Pollen ageing

SWS are useful to obtain direct indications of hydrocarbons (under UV light) and to differentiate between oil and gas. The technique is applied extensively to sample microfossils and pollen for stratigraphic analysis (age dating, correlation, depositional environment). Qualitative inspection of porosity is possible, but very often the sampling process results in a severe crushing of the sample thus obscuring the true porosity and permeability. 

Priestley, D.A., Warner, B.G., Leopold, A.C. McBride, M.B. (1985). Organic free radical levels in seeds and pollen. The effects of hydration and ageing. Physiologia Plantarum, 70, 88-94. 

Fig. 4.2. Paleotemperature change in Tertiary age estimated from pollen assemblages (modified after Yamanoi, 1993).

Pollen assemblage analysis indicated that temperature at middle Miocene age was high and after that it decreased rapidly (Fig. 4.2) (Yamanoi, 1993). Temperature from the middle Miocene to present time decreased gradually, however it increased from 4 to 3 Ma and then decreased (Fig. 4.2) (Yamanoi, 1993). 

Little is known about the effect of leaching on distribution of SOM with depth, which is unfavorable for evaluating the potential capacity of soil to sequester carbon. Sporopollen (pollen and spores) are abundant in upper soils, and their vertical distributions are controlled substantially by leaching (Zheng et al. 2002). The distribution of sporopollen with depth may be a useful index of leaching potential. We intended to evaluate the effect of leaching on SOM vertical distribution, based on variations in SOC concentration and SOM 14C apparent age with depth. The distribution of sporopollen with depth can serve as a reference for our evaluation. 

Bardare M, Zani G, Novembre E, Vierucci A Local nasal immunotherapy with a powdered extract for grass pollen-induced rhinitis in pediatric age. J Investig Allergol Clin Immunol 1996 6 359-363. 

Among 383 patients with food allergy, 37% revealed positive reaction to hazelnut (Etesamifar and Wiithrich 1998), and among pollen-allergic patients as much as 53% (Eriksson et al. 1982). In the areas where birch trees are endemic, hazelnut allergy is most often manifested as mild OAS, both in children and in adults (Cudowska and Kaczmarski 2004). However, the route of clinically relevant sensitization to hazelnut in children can be nonpollen related (Flinterman et al. 2006). Children can be sensitized to hazelnut at an early age. In many cases, reactions are very serious and frequently correlated with sensitivity to peanut or other tree nuts (Pumphrey et al. 1999). So far it has not been univocally settled which major allergens, and of which kind of nut, are responsible for the primary sensitization in children with objective reactions to hazelnuts. 

Liu, J., Wang, S., Qi, J., Wang, X., and Song, Y. 1998. The immunostimulatory effect of bioactive peptide from pollen on murine and human lymphocytes. Meek Ageing Dev. 104, 125-132. 

The bulb, foliage and seeds of the fennel plant all have secure places in the culinary traditions of the world, especially in India and the Middle East. Fennel pollen is the most potent form of fennel, but it is exceedingly expensive. Dried fennel seed is an aromatic, anise-flavoured spice the seeds are brown or green in colour when fresh and turn slowly to a dull grey as the seed ages. Green seeds are optimal for cooking. 

Brook et al. (1990) found pollen grains incorporated in the pore spaces within the speleothem fabric. Since the age of the encapsulating calcite could be determined by U/Th methods, the age of the pollen could also be determined far beyond the usual limitation of carbon-14 dating. From pollen speciation in speleothems. Brook et al. concluded that the Chihuahuan Desert of southwestern United States and the Kalahari Desert of northwestern Botswana were wetter during northern hemisphere glacial and interstadial times. In contrast, wetter conditions in the Somali-Chalbi Desert corresponded with interglacials and to a lesser extent with interstadials. 

Paleobotanists commonly collect and identify microscopic spores, pollen, and bits of larger tissues. They also may identify larger, macroscopic plant remains such as leaves and even fossil tree trunks. Often, only the major plant group to which these plant parts belong, such as order or family, can be identified. In the case of more recent plant fossils that represent species that are still extant (not extinct), the remains may even be identifiable down to genus or species. Sometimes, the age of samples is known quite accurately. Paleobotanical studies of some recent lake sediments have shown that sediment layers sometimes develop as annual accumulations. The total number of layers can be subtracted from the current year to determine an age for the sequence or any layer within. 

Palynology (the study of fossil spores and pollen) is an important sub-discipline of paleobotany, and can be used to illustrate the nature and breadth of paleobotanical research. Palynologists search samples of lake sediment, river sediment, or a bog peat of known age, carefully identifying and counting the microscopic pollen. Identification serves to place each specimen into whatever fossil group it belongs, down to the most specific level possible, which is often to the species. 

---