Managing near Vernal Pools using Good Forestry in the Granite State

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1 Managing near Vernal Pools using Good Forestry in the Granite State Matt Tarr Associate Extension Professor Wildlife Specialist University of New Hampshire Cooperative Extension NESAF Conference March 2014 Vernal pools are one of many different types of wetlands in NE emergent marsh scrub shrub vernal pool forested wetland lakes and ponds ALL types of wetlands are important for maintaining the full diversity of wildlife that occur on the NE landscape 1

2 Vernal pools are unique from other wetlands because they dry up fill with water in the fall or spring usually (but not always) dry by mid to late summer The fact that they dry makes them important habitats Because vernal pools dry, they contain fewer predators fish can t maintain viable populations in wetlands that dry contain fewer, large aquatic predaceous insects that eat tadpoles and young salamanders giant water bugs, predaceous diving beetles, dragonfly larvae are all eat larval amphibians 2

3 Vernal pools required/preferred habitat for numerous amphibians = these species have their best reproductive success in vernal pools wood frog (avoid wetlands with fish) spotted salamander (prefer vernal pools) blue spotted/jefferson s marbled salamander salamander These species live in the forest and reproduce in wetlands A Year in the Life of a Vernal Pool Amphibians (Winter) Vernal pool amphibians spend winter in the forest Salamanders over winter below the frost line in roots channels and small mammal burrows Wood frogs over winter in deep leaf litter (able to freeze thaw) 3

4 Winter (distribution of adults that breed in the VP) = wood frogs = spotted salamanders (marbled and bluespot/jeff s also here) A Year in the Life of a Vernal Pool Amphibians (Winter) Can expect the greatest density of amphibians in hardwood and mixed stands Stands with deep leaf litter and stable temps provided by overstory and understory vegetation likely the best overwintering habitat 4

5 A Year in the Life of a Vernal Pool Amphibians (Spring Breeding) Air temp 40F and rainy = signals adults to migrate to vernal pool to breed (April May for wood frogs) (April June for spotted salamanders) Adults mate within VP Females deposit egg masses in VP Spring (breeding) Most adults migrate to VP to breed = wood frogs = spotted salamanders 5

6 A Year in the Life of a Vernal Pool Amphibians (Spring Breeding) Adults almost always return to the same VP to breed but they can be tricked into breeding in ditches or ruts made along their migration route or near their breeding wetland ruts normally dry up before young amphibians are developed enough to escape Spring (after egg deposition) All adults leave pool and return to forest = wood frogs = spotted salamanders 6

7 May Fall Adults forage in forest while eggs and young develop = wood frogs = spotted salamanders May Fall Adults ultimately find where they will overwinter = wood frogs = spotted salamanders 7

8 A Year in the Life of a Vernal Pool Amphibians (Spring Fall) Adult amphibians sensitive to conditions that dry soil and leaf litter any openings that in let lots of sunlight and wind Can desiccate adults and reduce soil & litter macro invertebrates within opening and >50 into adjacent forest A Year in the Life of a Vernal Pool Amphibians (Spring Fall) Hardwood stands composed of a diversity of tree and shrub species tend to support the greatest abundance and diversity of soil and litter macro invertebrates = best foraging opportunities 8

9 A Year in the Life of a Vernal Pool Amphibians (Young developing in the VP) Eggs hatch into free swimming larvae Larvae must metamorphose and be able to leave the pool before it dries up VP must hold water for a minimum of 3 ½ 4 months Many factors can influence if eggs and young can develop successfully A Year in the Life of a Vernal Pool Amphibians (Young developing in the VP) Changes to hydrology can alter how long a wetland holds water. and/or rutting & ditching Diverting water away reduces length of time VP holds water = dries up too soon or doesn t fill at all water control Diverting water into can increase length of time VP holds water = if VP doesn t dry it can be suitable to more predators 9

10 A Year in the Life of a Vernal Pool Amphibians (Young developing in the VP) Poor BMP s can cause siltation in VP that can reduce egg and larvae survival rutting runoff from exposed soils windblown from nearby openings A Year in the Life of a Vernal Pool Amphibians (Young developing in the VP) Tree canopy adjacent to VP helps moderate water temp, dissolved oxygen, pool drying Leaf litter falling from trees and shrubs immediately adjacent to the VP support macro invertebrate populations within the VP 10

11 July Fall Juveniles emerge from pool = juvenile = wood frogs = spotted salamanders July Fall Juveniles forage near pool soon after emerging = juvenile = wood frogs = spotted salamanders 11

12 July Fall & Following Spring Juveniles disperse to new wetlands to breed = juvenile = wood frogs = spotted salamanders VP Recommended Voluntary* Best Management Practices 12

13 VP Vernal Pool Basin Breeding habitat for adults amphibians Nursery for amphibian eggs and larvae Habitat for unique invertebrates Feeding habitat for other wildlife Summer habitat where turtles escape heat Recommended Voluntary* Best Management Practices Mark the perimeter of VP s prior to timber harvesting Easiest in spring when pools are full! VP Vernal Pool Basin Breeding habitat for adults amphibians Nursery for amphibian eggs and larvae Habitat for unique invertebrates Feeding habitat for other wildlife Summer habitat where turtles escape heat Recommended Voluntary* Best Management Practices Don t excavate! Don t : make them deeper so they don t dry up! 13

14 VP Vernal Pool Basin Breeding habitat for adults amphibians Nursery for amphibian eggs and larvae Habitat for unique invertebrates Feeding habitat for other wildlife Summer habitat where turtles escape heat Recommended Voluntary* Best Management Practices Retain all trees and understory shrubs that shade the pool VP 200 buffer Protects water in VP from runoff Provides shade and leaf inputs to pool Habitat for adults and juveniles emerging from pool Recommended Voluntary* Best Management Practices Best Harvesting Methods: Single tree selection or Small groups located where advanced regeneration/dense shrub layer is present 14

15 VP 200 buffer Protects water in VP from runoff Provides shade and leaf inputs to pool Habitat for adults and juveniles emerging from pool Recommended Voluntary* Best Management Practices Locate main skid trails and truck roads outside of this area whenever possible VP 950 core habitat and beyond Cover and feeding habitat during nonbreeding Overwintering habitat Habitat for dispersal Recommended Voluntary* Best Management Practices Maintain natural drainage patterns & Follow all BMP s to avoid soil erosion 15

16 VP 950 core habitat and beyond Cover and feeding habitat during nonbreeding Overwintering habitat Recommended Voluntary* Best Management Practices Avoid ruts and excessive soil compaction Limit scarification to that required to meet silvicultural goals Considerations when making temporary forest openings Openings become more hospitable as they regenerate, in the meantime Shrubs and young regeneration provide shade and slow wind to moderate soil temp and moisture Maintain deep leaf litter, woody debris, surface stones, and add slash to provide refuges that moderate soil temp and moisture in openings 16

17 VERY SIMPLIFIED EXAMPLE! = wood frogs = spotted salamanders Beaver Pond 17

18 Beaver Pond Beaver Pond 18

19 VP 950 core habitat and beyond Cover and feeding habitat during nonbreeding Overwintering habitat Recommended Voluntary* Best Management Practices Locate permanent openings (e.g., food plots, fields, landings) as far as possible from VP s Try not to locate these openings between adjacent wetlands Confused? Any Questions? 19

20 Winter = wood frogs = spotted salamanders (marbled and bluespot/jeff s also here) Beaver Pond 20