气候变化对藏东北牧业生产关键期的影响

利用藏东北10个气象站1961-2013年逐日平均气温资料,采用反距离权重插值法、线性回归、Mann-Kendall检验等方法,分析了牧草生长季(PGS)、牧草青草期(GGD)、牲畜抓膘期(FD)和牲畜掉膘期(FLD)等牧业生产关键期的时空变化,预估了未来50 a和100 a牧业生产关键期的变化.结果表明:近53 a PGS因结束日推迟而延长1.70 d·(10a)^-1,GGD平均每10 a延长1.53 d,牲畜抓膘开始期线性趋势不明显,结束期趋于推迟,FD平均每10 a延长1.84 d;牲畜掉膘开始日期显著推迟,结束日明显提前,FLD以-4.33 d·(10a)^-1的速度显著缩短.PGS的变化趋势与经度呈正相关,与海拔高度为负相关.PGS突变发生较早,出现在1998年;2005年是GGD明显变长的突变点,而FD和FLD的突变时间均发生在2003年.在10 a年际变化尺度上,近30 a PGS、GGD和FD呈逐年代增加趋势,而FLD趋于减少.如果气候按升温率0.044℃·a^-1变化,50 a后PGS、GGD和FD分别延长20.2、18.4和21.6 d,FLD缩短23.2 d;未来100 a PGS、GGD和FD可能分别延长40.3、36.9和43.2 d,FLD缩短46.5 d.这种变化趋势十分有利于藏东北牧草生产.

Influence of climate change on various animal husbandry critical periods in northeastern Tibet Autonomous Region during 1961-2013

Based on daily mean air temperature data from ten meteorological stations in northeastern Tibet Autonomous Region from 1961 to 2013, the spatial and temporal distribution characteristics of the animal husbandry critical periods(the pasture growing season, green grass period, livestock fatten period and livestock losing weight period) were analyzed by using the methods of inverse distance weighted, inear regression and Mann-Kendall test et al, and the animal husbandry critical period in the next 50 years and 100 years are estimated. The results show that:(1) in the 53 years, the duration of pasture growing season had lengthened with a rate of 1.70 d·(10a)^-1due to the ending date delayed and the duration of green grass period had increased with a rate of 1.53 d·(10a)^-1; the first date of livestock fatten period had no obvious changed, but the ending date of the period postponed, thus the period had extended with a rate of 1.84 d·(10a)^-1; the livestock losing weight period had shortened with a rate of 4.33 d·(10a)^-1, resulting in beginning date significantly postponed and the ending date obviously early. In addition, the change of the pasture growing season was positively related with longitude, and negatively related with altitude.(2) M-K mutation test shows that the duration of pasture growing season had an earlier mutation in 1998, the green grass period had an obvious abruptly lengthened in 2005, while the abrupt of livestock fatten period and livestock losing weight period occurred in 2003.(3) In terms of decadal variations, from the 1980s to the 2000s, the durations of pasture growing season, green grass period and livestock fatten period had increased, but the livestock losing weight period had decreased.(4) Under the climate warming scenario with a rate of 0.044℃·a^-1, the durations of pasture growing season, green grass period and livestock fatten period would lengthen with a rate of 20.2, 18.4, 21.6 days, respectively, in the next 50 years and with a rate of 40.3, 36.9, 43.2 days, respectively, in the next 100 years; while the livestock losing weight period would shorten with a rate of 23.2 days in the next 50 years and with a rate of 46.5 days in the next 100 years. Obviously, this change tendency will be very beneficial to animal husbandry production in northeastern Tibet Autonomous Region.