Abstract Detail



Ecology

Devall, Margaret [1], Hawkins, Tracy [2], Schiff, nathan.schiff@usda.gov [1], Leininger, Ted [1].

Growth and survival of the federally endangered Lindera melissifolia and Lindera benzoin, a possible competitor, in varying densities and hydrologic regimes.

Pondberry (Lindera melissifolia [Walt] Blume, Lauraceae) is a rhizomatous, clonal shrub that usually grows in colonies of numerous stems with few branches and drooping leaves.  Pondberry is dioecious, with small yellow flowers that bloom in spring and scarlet drupes that mature in fall.  The species grows in low areas within bottomland hardwood forests in the western part of its range and on the margins of limestone sinks and wet depressions in pine forests in the eastern part.  Pondberry was listed as an en­dangered species in 1986 because habitat destruction and alteration, such as timber cutting, clearing of land, and local drainage or flooding of wetlands had affected its distribution and abundance.  Spicebush (Lindera benzoin (L.) Blume) is a dioecious woody shrub that grows in moist locations in floodplain forests.  Because spicebush could be a competitor for pondberry, we carried out a study that simulated disturbances to the hydrologic regime.  Randomly selected seedlings of similar size were transplanted into ∼31 cm (height) × 35 cm (diameter) pots containing a 2:1 v/v peat–sand medium supplemented with superphosphate and Milorganite. Plants were placed in a single circle, with individual plants equidistant from neighboring plants (if density equaled 1, the plant was placed in the center of the container). For densities >1, and in mixed plantings, species were alternated in the circle. We used an addition series design, with variation in both total densities and plant ratios – one addition series contained 4 monocultures (single species) and 6 mixtures (both species), 10 pots per series.  One series was placed in each of 1135 L aquaculture tanks.  Tanks were placed in the greenhouse in a randomized complete block design.  Three replicates of each addition series received one of four flooding treatments: no flooding (control), 7 day flooding, 14 day flooding, and 21 day flooding.  Flooding treatments were initiated 30 days after transplanting.  Seedlings were measured before flooding began and were measured and harvested one month after the 21 day flooding treatment.  Seedling stem, root and leaf weight were similar after 7 days of flooding, but varied as flooding increased.  Specific differences in measurements after increased flooding will be discussed. Most pondberry seedlings survived the 21 day treatment while many of the spicebush seedlings died.  This suggests that spicebush is probably not a competitor of pondberry in areas with 21 or more days of flooding but may be a competitor in drier habitats.


1 - U.S. Forest Sevice, P.O. Box 227, 432 Stoneville Road, Stoneville, MS, 38776.0, United States
2 - U.S. Forest Sevice, Center for Bottomland Hardwoods Research, Starkville, MS, USA

Keywords:
Endangered species
Competition
wetlands.

Presentation Type: Oral Paper
Number: 0010
Abstract ID:821
Candidate for Awards:None


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