Realm: Terrestrial
Climate: Temperate
Biome: Temperate broadleaf and mixed forests
Central latitude: 42.472553
Central longitude: -72.215279
Duration: 8 years, from 2006 to 2014

160 records

15 distinct species

Across the time series Aphaenogaster picea is the most frequently occurring species

Methods

Methods were extracted from the dataset record metadata on Environmental Data Initiative and the related paper Kendrick, J.A., Ribbons, R.R., Classen, A.T. and Ellison, A.M., 2015. Changes in canopy structure and ant assemblages affect soil ecosystem variables as a foundation species declines. Ecosphere, 6(5), pp.1-20. HF-HeRE is sited in Petersham, Massachusetts, within the 121-ha Simes tract at the Harvard Forest (42.4742.48° N, 72.2272.21° W; 215300 m a.s.l). A full description of HF-HeRE is in Ellison et al. (2010); only pertinent details are mentioned here. The experiment, established in 2003, consists of eight ?90 × 90 m (0.81-ha) plots, divided into two blocks. The four plots in the valley” block are situated in the central valley of the tract, whereas those on the ridge” block are ?500 m northeast of the valley plots. The valley block is characterized by poorly drained, swampy soils. Besides T. canadensis, A. rubrum, P. strobus, and mixed hardwoods are common in the valley block. Soils in the ridge block are better drained, and this area is dominated by Q. rubra, Q. alba L., and P. strobus, in addition to T. canadensis. Within each block, three hemlock-dominated (>65% of the canopy and basal area) plots and one hardwood plot were sited at the beginning of the experiment. Of the three hemlock-dominated plots, one was left untreated as a hemlock control” while the other two were manipulated. In the girdled” plots, the bark and cambium of every individual hemlock stem were cut through in May 2005 to simulate rapid decline and tree death associated with adelgid infestation (Yorks et al. 2003). In the logged” plots all hemlocks >20 cm DBH, 50% of merchantable oak and pine, and some poor-quality red maple and birch (for firewood) were felled and removed between February and April 2005 to mimic standard silvicultural practices used to salvage the value of the timber before the adelgid arrives (Foster and Orwig 2006). Because of the large size of the plots and the aspect of the blocks, plots were not randomly arrayed. Rather, to avoid shading manipulated plots in each block by the associated hemlock control plot, logged plots were always sited south of hemlock control plots, and girdled plots were in between the logged and hemlock control plots. Plots were separated from one another by 510 m. The fourth plot in each block was a hardwood control” plot dominated by young hardwoods, and which represented the expected near-term (2050 year) structure of forests from which hemlock has been lost (i.e., a space-for-time substitution) (Albani et al. 2010). In each block, the hardwood control was located >100 m from the three hemlock plots. Together, these four plot types are intended to serve as a short-term chronosequence of forests invaded by the adelgid; hemlock control plots represent hemlock stands pre-invasion, girdled and logged plots represent the immediate effects of infestation and salvage logging respectively, and hardwood control plots represent the eventual future of invaded stands. Within each canopy treatment plot, six 3 × 3 m ant manipulation subplots were installed in April 2006. Three subplot types were installed: control,” disturbance control,” and ant exclosure.” Each subplot type was replicated twice within each canopy treatment plot and was randomly sited within the 7200 m2 area of the canopy manipulation plot outside of the central 30 × 30 m core” area (which is otherwise intensively sampled for many other variables: Ellison et al. 2010) and at least 15 m from the edge of the canopy manipulation plot. This split-plot design (small replicate ant manipulation subplots within each large canopy manipulation plot) was used to separate direct effects of changes in ant assemblage structure on soil ecosystem variables from those caused by canopy manipulations and adelgid infestation, which themselves may affect ant species composition (Ellison et al. 2005a, Sackett et al. 2011). In each of the ant manipulation and associated control subplots, two 7-cm diameter × 10-cm deep, 230-ml plastic cups (pitfall traps”) were buried flush with the soil surface. From 2006 through 2014, three times each summer, traps were opened, partially filled (20 ml) with a mixture of water and a few drops of dishwashing detergent, and then left uncovered for 48 hours, after which time all ants in the pitfalls were removed, counted, and identified to species following Ellison et al. (2012). Voucher specimens are deposited in Harvard University's Museum of Comparative Zoology. In addition to supplying necessary data on ant assemblages that could be associated with changes in soil ecosystem variables, data from the control pitfalls were used to test for differences in ant assemblage composition among the canopy treatment plots, and data from the exclosures were used to verify that the exclosures effectively reduced ant activity.

Citation(s)

@Dataset{BioTIME_cit367, Study_id = {606}, Citation_id = {367}, Author = {Ellison, Aaron}, Publisher = {Environmental Data Initiative}, Title = {Ants and Ecosystem Function in Hemlock Removal Experiment at Harvard Forest 2006-2014 ver 23}, Year = {2021}, Doi = {10.6073/pasta/25e5267d98517976c3177babef7f115f}, Url = {doi.org/10.6073/pasta/25e5267d98517976c3177babef7f115f}, Language = {English}, Version = {23} }