Elisabeth Koch

Monitoring, Modelling and Forecasting of the Pollen Season

The section about monitoring covers the development of phenological networks, remote sensing of the season cycle of the vegetation, the emergence of the science of aerobiology and, more specifically, aeropalynology, pollen sampling instruments, pollen counting techniques, applications of aeropalynology in agriculture and the European Pollen Information System. Three data sources are directly related with aeropalynology: phenological observations, pollen counts and remote sensing of the vegetation activity. The main future challenge is the assimilation of these data streams into numerical pollen forecast systems. Over the last decades consistent monitoring efforts of various national networks have created a wealth of pollen concentration time series. These constitute a nearly untouched treasure, which is still to be exploited to investigate questions concerning pollen emission, transport and deposition. New monitoring methods allow measuring the allergen content in pollen. Results from research on the allergen content in pollen are expected to increase the quality of the operational pollen forecasts.

Global Framework for Data Collection – Data Bases, Data Availability, Future Networks, Online Databases

Since the 1990s, phenology has regained scientific interest as a biological indicator for climate change (Schwartz 2003). Menzel and Fabian (1999) and Chmielewski and Rotzer (2001) were able to demonstrate with the observation series of the International Phenological Gardens’ network that spring has advanced in Europe and autumn has come later. The autumn signal is not as significant as the earlier onset of spring, however, which results in a longer vegetation period in the middle and higher northern latitudes. The growing interest in, and importance of, phenology is also visible in the report of Working Group II, Assessment of observed changes and responses in natural and managed systems (Rosenzweig et al. 2007) of the 4th assessment report of the Intergovernmental Panel on Climate Change.

Results of a first look into the austrian animal phenological records

The year to year variability and trends of animal phenological phases (honey bee, cockchafer, 3 butterfly species, swallow and cuckoo) of the Austrian phenological observational network were related to each other and to mean monthly temperatures over the time period 1951-1998. Insect phases were well correlated with each other (r 2 = 0.4 to 0.6) and with temperature (r 2 = 0.25 to 0.55), whereas both bird phases were only well correlated with each other (r 2 = 0.57), but showed low common variance values with temperature and with other animal phases. The slope of the temperature-pheno regression, also termed as temperature sensitivity of the phenological phase, was high in the case of the insect phases (-3 to -5 days/°C), but low in the cases of both bird phases (about -1 days/°C). All animal phenological time series showed a trend towards later occurrence dates. The trends of the bird phases were even significant (p<0.1). There was a marked discrepancy between the trends of all animal phenological and temperature time series, especially between the insects and temperature: the mean temperature time series of February, March and April with the highest common variance with the insect phases showed a strongly increasing trend (0.027°C/year), whereas the first appearance dates of the insects tended to occur later (0.06 to 0.15 days/year). Both bird phases correlated weakly with the mean April temperature (r 2 about 0.1). The temperature trend of April was 0.0003°C/year, whereas the trend of the bird phases was 0.2 days/year for the cuckoo and 0.25 days/year for the swallow. From these observations we conclude that a strong temperature sensitivity of the phenological phase based on the year to year variability (in days/°C) does not necessarily result in corresponding trends of temperature and phenological phase. A strong trend of non-atmospheric factors such as population density influencing the animal phases is suspected. Factors other than local atmospheric temperature, like climatic conditions in the overwintering area and on the migration route, probably govern the arrival times of the migratory birds.

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.