THE 1920S DROUGHT RECORDED BY TREE RINGS AND ...

408 ERYUAN LIANG ET AL.TABLE IISite description and general characteristics of twenty-five published tree-ring width standardizedchronologies. The species (s) include 1–4 (see Table I); 5, Sabina tibetica;6,Larix sibirica;7,Piceaschrenkinna var. tianschanica. MI, moisture index; CP, calibrating period (years) between tree-ringchronologies and precipitation records in the nearby meteorological stationsElevation Trees/ PrecipitationCode S Latitude N Longitude E m asl Years Cores MS CP (pre) signal SourceHHT 1 40 ◦ 48 ′ 111 ◦ 17 ′ 1300 1622–1991 19/38 0.33 41 Feb–Jun pre Zhang, 1994BT 1 40 ◦ 50 ′ 110 ◦ 21 ′ 460 1724–1987 30/61 0.42 37 Feb–Jul pre Li et al., 1992; Liuet al., 2001HSE 2 34 ◦ 28 ′ 46 ′′ 110 ◦ 04 ′ 56 ′′ 2050 1458–1992 13/26 0.23 Apr–Jun pre Shao and Wu, 1994HSW 2 34 ◦ 28 ′ 55 ′′ 110 ◦ 04 ′ 45 ′′ 2050 1359–1992 13/26 0.23 40HSS 2 34 ◦ 28 ′ 43 ′′ 110 ◦ 04 ′ 43 ′′ 2100 1512–1992 14/28 0.22QYG 4 38 ◦ 08 ′ 30 ′′ 100 ◦ 32 ′ 50 ′′ 3500 1259–1993 15/24 0.26 37 May–Jul MI Zhang and Wu, 1997WL4 4 36 ◦ 40 ′ 76 ′′ 98 ◦ 24 ′ 97 ′′ 3700 900–2002 21/32 0.52 47 pJul–Jun pre Shao et al., 2005WL3 4 36 ◦ 44 ′ 52 ′′ 98 ◦ 13 ′ 13 ′′ 3720 681–2002 23/43 0.50DLH4 4 37 ◦ 26 ′ 19 ′′ 98 ◦ 03 ′ 23 ′′ 3660 1005–2002 27/46 0.51DLH5 4 37 ◦ 26 ′ 59 ′′ 97 ◦ 47 ′ 06 ′′ 3700 757–2002 24/47 0.62DLH3 4 37 ◦ 27 ′ 08 ′′ 97 ◦ 32 ′ 55 ′′ 3920 404–2002 22/42 0.45DLH1 4 37 ◦ 28 ′ 14 ′′ 97 ◦ 14 ′ 06 ′′ 3730 843–2002 25/41 0.36DLH2 4 37 ◦ 28 ′ 05 ′′ 97 ◦ 13 ′ 44 ′′ 3780 828–2002 25/41 0.45ZHD 5 33 ◦ 43 ′ 96 ◦ 17 ′ 3950 1374–2002 54/27 0.22 46 Apr-Jun MI Qin et al., 2003QML 5 33 ◦ 48 ′ 96 ◦ 08 ′ 4060 1480–2002 57/29 0.27YW1 6 43 ◦ 01 ′ 95 ◦ 02 ′ 2594 1456–1979 18/? 0.31 21 pOct–Jan pre Li, 1989HM1 6 43 ◦ 20 ′ 93 ◦ 18 ′ 3026 1678–1979 25/50 0.14 29 Jul–Sep pre Li, 1989JMS 7 43 ◦ 50 ′ 89 ◦ 07 ′ 1985 1510–1989 49/24 0.19 27 Drought days Zhang et al., 1996FKA 7 43 ◦ 54 ′ , 87 ◦ 59 ′ 2500 1660–1988 15/29 0.20 27 Drought days Zhang et al., 1996XGS 7 43 ◦ 16 ′ 35 ′′ 87 ◦ 14 ′ 05 ′′ 2070 1667–1993 94/47 0.44 34 May pre Yuan et al., 2001BEQ 7 43 ◦ 08 ′ 20 ′′ 87 ◦ 07 ′ 12 ′′ 2440 1630–1993 28/14 0.33 34 pJul–Feb pre Yuan et al., 2001XBY 7 43 ◦ 24 ′ 10 ′′ 87 ◦ 07 ′ 02 ′′ 2270 1752–1993 60/30 0.31 34 Yuan et al., 2001TL 7 42 ◦ 53 ′ 23 ′′ 81 ◦ 59 ′ 50 ′′ 2110 1580–1995 28/14 0.11 36 pJun–May Yuan et al., 2000TU 7 42 ◦ 50 ′ 32 ′′ 81 ◦ 58 ′ 24 ′′ 2724 1682–1995 28/14 0.11 36 pre Yuan et al., 2000ZL 7 42 ◦ 44 ′ 52 ′′ 81 ◦ 05 ′ 45 ′′ 2270 1676–1995 23/15 0.12 36 Yuan et al., 2000width chronologies of Tibet juniper (Sabina tibetica Kom.) in Zhiduo (ZHD) andQumalai (QML) have been developed by Qin et al. (2003).Nine published tree-ring width chronologies (YW1, HM1, JMS, XGS, BEQand XBY) from Regions 6 and 7 were also used in this study (Figure 1, Table II).Among them, two tree-ring chronologies of Siberian larch (Larix sibirica Ledeb)are from Hami (HM1) and Yiwu (YW1) in Region 6 (Li, 1989) and seven Tianshanspruce (Picea schrenkinna var. tianschanica) forest sites are located in Jimusare(JMS) (Zhang et al., 1996), the Urumqi River Basin (BEQ, XBY, XGS) (Yuan et al.,2001) and Yili (ZL, TU and TL) (Yuan et al., 2000) in Region 7 (Figure 1, Table II).2.2. CLIMATE IN THE STUDY AREAThe climate in Regions 1 and 2 is strongly influenced by the East Asian monsoon.Tree-ring sampling sites (XWT, HHT, JGB and BT) in Region 1 are near the