Lenka Hájková

The Onset, Course and Intensity of the Pollen Season

The onset, duration and intensity of the period when pollen is present in the air varies from year to year. Amongst other things, there is an effect upon the quality of life of allergy sufferers. The production and emission of pollens are governed by interacting environmental factors. Any change in these factors may affect the phenology and intensity of the season. Readiness to flower in a plant, and the amount of pollen produced, is the result of conditions during an often long period foregoing flowering. When a plant is ready to flower, temporary ambient circumstances e.g., irradiation and humidity, determine the timing of the actual pollen release. In order to understand variation between years and to be able to safely predict future situations, not least due to the ongoing climate change, it is necessary to know the determinants of all related processes and differences between and within species, here reviewed.

Pan European Phenological database (PEP725): a single point of access for European data

The Pan European Phenology (PEP) project is a European infrastructure to promote and facilitate phenological research, education, and environmental monitoring. The main objective is to maintain and develop a Pan European Phenological database (PEP725) with an open, unrestricted data access for science and education. PEP725 is the successor of the database developed through the COST action 725 “Establishing a European phenological data platform for climatological applications” working as a single access point for European-wide plant phenological data. So far, 32 European meteorological services and project partners from across Europe have joined and supplied data collected by volunteers from 1868 to the present for the PEP725 database. Most of the partners actively provide data on a regular basis. The database presently holds almost 12 million records, about 46 growing stages and 265 plant species (including cultivars), and can be accessed via http://www.pep725.eu/. Users of the PEP725 database have studied a diversity of topics ranging from climate change impact, plant physiological question, phenological modeling, and remote sensing of vegetation to ecosystem productivity.

Phenological Observation in the Czech Republic - History and Present

Periodicity in the life of plants and animals is considered to be an indirect indicator for the periodicity in the climate. This is because plants and animals continuously respond to changing climatic influences. It is at the same time a supporting science for biogeography, ecology and phytocenology. Phenology is a branch of science which deals with the study of periodically recurring natural life cycles in the course of time, called phenological phases of plants and animals, as they relate to environmental conditions, particularly climate and weather. The base of the word phenology emanates from the Greek word faino, which means “I reveal” (Krska, 2006). Dating from ancient times, the observation of the surrounding environment has been one of the basic features of everyday life, specific expressions in the acquired pieces of knowledge arise from weather proverbs e.g. “September brews the wine, in October we drink it”. The weather proverbs had of course great importance even for peasants and other professions. Phenological observations, which are according to the kind of observed organisms divided into phytophenological and zoophenological. In climatology the basic time period is a year together with its months but the growth and subsequent development of plants and animals do not follow our calendar. Natural life cycles of organisms are determined, simply said, by internal (genetic) and external (climatological) conditions. And we divide the year into phenological periods according to the response of nature to the real course of the weather (Rožnovský & Havlicek, 1999). Phenology season onset in relation to synoptic situation studied Hajkova & Kožnarova & Sulovska (2011). Agroclimatological classification is based on relation of plants to selected climatological characteristics as well as agroclimatological indicator of temperature, agroclimatological indicator of irrigation and agroclimatological indicator of hibernation (Žalud, 2010).

Variability of phenological stages of Dactylis glomerata in dependence on meteorological conditions in the Czech Republic

pressure (SLP) and 500 hPa geopotential height pattern over Europe on days with high concentration of ragweed pollen in Poznan in years 1996-2010. Methods: Ambrosia pollen data was collected by Hirst-type volumetric spore trap. Pollen grains were counted under the optical microscope (magni cation: 400x) and expressed as P m-3. Daily pollen concentrations were clustered in three intervals: low ( 30 Pm3) levels. For days attributed to these groups, synoptic charts were created on the basis of see level pressure (SLP) records from NCEP/NCAR reanalysis [2]. In addition, maps of 500 hPa geopotential heights were constructed. e method of interpolation was kriging. Results: Overall, 206, 23 and 17 days with low, medium and high concentration of ragweed pollen (respectively) were recorded in Poznan in years 1996-2010. Synoptic charts showed (Fig. 1) that during days with high pollen count of Ambrosia in Poznan the high pressure center was located in the area of northern Belorussia. e lowest pressure center was located over Iceland and the Atlantic Ocean in the south of the Iceland. As the geostrophic wind is parallel to the isobars and approximately determines the air mass transfer, it can be concluded that presented pressure pattern causes the air motion exactly from the Pannonian Plain to Poland, with south-east direction. Conclusions: e mechanism of long-range transport of Ambrosia pollen from Balkans to Poland highlighted by Sikoparija et al. [1] seems to be valid in all days with high concentrations of Ambrosia pollen in Poznan, 1996-2010. Averaged synoptic charts con rm that the air mass transport occurs from southeast to northwest with the strong high pressure center over Belorussia. When that pressure pattern is observed in weather forecast during August or September there is a possibility to record Ambrosia pollen in Poznan.