For more information about Dendrochronology contact 吉姆斯皮尔

Dendrochronology is the science that deals with the dating and studying of annual growth layers in wood.

• Dendron =“树”(希腊语)
• Chronology = "science deals with time and the assignment of dates to particular events."

The Value of Dendrochronology
It is the most accurate dating technique that we use today. It provides annual and even seasonal resolution throughout the entire record. Other records such as varved lake sediments, 一些冰芯, and coral records can provide annual resolution but it is not as consistently reliable as dendrochronology. Another factor that makes dendrochronology a useful tool is that trees are ubiquitous on the landscape. Most terrestrial-temperate regions of the globe have trees present that can be useful to the techniques of dendrochronology.

Time Frame of Dendrochronology
The time frame of dendrochronology covers anyw在这里 from the present back 10,000 years. But most chronologies are only a few hundred years long. T在这里 are some 1,000 year long chronologies scattered around the globe, but they are rare.

Short 历史 and Scope of Dendrochronology
Dendrochronology was developed by A.E. Douglass, founder of the first laboratory entirely devoted to tree-ring research. Douglass' initial interest was the impact of solar cycles on the 地球’s climate. While working in Flagstaff, Arizona in A.D. 1904, he noticed a distinct annual ring pattern in the stems of many ponderosa pine trees, a repeated signature of narrow and wide rings. 这个著名的图案, which Douglass subsequently found in trees throughout the region, became known as the Flagstaff signature. Ring-width patterns enable dendrochronologists to precisely and accurately date every individual tree ring in a chronology.

When all trees on a site are limited by a common factor, such as inter-annual variability in climate, the size of their annual growth rings is affected in a similar manner, and a common ring-width pattern emerges across the site or region. Crossdating,我.e., matching the ring patterns in tree-ring samples across a site, can provide an accurate chronological record of the natural history of the stand.

Among other applications, dendrochronology has been used to date:

• 考古遗址
• 气候变化
• 火灾历史
• 昆虫爆发
• 火山喷发
• 冰川运动

For Past Projects and Lab Presentations please view our Archive Page

Any information for ISU Dendro Lab Archived Projects can be found 在这里.

设备及设施

实验室
The Department of EES (地球 & Environmental Systems) at ISU has among others research laboratories dedicated to Biogeography/ Dendrochronology and Climatology. The Biogeography/Dendrochronology has workspace available for six student workers. The 气候学实验室 has recently been remodeled and has dedicated space allocated for archiving dendrochronological samples.
A sanding facility and a microscope lab are also available.

电脑
地球工程系 & Environmental Systems) also has the Center for Remote Sensing and Geographic Information Systems. This Center houses 26 computers complete with auxiliary printers and scanners, including a drum printer that can be used for the production of research posters for professional meetings. The Biogeography/Dendrochronology lab has two computers, which can be used for data analysis. The Climatology lab has computers dedicated to the acquisition of climate data.

主要设备
The Biogeography/Dendrochronology 实验室 currently houses one Velmex Measuring Machine connected to a Stereozoom Microscope on a boom stand and a microcomputer analysis system.
The lab equipment also includes:
13个增量孔
6台立体变焦显微镜
2个砂带(4X24”)
desktop and laptop computers
全球定位系统装置
1 Stihl Chain saw Stihl 046 with a 24" bar
手锯
罩
2个巡洋舰包
2土壤取样探头
孟塞尔图表
测量磁带
4个地图管
Paper straws, Poplar core mounts, skeleton plot paper