tions are of diverse geographic origin, with especially strong 

 representation for tropical Asia, Australia and the Americas. 

 Most woods have been processed into micro-slides and 60-70% 

 of these collections are documented with herbarium specimens 

 in the Harvard University Herbaria or elsewhere. 



The collection serves the international scientific community, 

 as a source of wood samples with matching microscope slides, 

 which can be used in not only botanical and wood technological 

 investigations but also in archeological, ethnological, ecological, 

 fine arts and forensic research. 



Archeologists and ethnologists often must identify wooden 

 objects to understand the uses of plants in past and present 

 cultures. Wood anatomy and growth rings of trees not only may 

 reveal the identity of the species, but also reflect the ecological 

 conditions experienced by the individual tree from year to year. 

 Even disease and insect attacks on trees are recorded in their 

 wood, as traumatic tissues which are easily detected. In many 

 cases, the mineral content of the wood reflects the nature of the 

 soil in which the tree grew: silica (sand) grains in the wood of 

 trees from sandy, siliceous soils; calcium oxalate crystals in trees 

 from limestone (i.e., calcium carbonate) soils; and aluminum 

 compounds in wood grown in aluminum-rich (bauxite) soils. 

 Hence, the study of wood structure can provide the archeologist, 

 botanist and ecologist with information about the climatic and 

 edaphic history of a particular region or site. 



Since trees of the temperate zones of the world normally pro- 

 duce a single growth increment annually, a tree's age can be 

 determined easily from its rings. The bristlecone pine (Pinus 

 aristata) of the Rocky Mountain region may reach an age of 

 4,000 years: growth rings thus provide both a calendar and cli- 

 matic record for historic and prehistoric times. Cross-matching 

 of the rings (of known age) with those of archeological timbers 

 (dendrochronology), can serve to estimate the age of these 

 timbers and the sites from which they were unearthed. Other 

 non-botanists who benefit from the wood collection are cabinet 

 makers, carpenters, museum conservators and fine arts profes- 

 sionals, who can use wood anatomy not only to identify and 

 authenticate wooden objects, but also to understand the chemi- 



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