MAINE
Vernal pools or seasonal wetlands, are defined as naturally occurring, seasonal bodies of water, free of predatory fish populations, that provide breeding habitat for one or more of Maine's four vernal pool indicator species- spotted and blue-spotted salamanders, wood frogs, and fairy shrimp.

  Maine Audubon Society




A SUMMARY OF VERNAL POOL PROTECTION MEASURES
Vernal pools are regulated as freshwater wetlands by the Maine Natural Resources Protection Act (NRPA) (38 M.R.S.A., Sections 480-A to 480-Y, 1996). According to the Act, however, the alteration of less that 4,300 square feet of fresh water wetland is exempt from any permit requirements. Therefore, those vernal pools that do not meet this size threshold can be altered.
In 1996, another protection mechanism was initiated through NRPA. Vernal pools were added to the definition of significant wildlife habitat. Significant wildlife habitats have to be defined, located, and mapped by the Maine Department of Fisheries and Wildlife, and then be adopted through the legislative rule-making process before they are regulated. Provision for the protection of vernal pools is in the law, but to date has not been implemented through rule-making (B. Stratton, Maine Department of Environmental Protection; pers. comm., 1997).

In 1997 the Maine Audubon Society developed a nonregulatory program to educate and inform the citizenry about vernal pool ecology and values (Calhoun 1997). A vernal pool is defined as a "temporary, seasonal, semi-permanent or permanent body of water that is essential breeding habitat for certain amphibians and invertebrates (referred to as indicator species) [and] that does not support fish." This definition differs from that of other states in that it does not include a minimum duration of flooding, it does not make reference to the presence of inlets or outlets, and it does include semi-permanent and permanent pools if they lack fish. Evidence of breeding by one or any combination of the following indicator species is required for designation of a vernal pool: spotted salamander (Ambystoma maculatum), blue-spotted (Ambystoma laterale), wood frog (Rana sylvatica), and fairy shrimp (order Anostraca). The Audubon Society states that "grassroots stewardship of this critical wetland type is the key to protection."

(Murphy and Golet 1998)
RARE AND ENDANGERED SPECIES
Maine has its own Endangered Species Act which is modeled after the Federal Endangered Species Act. In 1999, Maine had listed the following species of amphibians and reptiles as endangered (E), threatened (T), or special concern (SC).
  • Eastern Box Turtle (Terrapene carolina)(E)
  • Blanding's Turtle (Emydoidea blandingii) (E)
  • Eastern Racer Snake (Coluber constrictor) (E)
  • Spotted Turtle (Clemmys guttata) (T)
  • Loggerhead Turtle (Caretta caretta) (T)
  • Four-toed Salamander (Hemidactylium scutatum) (SC)
  • Spring Salamander (Gyrinophilus porphyriticus) (SC)
  • Northern Leopard Frog (Rana pipens) (SC)
  • Wood Turtle (Clemmys insculpta) (SC)
  • Brown Snake (Storeria dekayi) (SC)
  • Common Musk Turtle (Sternotherus odoratus) (SC)
  • Eastern Ribbon Snake (Thamnophis sauritus) (SC)

Maine's Endangered Species Act strictly prohibits possession, exporting, hunting, trapping, selling, transporting, feeding, baiting, or harassing any state-Endangered or Threatened species amphibian or reptile.

(Hunter et al. 1999)

FORESTRY BEST MANAGEMENT PLANS FOR CONSERVING VERNAL POOLS AND ADJACENT HABITATS IN MAINE

Forest management practices may directly affect vernal pools and the adjacent upland used by amphibians outside of the breeding season. Forest practices may be compatible with the conservation of vernal pools and breeding populations of amphibians provided some general guidelines are followed. Recommended best management practices for protecting vernal pool and the surrounding terrestrial amphibian habitat are described below and apply to three management zones:

 
  • THE VERNAL POOL DEPRESSION
  • THE VERNAL POOL PROTECTION ZONE (100ft)
  • THE AMPHIBIAN LIFE ZONE (500ft)

THE VERNAL POOL DEPRESSION
This zone includes the vernal pool depression at spring high water - which may or may not be wet during the period when timber is being harvested.

Management objective:Maintain the vernal pool in an undisturbed state

Rationale:

 
  • Rutting or compaction in the pool can alter the pool's water holding capacity.
  • It can disturb eggs that are overwintering (i.e.: marbled salamander) or larvae buried in the organic layer.
  • It can ultimately alter the environment in which the amphibians live/ breed.
  • Harvesting operation in the pool can disturb woody vegetation that may serve as egg attachment sites or that may provide shading.
  • Excess slash and tree tops from forestry operations that end up in the pool basin can hinder amphibian movement and alter water chemistry.

Recommendations:

 
  • The vernal pool depression should remain undisturbed. The should be no cutting, heavy equipment operation, or skidding activity in the vernal pool depression, even in the winter as the vegetation structure of the pool (if it is wooded) could be greatly altered.
  • The pool should be kept free of slash, tree tops, and sediment from forestry operations, including harvesting and road building.
  • If slash or other woody debris accidentally falls into the pool during the breeding season (March to June), it is best to leave it in place to avoid disturbing the egg masses. (Trees and branches do naturally into pools and serve as egg attachment sites.

VERNAL POOL PROTECTION ZONE
A 100 foot zone around the pool measured from the spring high watermark. During the dry season, the high watermark generally can be determined by the presence of blackened, water- or silt- stained leaves, aquatic debris along the edges, or a clear changes in topography from the pool depression to the adjacent upland.

Management objectives:
          (a)Protect vernal pool and surrounding habitat by maintaining or encouraging a closed canopy stand in a pole- or greater size                class that will provide shape, deep litter, and woody debris around the pool.
          (b)Maintain a shaded forest floor without ruts, bare soil, or sources of sedimentation/ erosion.

Rationale:
The integrity of the forest immediately surrounding the pool depression is critical for maintaining water quality, providing shade and litter for the pool, and providing suitable upland habitat for both resident amphibian populations and those migrating in and out of the pool. In the spring, high densities of adult salamanders and frogs occupy the habitat immediately surrounding the pool. Similarly, in the late summer and early fall, large numbers of recently metamorphosed salamanders and frogs occupy the surrounding pool. Juvenile spotted and blue-spotted salamanders are vulnerable to desiccation during the first months after metamorphosis ( late summer to early fall; Semlitch 1981). For this reason, a shaded, moist forest floor with ample loose litter material and coarse woody debris for cover is important.

Recommendations:

 
  • Limit harvesting to uniformly distributed, light, partial cutting while leaving a minimum of 70- 80% canopy cover.
  • Dead, dying, or intermediate and suppressed trees would be candidates for fulfilling the canopy requirements.
  • In some instances, it may be most practical to designate this area as a "no- cut" zone until, at some future date, basel area has increased beyond recommended minimum.
  • Harvesting operations should occur only on frozen ground outside of the season when juveniles and adults are active on the forest floor.

AMPHIBIAN LIFE ZONE
100 - 500 feet from the vernal pool depression as measured at high water.

Management Objectives:
          (a)Provide year-round habitat for amphibian populations.
          (b) Maintain forest floor conditions that will support amphibian populations including:

 
  • deep, uncompacted, natural litter
  • minimal disturbance to the forest floor organic layer
  • continuous supply of coarse woody debris (dead woody material) of various sizes and level of decay
  • a shaded, moist forest floor
  • undisturbed drainage within the pool watershed.

Rationale:

 
  • This zone around the pool is needed to support upland population of amphibians that breed in vernal pools.
  • A management zone of 500 feet was chosen to address the habitat needs of spotted salamanders because they are species potentially most limited up upland requirements.
  • The average dispersal distance of adult spotted salamanders and blue-spotted salamanders is estimated to be 430 and 830 feet, respectively (Williams 1973; Douglas and Monroe 1981). This means as much as half the population, in some instances, may disperse to even greater distances.
  • In a review of the literature on pool- breeding salamanders, Semlitch (1998) found that 76 % of all post-breeding adult salamanders and newly metamorphosed juveniles were found outside the 100-foot buffer zone around vernal pools typically recommended in some states.
  • Wood frog juveniles, on average, may disperse ¾ of a mile from a breeding pool (Berven and Grudzien 1990).
  • DeMaynadier and Hunter (1999) found that juvenile and adult wood frogs and spotted salamanders selected closed canopy forests during emigration and dispersal in managed forest landscapes.
  • Windmiller (1996) found radio-tagged spotted salamanders were directly under or within 1.5 feet of woody debris.
  • Rutting and scarification of the forest floor may prevent salamanders for traveling to breeding pools by creating barriers along their travel routes (Means et al. 1996).
  • If shallow ruts fill with water, vernal pool amphibians may deposit eggs in ruts that do not hold water long enough to produce juveniles

The following recommendations may further increase the probability of maintaining wildlife values and
successfully protecting vernal pool habitats:

(A) Bigger is better.
Whenever possible, expand the protection zones. The 500 foot Life Zone only protects a portion of blue-spotted and spotted salamander and wood frog populations. If we assume amphibians are distributed randomly around a pool, the current BMP's will protect only 1/3 to 1/2 of the local populations.

(B) Inventory

 
  • Develop a strategy for mapping and tracking potential vernal pools either from aerial photography or as discovered in the field (see Appendix A). Use this database to help design ground surveys for indicator species and future harvest plans.
  • Track losses or impacts to existing pools to aid in refining management strategies and/or identifying high risk areas. Archiving existing pools on Geographic Information Systems will aid in planning future operations.

(C) Identify highly productive pools for proactive management and consider more rigorous protection strategies:

 
  • If you have identified a pool that is particularly productive or if it is the only pool within a half mile, consider creating an undisturbed zone 100 feet around the pool and applying BMPs beyond the 500 foot recommendation.

  • If you have identified a cluster of pools with a half mile of each other, consider protecting the area as a unit with contiguous forest between the pools. Extend the recommended buffers around the cluster, rather than around each individual pool.