Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 107-117). Also available on the World Wide Web.

Landscapes are comprised of multiple ecosystems shaped by disturbances varying in severity and source. Moderate disturbance from weather, pathogens, insects, and age-related senescence, in contrast to severe disturbances that fell trees, may increase standing woody debris and alter the contribution of coarse woody debris (CWD) to total ecosystem respiration (RE). However, woody debris dynamics are rarely examined following moderate disturbances that substantially increase standing dead wood stocks. We used an experimental manipulation of moderate disturbance in an upper Great Lakes forest to: 1) examine decadal changes in CWD stocks through a moderate disturbance; 2) quantify in situ CWD respiration during different stages of decay for downed and standing woody debris and; 3) estimate the annual contribution of CWD respiration to the ecosystem C balance through comparison with RE and net ecosystem production (NEP). We found that the standing dead wood mass of 24.5 Mg C ha-1 was an order of magnitude greater than downed woody debris stocks and a large source of ecosystem C flux six years following disturbance. Instantaneous in situ respiration rates from standing and downed woody debris in the earliest stages of decay were not significantly different from one another. Independently derived estimates of ecosystem CWD respiration of 1.1to 2.1 Mg C ha-1 yr-1 six years following disturbance were comparable in magnitude to NEP and 12.5 % to 23.8 % of RE, representing a substantial increase relative to pre-disturbance levels. Ecosystem respiration and NEP were stable following moderate disturbance even though ecosystem CWD respiration increased substantially, suggesting a reduction in the respiratory C contribution from other sources. We conclude that CWD is an essential component of the ecosystem C balance following a moderate forest disturbance.

Thesis (M.S.)--Washington State University, 2003. / Title from PDF title page (viewed on May 22, 2005). Includes bibliographical references (p. 52-56).

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 88-102).

Thesis (M.S.)--University of Delaware, 2007. / Principal faculty advisor: James E. Pizzuto, Dept. of Geological Sciences. Includes bibliographical references.

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2007. / Thesis documentation sheet inserted. Includes appendix with four papers co-authored with others. Includes bibliographical references. Issued also electronically via World Wide Web in PDF format; online version lacks appendix.

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2006. / Thesis documentation sheet inserted. Appendix includes reproductions of six papers and manuscripts co-authored with others. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix of papers; ill. in online version displays in color.

This study uses a spatial model to visualize LWD mobility areas in an approximate 1km reach of Cummins Creek, a fourth-order stream flowing through an old-growth Sitka spruce-western hemlock forest in the Oregon Coast Range. The model solves a LWD incipient motion equation for nine wood size combinations (0.1m, 0.4m, 1.7m diameters by 1.0m, 6.87m, 47.2m lengths) during the 2-year, 10-year, and 100-year discharge events. Model input variables were derived from a combination of field survey, remotely sensed, and modeled data collected or derived between June 2010 and July 2011. LWD mobility map results indicate the 2-year discharge mobilizes all modeled diameters, but mobile piece lengths are shorter than the bankfull channel boundary. Mobility areas for each wood size combination increases with discharge; 10-year and 100-year discharge events mobilize wood longer than average bankfull width within a confined section of the main stem channel, and mobilize LWD shorter than bankfull width within the main stem channel, side channels, and floodplain. No discharge event mobilizes the largest LWD size combination (1.7m / 47.2). Recruitment process was recorded for all LWD during June 2010, revealing that all mobile wood in the study reach was shorter than bankfull width. Based on these conflicting results, I hypothesize the distribution of wood in Cummins Creek can be described in terms of discharge frequency and magnitude, instead of as a binary mobile/stable classification. Mobility maps could be a useful tool for land managers using LWD as part of a stream restoration or conservation plan, but will require additional calibration.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18107号 / 理博第3985号 / 新制||理||1575(附属図書館) / 30965 / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 朝倉 彰, 講師 宮崎 勝己, 教授 疋田 努 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

A frequent source of pine tree mortality in recent years can be attributed to pine bark beetles and their vectored Ophiostomatoid fungi, an organism that has been observed to attract subterranean termites that preferentially recruit to this downed woody debris. This interaction may significantly modify biogeochemical fluxes in bark beetle mass mortality events, but studies are often limited to singular regions or single pine-dominated ecosystems. Two studies were designed to test the interactive effects of these associations on terrestrial biogeochemical cycles and decomposition processes, the first using replicated field trials in Mississippi, Arizona, and Honduras across two years and the second across five years in Mississippi. Both studies utilized Ophiostomatoid inoculation and invertebrate exclusion techniques to determine the individual and interactive contributions from biotic factors on biogeochemical cycling. Local drivers were found to have greater influence on biogeochemical cycling and decomposition before climate drivers overwhelmed their influence in later years.