The North American Long-Term Soil Productivity Study / [Le programme nord-américain de recherche sur la productivité des sols à long terme]

2006 ◽  
Vol 36 (3) ◽  
Keyword(s):  
North American ◽  
Soil Productivity ◽  
The North

The North American long-term soil productivity experiment: Findings from the first decade of research

2005 ◽  
Vol 220 (1-3) ◽  
pp. 31-50 ◽  
Author(s):  
Robert F. Powers ◽  
D. Andrew Scott ◽  
Felipe G. Sanchez ◽  
Richard A. Voldseth ◽  
Deborah Page-Dumroese ◽  
...  
Keyword(s):  
North American ◽  
Soil Productivity ◽  
The North

Soil physical property changes at the North American Long-Term Soil Productivity study sites: 1 and 5 years after compaction

2006 ◽  
Vol 36 (3) ◽  
pp. 551-564 ◽  
Author(s):  
Deborah S Page-Dumroese ◽  
Martin F Jurgensen ◽  
Allan E Tiarks ◽  
Felix Ponder, Jr. ◽  
Felipe G Sanchez ◽  
...  
Keyword(s):  
Bulk Density ◽  
North American ◽  
Soil Compaction ◽  
Soil Bulk Density ◽  
Water Infiltration ◽  
Soil Productivity ◽  
Soil Monitoring ◽  
The North ◽  
The Impact

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.

Ontario, Canada’s LTSP Experience: Forging Lasting Research Partnerships and the Adaptive Management Cycle in Action

2020 ◽  
Vol 118 (3) ◽  
pp. 337-351
Author(s):  
Dave M Morris ◽  
Rob L Fleming ◽  
Paul W Hazlett
Keyword(s):  
Adaptive Management ◽  
Management Practices ◽  
Forest Policy ◽  
Lessons Learned ◽  
Soil Productivity ◽  
Research Partnerships ◽  
Foliar Nutrition ◽  
Individual Tree ◽  
The North

Abstract In this paper, we summarize Ontario’s Long-term Soil Productivity (LTSP) experience focusing on our efforts to forge lasting research partnerships, highlight the approaches we feel were effective in getting emerging science into forest policy within an adaptive management (AM) framework, and describe the future direction of Ontario’s LTSP program as new policy issues are emerging as part of the continuous AM cycle. Fourteen installations were established on nutrient-poor, conifer-dominated sites, considered to be the most sensitive to increased biomass removals. From 1993 to 1995, all sites were clearcut-harvested, with replicated (three reps per site) biomass removal treatments that included: stem only, full-tree, and full-tree + forest floor removal. Routine (every 5 years) measurements have been carried out to track changes in soil carbon and nutrient levels, as well as stand- and individual-tree growth and development metrics and foliar nutrition. The published results from Ontario’s LTSP program, in combination with the North American-wide LTSP synthesis outputs, have suggested that these nutrient-poor, conifer-dominated sites are less sensitive to biomass (nutrient) removals than previously thought. The evidence provided through peer-reviewed publications, conference and workshop presentations, and field tours was substantive and led to a review and revision of the full-tree logging direction within Ontario’s guidelines. We conclude with a set of recommendations (lessons learned) for the successful delivery of any new long-term, interdisciplinary research projects examining the sustainability of forest-management practices.

scholarly journals A Surface Wind Extremes (“Wind Lulls” and “Wind Blows”) Climatology for Central North America and Adjoining Oceans (1979–2012)

2015 ◽  
Vol 54 (3) ◽  
pp. 643-657 ◽  
Author(s):  
Jonny W. Malloy ◽  
Daniel S. Krahenbuhl ◽  
Chad E. Bush ◽  
Robert C. Balling ◽  
Michael M. Santoro ◽  
...  
Keyword(s):  
United States ◽  
North America ◽  
North American ◽  
North Atlantic Ocean ◽  
Grid Point ◽  
Surface Wind ◽  
Wind Speeds ◽  
The North ◽  
Anomalous Wind

AbstractThis study explores long-term deviations from wind averages, specifically near the surface across central North America and adjoining oceans (25°–50°N, 60°–130°W) for 1979–2012 (408 months) by utilizing the North American Regional Reanalysis 10-m wind climate datasets. Regions where periods of anomalous wind speeds were observed (i.e., 1 standard deviation below/above both the long-term mean annual and mean monthly wind speeds at each grid point) were identified. These two climatic extremes were classified as wind lulls (WLs; below) or wind blows (WBs; above). Major findings for the North American study domain indicate that 1) mean annual wind speeds range from 1–3 m s−1 (Intermountain West) to over 7 m s−1 (offshore the East and West Coasts), 2) mean durations for WLs and WBs are high for much of the southeastern United States and for the open waters of the North Atlantic Ocean, respectively, 3) the longest WL/WB episodes for the majority of locations have historically not exceeded 5 months, 4) WLs and WBs are most common during June and October, respectively, for the upper Midwest, 5) WLs are least frequent over the southwestern United States during the North American monsoon, and 6) no significant anomalous wind trends exist over land or sea.

scholarly journals Vegetation Dynamics within the North American Monsoon Region

2011 ◽  
Vol 24 (6) ◽  
pp. 1763-1783 ◽  
Author(s):  
Giovanni Forzieri ◽  
Fabio Castelli ◽  
Enrique R. Vivoni
Keyword(s):  
North American ◽  
Vegetation Dynamics ◽  
Vegetation Index ◽  
North American Monsoon ◽  
Terrain Attributes ◽  
The North ◽  
Short Period ◽  
Long Term Trends ◽  
Northwestern Mexico

Abstract The North American monsoon (NAM) leads to a large increase in summer rainfall and a seasonal change in vegetation in the southwestern United States and northwestern Mexico. Understanding the interactions between NAM rainfall and vegetation dynamics is essential for improved climate and hydrologic prediction. In this work, the authors analyze long-term vegetation dynamics over the North American Monsoon Experiment (NAME) tier I domain (20°–35°N, 105°–115°W) using normalized difference vegetation index (NDVI) semimonthly composites at 8-km resolution from 1982 to 2006. The authors derive ecoregions with similar vegetation dynamics using principal component analysis and cluster identification. Based on ecoregion and pixel-scale analyses, this study quantifies the seasonal and interannual vegetation variations, their dependence on geographic position and terrain attributes, and the presence of long-term trends through a set of phenological vegetation metrics. Results reveal that seasonal biomass productivity, as captured by the time-integrated NDVI (TINDVI), is an excellent means to synthesize vegetation dynamics. High TINDVI occurs for ecosystems with a short period of intense greening tuned to the NAM or with a prolonged period of moderate greenness continuing after the NAM. These cases represent different plant strategies (deciduous versus evergreen) that can be adjusted along spatial gradients to cope with seasonal water availability. Long-term trends in TINDVI may also indicate changing conditions favoring ecosystems that intensively use NAM rainfall for rapid productivity, as opposed to delayed and moderate greening. A persistence of these trends could potentially result in the spatial reorganization of ecosystems in the NAM region.

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