Study On Relevant Source Area Of Pollen And Relative Pollen Productivity Estimates Of The Forest In Changbai Mountains And Taiyue Mountains

Land cover change has a significant impact on the global carbon cycle and could change thermal radiation so that it will affect the global climate. Therefore, learning land cover change and land use has very important significance for understanding global climate change, reconstructing the paleovegetation and predicting the climate and environmental change in the future. Land cover change mainly depends on the vegetation change. Spores and pollen become one of important index in simulating paleovegetation change because their small size, wide spread and easy preservation in sediments. However the complexity of pollen spread and pollen deposition makes the relationships between pollen and vegetation more complex and changeable, which results the relationship becoming one of the most difficult research issues on palynology. The relationship between pollen and vegetation is affected by many factors, and pollen production and pollen source area are the most important factors. Therefore, understanding the pollen production of the plants from one region and its pollen source area are must be solved issues for interpreting the pollen assemblages and recovering the paleovegetation and paleoclimate correctly. Nowdays the common used model in calculating the relative pollen productivities (RPPs) and relevant source area of pollen (RSAP) is ERV model (Extend R Value model).We calculated the pollen fall speed and then estimated the RPPs for 14 pollen types from Changbai Mountains and 11 pollen types from Taiyue Mountains and RSAP of study area using ERV model based on pollen analysis and vegetation survey from 36 sampling sites in Changbai Mountains and 30 sites in Taiyue Mountains. The results are presented as follow:In the pollen assemblages of Changbai Mountains, the tree pollen types including Pinus, Quercus, Betula, Larix, Tilia, Ulmus and the herbaceous pollen types including Artemisia, Cyperaceae, Polygonaceae, Liliaceae, Compositae etc are dominant. In Taiyue Mountains, Pinus, Quercus, Betula, Juglandaceae, Elaeagnaceae, Artemisia, Cyperaceae, Ranunculaceae, Polygonaceae and Poaceae etc are dominant, which reflect the community appropriately.Pollen grain size plays a very important role in pollen fall speeds. In the study area of Changbai Mountains, Larix has relative larger pollen grain size (average 68.19×54.17μm), and then Pinus> Juglandaceae> Tilia> Polygonaceae> Cyperaceae> Liliaceae> Quercus> Ulmus> Betula> Fraxinus> Artemisia> Poaceae, while Chenopodiaceae pollen (average 18.86μm) has the smallest pollen grain size. In Taiyue Mountains, Larix also has relative larger pollen grain size (average 69.01×59.43μm), and then Pinus> Juglandaceae> Cyperaceae> Quercus> Poaceae> Elaeagnaceae> Betula> Chenopodiaceae> Artemisia, while Ranunculaceae (average 15.7×14.66μm) has the smallest pollen grain size. So the alphabet of pollen fall speed of Changbai Mountains is Larix 0.124 m/s> Pinus 0.1098 m/s> Polygonaceae 0.0358 m/s> Juglandaceae and Tilia 0.03 m/s> Cyperaceae 0.0256 m/s> Ulmus 0.022 m/s> Quercus 0.0214 m/s> Fraxinus 0.017 m/s> Betula 0.0166 m/s> Poaceae 0.0165 m/s> Liliaceae 0.0125 m/s> Artemisia 0.011 m/s> Chenopodiaceae 0.0108 m/s. The alphabet of pollen fall speed of Taiyue Mountains is Larix 0.1327 m/s>Pinus 0.086 m/s> Juglandaceae 0.03 m/s> Cyperaceae 0.0256 m/s> Poaceae 0.0202 m/s> Quercus 0.0193 m/s> Elaeagnaceae 0.0139 m/s> Betula 0.012 m/s> Chenopodiaceae 0.0118 m/s> Artemisia 0.0083 m/s> Ranunculaceae 0.0072 m/s.After running ERV model, the results show that the estimated RSAP of Changbai Mountains is about 800 m and that of Taiyue Mountains is about 450 m, which has little effect by wind speed and pollen fall speeds. Using Quercus as reference taxon (RPP is 1), the RPPs of 14 pollen types of Changbai Mountains estimated by ERV model shows that:Pinus (9.22±0.51), Artemisia (8.29±0.09), Betula (4.91±0.35) and Larix (3.21±0.35) have relative high RPPs; Chenopodiaceae (1.19±0.07), Juglandaceae (0.72±0.33), Poaceae (0.31±0.07), Fraxinus (0.13±0.07) and Tilia (0.20±0.11) have moderate RPPs; while Cyperaceae (0.01±0.09), Liliaceae (0.004±0.19), Polygonaceae(0.01±0.09) and Ulmus (0.0005±0.21) have relative low RPPs. The RPPs of 11 pollen types of Taiyue Mountains shows that:Pinus (4.54±0.44), Betula (2.23±0.52), Elaeagnaceae (2.21±0.64), Chenopodiaceae (2.04±0.1) and Juglandaceae (1.42±0.12) have relative high RPPs; Ranunculaceae (0.57±0.13), Artemisia (0.36±0.05), Larix (0.29±0.11) and Poaceae (0.17±0.08) have moderate RPPs; while Cyperaceae (0.01±0.003) has the lowest RPP.Comparing the results with other regions shows that the RPPs of the same pollen types show significant differences in different regions. The reasons are various:plant species composition and spatial distribution, climatic characteristics, vegetation survey methods, the choice of reference taxon, human activities and other factors will have an impact on the RPPs. Therefore, the RPPs from one region can not be directly applied to other regions.