Vernal Pool Habitat Management Guidelines

Retention trees flagged within 2010 gap, pre-harvest (photo. Rick Morrill) (photoID 1)
Retention trees flagged within 2010 gap, pre-harvest (photo. Rick Morrill)

The influence of management actions on wildlife habitat is an important consideration in forest management planning and the implementation of silvicultural activities.  Habitat Management Guidelines (HMGs) have been developed for Vernal Pools (Calhoun & deMaynadier 2004) that provide managers with details about both vernal pool ecology and recommendations for appropriate silviculture and harvesting practices around pools.  The University Forests, University of Maine, designed and installed a demonstration site in 2009-10 that utilizes an expanding gap silvicultural system or “femelschlag” to satisfy the vernal pool HMGs.    Applying this system to satisfy the vernal pool HMGs involved designing the shape and location of initial and proposed canopy openings so as to maintain canopy conditions favorable to the movement of vernal pool breeding amphibians, like wood frogs and salamanders, between the pool and critical upland habitat.  This design necessarily considered both the spatial and temporal arrangement of forest habitat. The design and field layout of the system were accomplished with the aid of GIS and GPS technology.  In addition, growth modeling, using the Landscape Management System (LMS), helps confirm assumptions about how habitat conditions will change over the course of the rotation while still maintaining the desired connectivity between the pool and upland forest.  This design represents one way to satisfy the HMGs for vernal pools. Among its advantages are the maintenance of >50% of the stand in productive habitat, a reduced harvest footprint, and greater operational efficiency over a uniform treatment approach.

2010 gap, post-harvest with retention trees (photo. Rick Morrill)
2010 gap, post-harvest with retention trees (photo. Rick Morrill)

Vernal Pool HMG Details: 3 VP Zones

Zone 1: VP Depression
Description: Site of amphibian breeding and predator feeding
Guidelines: Do not Disturb
Zone 2: VP Protection Zone _-100ft from VP

: Critical upland staging habitat for juvenile amphibian
: Limited harvest retain >75% canopy cover & retain abundant CWM
Zone 3: Amphibian Life Zone_-Area between 100ft & 400ft from VP
: Important upland habitat for pool breeding amphibians
: Limited harvest retain >50% canopy cover & retain/recruit abundant CWM

University Forests HMG Implementation:
Adapted expanding gap approach to satisfy the Vernal Pool HMGs
• Designed gaps and expansions to maintain habitat connectivity between pool and uplandhabitats (loosely organized like spokes on a wheel)
• Treated all of stand (outside zone 2) as if within Zone 3
• Used area control method to maintain >50% of stand in desirable habitat
• Retention tree selection focus on CWM maintenance and recruitment
• No machine entry into Zone 2• Reserve/control area designated to foster connectivity goals

Vernal Pool Handout (PDF)