Sci-Comm: An Introduction to Holt Research Forest Data

Scientific Communication Series

An Introduction to Holt Research Forest Data

Sci-Comm: An Introduction to Holt Research Forest Data is a new scientific communication series exploring the research and data produced at Holt Research Forest. This article will introduce the Holt Research Forest and its data collection efforts. Future articles will describe and summarize the publicly available datasets in detail and highlight any research findings.

Holt Research Forest research laboratory and office.

The Holt Research Forest is a long-term ecological monitoring site in Arrowsic, Maine. For nearly 50 years, data on the forest’s plant and animal populations have been collected and monitored for their response to timber harvests. As our research program expands, we are also interested in studying and facilitating forest adaptation to climate change. Ultimately, Holt Research Forest provides regional landowners and forest professionals with information regarding the impacts of management practices and other disturbances, including climate change, on forest health and growth, economic value, resiliency, and more.

Harvests at the Holt Research Forest

Before the first timber harvest in 1987, a 40-hectare (~100-acre) study grid was established to ensure accuracy and continuity in long-term datasets by providing a permanent and standardized system to collect data across the landscape. The design is a grid system divided into 40 one-hectare (0.4-acre) blocks, 160 50x50-meter quadrats, and 640 25x25-meter subquadrats. 

Map of Holt Research Forest and study grid.

In the winter of 1987-1988, the first group selection harvest was conducted on 10-hectares of the managed study area (western half). This harvest created openings in the canopy to release advanced regeneration and encourage new regeneration, adding a new age class to the forest. In the winter of 2020-2021, the second group selection harvest was conducted on 47-hectares of the entire study area, with 6-hectares left as uncut control blocks. For both harvests, we aimed to increase the diversity of tree ages and species, promote regeneration, and enhance wildlife habitats to create a more resilient forest. Some challenges faced with the recent 2020 harvest include defoliation and mortality in residual overstory oak caused by the oak leaf roller and increased deer browse of red oak regeneration.

Publicly Available Data

Data collected at Holt Research Forest are stored in the Forest Ecosystem Monitoring Cooperative (FEMC) data archive, which houses public research and monitoring projects and datasets related to forest ecosystems in the Northeastern US (https://www.uvm.edu/femc/CI4/holt). The Holt Research Forest archive comprises 59 datasets within 15 projects dedicated to monitoring the impacts of timber harvests and other disturbances on the forests’ plant animal populations.

Table summarizing the number of publicly available datasets at the FEMC data archive.

Project	# of Available Datasets
Annual Tree Seed Collection	5
Tree Seedlings Counts, 1m2 Plots	1
Timber Inventory	7
Understory Releve, 1m2 Plots	3
Understory Releve, S1 Lines	3
Understory Releve, Subquadrats	2
Oak Seedling Survey	1
Sapling Mapping, S10 Lines	2
Tree Heights, Estimated and Measured	2
Crown Measurements, S10 Plots	1
Tree Regeneration	6
Tree Volume	4
Salamander Counts and Measurements	5
Salamander Stations Timber Inventory	11
Small Mammal Stations Timber Inventory	6