Pondberry is a rare shrub that grows in floodplain forests of the southeastern United States. Since 1986, the U.S. Fish and Wildlife Service has listed pondberry as an endangered species, and it is protected by the Endangered Species Act. Because of this, one of the largest remaining pondberry colonies, which grows in the Lower Mississippi Alluvial Valley’s Delta National Forest, is protected.
A team of U.S. Forest Service scientists are studying pondberry’s response to flooding and changes in light levels to determine which habitat conditions the plant prefers. Brian Roy Lockhart, a research forester with the Southern Research Station Center for Bottomland Hardwoods Research, is lead author of a recent paper by the team published in the journal Plant Ecology.
The study showed that pondberry responds well to increased light and can tolerate long periods of flooding. These findings have important implications for pondberry management, which is currently passive. Passive management involves creating buffers around known colonies, and prohibiting active forest management inside buffer zones. This management strategy protects pondberry colonies from human disturbance, but as forests mature without active managmement, less light makes it to the forest floor, limiting the growth of understory plants.
Light availability appears to be a key factor for maintaining pondberry’s vigor, according to findings from the study. Lockhart and his colleagues looked at pondberry growth and survival under low, intermediate, and high light conditions, and found that pondberry preferred intermediate light and did poorly in heavy shade. These findings suggest that actively managing pondberry habitat for appropriate light conditions could promote survival and growth. Without active management to create these conditions for pondberry, its future sustainability may be in jeopardy, according to the authors.
Pondberry habitat includes low-lying floodplain forests and pond or wetland edges that are prone to flooding. Flooding can be very stressful and even lethal to plants, because water-saturated soils are low in oxygen. However, pondberry can tolerate flooding up to 90 days and, if given enough sunlight, can even continue growing while its roots are inundated. Pondberry’s ability to tolerate flooding probably gives it an advantage over other species, and lets it colonize small areas. Active management practices may be necessary to produce and maintain favorable pondberry habitat.
For more information, email Brian Lockhart at email@example.com