樹輪年代學,又稱樹木年輪學樹輪學(英語:Dendrochronology[1])是一種通過對樹木年輪進行科學分析而測定年代的方法。這門學科是20世紀上半葉由亞利桑那大學教授,樹輪研究實驗室的創辦人A. E. 道格拉斯英語A. E. Douglass發展起來的。在考古學美術史樹木氣候學英語Dendroclimatology領域有重要應用價值。

樹輪取樣和計數工具

樹輪年代學用於確定樣本的精確年代,特別常用於確定因為年代較近,用放射性測年僅能給出大致時段,無法確定精確年代的樣本。然而,為了精確給出一棵死亡樹木的年代,需要獲得包含樹木外沿的完整樣本——大多數經過加工的木板無法滿足這樣的要求。這種方法還能用來確定某些事件發生的時間或環境變化速率(大多數時候與氣候變化有關),或者確定考古發掘的木材、工藝品或建築的年代,比如古代版畫的年代。這種方法也用於檢查放射性測年的數據,以校準碳同位素測年的精度。[2]

上新生的細胞會在靠近樹皮處形成一層。一棵樹的生長速率會因為當年的氣候變化而發生有規律的變化,在樹幹上生成可見的生長輪。樹幹的每一輪都標誌着一個樹木經過了一個完整的季節周期或者一年的變化。[3] 直到2020年,準確的北半球樹木年輪數據已經回溯至13,910年之前。[4]目前還有一種較新的測年方法,利用每一個年輪的氧同位素之變化來測年。這種方法稱為「同位素樹木年輪法」(isotope dendrochronology),可以用於測定因為年輪太少或過於相似,不適於使用傳統樹木年輪法測定的樣本。[5]

歷史

編輯

希臘植物學家泰奧弗拉斯托斯首次提出樹木具有輪線。[6][7]達芬奇 (1452–1519)在《繪畫論》中則第一次指出樹木的輪線乃是年輪,其厚度有樹木發生的條件決定。[8]1737年,法國博物家Henri-Louis Duhamel du Monceau布豐考察了生長條件與樹木年輪形狀之關係。[9]他們發現,1709的嚴冬造成了獨特的深色樹輪,成為後來歐洲諸多自然學家的參考數據。[10]在美國,Alexander Catlin Twining (1801–1884)在1933年提出,樹木年輪的模式可以用來同步各種樹木的年代,因此可以用於重建整個地區從前的氣候條件。[11]英國博物學家查爾斯·巴貝奇(Charles Babbage)提出,可以使用樹木年輪學來定年泥碳沼中殘餘的樹木甚至地層(1835, 1838)。[12]

19世紀後半葉,關於樹輪的科學研究與樹木年輪學的應用逐漸多了起來。1859年,德國-美國裔的土地測量員Jacob Kuechler (1823–1893) 使用交叉定年法檢查了橡樹 (Quercus stellata)的年輪,試圖以此分析西得克薩斯州的氣候。[13]1866年,德國植物學家、昆蟲學家和森林學家Julius Ratzeburg (1801–1871)觀察到樹木年輪可能受到昆蟲侵害的影響。[14]到了1882年,這一觀察就已經寫入了森林學教科書。[15]1870年代,荷蘭天文學家雅各布斯·卡普坦 (1851–1922) 使用交叉定年法重建了荷蘭和德國的氣候。1881年,瑞士-奧地利森林學家Arthur von Seckendorff-Gudent (1845–1886)也開始使用交叉定年法。[16]從1869到1901年,德國森林病理學教授Robert Hartig (1839–1901)撰寫了一系列論文,討論樹木年輪的解剖學和生態學問題。[17]1892年,俄國物理學家Fedor Nikiforovich Shvedov (Фёдор Никифорович Шведов; 1841–1905) 寫到,他已經使用樹木年輪預測了1882至1891年期間的乾旱。[18]

20世紀初,天文學家A. E. Douglass亞利桑那大學創建了樹木年輪研究所。Douglass希望更好地理解太陽黑子活動與周期對地球氣候的影響,而氣候的變化則進一步記錄在樹木年輪之中(換句話說,太陽黑子 → 氣候 → 樹輪)。

注釋

編輯
  1. ^ 詞源解釋:源自古希臘語δένδρον,樹木;χρόνος,時間;-λογία,學科。
  2. ^ The term "dendrochronology" was coined in 1928 by the American astronomer Andrew Ellicott Douglass (1867–1962). Douglass, A.E. (1928). Climatic Cycles and Tree Growth. Vol. II. A Study of the Annual Rings of Trees in relation to Climate and Solar Activity. Washington, D.C., USA: Carnegie Institute of Washington. p. 5. From p. 5: "One can see that in all this we are measuring the lapse of time by means of a slow-geared clock within trees. For this study the name "dendro-chronology" has been suggested, or "tree-time."
  3. ^ Grissino-Mayer, Henri D. (n.d.), The Science of Tree Rings: Principles of Dendrochronology, Department of Geography, The University of Tennessee, archived from the original on November 4, 2016, retrieved October 23, 2016
  4. ^ van der Plecht, J; Bronck Ramsey, C; Heaton, T. J.; Scott, E. M.; Talamo, S (August 2020). "Recent Developments in Calibration for Archaeological and Environmental Samples". Radiocarbon. 62 (4): 1095–1117. doi:10.1017/RDC.2020.22.
  5. ^ Loader, Neil J.; Mccarroll, Danny; Miles, Daniel; Young, Giles H. F.; Davies, Darren; Ramsey, Christopher Bronk (August 2019). "Tree ring dating using oxygen isotopes: a master chronology for central England". Journal of Quaternary Science. 34 (6): 475–490. Bibcode:2019JQS....34..475L. doi:10.1002/jqs.3115.
  6. ^ Theophrastus with Arthur Hort, trans., Enquiry into Plants, volume 1 (London, England: William Heinemann, 1916), Book V, p. 423. From p. 423: "Moreover, the wood of the silver-fir has many layers, like an onion; there is always another beneath that which is visible, and the wood is composed of such layers throughout." Although many sources claim that Theophrastus recognized that trees form growth rings annually, this is not true.
  7. ^ For the history of dendrochronology, see: (Condensed from: James H. Speer, Fundamentals of Tree-ring Research (Tucson, Arizona: University of Arizona Press, 2010), Chapter 3: History of Dendrochronology, pp. 28–42.
  8. ^ See: - Leonardo da Vinci, Trattato della Pittura ... (Rome, (Italy): 1817), p. 396. From p. 396: "Li circuli delli rami degli alberi segati mostrano il numero delli suoi anni, e quali furono più umidi o più secchi la maggiore o minore loro grossezza." (The rings around the branches of trees that have been sawn show the number of its years and which [years] were the wetter or drier [according to] the more or less their thickness.) - Sarton, George (1954) "Queries and Answers: Query 145. — When was tree-ring analysis discovered?", Isis, 45 (4): 383–384. Sarton also cites a diary of the French writer Michel de Montaigne, who in 1581 was touring Italy, where he encountered a carpenter who explained that trees form a new ring each year.
  9. ^ du Hamel & de Buffon (27 February 1737) "De la cause de l'excentricité des couches ligneuses qu'on apperçoit quand on coupe horisontalement le tronc d'un arbre ; de l'inégalité d'épaisseur, & de different nombre de ces couches, tant dans le bois formé que dans l'aubier" Archived 2015-05-09 at the Wayback Machine (On the cause of the eccentricity of the woody layers that one sees when one horizontally cuts the trunk of a tree ; on the unequal thickness, and on the different number of layers in the mature wood as well as in the sapwood), Mémoires de l'Académie royale des science, in: Histoire de l'Académie royale des sciences ..., pp. 121–134.
  10. ^ du Hamel & de Buffon (4 May 1737) "Observations des différents effets que produisent sur les végétaux les grandes gelées d'hiver et les petites gelées du printemps" Archived 2015-05-09 at the Wayback Machine (Observations on the different effects that the severe frosts of winter and the minor frosts of spring produce on plants), Mémoires de l'Académie royale des science, in: Histoire de l'Académie royale des sciences ..., pp. 273–298. Studhalter (1956), p. 33, stated that Carl Linnaeus (1745, 1751) in Sweden, Friedrich August Ludwig von Burgsdorf (1783) in Germany, and Alphonse de Candolle (1839–1840) in France subsequently observed the same tree ring in their samples.
  11. ^ Alexander C. Twining (1833) "On the growth of timber — Extract of a letter from Mr. Alexander C. Twining, to the Editor, dated Albany, April 9, 1833" Archived May 14, 2015, at the Wayback Machine, The American Journal of Science, 24 : 391–393.
  12. ^ See: - (Anon.) (1835) "Evening meeting at the Rotunda" Archived 2015-05-14 at the Wayback Machine, Proceedings of the Fifth Meeting of the British Association for the Advancement of Science held in Dublin during the week from the 10th to the 15th of August, 1835, inclusive, pp. 116–117. - Charles Babbage (1838) "On the age of strata, as inferred from rings of trees embedded in them" Archived 2015-05-15 at the Wayback Machine, The Ninth Bridgewater Treatise: A Fragment, 2nd ed. (London, England: John Murray, 1838), pp. 256–264.
  13. ^ See: - Jacob Kuechler ( August 6, 1859) "Das Klima von Texas" (The climate of Texas), Texas Staats-Zeitung [Texas state newspaper] (San Antonio, Texas), p. 2. - "The droughts of western Texas", The Texas Almanac for 1861, pp. 136–137 ; see especially p. 137. Archived 2015-11-02 at the Wayback Machine
  14. ^ J. T. C. Ratzeburg, Die Waldverderbniss oder dauernder Schade, welcher durch Insektenfrass, Schälen, Schlagen und Verbeissen an lebenenden Waldbäumen entsteht. [The deterioration of forests or lasting damage that arises from feeding by insects, debarking, felling, and gnawing on living forest trees.], vol. 1, (Berlin, (Germany): Nicolaische Verlag, 1866), p. 10. Archived 2015-10-01 at the Wayback Machine From p. 10: "Die beiden, auf Taf. 42, Fig. 6 (mit dem Durchschnitt Fig. 7) und Fig. 1 (mit dem Durchschnitt Fig. 2) dargestellten Zweige hatten in dem Frassjahre 1862 einen doppelt so starken Jahrring als in dem vorhergehenden angelegt, und auch der (hier nicht abgebildete) Ring des jährigen Triebes war bei den gefressenen stärker as der eines nicht gefressenen." (Both branches that are presented in plate 42, fig. 6 (with the cross-section in fig. 7) and fig. 1 (with the cross-section in fig. 2) had produced, in the defoliation year of 1862, a growth ring that was twice as strong as in the preceding one, and so was the ring of the year-old shoot (not illustrated here) stronger in the case of the defoliated tree than one that was not defoliated.)
  15. ^ Franklin Benjamin Hough, The Elements of Forestry (Cincinnati, Ohio: Robert Clarke and Co., 1882), pp. 69–70. Archived 2015-10-01 at the Wayback Machine
  16. ^ See: - Seckendorff, Arthur von (1881) "Beiträge zur Kenntnis der Schwarzföhre Pinus austriaca Höss" [Contributions to our knowledge of the black pine Pinus austriaca Höss], Mitteilung aus dem forstlichen Versuchswesen Oesterreichs [Report from the Austrian Department of Forestry Research] (Vienna, Austria: Carl Gerold Verlag, 1881), 66 pages. - Speer (2010), p. 36.
  17. ^ Speer (2010), p. 36–37.
  18. ^ See: - Шведов, Ф. (Shvedov, F.) (1892) "Дерево, как летопись засух" (The tree as a record of drought), Метеорологический Вестник (Meteorological Herald), (5) : 163–178. - Speer (2010), p. 37.