Introduction
The rock vole (Microtus chrotorrhinus) is a rare species that usually occurs at higher elevations in coniferous or mixed wood types in BCR 14. It is listed as a Species of Greatest Conservation Need in one or more states in BCR 14.
Habitat Needs
This species usually occurs at higher elevations but has also been found in low-elevation spruce-fir. It needs cool moist rocky woodlands with herbaceous ground cover and flowing water nearby. It feeds primarily on a variety of ground vegetation.
Its territory size and population densities are unreported. Natural history information is incomplete for this species.
Habitat Management Practices
Maintain or increase high-elevation and low-elevation spruce-fir types with an herbaceous cover near small flowing streams.
When assessing properties for habitat potential look for soils that will produce the desired coniferous types such as Biddeford, Peacham, Scarboro very stony, Wonsqueak and others.
Silvicultural Practices
Use the general practices recommended for high-elevation and low-elevation spruce-fir types until more natural history information is available for this species.
LOW-ELEVATION SPRUCE-FIR
- Use uneven-age management. Group selection with groups ranging from 1/10 to 2 acres.
- Use a 90-year rotation age with entries every 15 years.
- Let 10 percent of the area of this type age to 120 years before rotating.
- Avoid entry during nesting season—April to June.
- Whole-tree harvest or cut-to-length is preferred.
HIGH-ELEVATION SPRUCE, SPRUCE-FIR AND FIR
High-elevation (generally above 2,500 feet) forest types are normally situated on soils that are shallow to bedrock or poor in quality. The soil conditions, coupled with climate conditions at high elevations, result in slow vegetative reproduction and growth. Since the habitat provided by this type at these elevations contains a large proportion of SGCN species, special care must be taken when management takes place at high elevations in this type. The management preference for optimal habitat is no management at all—allow natural processes to take place. If harvesting in this type at high elevation, contact your state wildlife agency before proceeding.
Composition and Structure Goals
- Within the managed area at least 60 percent should remain in stands with an average DBH of 4 inches or greater and a stocking of at least 90 square feet of basal area per acre.
- Leave 10 percent of the area unharvested. The remaining 30 percent of the area can be less than 4 inches in DBH and less than 90 square feet of basal area.
- Distribute these cut areas across the managed area rather than concentrating them.
- Direct management toward maintaining or increasing softwood types at high elevations.
Harvesting Provisions
- Use group selection with small groups— to ½ acre is preferred.
- Install larger groups (up to 3 acres) or small clearcuts (3 to 5 acres) only where adequate regeneration is in place.
- Minimize residual stand damage.
- Minimize soil compaction.
- Winter harvest is preferred.
- Avoid whole-tree harvest. Use a cut-to-length harvest method, leaving tops and limbs in place.
Retain three to five large live cull or cavity trees per acre.