干旱区生态环境知识资源中心(Arid): Carbon cycle dynamics within Oregon’s urban-suburban-forested-agricultural landscapes

Arid

报告编号	1363940
	Carbon cycle dynamics within Oregon’s urban-suburban-forested-agricultural landscapes
	Law, Beverly E.; Still, Christopher Jason; Schmidt, Andres
英文摘要	Our overarching goal was to develop and utilize an observation-based analysis framework to assess interactions between climate and mosaics of land use, land cover and urbanization on regional carbon, water, and energy dynamics, and potential changes associated with land management and climate. Carbon, water and energy cycling was quantified for the range of current and potential land uses under present and future climates. The study region of Oregon has a strong climatic gradient from the coastal mesic forests (2500mm ppt) to the Willamette Valley, Cascade Mountains, and the Northern Great Basin semi-arid “cold desert” to the east (300 mm). The study was focused on the effects of (1) conversion of semi-arid sagebrush and Willamette Valley agricultural crops to bioenergy production; (2) afforestation of idle land and rangelands deemed suitable for forests or poplar crops under future climate conditions. We found that net ecosystem production (NEP), the net of ecosystem photosynthesis and respiration, was 10 times higher in the high biomass forests of the Coast Range compared with drier regions like sagebrush in the Northern Great Basin, which was nearly zero (Schmidt et al. 2016). The state total NEP averaged about 30 teragrams carbon (Tg C) per year for the years 2012 to 2014 using our model framework that we developed for predictions of current and future NEP, and compared well with our detailed inventory estimates (28 Tg C annual average for 2011-2015 for forests only; Law et al. 2017). Running our model framework until the year 2050, we found that climate alone only increased NEP by less than 1 Tg C per decade (~3%) using the current trajectory of carbon dioxide emissions, however, changes are expected to be more rapid in subsequent years. We evaluated the possibility of land use change from grass seed crops to poplar for bioenergy, which slightly increased NEP by 2050. The most important variable for carbon sequestration estimates (net carbon sources and sinks) is net ecosystem carbon balance (NECB), which accounts for NEP and losses associated with harvest removals and wildfire emissions. Here, we focus on forests because they have the largest effect on carbon sequestration. We found that NECB in Oregon averaged 18.8 Tg C per year in 2011-2015, offsetting fossil fuel emissions (16 Tg C per year). Annual fire emissions reducing NECB by about 5% (0.97 Tg C per year) in the state. The mesic Coast Range and West Cascades ecoregions that make up the western third of Oregon account for 60% of the forest NECB. This analysis illustrates that annual emissions from forests disturbances are low relative to annual fossil fuel emissions for the same area (Law et al. 2017, Hudiburg et al. in review).
出版年	2017-06-15
国家	United States
来源学科分类	09 BIOMASS FUELS ; 54 ENVIRONMENTAL SCIENCES ; 60 APPLIED LIFE SCIENCES ; ecosystem carbon sequestration ; land use change ; bioenergy
URL	http://r.cnki.net/KCMS/detail/detail.aspx?DbCode=KJBG&dbname=KJBGW&filename=5c1c7f21413c33143c7b958a
资源类型	科技报告
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/274071
推荐引用方式 GB/T 7714	Law, Beverly E.,Still, Christopher Jason,Schmidt, Andres. Carbon cycle dynamics within Oregon’s urban-suburban-forested-agricultural landscapes,2017.