长白山阔叶红松林花粉通量的时空变化及其与气象因子的关系

Temporal and spatial variation of pollen influx and its relationship with meteorological factors in broad-leaved Korean pine forest in Changbai Mountains

花粉是重建古植被和古气候的重要代用指标。利用Tauber花粉收集器监测花粉通量是进行花粉-植被-气候关系研究的重要途径。本项研究分析了长白山阔叶红松林16个样点3年(2010~2012年)共94个Tauber花粉收集器的花粉数据,结果表明:阔叶红松林16个样点均以乔木花粉为主,占比多高于55%,针叶树种花粉在乔木花粉中的占比多高于10%;以松属(Pinus)、桦木属(Betula)、胡桃属(Juglans)、栎属(Quercus)、榆属(Ulmus)等花粉为主,5种主要花粉类型的百分含量在乔木花粉中的占比多高于85%;16个样点的AP/NAP(Arboreal Pollen/Non-Arboreal Pollen,乔木花粉与草本植物花粉之比)平均值为3.0,P/A(Pinus/Astemisia)平均值为2.0,P/Q(Pinus/Quercus)平均值为1.2,P/B(Pinus/Betula)平均值为0.6;年平均总花粉通量存在样点间差异(平均值为24231粒/(cm^(2)·a)),但乔木花粉百分含量、针叶树种和主要种在乔木花粉中的占比以及AP/NAP、P/A、P/Q、P/B等数值在研究区内大多数样点间的波动较小,可以更好地指示阔叶红松林的植被特征和植被不同的发育阶段。花粉通量存在明显的年际差异:2011年的总花粉通量最高(590884粒/(cm^(2)·a)),而2010年和2012年的总花粉通量较低(分别为284662粒/(cm^(2)·a)和301157粒/(cm^(2)·a))。总花粉通量、乔木花粉通量、灌木花粉通量和草本植物花粉通量与气象因子(前一年总降水量、生长季累积降水量、开花前冬季积温)呈正反馈。本研究结果为解释花粉通量与气象因子之间的关系提供了参考依据。

Pollen is an important proxy for the reconstruction of paleovegetation and paleoclimate.Using Tauber trap to monitor pollen influx is an important approach to investigate the relationship among pollen,vegetation and climate.94 Tauber traps were used to collect annual pollen data in 16 sites(42°13.50'~42°25.78'N,126°16.94'~126°36.12'E)of broad-leaved Korean pine forests in Changbai Mountains,Northeast China during 2010~2012.Spatial and temporal variations in pollen influx were analyzed,and the similarities and differences of pollen composition were compared among different sites.And the major factors influencing annual differences of pollen influx were further identified in the combination of different meteorological variables.Our results showed that arboreal pollen was dominant in 16 sites of broad-leaved Korean pine forest,accounting for more than 55%with an average of 64.93%.The proportion of coniferous pollen in arboreal pollen was more than 10%with an average of 14.62%.The average percentage of broad-leaved pollen in arboreal pollen was 85.38%.The major pollen taxa consisted of Pinus,Betula,Juglans,Quercus and Ulmus.The sum of percentages for five major pollen taxa in arboreal pollen was mostly higher than 85%with an average of 89.37%.The average percentage of herbaceous pollen in 16 sites was 34.25%.The average value for AP/NAP(Arboreal Pollen/Non-Arboreal Pollen),P/A(Pinus/Artemisia),P/Q(Pinus/Quercus)and P/B(Pinus/Betula)in 16 sites was 3.0,2.0,1.2 and 0.6,respectively.The total annual pollen influx varied from site to site with an average of 24231 grains/(cm^(2)·a).However,minor fluctuation of several pollen ratios was observed among most sites,including the percentage of arboreal pollen,the proportion of coniferous pollen or 5 major pollen taxa in arboreal pollen,and arboreal pollen/non-arboreal pollen,Pinus/Artemisia,Pinus/Quercus and Pinus/Betula.This suggests these pollen ratios can reflect the changes of vegetation composition for broad-leaved Korean pine forest.There were substantial interannual differences in pollen influx:the total pollen influx in 2011 was the highest with average of 590884 grains/(cm^(2)·a),while that in 2010 and 2012 was lower(284662 grains/(cm^(2)·a)and 301157 grains/(cm^(2)·a),respectively).Total pollen influx and the influx of arboreal,shrub and herbaceous pollen showed positive feedback with meteorological factors,including total precipitation of the previous year,cumulative precipitation during the growing season and accumulated temperature of last winter before flowering.Higher cumulative precipitation during the growing season before flowering or higher accumulated temperature of last winter before flowering can better meet the needs of plant growth,promote flowering and prolong the flowering period,thus resulting in higher pollen influx.The results of this study provide a reference basis for explaining the relationship between pollen and meteorological factors.