ROLE OF TREE PLANTING DIVERSITY IN DETERMINING PRODUCTIVITY, SUSCEPTIBILITY TO INSECT HERBIVORES, AND NATURAL ENEMY COMMUNITIES IN MANAGED FORESTS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: MCINTIRE-STENNIS
• Reporting Frequency: Annual
• Accession No.: 1018694
• Project Start Date: Feb 8, 2019
• Project End Date: Sep 30, 2022
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIV OF MARYLAND
(N/A)
COLLEGE PARK,MD 20742

Performing Department
Entomology

Non Technical Summary
Forests and forest plantations are critically important to human societies. Biodiversity is widely recognized as an important magnifier of productivity and a buffer against disturbance, yet nearly all forest plantations are planted as monocultures and natural forest stands are losing diversity worldwide. Within grassland systems greater plant diversity supports a higher abundance and diversity of natural enemies. These enemies, in turn, can control herbivore populations and prevent insect outbreaks. Whether this occurs in forested systems is less well-known. Here, we propose to collect and analyze data on the 1) natural enemy communities (predators and parasitoids), 2) natural enemy attack rates, and 3) tree damage and productivity found within monoculture vs. polyculture tree neighborhoods in an established five-year old tree biodiversity experiment in Edgewater, MD. Results from this study will determine whether diverse planting strategies can lead to more sustainable forest ecosystems and silvicultural plantations through the promotion of natural enemy populations as an important ecosystem service. Maintaining resource production in forests such as these will only become more important as the changing climate is predicted to increase insect herbivore damage and the need for carbon sequestration within forest land.

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	0699	1070	50%
123	3199	1130	50%

Knowledge Area
123 - Management and Sustainability of Forest Resources;

Subject Of Investigation
3199 - Invertebrates, general/other; 0699 - Trees, forests, and forest products, general;

Field Of Science
1130 - Entomology and acarology; 1070 - Ecology;

Keywords

managed forests

diversity

natural enemies

tree productivity

insects

monoculture

polyculture

ecosystem services

Goals / Objectives
Determine whether tree planting diversity can be utilized as a management tool in reforestation projects and managed forests to enhance natural enemy populations decreasing herbivore pest damage and outbreaks.Determine whether changes in the ecosystem service of pest suppression results in increases in tree productivity.Determine if these results are ubiquotous across all 10 tree species within the experiment (common in eastern deciduous forests of the mid-atlantic USA)Determine whether parasitods and generalist predators respond similarly to tree diversity

Project Methods
Scientific methods: This project utilizes a focal tree sampling design within an already established tree diversity experiment. The experiment consists of 16 species of tree planted in treatments of 1, 4, and 12 species mixtures (see proposal for more detail). On all 360 focal trees, we will sample natural enemy populations and quantify attack rates by parasitoids of insect herbivores across this diversity gradient at least twice over the course of the growing season. Further we will use standard methods to quantify tree damage and relative growth rates over the course of the season. The data will be analyzed to determine whether natural enemies exert different levels of top-down control of insect herbivores across the diversity treatments using a combination of g(LMM)s and path analysis. These results will be communicated to forest ecologists and entomologists through a peer-reviewed publication and presentations at scientific conferences. The results with be discussed with local land-managers and private forest owners through presentations and workshops organized through the University of Maryland Extension office. These efforts will be evaluated through a before/after impact survey conducted during the workshops and presentations.

Progress 10/01/20 to 09/30/21

Outputs
Target Audience:Forest ecologists and entomologists, land managers overseeing forests or afforestation/restoration projects (e.g. for riparian buffer reforestation), small and large holders of private forest lands. Changes/Problems:Other than a pause to the field collection of data in 2020 due to Covid, we are on track. What opportunities for training and professional development has the project provided?The project has provided professional developent for one early career PI and the ability to perform fieldwork and learn field and lab techniques within a tree biodiversity experimentfor 2undergraduates, and 1 graduate student, and one postdoc fellow. At least 2 projects will be presented and the National Entomological Society meeting in 2021. How have the results been disseminated to communities of interest?Through Extension talks to stakeholders through Smithsonian's Earth Optimism Lectures, UME Master Gardener Trainings, and MD Critical Area trainings. What do you plan to do during the next reporting period to accomplish the goals?After the Covid delay we now have the data needed to produce final data analysis and publications.

Impacts
What was accomplished under these goals? After the 2020 data collection season was postponed due to Covid-19 and the closing of field sites, We were able to collect a full complement of data within the experiment in the 2021season including, tree growth, leaftrait, caterpillar, spider, and parasitoid communities. This sets us up well to analyze data this winter-spring and produce additional publications.

Publications

• Type: Journal Articles Status: Published Year Published: 2021 Citation: Schmitt, L^. and Burghardt, K.T*. (2021) Urbanization as a disrupter and facilitator of insect herbivore behaviors and life cycles. Current Opinion in Insect Science: 45, 97-105. https://doi.org/10.1016/j.cois.2021.02.016
• Type: Other Status: Published Year Published: 2020 Citation: Karin T. Burghardt; University of Nevada Reno, Ecology, Evolution, and Conservation Biology Program Seminar: Plant-herbivore interactions in human-dominated landscapes
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Max H. Ferlauto and Karin T. Burghardt, Ecological Society of America National Meeting; Salt Lake City, UT Assessing the impacts of seasonal leaf litter disturbance on overwintering pollinators and natural enemies

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

Outputs
Target Audience:Forest ecologists and entomologists, land managers and urban planners overseeing forests or afforestation/restoration projects(e.g. for riparian buffer reforestation), small and large holders of private forest lands and yards. Changes/Problems:Unfortunately the onset of Covid-19 in March 2020 meant that we were not able to access the tree experiment in the 2020 spring/summer/fall field season due to restrictions imposed by the Smithsonian Institution. This prevented our planned measurements in 2020 and we shifted our approach to include other activities instead. Those restrictions have currently been lifted and we are looking forward to collecting that data in the 2021 field season instead. Further, backorders on reagents have limited our planned barcoding of specimens but we are hopeful to begin that process again soon. What opportunities for training and professional development has the project provided?An undergraduate student learned how to collect spider community data and is nowworking to analyze that data for an Honor's thesis project in the University of Maryland Entomology Department. A graduate student is being trainedto identify the parasitoid species collected from reared individuals and take research quality images. How have the results been disseminated to communities of interest?Through twotalks at professional conferences and twotalks targetingthe general public green industry professionals. I have also presented the work at two invited departmental seminars. Further, the work is highlighted through alab research and extension website and blog as well as a twitter account. What do you plan to do during the next reporting period to accomplish the goals?If Covid allows, we plan to collect tree, caterpillar, and parasitoid data in the summer of 2021 and continue analysis of previous data. We are also planning to expandthe processes examined in the tree diversity experiment to leaf litter decomposition.

Impacts
What was accomplished under these goals? We collected asecond year of tree growth metric data in Feb-Mar 2020and substantial progress was made on identifying parasitoids and analyzing generalist predator data. Currently our analysis suggests that generalist predators are more influenced by tree species than surrounding tree diversity although that is a preliminary result.

Publications

• Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Karin T. Burghardt, Eric Griffin, and John Parker; Entomological Society of America- National Meeting: Hidden players in forests and oldfields: Microbes both respond to and shape plant/insect interactions, St. Louis, MO
• Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Karin T. Burghardt; American Naturalist Society Conference: The role of tree neighborhoods in structuring tree/insect/microbe interactions, Pacific Grove, CA

Progress 02/08/19 to 09/30/19

Outputs
Target Audience:Forest ecologists and entomologists, land managers and urban planners overseeing forests or afforestation/restoration projects(e.g. for riparian buffer reforestation), small and large holders of private forest lands and yards. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training activities: This project provided training in field experiment and collection and rearing skills for one undergraduate student researcher and one research technician along with one on one mentoring for data analysis with the undergraduate trainee. How have the results been disseminated to communities of interest?Through Sept 2019, I have incorporated these results into one Extension talk for the Southern Maryland Urban Pest Management Conference. What do you plan to do during the next reporting period to accomplish the goals?Data collection of all parameters will continue for a second year. The previous season's data will be analyzed and incorporated into research and extension publications, talks, and grant proposals.

Impacts
What was accomplished under these goals? Over the 7 months of the project thus far we collected data on 540 trees of 15 species located across an experimental gradient of tree diversity. These measurements included: 1) tree growth (root collar diameter, DBH, canopy volume, height) 2) leaf damage metrics 3) Paritism rates of 1000+ caterpillars sampled and reared in the lab from focal trees 4) Abundance of spider predators on focal trees In combination, once analyzed these metrics will allow us to achieve the major goals of the project as stated above.

Publications