53 pollen traps and surface samples were collected in order to detect the characteristics of pollen assemblages and their relationships with vegetation and climate in 16 forest communities located in 10 mountains in n...53 pollen traps and surface samples were collected in order to detect the characteristics of pollen assemblages and their relationships with vegetation and climate in 16 forest communities located in 10 mountains in northern China. The results show that 72% of the pollen taxa (80 taxa) are the same between the traps and the surface samples. The dominant taxa in the plant communities are consistent with the main pollen taxa in the pollen assemblages at the same sites. In Pinus plant communities, both Pinus pollen influx and concentration are higher, indicating the high pollen productivity and good pollen preservation ability of Pinus. In Picea and Abies plant communities, Picea and Abies have lower pollen influxes but higher concentrations, suggesting their low pollen productivities but better pollen preservation abilities. In Betula and Quercus plant communities, Betula and Quercus have higher pollen influxes but lower concentrations, revealing their high pollen productivities but poor pollen preservation abilities. The study of relationships between pollen and vegetation with discriminant analysis shows that pollen assemblages from both trap and surface samples can reflect the characteristics of different communities and distinguish different ecological areas, but surface samples can reflect the dominant components of communities much better than the traps. The study on correlations between pollen assemblages and climate with DCCA reveals that significant correlations exist between pollen assemblages and mean temperature of the coldest month (r = 0.84 for trap samples, r = 0.72 for surface samples), and then annual mean precipitation (r = 0.73 for trap samples, r = 0.71 for surface samples).展开更多
Pollen productivity is a critical parameter in the interpretation of pollen-vegetation relationships,and in the quantitative reconstructions of past vegetation from fossil pollen records.One-year monitoring records we...Pollen productivity is a critical parameter in the interpretation of pollen-vegetation relationships,and in the quantitative reconstructions of past vegetation from fossil pollen records.One-year monitoring records were collected for 143 pollen traps in various parts of northern China,together with modern vegetation data.Absolute Pollen Productivity Estimates(APPE)were calculated for 11 taxa using the ratio of pollen influx to plant coverage at each applicable sampling site,in which the plants of the target taxon were present.Relative Pollen Productivity Estimates(RPPE)were calculated for the 11 taxa(taking Poaceae as the reference taxon)at those sites in which each taxon occurred together with Poaceae.Artemisia and Chenopodiaceae were found to have the highest RPPEs and the largest RPPEs ranges,while Pinus and Quercus also had higher RPPEs than Poaceae;Abies,Betula,Larix,Picea and Cyperaceae had relatively low RPPEs.Variations in RPPE between different areas may be explained by variations in climatic conditions,plant coverage and land use practices which might influence plant growing situation.Marked effect that variations in pollen productivity can have on vegetation reconstructions was demonstrated by applying these distinct RPPEs to reconstructions of Holocene vegetation in the Lake Daihai area(northern China),such as a large range of RPPE produces a large range of plant coverage.Variations in RPPEs within a single taxon,related to vegetation coverage and climatic conditions,therefore need to be considered in future vegetation reconstructions.展开更多
基金Preliminary Special Foundation for National Key Basic Research of China, No.2003CCA01800Key National Natural Science Foundation of China, No.40730103+3 种基金National Natural Science Foundation of China, No.40672107 No.40571166Natural Science Foundation of Hebei Province, No.D2008000186 No.D2009000300
文摘53 pollen traps and surface samples were collected in order to detect the characteristics of pollen assemblages and their relationships with vegetation and climate in 16 forest communities located in 10 mountains in northern China. The results show that 72% of the pollen taxa (80 taxa) are the same between the traps and the surface samples. The dominant taxa in the plant communities are consistent with the main pollen taxa in the pollen assemblages at the same sites. In Pinus plant communities, both Pinus pollen influx and concentration are higher, indicating the high pollen productivity and good pollen preservation ability of Pinus. In Picea and Abies plant communities, Picea and Abies have lower pollen influxes but higher concentrations, suggesting their low pollen productivities but better pollen preservation abilities. In Betula and Quercus plant communities, Betula and Quercus have higher pollen influxes but lower concentrations, revealing their high pollen productivities but poor pollen preservation abilities. The study of relationships between pollen and vegetation with discriminant analysis shows that pollen assemblages from both trap and surface samples can reflect the characteristics of different communities and distinguish different ecological areas, but surface samples can reflect the dominant components of communities much better than the traps. The study on correlations between pollen assemblages and climate with DCCA reveals that significant correlations exist between pollen assemblages and mean temperature of the coldest month (r = 0.84 for trap samples, r = 0.72 for surface samples), and then annual mean precipitation (r = 0.73 for trap samples, r = 0.71 for surface samples).
基金This research was supported by the National Natural Science Foundation of China(Grant Nos.41877459 and 41630753)the CAS Pioneer Hundred Talents Program(Xianyong Cao)the German Research Foundation(DFG)(No.41861134030).
文摘Pollen productivity is a critical parameter in the interpretation of pollen-vegetation relationships,and in the quantitative reconstructions of past vegetation from fossil pollen records.One-year monitoring records were collected for 143 pollen traps in various parts of northern China,together with modern vegetation data.Absolute Pollen Productivity Estimates(APPE)were calculated for 11 taxa using the ratio of pollen influx to plant coverage at each applicable sampling site,in which the plants of the target taxon were present.Relative Pollen Productivity Estimates(RPPE)were calculated for the 11 taxa(taking Poaceae as the reference taxon)at those sites in which each taxon occurred together with Poaceae.Artemisia and Chenopodiaceae were found to have the highest RPPEs and the largest RPPEs ranges,while Pinus and Quercus also had higher RPPEs than Poaceae;Abies,Betula,Larix,Picea and Cyperaceae had relatively low RPPEs.Variations in RPPE between different areas may be explained by variations in climatic conditions,plant coverage and land use practices which might influence plant growing situation.Marked effect that variations in pollen productivity can have on vegetation reconstructions was demonstrated by applying these distinct RPPEs to reconstructions of Holocene vegetation in the Lake Daihai area(northern China),such as a large range of RPPE produces a large range of plant coverage.Variations in RPPEs within a single taxon,related to vegetation coverage and climatic conditions,therefore need to be considered in future vegetation reconstructions.
