Author
Sauer, Thomas | |
CHENDEV, YURY - Belgorod State University | |
HERNANDEZ-RAMIREZ, GUILLERMO - University Of Alberta | |
PETIN, ALEXANDR - Belgorod State University | |
HALL, RICHARD - Iowa State University | |
NOVYKH, LARISA - Belgorod State University | |
ZAZDRAVNYKH, EVGENY - Belgorod State University |
Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 3/15/2014 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Tree windbreaks are an attractive multiple-benefit land use through their ability to mitigate climate change by modifying the local microclimate to improve crop growth and by sequestering carbon in the soil and tree biomass. Recently, such agroforestry practices are also being considered for their bioenergy potential as the wood could be harvested for direct combustion, cellulose to ethanol conversion, or pyrolysis to bio-oils. The objective of this project was to use detailed soil profile descriptions and spatially-distributed soil sampling to determine the soil carbon sequestration potential of tree plantings across climatic gradients in the Central Russian Uplands and the U.S. Great Plains. Three Russian sampling locations, Streletskaya, Yamskaya, and Kamennaya spanned a gradient of mean annual temperature from 5.3 to 5.8°C and precipitation from 480 to 580 mm. Three U.S. sampling locations, Reynolds, North Dakota; Huron, South Dakota; and Norfolk, Nebraska, had ranges of annual temperature from 3.9 to 9.2°C and precipitation from 450 to 690 mm. Tree species at the sampling sites included black poplar (Populus nigra), silver birch (Betula pendula), box elder (Acer negundo), English oak (Quercus robur) and balsam poplar (Populus balsamifera) in Russia and green ash (Fraxinus pennsylvanica), redcedar (Juniperus virginiana), Siberian elm (Ulmus pumila, L.), mulberry (Morus rubra, L.), and cottonwood (Populus deltoides) in the U.S. Trees ranged in age from 19 to 70 years. Soil core samples (30 cm depth) were taken in a grid across each windbreak and subdivided into 0-15 and 15-30 cm sections. Soil pit and auger samples to 1.2 m or greater were collected in each land cover (tree, crop, and undisturbed grassland as reference). Samples were analyzed for organic (SOC), inorganic (SIC), and permanganate oxidizable (POXC) carbon as well as for stable carbon isotope signature (del 13C, natural abundance). Soil pH and total nitrogen (TN) content were also determined. For all six sampling sites, SOC content in the surface 30 cm beneath the trees averaged 22.4% greater than the adjacent cropped fields. Stable carbon isotope and POXC data indicate that a significant proportion of this accumulation could be attributed to tree sources. Changes in soil pH and TN were also observed with implications for soil chemical and physical quality and nutrient cycling dynamics. Windbreaks from more cool and moist climate conditions were found to be more favorable for SOC accumulation in the surface soil layers. The relationship between SOC accumulation and climate as characterized by the hydrothermal coefficient of Selyaninov (1928) enables the estimation of soil carbon stocks in existing windbreaks and the potential to predict carbon sequestration in future plantings. |