Peru Town Forest – "Seed-Tree" Treatment to Favor White Ash Regeneration

The goal of this treatment was to create conditions favorable for the regeneration of white ash in a stand with a higher risk of infestation from the emerald ash borer (EAB) in the near future due to proximity to a confirmed infestation and where overstory white ash are already exhibiting symptoms of decline due to a causal agent other than EAB. A “seed-tree” treatment was implemented on approximately 8 acres where all stems down to 2” DBH were removed excepting those trees selected as “Leave Trees.” White ash in dominant canopy positions in the pre-treatment overstory and exhibiting good vigor / lack of symptoms of decline, were selected as “Leave Trees” at an average rate of 10 stems per acre. Of those trees selected for retention, female trees were prioritized.

Peru, Vermont

The study area is situated within Stand 3 on the Peru Town Forest (see attached map)

From Route 30 in Peru head south on South Road until the intersection with Rock Bottom Lane. Turn left onto Rock Bottom Lane and travel approximately .4 miles to the catamount trail parking area (on left at intersection with catamount trail). The main entrance / landing area and boundary (orange and red blazes) of the Peru Town Forest can be observed immediately west of the parking area. Follow the main skid trail out of the landing area and continue south to reach the study area (approx. 1600’ / .3 miles).

Accessible by foot

Town of Peru

+1 802-864-3065

9 acres

Northern Hardwoods

Northern Hardwood Forest

Evidence suggests that a stand replacing event occurred approximately 100 years ago. This stand is currently even-aged and is characterized by an overstory of sawtimber sized northern hardwoods. Many stems in dominant and dominant canopy positions have reached diameters of 22" or greater. The relatively small proportion of stems found in the poletimber and small-sawtimber diameter classes are typically situated in suppressed canopy positions and exhibit symptoms of low-vigor and should not be construed as a distinct age class. A significant proportion of dominant and co-dominant stems (primarily white ash) are now exhibiting symptoms of disease / decline (most likely ash yellows), and several standing dead stems, formerly in dominant and co-dominant canopy positions, were observed.

ash yellows disease

emerald ash borer

Peru fine sandy loam - “moderately well-drained, typically deep to bedrock, “very rocky” / “very stony.”

1920

Evidence of a former "sugar house" was observed in this stand and suggests the area was once utilized as a sugarbush. The presence of scattered, large diameter sugar maples supports this assumption. It is likely that a stand replacing event occurred.

Sugar Maple: 57 (feet) or 53 cu.ft. per acre per year

There is no documented management history for this even-aged stand, however evidence of past sugaring activities can be observed (foundations of old sugar house / arch). It is therefore likely that this area was once managed for the production of maple sap, and that hard maple (sugar maple) once comprised a much larger proportion of the overall species composition. The current species composition (nearly 65% white ash by basal area) and even-aged structure suggest that most of the maple trees that once comprised the “sugarbush” were likely harvested in a stand-replacing event approximately 100 years ago. It is unclear whether this harvest simply sought to remove merchantable trees following abandonment from sugaring use, or may have been a salvage-oriented response to a damaging biotic or abiotic event. The result was a nearly 100% harvest of the maple overstory and the creation of conditions that allowed for the establishment of a new cohort of white ash. As stated previously, this cohort of white ash is now approximately 100 years old, occupies a majority of the dominant and co-dominant canopy positions, and contains many individuals showing advanced symptoms of decline.

While white ash represented approximately 64% of the species composition in general, the percentage of white ash in dominant and co-dominant overstory positions was estimated to be significantly more. Sugar Maple comprised approximately 20% of the composition while other species including yellow birch, black cherry, and hop-hornbeam were found in relatively small proportions.

Fraxinus americana (white ash)

64%

Acer saccharum (sugar maple)

20%

Past management plans identified “Ash Yellows” as an ongoing concern. During the 2020 inventory it was observed that a significant proportion of the ash population was exhibiting symptoms of advanced decline consistent with “Ash Yellows." Many stems exhibit extensive dieback in the crown and / or epicormic sprouting. Numerous standing dead stems were observed, many of which previously occupied dominant canopy positions. This stand is within the “high risk” area associated with a confirmed infestation of Emerald Ash Borer. Due to the fact that stressed and declining stems have proven to be more attractive to EAB than healthy stems this stand was considered to be at an increased risk for future infestation. No invasive plants were observed within this stand, however a small (8 – 10 individual plants) population of mature invasive honeysuckle was observed in an adjacent stand. Accidental movement of seed via machinery is possible on this site.

Due to widespread decline in the ash population and the threat of significant losses to EAB, as well as maturity of the stand, it was recommended that this stand be regenerated through an even-aged management approach with a focus on creating conditions favorable for the regeneration of white ash.

The relatively high proportion of mature white ash trees in this stand are at a high risk of infestation by EAB. A primary objective of management in this stand is to establish a cohort of young white ash that will escape the initial “killing front” or wave of EAB infestation due to their small size at the time of overstory infestation. If considerable white ash regeneration is established this site may satisfy conditions required for EAB biocontrol release and ongoing study.

The goals and objectives expressed in the original 1989 forest management plan included the production of high-quality forest products, the enhancement of wildlife habitat / food sources, and the protection of historical sites on the property. Later revisions to the forest management plan would include the goal of utilizing the Peru Town Forest as a demonstration site to showcase responsible, intentional, and carefully planned / researched forest management. As a demonstrations site, the Peru Town Forest is a valuable educational resource for private landowners, their neighbors, and forestry practitioners. This 2021 revision of the forest management plan elaborates on the original goals and objectives to include the protection and preservation of forestland and the maintenance and enhancement of forest health and resiliency. Objectives specific to this treatment in Stand 3 are the production of high-quality forest products, the demonstration of responsible, intentional, and carefully planned / researched forest management activities, the maintenance and enhancement of stand health and resiliency and the promotion of species diversity by maintaining a component of white ash in the forest, and the creation of a potential biocontrol study site. An additional objective is the creation of early successional habitat for the benefit of associated wildlife habitat and the creation of browse.

Implement a “reserve tree” / “seed-tree” harvest on approximately 7-8 acres of this stand. Cut / remove all stems down to 2” DBH, excepting those stems selected as “leave-trees” / “seed-trees.” The retention of “seed-trees” will act as a continued source of seed and may influence species composition in the newly regenerated stand. Individuals selected as “seed-trees” shall be vigorous, thrifty, and of seed-bearing age and will be selected at a rate of approximately 10 stems / acre. Female white ash individuals will be prioritized for selection as seed-trees. Some scattered hard maple stems (remnants of former sugarbush) and yellow birch stems will also be favored for retention. Standing snags and trees with cavities will be retained for wildlife value. Stocking levels in the post-cut stand will be variable and will range from 0 sqft/acre to 30 sqft/acre (BAF 10). Tops of felled trees should be left unlopped to help protect the young cohort from over-browsing.

This harvest will function to regenerate this stand with a cohort of desirable hardwood species and create an area of early successional habitat for the benefit of associated wildlife. A mixture of white ash, red maple, sugar maple, and yellow birch are expected to be primary components in the new stand, while black birch, black cherry, and white pine are expected as potential minor associates. White ash is favored by the selection of “seed-trees” / “leave-tress” in the residual overstory.

seed-tree

• forest health
• invasive species
• wildlife habitat

Barko 260B tracked harvester + Rottne F15 forwarder

yes

yes

In the post-harvest stand slightly higher residual stocking levels are found in the northern 1/3 of the treatment area on north-eastern facing slopes. Lower residual stocking levels are found on the southern 2/3 of the stand on western facing and south-eastern facing slopes. Residual stems appear vigorous and healthy following treatments. Minimal (only 1 stem as of fall 2023) blowdown has occurred in the residual stand.

The treatment was completed January 2022. Cutting / harvesting was completed using a combination of a Barko 260B tracked harvester and Rottne F15 forwarder (tracks installed). Although freezing temperatures prevailed for the duration of the harvest, snow cover was minimal and a fair amount of soil scarification was achieved, especially in the southern-most 1/3 of the stand where aspect is south-eastern. It was difficult to keep the harvester operator from crushing tops and therefore we will not see the impact of “un-lopped” tops.

A regeneration survey / inventory has not been completed at this time (fall 2023), however observations made in the summer of 2023 revealed significant numbers of red maple, sugar maple, and striped maple seedlings were present. Rubus species have also become well established throughout the treatment area. Beech regeneration and ferns are generally lacking / not present. Annual regeneration surveys will begin in 2024 to track regeneration progress.

145

• feet squared per acre

148

15

Cory Creagan

Bennington County Forester

Vermont Department of Forests, Parks, and Recreation

• StandMap.pdf
• ManagementProjectsMap.pdf