U.S. Geological Survey Home Page USGS Patuxent Wildlife Research Center Science Meetings; dedicated to Chandler S. Robbins USGS Patuxent Wildlife Research Center; Science Meetings dedicated to Chandler S. Robbins Dedicated to Chan Robbins USGS Patuxent Wildlife Research Center; Science Meetings dedicated to Chandler S. Robbins Poster Abstracts from USGS Patuxent Wildlife Research Science Meetings, October, 2006
Patuxent Science Meeting 2006 Poster Abstract

Small patches of fast-growing trees enhance forest structure on

restored bottomlands

Twedt DJ

Despite the diversity of trees in bottomland forests, restoration on bottomland sites is often

initiated by planting only a few species of slower-growing, hard-mast producing trees. Although

successful at establishing trees, these young forests are slow to develop vertical structure,

which is a key predictor of forest bird colonization. Furthermore, when natural seed sources are

few, restored sites may be depauperate in woody species. To increase richness of woody

species, maximum tree height, and total stem density, I supplemented traditional plantings on

each of 40 bottomland restoration sites by planting 96 Eastern cottonwood (Populus deltoides)

and American sycamore (Platanus occidentalis) in 8 clusters of 12 trees. First-year survival of

cottonwood stem cuttings (25%) and sycamore seedlings (47%) was poor but survival increased

when afforded protection from competition with weeds. After 5 growing seasons, 165 of these

320 supplemental tree clusters had at least 1 surviving tree. Vegetation surrounding surviving

clusters of supplemental trees harbored a greater number of woody species, increased stem

density, and greater maximum tree height than was found on paired restoration sites without

supplemental trees. These increases were primarily accounted for by the supplemental trees.

Friday, September 22, 2006



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