The Natural Altitudinal Limit of Forest in the Scottish Grampians

The present upper forest margins of the north east Scottish Grampians are not at their natural level. Evidence for the natural altitudinal limit of the Caledonian Forest in this region today is examined. The available temperature data indicates a tree-line approaching 760 m. The results of simple experiments to measure relative wind exposure in the Cairngorm Mountains are presented. Wind is shown to be an important factor and to modify significantly the level determined by temperature alone. Data on the distribution of high-level tree seedlings, subalpine scrub and Gaelic place-names also suggest a lower level. On exposed slopes the potential tree-line is unlikely to exceed 610 m. It would probably extend to 685 m in sheltered localities. A map of the natural limits is included. Pe3IoMe BepXHRe rpaHHR~bx JIeCOB B CeBepO-BOCTOqHbIX fp3MiHneHC He IBJIqHOTCS UepBWqHbIMH. B HacTO~lgee BpeM5 Ae)ja1OTCq IIOI1bITKH YCTaHOBHTB eCTeCTBeHHbIe rpaHHU.6 jieCOB KaJieAOHHH. TeMnepaTypHbIe AaHHbie rlOKa3bIBaToT, 'TO AepeBBS MOryT HpOH3paCTaTB H HHa BbICOTe OKORO 760 M. npHBegeHbI pe3yYJNBTaTb1 HCCiieAOBaHHR CIIJIbI H HaIIpaBRemIq BeTpa B ropax K3ApHropM. BeTep AB1IeTCS OqeBHAHO BaNCHbIM 4)aKTOpOM, orIpeAeJIHIowHM rpaHHtjy JIecOB. XapalCTep pacnpeAeneiHsR IaOxpOCTa AepesBbeB H cy6aIbiirHACKHX KYCTaPHHKOB B ropax TaKxce cBHJeTeJlbcTByeT o 6onee HH3KOM YpOBHe pacripOCTpaHeUq 3TOR paCTHTeJibHOCTH, 'eM IIO3BOjiqeT TeMirepaTypHlbfl pexdHM. Ha nporpesaembix CKJIoHax IHOTeHLAHaJrbHaS rpaHaixa JIeca flpeBbILaeT BbICOTy 610 M. OHa MoxCeT BepOSTHO AOXORHTb Ao 685 M B YKPbITBIX OT BeTpa MeCTax. aaeTCS KapTa eCTeCTBeHHbIX rpaHHU JIeCOB B ropax. Manuscript accepted February 1967. 5 OIKOS 19, 1 (1968) This content downloaded from 157.55.39.35 on Mon, 29 Aug 2016 06:10:44 UTC All use subject to http://about.jstor.org/terms