Pollen morphology of eight species of Saxifraga,i.e.S.cespitosa,S.oppositifolia,S.cernua,S.nivalis,S.aizoides,S.rivularis,S.hieraciifolia,and S.hirculus,collected from Ny-Alesund,Svalbard,Arctic was examined using light and scanning electron microscopy.Pollen grains of Saxifraga species are subprolate or prolate,3-colpate,15.4–44.4μm in the polar axis,11.4–34.6μm in the equatorial axis,and show a P/E ratio 1.19–1.40.On the basis of exine ornamentation,four pollen types,viz.,the S.oppositifolia type(striate without scabrae on the muri),S.cernua type(striate with scabrae on the muri),S.nivalis type(microreticulate and operculum absent),and S.cespitosa type(microechinate and operculum present),were recognized.Hierarchical cluster analysis of the pollen morphological characters indicated that pollen morphology supports the infrageneric classification of the genus Saxifraga.
The present article deals with the use of tree barks as a natural trap for airborne spores and pollen grains in China.The study carried out at the southern part of Beijing Botanical Garden,Institute of Botany,Chinese Academy of Sciences has yielded a variety of palynomorphs mostly belonging to tree taxa.New methodologies for extraction of palynomorphs from tree barks have been suggested.Bark samples were collected from three taxa,i.e.,Paulownia fortunei Hemsl.(Scrophulariaceae),Quercus dentata Thunb.(Fagaceae),and Picea meyeri Rehder&E.H.Wilson(Pinaceae)having different bark morphologies.P.fortunei with a comparatively soft and fissured bark is believed to have a greater potential for trapping airborne spores and pollen grains compared to the stiff and less fissured barks of Q.dentata and the scaly bark of P.meyeri.Old barks yield better data in terms of quantity and quality of trapped pollen and spores.The present study throws new light on the modern pollen rain,spore-pollen dispersal,and their deposition in and aroundBeijing Botanical Garden,and other different parts of China.
Xiaoyan SongSubir BeraYifeng YaoDavid K.FergusonChengsen Li
Climate warming has become evident in the maritime Antarctic over the past decades, and has already influenced the growing season and the population size of two native vascular plants in Antarctica, Deschampsia antarctica and Colobanthus quitensis. Both vascular plant species are therefore regarded as good bioindicators of regional warming in west Antarctica. To carry out long-term monitoring of vegetation(mainly using D. antarctica) and build a comprehensive research platform for multi-disciplinary study(including botany, microbiology, ecology, and environmental science) for Chinese scientists, 13 permanent plots were established in January and February of 2013–2015 in the area of Fildes Peninsula(King George Island). Here we present the benchmark data of the first observations from these plots, including site characteristics, and the population and associates of D. antarctica in each plot. The basic data are important to understand the vegetation change, distribution range, and expansion of D. antarctica in Antarctica under future climate change scenarios.
We did a comparative analysis of pollen and spores from five kinds of natural pollen traps at Wenbi Reservoir, northwest Yunnan, China. The natural traps were the surface soil, ground inhabiting mosses, spider webs, tree bark and moss/lichen on trees. These traps showed qualitative and quantitative variations in the pollen and spore spectra. The palynomorphs recovered from the soil samples of trees and shrubs ranged from 90.54% to 95.98% of the total counts. These counts were higher than counts from ground mosses(53.13%–81.66%), spider webs(61.71%), bark samples(53.8%) and moss/lichen on trees(50%–53.6%). The result of pollen/spore analysis showed that surface soil, ground mosses and spider webs better reflect the local vegetation compared with tree bark or moss/lichen on trees.
SONG XiaoYanBERA SubirYAO YiFengBLACKMORE StephenLI ChengSen
