No description available.

Writing is much like any other activity-the more you read and write, the more proficient you become as a scientist. Here, I provide canons for writing and editing scientific papers that should help novice writers avoid common hazards that could render a manuscript unpublishable. Abstracts should be well-written and concise and contain all the major results and conclusions. The manuscript should be well organized. Sentences in all paragraphs should stick to the central theme of the paragraph. Writers should provide Latin names for species analyzed, and should use SI units in all cases. The use of bulleted lists, active voice, and commas after introductory phrases will improve the clarity of the manuscript. Tables and figures should be clear, well-organized, stand-alone accessories to the text, and usually convey data and results that are numerous or complex. Writers should avoid both plagiarism and self-plagiarism, and should have their manuscript proofread before submitting to a journal. Finally, authors should consult primary references (such as Scientific Style and Format, published by the Council of Biology Editors in 1994) to become familiar with troublesome words and phrases.

Old Douglas-fir (Pseudotsuga menziesii) trees were sampled in the Sierra Madre Oriental of northeastern Mexico and used to develop a 219-year chronology of earlywood width. This chronology is correlated with monthly precipitation totals from January to June recorded at Saltillo some 55 km northwest of the collection site. The chronology was used to reconstruct winter-spring precipitation (January-June total) from 1782-2000. The reconstruction indicates large interannual, decadal, and multidecadal variability in winter-spring precipitation over Saltillo. This variability is vaguely apparent in the short and discontinuous instrumental record from 1950-1998, with January-June totals ranging from 15 to 310 mm, multiyear droughts, and a negative trend in January-June precipitation over the last 50 years. The reconstruction indicates that severe dryness was prevalent over a 24-year period from 1857-1880. This mid-19th century drought exceeds the duration of any droughts witnessed during the 20th century. However, three episodes of winter-spring dryness have prevailed in the Saltillo region after 1950, a much higher frequency of decadal drought than estimated over the past 219 years and aggravating the regional water supply problems associated with this booming manufacturing and ranching center.

The Giant Sequoia played several crucial roles in the founding of the modern science of tree-ring dating. These included at least two central theoretical constructs and at least two minor ones; however, historical studies of dendrochronology are actively continuing and this list is expected to expand. Second only to the importance of the ponderosa pine (Pinus ponderosa) in the earliest days of the infant science, the Giant Sequoia (Sequoiadendron giganteum) was at the very center of the establishment of the discipline of dendrochronology. How the sequoia came to be used by A.E. Douglass, and what vital information and how it provided such information is the topic here.

No description available.

Increment cores that dry with a spiral twist are a problem in any study where a clear view of transverse wood anatomy is required. This problem may become acute when working with wood that is partially decomposed. After soaking cores in a urea solution, we can remove spiral twists by applying steam to the cores and gently twisting cores until they straighten. Treatment does not result in a serious distortion of ring widths.

No description available.

Since the mid-1700s, slash (Pinus elliottii Engelm.) and longleaf (Pinus palustris Mill.) pines growing in the coastal plain region of the southeastern United States were intentionally wounded ("boxed" and/or "chipped ") to induce the production of resin, which was then collected and distilled into turpentine and its derivatives (termed "gum naval stores "). Relicts from this once-dominant industry are seen throughout southern pine forests as boxed and chipped stumps or (rarely) still living trees. In this study, we dated the years of chipping on slash pines growing in two locations in Lowndes County, Georgia, to (1) better understand past forest land use patterns, and (2) raise public awareness of the ethnohistorical importance of these trees to the cultural heritage of southern Georgia. We collected cores from ten living trees with characteristic chipped surfaces ("catfaces ") from Taylor-Cowart Memorial Park (TCMP) in Valdosta, Georgia, and cross sections from ten chipped stumps in the area surrounding Lake Louise, 12 km south of Valdosta. We conclude that chipping at TCMP occurred in 1947-1948, while two chipping events occurred at Lake Louise around 1925 and between 1954-1956. Our dating was facilitated by observing periods of growth suppression, distorted and /or discolored rings, and the absence of some growth rings that may indicate possible chipping events. We recommend that these chipped stumps and living trees be preserved intact for their ethnohistorical significance, educational importance, and potential for future research.

Six mean ring-width tree-ring chronologies were constructed for living Scots pine (Pious sylvestris L.), growing near the species' upper and northern limits in the area between the Ob River and the subpolar Ural Mountains in Russia. All ring-width series were standardized by fitting cubic smoothing splines and chronologies were constructed as biweight robust means. The six chronologies ranged from 181 to 276 years in length. Response function analysis showed all chronologies to have negative responses to winter precipitation. Most chronologies also showed positive, but relatively low responses to temperatures of the current and previous summer. Total October-May precipitation was reconstructed back to A.D. 1843 using the lagged and unlagged chronologies as candidate predictors. In addition to reflecting an unstable and time-varying growth-climate link, moderate verification results may partly be due to problems with short verification periods. The reconstruction contains almost equal amounts of high-frequency (<8 years) and low-frequency ( >8 years) variations, among them a significant 30-year variation. The precipitation signal may add an important aspect to reconstructing paleoclimatic fluctuations in the northern hemisphere. Continuing work with the Scots pine from this area depends on improving the quality of a precipitation reconstruction and finding older living and subfossil wood.

A 155-point US grid of tree-ring reconstructed summer (JJA; Cook et al. 1996) averaged Palmer Drought Severity Index (PDSI) was used to document the history and investigate the external forcing of growingseason climate anomalies for the period 1700 to 1978. Statistical analysis software was used to composite years temporally by computing averages for the years of known dates of major potential climate-forcing events. A geographic information system (GIS) was used to display the composites as well as individual years. The forcing factors investigated were the 22-year Hale solar magnetic cycle, major El Niño (warm) and La Niña (cold) events based on the Southern Oscillation Index (SOI), and large magnitude low latitude volcanic eruptions. Positive and negative moisture anomalies appear around Iowa in the alternate 11-year sunspot cycles that make up the Hale solar magnetic cycle. Experimentation with the grouping of years in the Hale cycle composites led to unexplained spatial shifts of the moisture anomalies in the same region. The El Niño episodes usually show positive (wet) PDSI anomalies in the Southwest from California to Texas, while La Niña events usually have drought in the same area, with some inconsistent signals in the north central Plains and the Northwest. The eastern and northern US were unaffected by the Southern Oscillation, although the summer season reconstructed PDSI may have missed the SOI variation, which is primarily a winter signal. The three largest tropical volcanic eruptions since 1800 failed to follow a consistent pattern, but the 1815 eruption of Tambora in Indonesia was followed by a very strong positive growth anomaly in the Southwest in 1816 and 1817. Important regional studies with the winter-spring season could be done with this network of tree-ring chronologies and observed monthly PDSI data.