CHAPTER IV: WILFLIFE HABITATS FOR MISSISSIPPI’S SGCN,
THREATS AND CONSERVATION ACTIONS^18811.4 Ephemeral (Temporary) Ponds
Value to SGCN - 119
Rank - 3rd of 18 Lotic and Lentic SystemsDESCRIPTION
Ephemeral ponds, also referred to as spring ponds or
vernal pools, are temporary wetlands that hold water
during the winter-spring season but normally dry out by
late summer. They can be classified by their vegetative
cover as marshes or swamps, but their special designation is necessary due to their importance to many
species.
Ephemeral ponds commonly form along moderate to larger size streams, but many are also be found in
disturbed habitats, such as ditches, croplands or other such depressions. As seasonal high flows peak
and subsequently recede from the floodplain into the stream channel, ponds temporarily form in
floodplain depressions. They serve as important breeding habitats for many crustaceans and amphibians
and provide significant energy sources to birds, mammals and reptiles that feed on fish trapped in these
pools.
Grady ponds are naturally occurring ephemeral ponds of the lower coastal plain. They are found in
ancient abandoned deltaic stream channels, on the upper reaches of small tributaries, and in upland
depressions apparently caused by the subsidence of underlying strata. Several of the ponds were formed
by alluvial processes on wide flats of ancient riverine floodplains. Minor scroll lines of the ancient
rivers are evident today. The ephemeral ponds are located in minor distributaries channels of the old
stream systems that no longer connect to local drainages. Other ponds occur in swales along the far
upper reaches of small drainageways of wide coastal flats. In such instances the depressions will
periodically connect with stream systems but considering the gentle local relief and the low stream flow,
connectivity to the stream system is brief and accessibility by fish is minimal. Essentially, the amount of
flow through the swales is very low and less likely to be utilized by predatory fish. If fish gain access to
the ponds, their occupancy is short-lived because the ponds usually dry up during the fall. In addition,
some of the swales may have formed through local subsidence of uplands on ridge tops and side ridges
independent of streams. These upland ponds have greater importance to smaller species of amphibians
than riverine derived ponds because the latter are more shaded and subject to periodic flooding that
threatens tadpole survival. Ephemeral ponds are dependent on fire to maintain open, herbaceous habitat,
which is ideal for breeding amphibians. Grady ponds are essential to the survival of the endangered and
endemic dusky gopher frog.
Photo courtesy of MDWFP.