http://cfs.nrcan.gc.ca/authors/read/20230?lang=en_CA Publications by D.S. Page-Dumroese en-ca 2012-06-07 09:30:26 MST 2012-06-07 09:30:26 MST webmaster@nofc.cfs.nrcan.gc.ca http://cfs.nrcan.gc.ca/publications?id=33767 We examined 10th year above-ground planted tree and total stand biomass, and planted tree foliar N and P concentrations across gradients in soil disturbance at 45 North American Long-Term Soil Productivity (LTSP) installations. While ranging across several climate regions, these installations all share a common experimental design with similar measurement protocols. Across all installations planted tree biomass with stem-only harvest (OM0), no compaction (C0) and chemical vegetation control (VC), ranged from 2 to 90Mg ha1. When compared with the OM0, full-tree harvest (OM1) had little consistent effect on any response variable. Full-tree harvest plus forest floor removal (OM2) also demonstrated few consistent effects on planted tree biomass, although Boreal – Great Lakes conifers showed some positive effects, reflecting high survival, but also negative effects on foliar nutrition. Compaction (C2), regardless of OM treatment, increased planted tree stand biomass consistently in Warm Humid climates, and compaction with intact forest floors (OM0C2) did so across all regions. However, most installations had medium – or coarse-textured soils and compaction did not achieve theoretical growth-limiting bulk densities. Combining OM2 with C2 resulted in lesser gains in planted tree biomass. Planted tree biomass gains with the OM0C2 were attributed largely to changes in physical soil characteristics, not to vegetation control or nutrient availability. Total stand biomass (Mg ha1) was either unaffected or, with aspen, reduced by compaction. Vegetation control (VC) consistently enhanced planted tree biomass, regardless of climate, and also enhanced foliar nutrient concentrations on Warm Humid and Mediterranean sites. VC also increased total stand biomass on sites without abundant woody competitors, but decreased it on shrubdominated Mediterranean sites. For many of the site types and species investigated, harvest-related organic matter removal and soil compaction (excepting aspen vegetative reproduction) have not resulted in large losses in stand biomass 10 year after harvest. Most stands, however, have not yet reached canopy closure, and treatment effects may continue to evolve. Thu, 07 Jun 2012 http://cfs.nrcan.gc.ca/publications?id=33767 http://cfs.nrcan.gc.ca/publications?id=26165 We examined fifth-year seedling response to soil disturbance and vegetation control at 42 experimental locations representing 25 replicated studies within the North American Long-Term Soil Productivity (LTSP) program. These studies share a common experimental design while encompassing a wide range of climate, site conditions, and forest types. Whole-tree harvest had limited effects on planted seedling performance compared with the effects of stem-only harvest (the control); slight increases in survival were usually offset by decreases in growth. Forest-floor removal improved seedling survival and increased growth in Mediterranean climates, but reduced growth on productive, nutrient-limited, warm–humid sites. Soil compaction with intact forest floors usually benefited conifer survival and growth, regardless of climate or species. Compaction combined with forest-floor removal generally increased survival, had limited effects on individual tree growth, and increased stand growth in Mediterranean climates. Vegetation control benefited seedling growth in all treatments, particularly on more productive sites, but did not affect survival or alter the relative impact of organic matter removal and compaction on growth. Organic matter removal increased aspen coppice densities and, as with compaction, reduced aspen growth. Mon, 24 Apr 2006 http://cfs.nrcan.gc.ca/publications?id=26165 http://cfs.nrcan.gc.ca/publications?id=26167 The impact of forest management operations on soil physical properties is important to understand, since management can significantly change site productivity by altering root growth potential, water infiltration and soil erosion, and water and nutrient availability. We studied soil bulk density and strength changes as indicators of soil compaction before harvesting and 1 and 5 years after harvest and site treatment on 12 of the North American Long-Term Soil Productivity sites. Severe soil compaction treatments approached root-limiting bulk densities for each soil texture, while moderate compaction levels were between severe and preharvest values. Immediately after harvesting, soil bulk density on the severely compacted plots ranged from 1% less than to 58% higher than preharvest levels across all sites. Soil compaction increases were noticeable to a depth of 30 cm. After 5 years, bulk density recovery on coarse-textured soils was evident in the surface (0–10 cm) soil, but recovery was less in the subsoil (10–30 cm depth); fine-textured soils exhibited little recovery. When measured as a percentage, initial bulk density increases were greater on fine-textured soils than on coarser-textured soils and were mainly due to higher initial bulk density values in coarse-textured soils. Development of soil monitoring methods applicable to all soil types may not be appropriate, and more site-specific techniques may be needed for soil monitoring after disturbance. Mon, 24 Apr 2006 http://cfs.nrcan.gc.ca/publications?id=26167