CAN FORESTS TAKE THE HEAT? MANAGING PESTS AND ECOSYSTEM SERVICES IN A WARMING CLIMATE

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: AFRI COMPETITIVE GRANT
• Reporting Frequency: Annual
• Accession No.: 1001433
• Grant No.: 2014-67013-21726
• Project No.: 02276
• Proposal No.: 2013-02476
• Program Code: A1111
• Project Start Date: Jan 15, 2014
• Project End Date: Jan 14, 2019
• Grant Year: 2014

Project Director
Frank, S.

Recipient Organization
NORTH CAROLINA STATE UNIV
(N/A)
RALEIGH,NC 27695

Performing Department
Entomology

Non Technical Summary
Urban forests provide important benefits to urban residents and in mitigating climate change. However, US urban forests are shrinking due in large part to arthropod pests which are more abundant and damaging in urban than rural forests. Our hypothesis, supported by extensive preliminary data, is that elevated temperatures due to the urban heat island effect increases arthropod pest abundance in cities and that urban forests predict pest outbreaks that will occur in rural forests due to global warming. We test these hypotheses by examining the ecological mechanisms that lead to increased scale insect abundance on trees in the hottest parts of Raleigh, NC and comparing our results to long-term experimental warming chambers in a nearby rural forest. We will investigate the how urban heat affects scale insect abundance directly (survival, aclimation) and indirectly by altering interactions with natural enemies or host plants. Then we will determine the consequences of temperature and scale insect abundance on tree growth and the ecosystem services using scale removal experiments and existing databases of urban temperature and the health of multiple urban trees species. This will generate recommendations of which tree species can 'take the heat' and tolerate the hottest sites in urban heat islands. Finally we will compare pest abundance and ecological interactions in rural forests under experimental warming to that of urban pest populations. Ultimately our project will unify existing theories on pest outbreaks in urban forests and be the first to understand the relationship between urban and global warming on forest health.

Animal Health Component

0%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
211	0530	1130	100%

Knowledge Area
211 - Insects, Mites, and Other Arthropods Affecting Plants;

Subject Of Investigation
0530 - Parks and urban green space;

Field Of Science
1130 - Entomology and acarology;

Keywords

arthropod pests

global warming

urban forests

urban heat island

Goals / Objectives
The long-term goals of this project are to determine how temperature and arthropod pests interact to affect tree health and ecosystem services, to improve the health and management of urban and rural forests under a changing climate, and to suggest whether urban forests are valuable predictors of future pest outbreaks in warming rural forests. Specifically, our objectives are to: 1. Document ecological mechanisms that lead to higher pest abundance in the hottest urban areas. We predict that temperature alters pest abundance by exerting direct effects on insect development, by causing phenological mismatches between pests and natural enemies, and by interacting with host plant quality and defense. We will test these mechanisms using factorial experiments in urban field sites and controlled greenhouses. 2. Evaluate the effect of urban temperature, pest abundance, and their interaction on ecosystem services, especially cooling and CO2 assimilation, provided by city street trees. We will measure growth and photosynthesis in urban trees and in controlled factorial experiments that vary both temperature and pest load. 3. Determine how elevated temperature affects tree health and pest outbreaks on multiple tree species on a landscape scale and identify species characteristics that predict tree performance. Using remotely sensed thermal data and existing GIS tree inventories of Raleigh, NC, and Boston, MA, we will model the relationship between temperature, pest abundance, tree characteristics, and tree health. 4. Determine whether mechanisms identified in Objective 1 also occur in warming rural forests. We will monitor pest and parasitoid abundance and plant quality in established warming chambers in a rural forest (Duke Forest, NC), to suggest whether effects of present-day urban warming on trees and pests predict future effects of climate change in rural forests.

Project Methods
Methods for Objective 1: We will conduct a 2 x 2 factorial experiment similar to that described in the preliminary results and in (13), in which P. quercifex ovisacs from hot and cold urban sites are reared in hot and cold Phytotron chambers programmed to mimic seasonal conditions of our urban sites. Scales will be reared on 20 willow oak saplings, which we will purchase in spring as bare-root stock from a local supplier. Each sapling will receive two ovisacs from a single source tree. For two years, we will record P. quercifex life stage and abundance on the saplings every week from March through June. We will analyze scale abundance and fecundity as a function of temperature treatment and source population using repeated measures ANOVA in the MIXED procedure of SAS software version 9.3 (SAS Institute, Cary, NC). Direct effects II. To evaluate the phenology and composition of natural enemy communities at hot and cold sites, we will hang a 3" x 5" yellow sticky card in each of 16 hot and 16 cold willow oak street trees. During the March-June critical period, we will replace sticky cards every week until crawlers on all trees have settled on leaves. During the summer, fall, and winter we will hang sticky cards once per month. We will repeat this procedure in years 1 and 2. On the same schedule, we will collect a 12cm branch from each cardinal direction of each tree. We will count the scales on half of each branch and place it in a glass vial with cotton plug in a growth chamber (28°C) to rear parasitoids. On the other half, we will count and dissect all scales to determine 1) scale developmental stage; 2) number of eggs present; and 3) number of parasitoids present. Top-down effects II. To isolate the effects of natural enemies and temperature on scale insect survival and abundance at hot and cold sites, we will conduct an exclusion experiment using the same study population of 16 hot and 16 cold willow oak street trees (Spring 2015). We will select two branches per tree and groom the terminal 1m of each branch so it has 1 ovisac and 100 leaves. One branch per tree will be covered with a sleeve cage to exclude predators and parasitoids; the other will be covered with a sham cage that allows natural enemy access. We will count scales in the cages every month for one year to determine how many crawlers emerge from the ovisac and how many survive each season. We will determine how temperature, exclusion, and their interaction affect the abundance of each scale life stage separately using Repeated Measures ANOVA in the MIXED Procedure of SAS. Bottom-up effects. To assess host plant quality, we will monitor water stress and foliar nitrogen both in our Phytotron saplings and in our willow oak street trees for two years, once per month when leaves are present (2014-2015). To assess water stress, we will use a PMS 1505D Pressure Chamber Instrument to measure leaf midday water potential (Ψ, in megapascals). We will determine how temperature, host nitrogen, host water stress, and their interactions affect scale abundance on Phytotron and fields trees using linear regression in the REG Procedure of SAS 9.3. In the Phytotron Analysis Temperature will be a categorical (dummy) variable since all trees in the hot or cold chambers experience the same temperature. Methods for Objective 2: Consequences I.To monitor tree growth, we will record the height of each sapling on the first day of the experiment and once per month thereafter. To calculate the rate and efficiency of photosynthesis (120), we will use a LI-COR LI-6400 portable photosynthesis system with a 6400-40 leaf chamber fluorometer to simultaneously measure leaf gas exchange (μmol CO2 and H2O per square meter per second) and chlorophyll fluorescence under mid-morning steady-state conditions. We will use repeated measures ANOVA in the MIXED Procedure of SAS to determine how temperature treatment (hot or cold), scale abundance (continuous; ANCOVA) and their interaction affect tree growth, photosynthetic rate, and photosynthetic efficiency. Consequences II. Baseline scale abundance in each tree will be established by counting live scales on four 15cm branches per tree in late winter. After sampling, trees in the scale-removal treatment will be sprayed with horticultural oil insecticide using a Stihl backpack insecticide blower. We will: (1) measure gas exchange and fluorescence of 3 leaves per tree twice per year over three years, using the LI-6400; (2) measure diameter at breast height (DBH) each year; (3) at the end of the experiment, collect four 1m branches per tree to measure annual growth between bud scars (79); and (4) collect and count seeds (maple samaras in spring, oak acorns in fall) from 10 randomly selected branches per tree per year. Samaras and acorns will be measured, dried, and weighed (83). We will use linear regression in the REG and GLM Procedures of SAS to determine how temperature, scale insect abundance, and their interaction affect photosynthesis rate and efficiency, DBH, branch growth, and seed production with map grid cell as a blocking factor. Methods for Objective 3: We will use existing municipal street-tree inventories in conjunction with Landsat thermal imagery. We currently have access to inventories for Raleigh, NC, and Boston, MA. For each tree, these databases include species, geographic coordinates, and condition. We will overlay a shapefile of all trees with a thermal map of their city in ArcMap 10. We have already developed these maps using publicly available Landsat 5 images, according to (123). The temperature of each pixel will be associated with the health score of the tree it contains (or, when multiple trees reside in the same pixel, their mean health score). We will use regression analyses to determine the relationship between health score on temperature for each species. A significant regression model with a negative slope indicates that a species declines in condition at high temperature. We will use the slopes from the regression analyses of each species to construct and test models in the GENMOD Procedure of SAS that predict tree performance (the slopes of the health-temperature regressions for each species) on the basis of these traits. Methods for Objective 4: The study system is a set of 12 open-top chambers, 5m wide and warmed 0-5.5°C above ambient with a forced-air system since 2009 (104). We will continue to monitor scale insect abundance on all red maple saplings in the chambers twice per year to extend our preliminary data and document the ongoing effects of this short-term warming experiment. We will also test chamber plants for potential bottom-up effects via water stress and nitrogen, as described above. To document direct and top-down effects of temperature on scale insects, we will introduce scales on potted maples because existing populations in cool chambers are too small (zero to 5 individuals) to yield meaningful results. We will monitor scale abundance and developmental stage every two weeks in the spring and fall, and every two months throughout the year, for two years (2016-2017). We will determine how temperature, exclusion, and their interaction affect the abundance of each scale life stage separately using Repeated Measures ANOVA in the MIXED Procedure of SAS.

Progress 01/15/14 to 01/14/19

Outputs
Target Audience:The target audiences for this project include scientists in the fields of urban forestry, urban ecology, climate change, entomology, integrated pest management, and others. The target audiences for dissemination of results includes these science fields but also professionals in the tree care and landscape industries, extension personnel, urban foresters, urban planners, and others. We provided extension presentations to landscape professionals, arborists, urban foresters, and related clientele. We provided outreach to the general public at a science cafe presentation at the North Carolina Museum of Natural Sciences. We reached academics and researchers at professional meetings such as Entomological Society of America and during visits to other universities. We presented to USFS and USGS personel via webinars and presentations. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided opportunities to train high school students, undergraduate and graduate students, and postdocs. We have also used results to train extension personnel and end users such as arborists and urban foresters. How have the results been disseminated to communities of interest? What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? 1. Document ecological mechanisms that lead to higher pest abundance in the hottest urban areas.We tested these mechanisms using factorial experiments in urban field sites and controlled greenhouses. We measured tree growth and physiological processes of willow oaks and red maples in the field and in controlled growth chamber experiments. We documented greater scale insect growth and survival in warmer sites and in warmer growth chambers. A mechanism for this was greater fecundity on hot and water stressed trees. We also studied the role of natural enemies which played a non-significant role after accounting for effects of warming and drought stress. We also considered effects of tree genotype and habitat complexity. 2. Evaluate the effect of urban temperature, pest abundance, and their interaction on ecosystem services, especially cooling and CO2assimilation, provided by city street trees.We measured growth and photosynthesis in urban trees and in controlled factorial experiments that vary both temperature and pest load. We document the ecosystem service of carbon sequestration was reduced by a combination of factors including high temperatures and pests. Other ecosystem services related to leaf level prcesses such as cooling via transpiration were likely also reduced but not measured. 3. Determine how elevated temperature affects tree health and pest outbreaks on multiple tree species on a landscape scale and identify species characteristics that predict tree performance.Using remotely sensed thermal data and existing GIS tree inventories of Raleigh, NC, and other cities we modeled the relationship between temperature, pest abundance, tree characteristics, and tree health. We found that the role of impervious surface cover as a variable that accounts for warming and drought has consistent negative effects on trees throughout the southeastern US and mid-atlantic regions. 4. Determine whether mechanisms identified in Objective 1 also occur in warming rural forests.We measured pest abundance in urban trees and adjacent forest areas as another measure of how temperature may affect urban trees at different latitudes.

Publications

• Type: Journal Articles Status: Published Year Published: 2018 Citation: Meineke, E.K. and Frank, S.D. (2018) Water availability drives urban tree growth responses to herbivory and warming. Journal of Applied Ecology, DOI: 10.1111/1365-2664.13130.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Hamblin, A.L. , Youngsteadt, E., Frank, S.D. (2018) Wild bee abundance declines with urban warming, regardless of floral density. Urban Ecosystems, https://doi.org/10.1007/s11252-018-0731-4.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: McCluney, K.E., George, T., Frank, S.D. (2018) Water availability influences arthropod water demand, hydration and community composition on urban trees. Journal of Urban Ecology, 4(1): https://doi.org/10.1093/jue/juy003.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Lahr, E.C., Dunn, R.R., and Frank, S.D. (2018) Variation in photosynthesis and stomatal conductance among red maple (Acer rubrum) urban planted cultivars and wildtype trees in the southeastern United States. PLOS One: 13(5): e0197866.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Lahr, E.C., Dunn, R.R., and Frank, S.D. (2018) Getting ahead of the curve: cities as surrogates for global change. Proceedings of the Royal Society B, 285: 20180643. http://dx.doi.org/10.1098/rspb.2018.0643.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Just, M.G., Frank, S.D., and Dale, A.G. (2018) Impervious surface thresholds for urban tree site selection. Urban Forestry & Urban Greening, 34: 141-146. https://doi.org/10.1016/j.ufug.2018.06.008.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Dale, A.G. and Frank, S.D. (2018) Urban plants and climate drive unique arthropod interactions with unpredictable consequences. Current Opinion in Insect Science, 29: 27-33. https://doi.org/10.1016/j.cois.2018.06.001.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Long, L.C. , DAmico, V., Frank, S.D. (2019) Urban forest fragments buffer trees from warming and pests. Science of the Total Environment, 658: 1523-1530.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Frank, S.D., Backe, K.M. , McDaniel, C.*, Green, M., Widney, S., Dunn, R.R. (2019) Exotic urban trees conserve similar natural enemy communities to native congeners but have fewer pests. PeerJ: 7:e6531 https://doi.org/10.7717/peerj.6531.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Just, M.G., Long, L.C. , Dale, A.G., and Frank, S.D. (2019) Urbanization drives unique latitudinal patterns of insect herbivory and tree condition. Oikos. https://doi.org/10.1111/oik.05874.

Progress 01/15/17 to 01/14/18

Outputs
Target Audience: The target audiences reached include urban foresters, landscapers, arborists, and municipal personnel. The general public was also educated during this reporting period. We also made presentations and publications targeting scientists and extension personnel. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? This grant has contributed to training 2 postdocs and 3 graduate students. We have had undergraduates and highschool students also contribute to this project and present work at national meetings. How have the results been disseminated to communities of interest? We provided extension presentations to landscape professionals, arborists, urban foresters, and related clientele. WE also publish articles in industry publications like Landscape Management and news letters of the NC Urban Forest Council. We provided outreach to the general public at the North Carolina Museum of Natural Sciences and other public events. We reached academics and researchers at professional meetings such as Entomological Society of America and during visits to other universities. We presented to USFS and USGS personel via webinars and presentations. What do you plan to do during the next reporting period to accomplish the goals?We will focus on finishing data collection and analysis for Objective 3 and continue writing peer reviewed papers with data collected for other objectives.

Impacts
What was accomplished under these goals? 1. Document ecological mechanisms that lead to higher pest abundance in the hottest urban areas. In this objective we continued sampling scale insect abundance and natural enemy abundance on urban trees and neaby urban forests to compare the effects of temperature and habitat. 2. Evaluate the effect of urban temperature, pest abundance, and their interaction on ecosystem services, especially cooling and CO2 assimilation, provided by city street trees. For this objective we documented lower photosynthesis at hotter sites and thus less growth and carbon sequestration. We expanded this investigation to include the effects of drought on tree stress, growth, and pests. 3. Determine how elevated temperature affects tree health and pest outbreaks on multiple tree species on a landscape scale and identify species characteristics that predict tree performance. Work on this objective is still underway. 4. Determine whether mechanisms identified in Objective 1 also occur in warming rural forests. We have continued comparing the effects of warming in urban street trees with trees atthe edge and interior of natural forests along a latitudinal gradient. We have collected data in an outdoor warming experiment that is still being processed and analyzed. The impact of this project has been development of planting recommendations that take into account the amount of impervious surface cover, and thus heat and drought, around a tree or planting site. We produced thresholds so that urban planners and planters can assess tree locations for how they will affect the longer term health and services of the tree. Using these recommendations will have a longterm impact on the healt of urban forests and thus maximize the environmental and human health benefits of urban trees.

Publications

• Type: Journal Articles Status: Published Year Published: 2017 Citation: Hamblin, A.L. , Youngsteadt, E., L�pez-Uribe, M.M., Frank, S.D. (2017) Physiological thermal limits predict differential responses of bees to urban heat-island effects. Biology Letters. 13: 20170125.

Progress 01/15/16 to 01/14/17

Outputs
Target Audience:The target audiences for this project are: 1)scientific community interested in the effects of urban and climate warming on arthropod pests and tree health 2)extension personnel who work with landscapers, arborists, municiple foresters, and other land managers and IPM professionals 3)landscapers, arborists, municiple foresters, and other land managers and IPM professionals Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? We have had undergraduates and highschool students also contribute to this project and present work at national meetings. How have the results been disseminated to communities of interest? We provided extension presentations to landscape professionals, arborists, urban foresters, and related clientele. We reached academics and researchers at professional meetings such as Entomological Society of America and during visits to other universities. We presented to USFS and USGS personel via webinars and presentations. What do you plan to do during the next reporting period to accomplish the goals? Continue our experiments and analysis of data we have already collected.

Impacts
What was accomplished under these goals? WE have continued progress on objective 1 by investigating how warming affects natural enemies such as parasitoids and spiders. We have addressed objective 2 this period by measuring and calculating the growth and carbon sequestration by trees under different urban warming regimens. We have characterised the habitat variables, especially impervious surface cover, that predict red maple growth and health and used these to develop thresholds for tree planting to address objective 3. We published work that relates the effects of urban warming to that of warming in natural forests for scale insect pest abundance.

Publications

• Type: Journal Articles Status: Published Year Published: 2016 Citation: Meineke, E.K. , Holmquist, A.J.*, Wimp, G.M., Frank, S.D. (2017) Changes in spider community composition are associated with urban temperature, not herbivore abundance. Journal of Urban Ecology, 3 (1): juw010. doi: 10.1093/jue/juw010.
• Type: Journal Articles Status: Published Year Published: 2017 Citation: McCluney,K.E., Burdine, J.D., Frank, S.D. (2017) Variation in arthropod hydration across US cities with distinct climate. Journal of Urban Ecology, 3 (1): jux003. doi: 10.1093/jue/jux003
• Type: Journal Articles Status: Published Year Published: 2017 Citation: Dale, A.G. , Frank, S.D. (2017) Warming and drought combine to increase pest insect fitness on urban trees. PLoS ONE 12(3): e0173844. doi:10.1371/journal.pone.0173844.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Youngsteadt, E., Henderson*, R. C., Savage, A. M., Ernst, A. F., Dunn, R. R. and Frank, S. D. (2014) Habitat and species identity, not diversity, predict the extent of refuse consumption by urban arthropods. Global Change Biology, doi: 10.1111/gcb.12791.
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Dale, A.G. , Youngsteadt, E., Frank, S.D. (2016) Forecasting the effects of heat and pests on urban trees: Impervious surface thresholds and the Pace to Plant technique. Arboriculture & Urban Forestry, 42(3): 181-191.
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Meineke, E.K. , Youngsteadt, E.K., Dunn, R.R., Frank, S.D. (2016) Urban warming reduces aboveground carbon storage. Proceedings of the Royal Society  B, 283: 20161574.
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Youngsteadt,E., Ernst, A.F., Dunn, R.R., Frank, S.D. (2016) Responses of arthropod populations to warming depend on latitude: evidence from urban heat islands. Global Change Biology, doi: 10.1111/gcb.13550

Progress 01/15/15 to 01/14/16

Outputs
Target Audience:The target audiences reached include urban foresters, landscapers, arborists, and municipal personnel. The general public was also educated during this reporting period. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This grant has contributed to training 2 postdocs and 3 graduate students. We have had undergraduates and highschool students also contribute to this project and present work at national meetings. How have the results been disseminated to communities of interest?We provided extension presentations to landscape professionals, arborists, urban foresters, and related clientele. We provided outreach to the general public at the North Carolina Museum of Natural Sciences and UNC Botanical Gardens. We reached academics and researchers at professional meetings such as Entomological Society of America and during visits to other universities. We presented to USFS and USGS personel via webinars and presentations. What do you plan to do during the next reporting period to accomplish the goals?Continue our experiments and analysis of data we have already collected.

Impacts
What was accomplished under these goals? We have continued progress on objective 1 by investigating physiological mechanisms such as increased egg load and survival of scale insects for pest outbreaks and mechanisms associated with poor biocontrol by natural enemies such as a phenological mismatch between parasitoids and scales. We continued working on objective 2 by measuring photosynthesis, growth, and stress of our study trees and conducting experiments to assess the role of drought and of interactions between herbivores and heat. Wehave begun work on Objective 3 investigating multiple tree species and their condiction under different thermal environments. We have also worked on objective by collecting data from duke forest and from historical herbarium specimens.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: Youngsteadt, E., Appler, R.H., L�pez-Uribe, M., Tarpy, D.R., Frank, S.D. (2015) Urbanization increases pathogen pressure on feral and managed honey bees. PLoS ONE, 10(11): e0142031.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Meineke, E. K. , Dunn, R. R., Frank, S. D. (2014) Early pest development and loss of biological control are associated with urban warming. Biology Letters, doi: 10.1098/rsbl.2014.0586.

Progress 01/15/14 to 01/14/15

Outputs
Target Audience: Nothing Reported 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? We provided extension presentations to landscape professionals, arborists, urban foresters, and related clientele. We provided outreach to the general public at a science cafe presentation at the North Carolina Museum of Natural Sciences. We reached academics and researchers at professional meetings such as Entomological Society of America and during visits to other universities. We presented to USFS and USGS personel via webinars and presentations. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? We have made progress on objective 1 by investigating physiological mechanisms for pest outbreaks and mechanisms associated with natural enemies. We began working on objective 2 by measuring photosynthesis, growth, and stress of our study trees. to assess ecosystem services and tree health. We have also worked on objective 4.

Publications

• Type: Journal Articles Status: Published Year Published: 2014 Citation: Youngsteadt, E., Dale, A.G., Terando, A., Dunn, R.R., Frank, S.D. 2014. Congruent effects of urban and global warming on an insect herbivore. Global Change Biology. doi: 10.1111/gcb.12692
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Dale, A.G. and Frank, S.D. 2014. Heat and pests combine to reduce street tree condition. PloS One. DOI: 10.1371/journal.pone.0102996
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Frank, S.D. 2014. Bad neighbors: urban habitats increase cankerworm damage to non-host understory plants. Urban Ecosystems. Doi: 10.1007/s11252-014-0368-x
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Dale, A.G. and Frank, S.D. 2014. Urban warming trumps natural enemy regulation of herbivorous pests. Ecological Applications. doi.org/10.1890/13-1961.1