Effects of warming on the structure and function of a boreal black spruce forest

doi:10.2172/972910

GSTDTAP > 地球科学

DOI	10.2172/972910
报告编号	MSN-101545
来源ID	OSTI ID: 972910
	Effects of warming on the structure and function of a boreal black spruce forest
	Stith T.Gower
	2010-03-03
出版年	2010
语种	英语
国家	美国
领域	地球科学
英文摘要	A strong argument can be made that there is a greater need to study the effect of warming on boreal forests more than on any other terrestrial biome. Boreal forests, the second largest forest biome, are predicted to experience the greatest warming of any forest biome in the world, but a process-based understanding of how warming will affect the structure and function of this economically and ecologically important forest biome is lacking. The effects of warming on species composition, canopy structure and biogeochemical cycles are likely to be complex; elucidating the underlying mechanisms will require long-term whole-ecosystem manipulation to capture all the complex feedbacks (Shaver et al. 2000, Rustad et al. 2001, Stromgren 2001). The DOE Program for Ecosystem Research funded a three year project (2002-2005) to use replicated heated chambers on soil warming plots in northern Manitoba to examine the direct effects of whole-ecosystem warming. We are nearing completion of our first growing season of measurements (fall 2004). In spite of the unforeseen difficulty of installing the heating cable, our heating and irrigation systems worked extremely well, maintaining environmental conditions within 5-10% of the specified design 99% of the time. Preliminary data from these systems, all designed and built by our laboratory at the University of Wisconsin, support our overall hypothesis that warming will increase the carbon sink strength of upland boreal black spruce forests. I request an additional three years of funding to continue addressing the original objectives: (1) Examine the effect of warming on phenology of overstory, understory and bryophyte strata. Sap flux systems and dendrometer bands, monitored by data loggers, will be used to quantify changes in phenology and water use. (2) Quantify the effects of warming on nitrogen and water use by overstory, understory and bryophytes. (3) Compare effects of warming on autotrophic respiration and above- and belowground net primary production (NPP) budgets. Autotrophic respiration budgets will be constructed using chamber measurements for each tissue and NPP and standard allometry techniques (Gower et al. 1999). (4) Compare microbial and root dynamics, and net soil surface CO2 flux, of control and warmed soils to identify causes that may explain the hypothesized minimal effect of soil warming on soil surface CO2 flux. Fine root production and turnover will be quantified using minirhizotrons, and microbial dynamics will be determined using laboratory mineralization incubations. Soil surface CO2 flux will be measured using automated soil surface CO2 flux systems and portable CO2 analyzers. The proposed study builds on the existing research programs Gower has in northern Manitoba and would not be possible without in-kind services and financial support from Manitoba Hydro and University of Wisconsin.
英文关键词	boreal forest climate warming carbon cycle
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来源平台	US Department of Energy (DOE)
引用统计
文献类型	科技报告
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/4862
专题	地球科学
推荐引用方式 GB/T 7714	Stith T.Gower. Effects of warming on the structure and function of a boreal black spruce forest,2010.