太白山北坡花粉通量与表土花粉研究

太白山北坡各森林植被带乔木花粉百分比多高于45%,与植被组成类似。高山草甸带捕捉器样品乔木花粉百分比低于15%,与植被组成一致,但表土花粉组合中乔木花粉百分比高于50%,外来花粉数量较多,进行高山带古环境研究应予注意。太白红杉林花粉通量最低,高山灌丛草甸最高。落叶栎林带表土花粉浓度最低,红桦林带最高。表土中松、冷杉属花粉百分比远高于花粉捕捉器,表明其在表土中有较好的保存能力。落叶松属和杜鹃花科花粉在表土及捕捉器中百分比均较低,表明对植被指示性良好。栎属与桦属花粉通量类似,但桦属花粉浓度大于栎属,表明栎属较桦属易于保存。

Pollen influx and surface pollen assemblage on the northern slope of Taibai Mountain

The pollen influx, pollen concentrations and pollen assemblages are studied based on pollen tauber traps and surface pollen samples coming from 6 different vertical vegetation zones on the northern slope of the Taibai Mountain. The results indicate that pollen influxes are more than 10000 grains /cm2/y, with the maximum in Larix Chinese belt and the minimum in shrub and meadows belt. Pollen concentrations are more than 25000 grains/g with the maximum in Betula albo-sinensis belt and the minimum in deciduous broad-leaved Quercus belt. The arboreal pollen percentages are mostly more than 45% in 5 forest belts both for pollen traps and surface samples, which are consistent with the vegetation composition. But the arboreal pollen percentages are less than 20% in pollen trap samples and more than 50% in surface samples coming from alpine shrub and meadows, indicating that more ex-local arboreal pollen appeared in surface pollen assemblages. The Abies and Pinus pollen percentages are much higher in surface samples than in pollen trap, suggesting that they can be easily preserved in moss or surface soil. Larix and Ericaceae have rather lower percentages both in pollen trap or in surface samples, compared with vegetation coverages, showing that they have not only lower pollen productions,short transported distance, but poor pollen preservation ability,and can indicate vegetation well. The study on pollen influx of Betula and Quercus shows that the pollen productions are similar, but Quercus pollen concentrations are much lower than Betula in respective forests, showing that Quercus pollen grains can not be preserved as well as Betula in moss or surface soil. The results are obtained from one year's experiments, so further research work should be done.