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Locally produced wood biochar increases nutrient retention in agricultural soils of the San Juan Islands, WA, USA
Biochar additions to agricultural soil have been shown to result in many benefits; however, most studies have been conducted in greenhouse or laboratory trials with few being conducted in the field and particularly in association with organic farming systems. Herein, this gap was addressed by conducting on-farm studies on ...
Identifying Mycorrhizas Present in Bigleaf Maple Canopy and Forest Floor Soils in a Coastal Old-Growth Temperate Rainforest in Western Washington
The temperate rainforests of Western Washington are known for their old-growth forests and unique ecosystem processes. In these stands of old-growth, it is common for trees to be 200-300 years old. On branches, Epiphytic mats form in the canopy. The bottom layer of these mats starts to decompose over time, forming a layer of ...
Douglas-Fir Stump Decomposition:Modeling Carbon Residence Times
Stumps are a significant portion of the woody debris in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantation forests in western Washington State. Very few studies have attempted to quantify the amount of carbon that is held in stumps or the rate at which that carbon is lost. This study assessed carbon and nitrogen ...
The Effects of Different Harvest Intensities on the Distribution of Soil Phosphorus and Nutrient Stocks in a Brazilian Oxisol
Forest soils form an important reservoir in ecosystem nutrient and carbon budgets, which are crucial for sustained productivity of forests. Nutrient fluxes and transformations in forest soils are a result of a complex interchange between the atmosphere, plants, and soil. Consequently, soils are a critical source of plant ...
Soil Carbon and Nitrogen Stocks: Underestimation with Common Sampling Methods, and Effects of Thinning and Fertilization Treatments in a Coastal Pacific Northwest Forest
Soil contains substantially more carbon (C) than the atmosphere and vegetation combined. Consequently, the fate of soil organic C (SOC) in response to changes in climate, land use, and management is of great concern. The ability to accurately quantify and compare SOC stocks over time is an important part of understanding ...
Diversity of ammonia-oxidizing archaea in soils under managed and native conditions
Ammonia oxidizing archaea (AOA) contribute to a significant portion of ammonia oxidation in soil. These organisms have significant impacts on plant proliferation, as well as production of fugitive gases. AOA community distribution patterns are influenced by multiple factors, of which, biogeography has emerged as an important ...
Reservoir Sediment Carbon along the Elwha River after Dam Removal
Worldwide, numerous dams are aging and will either need to be replaced or removed within the next few decades. Little is understood about the fate of carbon stored in sediments that become soil when a reservoir is drained due to dam removal. This study assessed the pool of carbon in the sediments of former Lake Mills and ...
Deep Soil: Quantification, Modeling, and Significance of Subsurface Carbon and Nitrogen
Soil is the primary sink for C in forest ecosystems, but is often overlooked in ecosystem C budgets. Efforts to quantify C pools often sample soils to a depth of 0.2 m despite observations that deep soil C is neither scarce nor entirely stable. This study examined the systematic sampling depth for ecosystem C analyses in the ...
The Effects of Biogeoclimatic Properties on Water and Nitrogen Availability and Douglas-Fir Growth and Fertilizer Response in the Pacific Northwest
(2012-09-13)
Coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is the predominant plantation species of the western Pacific Northwest, although soil and climate characteristics vary throughout the region. This study investigated the effects of water and nitrogen availability on Douglas-fir growth throughout the region. Sixty ...
Foliar nutrient levels in Douglas-fir plantations 25 years after stump removal and fertilization to control Phellinus weirii
(2012-09-13)
Removal of stumps and fertilization after harvesting have been proposed to reduce root diseases in succeeding stands. Potential impacts such as compaction and loss of soil C or N could limit the use of this technique. This research examined forest soils and foliar nutrient levels in five Pacific Northwest stands 22-29 years ...