Tree line shifts and disturbance events for sites studied in the Torneträsk area of sub-Arctic Sweden for the period 1800-2009

Aim: Models project that climate warming will cause the tree line to move to higher elevations in alpine areas and more northerly latitudes in Arctic environments. We aimed to document changes or stability of the tree line in a sub-Arctic model area at different temporal and spatial scales, and particularly to clarify the ambiguity that currently exists about tree line dynamics and their causes. Location: The study was conducted in the Tornetrask area in northern Sweden where climate warmed by 2.5 °C between 1913 and 2006. Mountain birch (Betula pubescens ssp. czerepanovii) sets the alpine tree line. Methods: We used repeat photography, dendrochronological analysis, field observations along elevational transects and historical documents to study tree line dynamics. Results: Since 1912, only four out of eight tree line sites had advanced: on average the tree line had shifted 24 m upslope (+0.2 m/year assuming linear shifts). Maximum tree line advance was +145 m (+1.5 m/year in elevation and +2.7 m/year in actual distance), whereas maximum retreat was 120 m downslope. Counter-intuitively, tree line advance was most pronounced during the cooler late 1960s and 1970s. Tree establishment and tree line advance were significantly correlated with periods of low reindeer (Rangifer tarandus) population numbers. A decreased anthropozoogenic impact since the early 20th century was found to be the main factor shaping the current tree line ecotone and its dynamics. In addition, episodic disturbances by moth outbreaks and geomorphological processes resulted in descent and long-term stability of the tree line position, respectively. Main conclusions: In contrast to what is generally stated in the literature, this study shows that in a period of climate warming, disturbance may not only determine when tree line advance will occur but if tree line advance will occur at all. In the case of non-climatic climax tree lines, such as those in our study area, both climate-driven model projections of future tree line positions and the use of the tree line position for bioclimatic monitoring should be used with caution.

Report of the commissioners appointed ... to inquire concerning charities in England [and Wales] for the education of the poor ...

Set consists of 32 reports, together with indexes and digests, pub. in Reports and papers of the House of Commons, 1819-1843. cf. General index to the bills, reports, accounts and other papers printed by order of the House of Commons: 1801-1832, p. 144; and 1832-1844, p. 218.

Extrusion of uranium, uranium alloys, and uranium compacts : a literature search /

This literature search consisting of 240 references to unclassified reports and published literature has been taken from Nuclear Science Abstracts, the official abstract journal of the United States Atomic Energy Commission. The period covered is January 1951 through May 31, 1961. Abstracts for the references can be found by use of the NSA abstract numbers provided.

Report and findings : transmitted to the Committee on Standards of Official Conduct, July 30, 2010 and released publicly pursuant to H. Res. 895 of the 110th Congress as amended [subject, Eliot L. Engel] /

July 2010."

Signals, traffic software, and lighting: courses and basic references.

Mode of access: Internet.

The New Zealand law reports.

Vols. for 1933-1936 include "The Law journal supplement to the New Zealand law reports."

Problem identification course. Administrative and instructional guide.

National Highway Traffic Safety Administration, Washington, D.C.

Synthesis and fabrication of refractory uranium compounds.

"Contract No. AT-(40-1)-2558"

Choices for conservation : final report to the President and Congress, July 1979 /

"SW-779"--p. 2 of cover.

Radiation shields and shielding : [a bibliography] /

Included are 687 selected references to unclassified reports and scientific journal literature on radiation shields and shielding. Author, report number, and subject indexes are also included.

Japanese science and technology : a bibliography with indexes /

"A selection of annotated references to reports and journal articles entered into the NASA scientific and technical information system during 1985."

Bio-medical reports of the 406 Medical Laboratory.

Mode of access: Internet.

Annual report ... for ...

Reports for 1859-1876 were printed by the state of Massachusetts as Senate documents. Since 1877/78 the reports of the curator to the president and fellows of Harvard College have been printed with the president's reports, and also as a separate series in 8vo. form. cf. Bowker, Publications of societies, 1899.

Report, returns and statistics of the Inland Revenues of the Dominion of Canada ...

"First-[Second] report of the Commissioner of Inland Revenue on the inspection of weights, measures and gas," 1873-1874, were pub. as separate reports and not as supplements to the departmental report.

Periodic reports of the Agricultural Marketing Service.

Vol. for 1956 never published.