The International Tree-Ring Data Bank (ITRDB) is an invaluable resource, providing access to a massive and growing cache of tree-ring data. Oxygen, carbon, nitrogen and hydrogen isotope treering studies, which have provided valuable climatic and ecological information, have proliferated for decades so an ITRDB expansion to include isotopic data would likewise benefit the scientific community. An international tree-ring isotope databank (ITRIDB) would: (1) allow development of transfer functions from extended isotopic data sets, (2) provide abundant tree-ring isotopic data for meta-analysis, and (3) encourage isotopic network studies. A Europe network already exists, but the international data bank proposed here would constitute a de facto global network. Associated information to be incorporated into the database includes not only the customary ITRDB entries, but also elements peculiar to isotope chronologies. As with the current ITRDB, submission of data would be voluntary and as such it will be crucial to have the support of the tree-ring isotope community to contribute existing and forthcoming isotope series. The plan is to institute this isotope database in 2010, administered by the National Climatic Data Center.

Tree-ring studies have demonstrated that conifer latewood measurements contain information on long-term North American monsoon (NAM) variability, a hydroclimatic feature of great importance to plants, animals, and human society in the US Southwest. This paper explores data-treatment options for developing latewood chronologies aimed at NAM reconstruction. Archived wood samples for five Douglas-fir (Pseudotsuga menziesii, Mirb. Franco) sites in southeastern Arizona are augmented with new collections. The combined dataset is analyzed along with time series of regionally averaged observed precipitation to quantify the strength of regional precipitation signal in latewood time series and to identify ways of increasing the signal strength. Analysis addresses the signal strength influences of including or excluding ‘‘false’’ latewood bands in the nominal ‘‘latewood’’ portion of the ring, the necessary adjustment of latewood width for statistical dependence on antecedent earlywood width, and tree age. Results suggest that adjusted latewood width chronologies from individual sites can explain around 30% of the variance of regional summer (July–August) precipitation—increasing to more than 50% with use of multiple chronologies. This assessment is fairly insensitive to the treatment of false latewood bands (in intra-annual width and 𝛿¹³C variables), and to whether latewood-width is adjusted for dependence on earlywood-width at the core or site level. Considerations for operational chronology development in future studies are (1) large tree-to-tree differences in moisture signal, (2) occasional nonlinearity in EW-LW dependence, and (3) extremely narrow and invariant latewood width in outer portions of some cores. A protocol for chronology development addressing these considerations is suggested.

The eruption of Parícutin (1943–1952), a cinder cone volcano in Michoacán, Mexico, caused dendrochronological and dendrochemical responses that might be useful as general dating tools for eruptions. For the eruption period, pines near Parícutin have slightly suppressed ring widths plus high inter-annual variability of width. Wood anatomy changes include traumatic resin ducts and thin bands of false latewood. Dendrochemistry of tree rings shows little temporal variation in most elements, but beginning in 1943 sulfur content increased in rings of four trees and phosphorus content increased in rings of two trees. Hypotheses for increased S and P include new availability of pre-existing soil S and P and/or new input of S and P from the tephra itself. Pines at Parícutin also show suppressed ring widths for five years beginning in 1970, and had the eruption date not been known, the most likely conclusion from ring-width data alone would have been an eruption from 1970 to 1974. However, the 1970s suppression was in response to defoliation by a pine sawfly outbreak, not an eruption. For dendrochronological dating of cinder-cone eruptions, a combination of multiple characteristics (width, chemistry, and anatomy) would be more reliable than depending on any one characteristic alone.

Dendrochronological collections include continuously expanding multi-taxon records of tree growth that encompass millennia and often offer irreplaceable sources of biological, environmental, and cultural information. Nevertheless, each departure of a scholar from the field—whether because of death, retirement, career change, shift in research priorities, or even move to a new institution—places collections in increased danger of being lost as viable resources. Without an organized and concerted effort to address outstanding and future issues of specimen curation, dendrochronology as a whole may become mired in the same trap that befalls many other scientific fields: collections apathy. Dendrochronological collections exist as a result of decades of effort and should function to support current and future scientific endeavors, education, and outreach, but cannot do so without adequate attention to their future. Intended as a ‘‘call to arms’’ this paper, focused on dendrochronology in the academic and public sector, aims to encourage discussion and, more importantly, to provide a foundation for and to instill a sense of urgency regarding long-term preservation of dendrochronological specimens.

Ring-width chronologies from Pinus resinosa Ait., Pinus strobus L., and Thuja occidentalis L. were developed in two areas of the Boundary Waters Canoe Area Wilderness to assess their growth climate response and their potential for developing reconstructions of climate. New red pine chronologies were combined with existing chronologies to extend the ring-width record both into the past and into the present. Ring-width response to climate, assessed using correlation analysis and response functions, was broadly similar among all three species with relatively significant positive relationships with June–July precipitation and significant negative (but less consistent) associations with June–July temperatures (p < 0.05). White-cedar appeared to have a broader phenological window of response with a stronger spring influence when compared to other species included in this study. Comparisons with other nearby proxies showed relatively strong coherence overall but with some important regional differences. Overall, these species may be useful for placing current climatic patterns in the Boundary Waters within a longer term perspective but care should be taken with respect to identifying appropriate climatic records for calibration.

Dendroarchaeological samples can contain three kinds of information: chronological, behavioral, and environmental. The decisions of past people regarding species selection, beam size, procurement and modification techniques, deadwood use, and stockpiling are the most critical factors influencing an archaeological date distribution. Using dendrochronological samples from prehistoric and historic period sites in the same area of eastern Utah, this paper examines past human behavior as the critical factor in dendroarchaeological date distributions.