Synoptic weather stations were designed to measure weather conditions on airfields, and are designed to exclude the substantial influence that trees have on maximum and minimum temperature, windspeed and humidity. Yet data from such stations, and models calibrated on them are often referred to as climate data, rather than as descriptors of open-field climates. Models of global climate change predict location-specific changes in key parameters – some of which may exceed the tolerance range of crops. While the standard agronomic interpretation is that in such cases a change of crops or crop cultivar will have to be the primary adaptive response, the potential effects of modifying or returning tree cover to agricultural production landscapes might provide alternative solutions. Urban heat islands have been recognized as leading to hotter and drier conditions than synoptic weather data quantify, while urban trees, green walls and evaporative surfaces lead to cooling, potentially beyond what the weather stations indicate. The cooling effect of trees in agricultural landscapes might be understood in similar ways and enhanced accordingly.
As steps towards such a strategy, we’ll need to explore rules of the game for micro- and meso climatic effects, which tend to be distance functions from the nearest tree, accountting for its size. Micro-climate effects can be understood to operate within the area shaded by trees (at least part of the time), while mesoclimatic effects extend beyond. Existing data in grey and published literature can help to put bounds on the magnitude of the effects and their interaction with other parameters. Another starting point is the use of physical energy-based models of the interaction between solar radiation and the earth’s surface.
The aim of this research is to first estimate the magnitude of such micro- and meso climatic effects and then to develop and test hypotheses about the way effects depend on other variables and circumstances. As third step the micro- and mesoclimate modifications can be linked to dynamic crop growth models that so far have used standard weather data as input. Effective coupling routines will initially operate as stand alone, but may later be integrated into crop models.
Interest in this topic has developed within the World Agroforestry centre (ICRAF) and some initial microclimatic data sets were developed for parklands in Burkina Faso. Initial contacts have been made with the World Meteorological Organization, with access to metadata from weather stations around the globe.
Preferably a background in plant sciences with an interest in meteorology, a strong interest in modelling, e.g. a successful completion of the course Systems Analysis, Simulation and Systems Management and Crop Ecology.
Location and Period
Wageningen; Any time
Meine van Noordwijk 0317-482141 firstname.lastname@example.org