uid=HFR,o=lter,dc=ecoinformatics,dc=org all public read doi:10.6073/pasta/a1b9f08bc955075cd43e55798ae2fbf9 David Orwig https://orcid.org/0000-0001-7822-3560 Nina Lany https://orcid.org/0000-0003-0868-266X Evan Preisser https://orcid.org/0000-0002-8737-5619 2023 English

In the eastern USA, eastern hemlock (Tsuga canadensis) is the host plant for two invasive insect species - hemlock woolly adelgid (Adelges tsugae) and elongate hemlock scale (Fiorinia externa). We observed the density of adult hemlock woolly adelgid and elongate hemlock scale on eastern hemlock branches on five occasions over 14 years at 142 stands across a latitudinal transect encompassing 7,500 km2 in Connecticut and Massachusetts to assess whether there is a difference in the response to abiotic conditions (winter temperature, summer temperature, summer precipitation) between the two species, and whether the distribution and abundance of each insect species is dependent on biotic interactions with the co-occurring insect species.

abundance climate hemlock hemlock woolly adelgid invasive species LTER controlled vocabulary populations disturbance LTER core area Harvard Forest HFR LTER USA HFR default

This dataset is released to the public under Creative Commons CC0 1.0 (No Rights Reserved). Please keep the dataset creators informed of any plans to use the dataset. Consultation with the original investigators is strongly encouraged. Publications and data products that make use of the dataset should include proper acknowledgement.

Creative Commons Zero v1.0 Universal https://spdx.org/licenses/CC0-1.0.html CC0-1.0 https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf289 Eastern Connecticut, Eastern Massachusetts. Coordinates based on WGS84 datum. -72.75 -72.13 +42.71 +41.27 0 378 meter 1997 2011 genus Adelges species tsugae hemlock woolly adelgid genus Fiorinia species externa elongate hemlock scale complete Information Manager Harvard Forest

324 North Main Street Petersham MA 01366 USA

(978) 724-3302 hf-im@lists.fas.harvard.edu Harvard Forest

324 North Main Street Petersham MA 01366 USA

(978) 724-3302 (978) 724-3595 https://harvardforest.fas.harvard.edu

Forest stands containing at least 10% eastern hemlock (Tsuga canadensis) cover in eastern Connecticut and Massachusetts were located via black-and-white aerial photographs, and 142 eastern hemlock stands within the study area were intensively sampled. In the initial year of sampling (1997 in Connecticut and 2002-2003 in Massachusetts), each stand was given an ordinal score for each insect species (hemlock woolly adelgid and elongate hemlock scale) representing the average infestation level of the stand based on thorough examination of trees as follows: 0 = 0 insects per meter of branch; 1 = 1-10 insects per meter; 2 = 11 – 100 insects per meter; 3 = more than 100 insects per meter. In subsequent years (2005, 2007, 2009, 2011), 50 trees were haphazardly selected in each stand for observation, and the density of each insect species on each tree was assigned to one of the above categories. Individual trees could not be marked. Fewer than 50 trees were sampled per stand in some highly-damaged stands, and stands impacted by logging or development during the study period were not sampled post-disturbance.

Daily temperature (maximum/minimum) and precipitation data were obtained for each stand from 1996 to 2011 from the online PRISM Gridded Climate database (PRISM Climate Group, Oregon State University, http://prism.oregonstate.edu, created 26 Mar 2015) by interpolating 4km2 resolution climate data at the centroid of each eastern hemlock stand using values from surrounding grid cell centers and inverse-distance squared weighting.

Harvard Forest

324 North Main Street Petersham MA 01366 USA

(978) 724-3302 (978) 724-3595 https://harvardforest.fas.harvard.edu https://ror.org/059cpzx98 pointOfContact The Harvard Forest Long-Term Ecological Research (LTER) program examines ecological dynamics in the New England region resulting from natural disturbances, environmental change, and human impacts. National Science Foundation LTER grants: DEB-8811764, DEB-9411975, DEB-0080592, DEB-0620443, DEB-1237491, DEB-1832210. hf289-01-stand.csv stand characteristics hf289-01-stand.csv 6584 98cb10cd042407f62a601a2b57e1265a 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf289/hf289-01-stand.csv plot character identifying each eastern hemlock stand character identifying each eastern hemlock stand NA missing value year year the plot was first sampled YYYY 1 year NA missing value long longitude degree 0.0001 real NA missing value lat latitude degree 0.0001 real NA missing value elevation elevation in meters above sea level meter 1 whole NA missing value area area of stand hectare 0.0001 real NA missing value 142 hf289-02-stand-year.csv data specific to each stand-year hf289-02-stand-year.csv 36516 2317c6d849b8c5c8e80a39691d544fe2 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf289/hf289-02-stand-year.csv plot character identifying each eastern hemlock stand character identifying each eastern hemlock stand NA missing value year year of sampling YYYY 1 year NA missing value sample.size number of trees in the stand for which abundance was recorded in the year of sampling number 1 whole NA missing value temp.min minimum winter temperature in the preceding winter celsius 0.1 real NA missing value tmean.winter mean winter temperature (Dec 1 through Mar 31) in the winter preceding sampling celsius 0.1 real NA missing value precip precipitation sum April 1 – Sept 30 of the sampling year millimeter 0.01 real NA missing value temp.max maximum temperature April 1 through Sept 31 of the sampling year celsius 0.1 real NA missing value 852 hf289-03-tree.csv tree-level ordinal abundance data hf289-03-tree.csv 672990 e54b221f845c1f563b3e8b2c1f709342 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf289/hf289-03-tree.csv plot character identifying each eastern hemlock stand character identifying each eastern hemlock stand NA missing value year year of sampling YYYY 1 year NA missing value tree tree number (individual trees were not marked, so e.g. tree #3 is the third tree observed in a stand in a year, but tree #3 is not the same individual year after year) tree number (individual trees were not marked, so e.g. tree #3 is the third tree observed in a stand in a year, but tree #3 is not the same individual year after year) NA missing value hwa hemlock woolly adelgid density per meter of branch 0 0 insects per meter of branch 1 1-10 insects per meter 2 11 – 100 insects per meter 3 more than 100 insects per meter NA missing value ehs elongate hemlock scale density per meter of branch 0 0 insects per meter of branch 1 1-10 insects per meter 2 11 – 100 insects per meter 3 more than 100 insects per meter NA missing value 27050 conservation invasive plot community regional long-term measurement https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf081