Red-backed Salamanders as Indicators of Hemlock Forest Health at Harvard Forest 2014

doi:10.6073/pasta/54f3d3e9429111d446b3f15882e867c6 Red-backed Salamanders as Indicators of Hemlock Forest Health at Harvard Forest 2014 Aaron Ellison https://orcid.org/0000-0003-4151-6081 Ahmed Siddig https://orcid.org/0000-0002-8145-0964 Alison Ochs 2023 English

Species that react quickly to ecological changes are useful indicators for assessing forest health. Red-backed salamanders (Plethodontid cinereus) may be used as an indicator species in declining hemlock forests, allowing for assessment of soil quality and forest health. We hypothesized that decline of hemlock stands due to the effect of hemlock woolly adelgid would negatively impact the abundance of red-backed salamanders by altering soil quality. In the Hemlock Removal Experiment at Harvard Forest, eight-0.8ha plots were treated either with girdling to simulate adelgid invasion, logging to simulate preemptive logging strategies, no treatment in hemlock areas, or no treatment in hardwood areas. Within these treatments in June and July of 2014, P. cinereus relative abundance was determined from coverboard surveys. Soil quality was determined from core samples. Bulk density, pH, carbon-nitrogen ratio, moisture, soil temperature, and litter depth were measured, and ordination was used to create an index of soil quality from these. There was a significant correlation between plot treatment and soil quality (p less than 0.05). Temperature, CN ratio, and pH influenced a strong significant negative correlation between soil quality and salamander abundance (pless than 0.05). Soil quality affected by hemlock decline influenced salamander abundance. These data suggest that we could gain an understanding of forest health and soil quality by examining salamander abundance. Assessing adelgid invasion can be difficult and objective, whereas salamander abundances are easily measured; therefore, we suggest that salamander abundances could be useful in assessing the health of hemlock forest ecosystems.

carbon leaf litter nitrogen salamanders soil chemistry soil moisture soil temperature 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=hf292 Simes Tract (Harvard Forest). Coordinates based on WGS84 datum. -72.2182 -72.2114 +42.4793 +42.4658 200 240 meter 2014 2014 genus Plethodon species cinereus red-backed salamander genus Tsuga species canadensis eastern hemlock complete Information Manager Harvard Forest

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

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Soil Collection Soil cores of consistent diameter were taken from 3 randomly chosen sites at each plot. The depth of leaf litter and the length of the soil core was measured in centimeters. By multiplying the diameter of the core by pi and the length of the core we determined the sample volume. We examined the soil to qualitatively determine its texture, and obtained the temperature from a thermometer inserted into the soil near the core. Samples were placed in plastic bags in a cooler and transported to the lab.

Soil Analysis Soil samples were weighed and placed in brown paper bags. We dried the samples at 100*C for 48 hours, then weighed the dried samples. By subtracting the dry weight from the wet weight and dividing the difference by the wet weight, we obtained the soil percent moisture. We divided the dry weight, adjusted to account for the moisture of the bag, by the sample volume to determine the bulk density. The samples were sieved with a 2mm sieve and ground. To measure pH, we mixed 5 grams of soil with 25 mL of deionized water, stirred the solution for 1 minute using a magnetic stirrer, let the solution sit for 30 minutes, repeated the stirring and sitting process, then measured the pH with a pH electrode. C:N ratios were determined from dry combustion analysis of dried, sieved and ground samples of 5 mg.

Salamander Data In each of the 8 plots, coverboards of 100x25x2 centimeters were set up and checked once a week. From the three coverboards in each plot where soil samples were taken, we averaged the number of salamanders found under the board for 6 sessions.

Harvard Forest Long-Term Ecological Research Harvard Forest

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(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. hf292-01-salamander.csv plot and salamander abundance data hf292-01-salamander.csv 1616 dc9a54dd4105f9a9212387daf2dcf838 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p29/hf292/hf292-01-salamander.csv plot plot number plot number NA missing value transect transect number in each plot transect number in each plot NA missing value coverboard coverboard number in each transect coverboard number in each transect NA missing value treatment treatment type HE hemlock control G girdled L logged HW hardwood control NA missing value moisture percent soil moisture content of sample dimensionless 0.000000001 real NA missing value bd soil bulk density of sample dimensionless 0.000000001 real NA missing value ll.depth leaf litter depth millimeter 0.1 real NA missing value temp temperature of sample celsius 0.1 real NA missing value ph soil pH dimensionless 0.01 real NA missing value cn average carbon-nitrogen ratio of sample dimensionless 0.00000001 real NA missing value rbs average red-backed salamander abundance under coverboard number 0.000000001 real NA missing value 24