Increasing the number of herbaceous species appropriate for restoration of nutrient capture by forest remnants in agricultural landscapes

The researchers investigated methods for restoration of six forest herbaceous perennial species with potential for increasing nutrient capture and storage in degraded remnant forest systems in Iowa. They conducted common garden (greenhouse) and field planting experiments using local and non-local propagules

Influence of root system morphology and site characteristics on development of transplanted northern red oak (Quercus rubra L.) seedlings

The purpose of this study was to evaluate the performance of one-year-old red oak seedlings with graded root systems on different sites, to determine if initial root system morphology would influence seedling survival and growth, and to determine whether differences in root system quality would be important over time regardless of outplanting site characteristics. Nursery-run bare-root northern red oak seedlings from the Iowa Department of Natural Resources State Forest Nursery in Ames were graded according to numbers of large first-order lateral roots and outplanted in spring, 1987, on nine plots distributed among three sites in central Iowa;Annual counts of survival and field measurements of height and diameter began in fall, 1987. Also beginning in fall, 1987, six trees per plot were carefully excavated each year for three years, preserving as much of the root system as possible. Excavated seedlings were measured to determine height, diameter, and numbers of roots, and were oven-dried to determine root and shoot dry weights;Survival, height growth, and diameter growth were significantly greater for seedlings with 10 or more large first-order lateral roots than for seedlings with 4 or fewer, and also varied significantly according to outplanting site. Based on analyses of partial correlations, seedling survival and growth were significantly related to initial root grade and to certain soil properties. Measurements of harvested trees indicated statistical differences between seedlings with fewer than 4 large laterals and seedlings with 10 or more, and among sites, for most shoot and root characteristics. Inadequate height growth for all seedlings at the end of three years was attributed to drought conditions, animal damage, and poor control of competing vegetation;Combined results for seedling survival and growth indicated that red oak seedlings with 5 or more large first-order lateral roots have a greater probability of success both in terms of establishment and competitive early growth than those with 4 or less. Variation in performance of seedlings from the three root grade groups on different sites suggested that prescription planting of red oak stock according to outplanting site characteristics may be useful

Linking Forest Communities and Water Quality

This two-page fact sheet describes preliminary results from a project studying how understory plant communities in forests and woodlands can improve water quality

Vegetative buffers for fan emissions from poultry farms: 2. ammonia, dust and foliar nitrogen

This study evaluated the potential of trees planted around commercial poultry farms to trap ammonia (NH3) and dust or particulate matter (PM). Norway spruce, Spike hybrid poplar, hybrid willow, and Streamco purpleosier willow were planted on five commercial farms from 2003 to 2004. Plant foliage was sampled in front of the exhaust fans and at a control distance away from the fans on one turkey, two laying hen, and two broiler chicken farms between June and July 2006. Samples were analyzed for dry matter (DM), nitrogen (N), and PM content. In addition, NH3concentrations were measured downwind of the exhaust fans among the trees and at a control distance using NH3 passive dosi–tubes. Foliage samples were taken and analyzed separately based on plant species. The two layer farms had both spruce and poplar plantings whereas the two broiler farms had hybrid willow and Streamco willow plantings which allowed sampling and species comparisons with the effect of plant location (control vs. fan). The results showed that NH3 concentration h− 1 was reduced by distance from housing fans (P ≤ 0.0001), especially between 0 m (12.01 ppm), 11.4 m (2.59 ppm), 15 m (2.03 ppm), and 30 m (0.31 ppm). Foliar N of plants near the fans was greater than those sampled away from the fans for poplar (3.87 vs. 2.56%; P ≤ 0.0005) and hybrid willow (3.41 vs. 3.02%; P ≤ 0.05). The trends for foliar N in spruce (1.91 vs. 1.77%; P = 0.26) and Streamco willow (3.85 vs. 3.33; P = 0.07) were not significant. Pooling results of the four plant species indicated greater N concentration from foliage sampled near the fans than of that away from the fans (3.27 vs. 2.67%; P ≤ 0.0001). Foliar DM concentration was not affected by plant location, and when pooled the foliar DM of the four plant species near the fans was 51.3% in comparison with 48.5% at a control distance. There was a significant effect of plant location on foliar N and DM on the two layer farms with greater N and DM adjacent to fans than at a control distance (2.95 vs. 2.15% N and 45.4 vs. 38.2% DM, respectively). There were also significant plant species effects on foliar N and DM with poplar retaining greater N (3.22 vs. 1.88%) and DM (43.7 vs. 39.9%) than spruce. The interaction of location by species (P ≤ 0.005) indicated that poplar was more responsive in terms of foliar N, but less responsive for DM than spruce. The effect of location and species on foliar N and DM were not clear among the two willow species on the broiler farms. Plant location had no effect on plant foliar PM weight, but plant species significantly influenced the ability of the plant foliage to trap PM with spruce and hybrid willow showing greater potential than poplar and Streamco willow for PM2.5(0.0054, 0.0054, 0.0005, and 0.0016 mg cm− 2; P ≤ 0.05) and total PM (0.0309, 0.0102, 0.0038, and 0.0046 mg cm− 2, respectively; P ≤ 0.001). Spruce trapped more dust compared to the other three species (hybrid willow, poplar, and Streamco willow) for PM10 (0.0248 vs. 0.0036 mg cm− 2; P ≤ 0.0001) and PM\u3e 10 (0.0033 vs. 0.0003 mg cm− 2; P = 0.052). This study indicates that poplar, hybrid willow, and Streamco willow are appropriate species to absorb poultry house aerial NH3–N, whereas spruce and hybrid willow are effective traps for dust and its associated odors