As spring advances, signs of renewed life are appearing at the Reserve in each of the four elements. Amphibians have laid their eggs in the water, insects are hatching and beginning to fill the air, buds are swelling along with new growth appearing from the earth and we recently performed the annual prescribed burn of the Wildflower Labyrinth! All of these components of life’s cycles are occurring in line with the vernal equinox.
Amphibians
Of these manifestations of awakening, we focus here on amphibians. The Southeast, recognized as the center of amphibian biodiversity in the United States, supports over 140 species of frogs, toads and salamanders [1]. North Carolina alone is home to more than 60 salamander species (more than anywhere else in the world) with some of those being found only in our state [2]. Two in particular, the northern pigmy salamander (Plethodon organi) and Weller’s salamander (P. welleri), are species of conservation concern dependent upon this ecosystem as habitat. The Reserve is home to several known species (as well as likely many not yet seen and identified): the wood frog (Lithobates sylvaticus), spotted salamander (Ambystoma maculatum), three-lined salamander (Eurycea guttolineata) and red spotted newt (Notophthalmus viridescens). Newts, the subfamily Pleurodelinae of the family Salamandridae, are semi- or fully-aquatic as adults as opposed to other salamanders that follow the reverse life cycle.
Why Are Amphibians in Decline?
Amphibians as a whole have been in decline for over 20 years, leading all taxonomic groups, with approximately one third of the species listed as threatened on the International Union for Conservation of Nature’s Red List. This is due in part to their biphasic life stages, meaning they rely on both aquatic and terrestrial systems. As most alternate between life in the water while juveniles, to adult life on land (some species exhibit the reverse progression) with a return to the water to mate and lay eggs, they are susceptible to adverse conditions of both ecosystems. Their moist, permeable skin not only absorbs most of the water needed for survival, it is also a sensitive respiratory organ, therefore taking in both water and air pollutants. Centrally located in the food web, these consumers of aquatic vegetation, invertebrates and other vertebrates are also prey for fish, snakes, birds and others. Strongly influencing biodiversity and acting as early indicators of ecosystem change, amphibians are considered to be proverbial canaries in the coalmine regarding climate change [3]. Increasingly erratic rainfall patterns with greater deluges and longer periods of drought present impossible obstacles for these creatures that are simultaneously being threatened by habitat loss, disease, invasive species and overexploitation.
What Helps?
USGS scientists found that restoration of degraded, damaged or destroyed wetland hydrology provides the most immediate benefit to frogs and toads [1], and presumably salamanders. This process involves reestablishing water flow conditions to historic natural states, as we have been doing at the Reserve, and benefits not only amphibians, but all native plant and animal species. Our recent modifications include adding hydra humps with rock outlets, adding turf and rock swales and altering existing swales to better direct the water. We are also constructing step pools and rock check damns within the swales to control water velocity. Finally, we are experimenting with large woody debris (LWD) in a subwatershed to slow sheet-flow across the landscape and prevent valuable soil and nutrient loss.
What You Can Do
If you want to help protect amphibians and their habitat because you value biodiversity, for ethical reasons or perhaps because you have warm memories of sitting on a back porch being gently eased into the evening hours by a chorus of frogs, we have some additional suggested places to begin.
- Leave ground cover such as dead wood, leaf litter and rocks in your yard to provide moist shelter
- Avoid pesticide and fertilizer use
- Plant native species that are more resilient against disease and pests
- Fertilize with manure and compost
- Buy organic food
- Build a pond with gently sloping sides and vegetation along the edges
- Choose native plants that help support amphibian life
- Do not stock with fish
If you have wetlands on your property, you can even participate in the USDA Wetland Reserve Program offering landowners the opportunity to protect, restore and enhance wetlands voluntarily. These sites have been found to host more species and more individuals of those species of amphibians than neighboring land, so the efforts work [1]. So, as always with conservation, protection and the overall health of our planet, it is in the hands of us all.
1. Science Daily
2. Charlotte Observer
3. USDA