ABSTRACT
A better understanding of the effects of urban environment on urban trees might be obtained by large-scale experiments in which it is possible to control many factors simultaneously. Investigations under urban environmental conditions may represent an opportunity to study long-term plant responses to environmental factors and thus to focus on adaptation mechanisms of plants growing permanently in a manipulated plot. This chapter presents most of the techniques that are applied at a leaf, branch or plant scale and provide only limited temporal and spatial information about the urban trees functionality in terms of photosynthesis, evapotranspiration, pollutants uptake and deposition, and more general in terms of tree growth, development and stress evaluation. To understand and analyze the functional responses of the entire urban forest community in relation to the urban environment it is necessary to scale up to ecosystem level. This can be based on the results from physiological measurements using appropriate models or combining techniques from different scales.
