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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 ...
Creating Novel Soil Amendments Using Class A Biosolids
By blending Class A biosolids with organic and inorganic materials, thirteen unique soil amendments were created with a goal of developing a product able to access a wider market than unblended Class A biosolids. A set of criteria were developed to assess if the developed blends could be successful general-purpose soil ...
Fire, Charcoal, and the Biogeochemistry of Carbon and Nitrogen in Pacific Northwest Forest Soils
The rain shadow forests of the Olympic peninsula represent a unique, mixed-severity fire regime class in the midst of a highly productive landscape where spatial heterogeneity of fire severity may have significant implications for below and aboveground post-fire recovery. The purpose of this study was to quantify the impacts ...
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 ...
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 ...
Metal response of Douglas-fir: a comparison of foliar metals and phytochelatin production in trees planted in soils amended with biosolids or metal salts
(2013-11-14)
This study was designed to explore the relationship between metals in soil, foliar metal concentrations and phytochelatin (PC) production in Douglas-fir trees planted in soils amended with biosolids or metal salts. Both a greenhouse and field study were conducted to determine whether PC production could be correlated with ...
Evaluation of Northwestern Seattle Parking Strip Soil for Urban Horticulture Land Use and Urban Food Production
(2013-04-17)
With urban agriculture on the rise in many cities, areas for urban agriculture and vegetable gardening practices are being explored. The parking strip, street side right-of-way land, is a proposed area for vegetable gardening in Seattle. In the Northwest corner of Seattle, 141 acres of parking strips have been identified. ...
Nitrogen Cycling Under Increased N Loads in Two Forested Ecosystems
The coupled role of the terrestrial nitrogen (N) and carbon (C) cycles is of increasing importance, particularly in light of global climate change. Forested ecosystems contain over half of the terrestrial C pool and currently absorb as much as 30% of anthropogenic CO2 emissions. Many forests, particularly Douglas-fir forests ...