural practices can be used to achieve desired ecosystem services. Characterize the physical forest stand structural conditions associated with the habitat of the sensitive Neotropical migratory bird species the cerulean warbler using remote sensing data. Develop and improve trans-scale quantitative estimates of forest stand growth (affecting productivity) and structural complexity (affecting ecosystem function and habitat quality) using cost-effective technologies and available databases. Milestones: Complete laboratory analysis of cores and cross-sections; conduct analyses. Submit funding proposal to the Fish & Wildlife Service; obtain USFS migratory bird database data; obtain and extract LiDAR statistics; develop models. Submit funding proposal to the Environmental Protection Agency and the Smithsonian Institution; obtain and extract LiDAR statistics; develop models. Deliverables: The results from all objectives will be presented between 2014-2017 at state, regional, national, and international meetings and conferences, workshops, outreach, manuscripts.

Project Methods
1. Temporal dynamics of neighborhood-level structural complexity will be investigated in two 2.25 ha stem-mapped mixed hardwood stands in central Pennsylvania to test the hypotheses that a) naturally regenerated uneven-sized stands in this region are not necessarily uneven-aged, and b) oak canopy dominance can be achieved despite long-term neighborhood-level competition with initially faster growing species. In 2007, the spatial position of every live tree ≥ 5 cm in diameter at breast height (DBH), species, DBH, and crown class were recorded and a subset of trees were cored. The age reconstruction, data analysis relating crown position and species relative abundance to the abundance and temporal pattern of competition, and manuscript preparation remain. Growth dynamics will also be analyzed in 6 23-36 year old mixed hardwood stands in which a total of 283 trees in three- to four-tree mixed-species neighborhoods were sampled in 2008. A diameter growth competition index will be developed from cross-sections to predict growth under given neighborhood conditions. 2. Cerulean warblers and associated bird species were surveyed in North Central Pennsylvania in 2005-2010. Sites with conditions known to be associated with Cerulean warblers will be chosen for analysis at the territory- (ca. 1.5 ha), stand- (ca. 100 ha), and landscape- (ca. 3000 ha) levels. Logistic regression and discriminant analysis will distinguish stands in which the Cerulean warbler was present from those in which it was absent based on available stand inventory data. Standard leaf-off PAMAP LiDAR structure summary statistics will be extracted using FUSION. This project will test the hypotheses that a) existing standard inventory data can be used to identify potential Cerulean warbler habitat, b) cost-effective leaf-off aerial LiDAR data can be used to identify potential Cerulean warbler habitat. 3. A 16-ha stem-mapped Smithsonian Institution Global Earth Observatory (SIGEO) plot located at the Smithsonian Environmental Research Center (SERC) in Maryland will be used to relate previously collected data (three years of dendrometer band growth measurements on individual trees, percent vegetation cover measurements from regularly spaced 1-m plots, and four years of portable ground-based canopy LiDAR measurements) to high-quality areal LiDAR measurements available from NASA. Summary statistics of the LiDAR point cloud distribution will be extracted using FUSION, multiple linear regression analyses will evaluate the degree of association between areal LiDAR summary statistics and the responses of growth, vegetation cover, and ground-based LiDAR measurements at multiple scales (e.g., 0.25 ha, 1 ha, 5 ha, 10 ha). This project will test the hypothesis that a) cost-effective aerial LiDAR provides comparable information about forest structural complexity to cost-intensive ground-based LiDAR, b) cost-effective aerial LiDAR provides information about forest structural complexity that is sufficiently associated with intensively measured biodiversity responses to be used as a surrogate for those responses.

Progress 01/01/13 to 12/31/17

Outputs
Target Audience:The intended target audiences are forestry professionals, particularly within the Pennsylvania Bureau of Forestry and the USDA Forest Service, consulting foresters, and private forest landowners who intend to more actively and ecologically manage their woodlots, ecologists and natural resources professionals who work for NGOs, and national and international researchers in the fields of forestry and ecology.Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?In addition to training and mentoring the four graduate students directly involved in studies supported by this project (totaling 8 Graduate Student Years), the findings of this project have been translated into annual training at the undergraduate level (FOR 410: Forest ecosystem management; FOR 421: Silviculture) and professional development for practicing foresters working for the federal government (via an annually taught module of the National Advanced Silviculture Workshop). How have the results been disseminated to communities of interest?Research results were disseminated during national and international conferences, informal meetings with local foresters, workshops, and field trips. The most significant dissemination activities throughout for the entire life of the project were presentations and workshops to practicing foresters, forest landowners, administrators, and researchers (a) regionally at the annual meetings of the Association of Southeastern Biologists and the Minnesota Society of American Forests (SAFMN), (b) nationally at the National Convention of the Society of American Foresters and the Ecological Society of America Annual Meeting, and (c) internationally at several meetings of the International Union of Forest Research Organizations and at many different universities and research organizations around the world. What do you plan to do during the next reporting period to accomplish the goals?Data analyses and manuscript preparation based on the current project will be ongoing into the next several years.

Impacts
What was accomplished under these goals? Example accomplishments include a better understanding of (1) the development of forest structure in natural old-growth forests as well as following different management entries, enabling better silvicultural prescriptions for close-to-nature management; (2) the response of the ground flora following different harvest treatments in riparian areas, facilitating riparian management guidelines; (3) stand development trajectories (species composition and structure) over 15 years in various stands throughout Pennsylvania that experienced a variety of silvicultural treatments, improving the predictive power of management activities; (4) above-ground carbon allocation patterns under different silvicultural treatments, elucidating the potential for carbon sequestration in Pennsylvania; (5) the growth dynamics of even- and uneven-aged forests as a function of growing stock and structural complexity, demonstrating the potential to maintain both volume growth and structural complexity; (6) the use of several spatially independent attributes and spatially explicit metrics for describing small-scale structural complexity and associated processes in stands with different management histories (even-sized and uneven-sized stands), improving our characterization of structural complexity; (7) the representativeness of small patches of old-growth forests relative to much larger forest dynamics, yielding insights into the restoration of mature forests to old-growth; (8) the requisite conditions for developing better classification systems for development phases, to prevent researchers from drawing spurious conclusions; (9) why (i.e., a new ecological hypothesis) forests are characterized by subtle structural differences not captured by stand-level diameter distributions; (10) why (i.e., an improved ecological hypothesis) these empirical data show only subtle structural differences among forest development stages; (11) the utility of Lidar for classifying structure and habitat quality and predicting potential stands in Pennsylvania that may be suitable habitat for cerulean warblers, a species of concern; and (12) the quantification of adverse effects of soil compaction following skidding operations on tree morphology, growth, and architecture and on physical and chemical properties of forest soils.

Publications

• Type: Book Chapters Status: Published Year Published: 2013 Citation: Nagel, T.A., E.K. Zenner, and P. Brang. 2013. Research in old-growth forests and forest reserves: implications for integrated forest management. P. 4450 In: Integrative approaches as an opportunity for the conservation of forest biodiversity. D. Kraus and F. Krumm (eds.), European Forest Institute. 284 p.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Zenner, E.K. 2014. Discussion: The ongoing story of silviculture on our natural public forestlands. Journal of Forestry 112(6): 611-616.
• Type: Journal Articles Status: Published Year Published: 2017 Citation: Pretzsch, H., and E.K. Zenner. Toward managing mixed-species stands: from parametrization to prescription. Forest Ecosystems, 4(19)1-17.

Progress 10/01/15 to 09/30/16

Outputs
Target Audience:Predominantly forestry professionals, particularly within public land management agencies such as the Bureau of Forestry and the USDA Forest Service, as well as NGOs interested in creating and maintaining structural complexity in managed forests. Efforts include formal classroom instruction to undergraduate and graduate students (FOR 410: Forest ecosystem management; FOR 421: Silviculture) and presentations to foresters, ecologists, natural resources professionals, and farmers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Graduate student, teaching a workshop How have the results been disseminated to communities of interest?Results of our research were disseminated one national conference in Duluth, Minnesota. The PI was invited to teach a 2-day workshop module on forest stand dynamics to the National Advanced Silviculture Workshop at the University of Tennessee. The PI has served as peer-reviewer on several scientific papers and continued his outreach efforts with local, national, and international stakeholders. The PI continues his work as Deputy Coordinator for the IUFRO working group on uneven-aged forests and helped organized this year's conference that was held in Little Rock, Arkansas. What do you plan to do during the next reporting period to accomplish the goals?I will continue to analyze data that have been collected this summer in nine old-growth stands in the Pacific Northwest and prepare several manuscripts on structure and its complexity and development.

Impacts
What was accomplished under these goals? Based on our investigation of spatial patterns and forests structures of various forests throughout North America and Europe we have developed a new method for characterizing sub-stand structures that relies on the method of floating neighborhoods. We have tested the method in an old-growth stand from the Pacific Northwest and are now applying the same to test a new hypothesis (gap absorption hypothesis) in forests that are characterized by small-scale gap dynamics. We are in the last stages of finishing several manuscripts detailing this new method and employing it to test the gap absorption hypothesis, which may provide a paradigm shift in thinking about the stand dynamics away from development phases that have dominated the thinking about ecological processes in old-growth forests for decades. We will apply this method to a dataset of a 10 ha stem-mapped plot of a virgin European beech forest located in the Carpathian Mountains in the Ukraine next year. Analyses of leaf-off LiDAR describing the three-dimensional forest structure of several large landscapes across Pennsylvania are have been completed, landscape-level models have been developed to link the presence of cerulean warblers to landscape topology and forest structure, and the student working on this project has defended her thesis. We are in the process of writing up the thesis for publication. It is our hope that conservation biologists may use these models to predict likely places in the landscape where Ceruleans may be detected and use this as a starting point for managing this species of concern in Pennsylvania. Previously collected band growth measurements on individual trees from a 16-ha stem-mapped Smithsonian Institution Global Earth Observatory (SIGEO) plot located at the Smithsonian Environmental Research Center (SERC) in Maryland have been analyzed and new types of growth models have been formulated. Manuscripts are being developed that describe these results. Further, tree growth (i.e., carbon sequestration) models as a function of local neighborhood structures and competition have been developed and these results are also in the process of being written up.

Publications

• Type: Journal Articles Status: Published Year Published: 2016 Citation: Zenner, E.K., J.E. Peck, M.L. Hobi, and B. Commarmot. 2016. Validation of a classification protocol: meeting the prospect requirement and ensuring distinctiveness when assigning forest development phases. Applied Vegetation Science, 19:541552.
• Type: Book Chapters Status: Published Year Published: 2016 Citation: Zenner, E.K. Managing Central hardwood forests within the context of the historic range of variability (HRV): challenges and opportunities. 2016. P. 371-391 In: Natural disturbances and range of variation: type, frequency, severity, and post-disturbance structure in Central hardwood forests. C.H. Greenberg and B. Collins (eds), Springer Verlag, Volume 32 of the series Managing Forest Ecosystems. 400 p.
• Type: Other Status: Published Year Published: 2016 Citation: Zenner, E.K. 2016. Discussion: Desirable and undesirable conditions as guides in natural resources management. Journal of Forestry 114(6): 666-667.
• Type: Journal Articles Status: Awaiting Publication Year Published: 2017 Citation: Jourgholami M., A. Khoramizadeh, and E.K. Zenner. 2016. Effects of soil compaction on seedling morphology, growth, and architecture of chestnut-leaved oak (Quercus castaneifolia C.A.M.) in greenhouse situations. iForest In press.
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Nahgdi, R., A. Solgi, E.R. Labelle, and E.K. Zenner. 2016. Influence of ground-based skidding on physical and chemical properties of forest soils and their effects on maple seedling growth. European Journal of Forest Research, 135:949962.
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Zenner, E.K. 2016. Differential growth response to increasing growing stock and structural complexity in even- and uneven-sized mixed Picea abies stands in southern Finland. Canadian Journal for Forest Research, 46:11951204.

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:Predominantly forestry professionals, particularly within public land management agencies such as the Bureau of Forestry and the USDA Forest Service, as well as NGOs interested in creating and maintaining structural complexity in managed forests. Efforts include formal classroom instruction to undergraduate and graduate students (FOR 410: Forest ecosystem management; FOR 421: Silviculture) and presentations to foresters, ecologists, natural resources professionals, and farmers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Graduate student training; outreach to professional foresters and wildlife managers. How have the results been disseminated to communities of interest?Publications, conferences, outreach in the field What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? My lab is continuing to investigate spatial patterns and forests structures of various forests throughout North America and Europe and we are beginning to develop new ecological hypothesis and concepts to explain stand dynamics. We are working toward a paradigm shift in thinking about the stand dynamics that is more aligned with currently accepted ecological hypothesis. We will continue to explore a dataset of a 10 ha stem-mapped plot of a virgin European beech forest located in the Carpathian Mountains in the Ukraine as the basis for this work and explore the linkages of forest structure to stand development phases at multiple scales. Analyses of leaf-off LiDAR describing the three-dimensional forest structure of several large landscapes across Pennsylvania are have been completed and landscape-level models have been developed to link the presence of cerulean warblers to landscape topology and forest structure. These models can be used as a starting point for a search image where Ceruleans may be found. Previously collected band growth measurements on individual trees from a 16-ha stem-mapped Smithsonian Institution Global Earth Observatory (SIGEO) plot located at the Smithsonian Environmental Research Center (SERC) in Maryland have been analyzed and new types of growth models have been formulated. Next steps are to investigate to what extent tree growth (i.e., carbon sequestration) is a function of local neighborhood structures and competition. Results of our research were disseminated one international conference: a IUFRO meeting about spruce management that took place in Edmonton, Canada. The PI was invited to give presentations of his research on two occasions in Birmensdorf, Switzerland. The PI was invited to teach a 2-day workshop module on forest stand dynamics to the National Advanced Silviculture Workshop at the University of Tennessee. The PI has served as peer-reviewer on several scientific papers and continued his outreach efforts with local, national, and international stakeholders. The PI has been re-appointed as Deputy Coordinator for the IUFRO working group on uneven-aged forests.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: Zenner, E.K., J.E. Peck, M.L. Hobi, and B. Commarmot. 2015. The dynamics of structure across a primeval European beech stand. Forestry, 88:180-189.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Zenner, E.K., K. Sagheb-Talebi, R. Akhavan, and J.E. Peck. 2015. Integration of small-scale canopy dynamics smoothes live-tree structural complexity across development stages in old-growth Oriental beech (Fagus orientalis Lipsky) forests at the multi-gap scale. Forest Ecology and Management, 335:26-36.
• Type: Journal Articles Status: Awaiting Publication Year Published: 2015 Citation: Peck, J.E., B. Commarmot, M.L. Hobi, and E.K. Zenner. 2015. Should reference conditions be drawn from a single 10 ha plot? Assessing representativeness in a 10,000 ha old-growth European beech forest.

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Predominantly forestry professionals, particularly within public land management agencies such as the Bureau of Forestry and the USDA Forest Service, as well as NGOs interested in creating and maintaining structural complexity in managed forests. Efforts include formal classroom instruction to undergraduate and graduate students (FOR 410: Forest ecosystem management; FOR 421: Silviculture) and presentations to foresters, ecologists, natural resources professionals, and farmers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Results from previous and ongoing studies are in preparation and some have been published in several peer-reviewed journal articles. Examples of findings include a better understanding of (1) the development of forest structure in European beech old-growth forests; (2) the use of several spatially independent attributes and spatially explicit metrics for describing small-scale structural complexity and associated processes; (3) the exploration of the use of Lidar for classifying the structure and habitat quality of stands for the cerulean warbler. We have disseminated these research results in various meetings and at workshops to researchers, professional foresters, and landowners with the intent that managers consider our research results when implementing silvicultural prescriptions. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Analyses of a dataset of a 10 ha stem-mapped plot of a virgin European beech forest located in the Carpathian Mountains in the Ukraine has been completed for scale effects on forest structure and spatial patterns. Further analyses linking forest structure to stand development phases are in progress. Analyses of leaf-off LiDAR describing the three-dimensional forest structure of several large landscapes across Pennsylvania are in progress. The analyses aim to link the presence of cerulean warblers to forest structures to aid management for this species of concern. Previously collected band growth measurements on individual trees from a 16-ha stem-mapped Smithsonian Institution Global Earth Observatory (SIGEO) plot located at the Smithsonian Environmental Research Center (SERC) in Maryland have been analyzed and we are in the process of writing up these results for publication. Results of our research were disseminated at national and international conferences: a Symposium on natural disturbances and historic range of variation in central hardwood forests organized by the Association of Southeastern Biologists in Spartanburg, SC and an IUFRO meeting about uneven-aged forestry in Birmensdorf, Switzerland. The PI was invited to give presentations of his research at a Symposium on natural early-seral forest ecosystems, Nationalpark Bayerischer Wald, Hohenau, Germany. The PI was invited to teach a 2-day workshop module on forest stand dynamics to the National Advanced Silviculture Workshop at the University of Tennessee. The PI has served as peer-reviewer on numerous scientific papers.

Publications

• Type: Journal Articles Status: Published Year Published: 2014 Citation: Kastendick, D., B. Palik, E.K. Zenner, R. Kolka, C. Blinn, and J. Kragthorpe. 2014. Regeneration responses in partially-harvested riparian management zones in northern Minnesota. Journal of Water Resource and Protection, doi: 10.4236/jwarp.2014.66054.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Dickinson, Y.L., E.K. Zenner, and D. Miller. 2014. Examining the effect of diverse management strategies on landscape scale patterns of forest structure in Pennsylvania using novel remote sensing techniques. Canadian Journal of Forest Research, 44:301-312.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Peck, J.E., E.K. Zenner, P. Brang, and A. Zingg. 2014. Tree size distribution and abundance explain structural complexity differentially within stands of even- and uneven-aged structure types. European Journal of Forest Research, 133:335-346.

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: Predominantly forestry professionals, particularly within public land management agencies such as the Bureau of Forestry and the USDA Forest Service, as well as NGOs interested in creating and maintaining structural complexity in managed forests. Efforts include formal classroom instruction to undergraduate and graduate students (FOR 410: Forest ecosystem management; FOR 421: Silviculture) and presentations to foresters, ecologists, natural resources professionals, and farmers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Professional development was provided in the form of seminars and workshops that were offered by the PI. How have the results been disseminated to communities of interest? Via publications, workshops, and presentations at conferences What do you plan to do during the next reporting period to accomplish the goals? Continue to follow the plan as laid out in the proposal

Impacts
What was accomplished under these goals? Ten study sites composed of even-aged mixed conifer stands located throughout Switzerland for which long-term datasets are available were analyzed and changes of structural complexity following different thinning entries were analyzed. Stand inventories noting tree position, species, and diameter at breast height were conducted immediately before thinning entries and the spatial position of every tree noted. Data collection and analysis have been completed and a manuscript is on review. A second dataset of a 10 ha stem-mapped plot of a virgin European beech forest located in the Carpathian Mountains in the Ukraine has been obtained and analyses of structural complexity and spatial patterns are in progress. Manuscripts reporting on the amount of carbon stored in different mixed oak forests following six different cutting treatments have been submitted for review. Several stands in and around the Allegheny National Forest in North Central Pennsylvania were surveyed for the Cerulean warbler and other associated bird species. Work concentrated on hardwood stands > 5 acres and > 50 years old with values for stocking percent (relative density), basal area, and average diameter at breast height (dbh) that are known to be associated with the presence of the Cerulean warbler. Leaf-off aerial LiDAR data for all sites has been obtained from PAMAP. We are in the process of preparing data. Previously collected band growth measurements on individual trees from a 16-ha stem-mapped Smithsonian Institution Global Earth Observatory (SIGEO) plot located at the Smithsonian Environmental Research Center (SERC) in Maryland are currently being analyzed.

Publications

• Type: Book Chapters Status: Awaiting Publication Year Published: 2014 Citation: Nagel, T., Zenner, E.K., and P. Brang. What can a forest manager learn from research in old-growth forests? Contribution to a book published by the European Forest Institute, in press.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Zenner, E.K., M.A. Martin, B.J. Palik, J.E. Peck, and C.R. Blinn. 2013. Response of herbaceous plant community diversity and composition to overstorey harvest within riparian management zones in northern hardwoods. Forestry, 86:111-117.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Zenner, E.K., Y.L. Dickinson, and J.E. Peck. 2013. Recovery of forest structure and composition to harvesting in different strata of mixed even-aged central Appalachian hardwoods. Annals of Forest Science, 70:151-159.