Description

Vegetation provides numerous benefits for improving environmental quality and safeguarding the health of urban residents (Elmqvist et al., 2015). Some of these benefits include (but are not limited to) mitigation of the Urban Heat Island (UHI) effect, control of storm water flow, dispersal of atmospheric pollutants and provision of aesthetic values. Therefore, in addition to understanding how vegetation loss affects ecosystem services (De Carvalho and Szlafsztein, 2019), knowing how the timing and duration of vegetation seasonal growth and development cycles (vegetation phenology) are affected by urbanisation is equally important for the effective planning and management of green spaces.

The urban-rural dichotomy is a commonly used approach to distinguish between the effects of urban and rural areas on phenology (see Jochner and Menzel, 2015; Li et al., 2019). However, urban and rural are impossible to define universally for their physical structure, surface properties and urban climate attributes (Stewart and Oke, 2012). In other studies, more robust urban characterisation technics than the urban-rural dichotomy have been used to account for effects of the degree of urbanisation on phenology (e.g. Gazal et al., 2008; Jochner et al., 2013; Wohlfahrt, Tomelleri and Hammerle, 2019). However, the use of class names that are specific to regions, lack of a full set of surface climate properties to define all classes and omission of rural areas (Stewart and Oke, 2012) pose a challenge for comparison of phenological processes across cities, regions and studies.

The Local Climate Zone (LCZ) classification scheme is a robust, systematic and objective typology for characterising urban form and structure universally, overcoming the challenges posed by a wide range of urban structure characterisation methods (Stewart and Oke, 2012). LCZs represent areas of uniform surface cover, structure, material, human activity and climate regime that span hundreds to thousands of metres horizontally. A total of 17 LCZ classes span both urban and rural areas, 10 of which represent urban classes. LCZs have been widely used for urban climate research, specifically the UHI effect (e.g. Kotharkar and Bagade, 2018; Bechtel, Demuzere, et al., 2019) and substantial developments for mapping LCZs have been made through the World Urban Database and Access Portal Tools network (Ching et al., 2018; Bechtel, Alexander, et al., 2019). LCZs have the potential to advance our understanding of the effect of urbanisation and local scale climate on vegetation phenology and enable comparison of phenological processes across cities, yet they remain unexplored to this effect.

Objectives and Methodology

The objectives of the MSc dissertation is to investigate the suitability of the LCZ scheme's, specifically WUDAPT L0 data for phenology characterisation. This shall be achieved using Pan-European phenology data sets (leaf development, flowering fruiting and leaf senescence), an LCZ level 0 map of Europe (Demuzere et al., 2019) and Surface UHI (SUHI) Analysis (Bechtel, Demuzere, et al., 2019). This way, differences in the phenology will be related to the built environment (LCZ) and Land Surface Temperature (i.e. SUHI). The following sub-objectives will be investigated
-To asses phenological differences between LCZ classes
-To assess phenological differences within similar LCZs
-To evaluate the relationship between SUHI and phenology.

Further reading

-Bechtel, B., Alexander, P. J., et al. (2019) ‘Generating WUDAPT Level 0 data – Current status of production and evaluation’, Urban Climate, 27, pp. 24–45. doi: https://doi.org/10.1016/j.uclim.2018.10.001.
-Bechtel, B., Demuzere, M., et al. (2019) ‘SUHI analysis using Local Climate Zones—A comparison of 50 cities’, Urban Climate. doi: 10.1016/j.uclim.2019.01.005.
-De Carvalho, R. M. and Szlafsztein, C. F. (2019) ‘Urban vegetation loss and ecosystem services: The influence on climate regulation and noise and air pollution’, Environmental Pollution. Elsevier Ltd, 245, pp. 844–852. doi: 10.1016/j.envpol.2018.10.114.
-Ching, J. et al. (2018) ‘WUDAPT: An urban weather, climate, and environmental modeling infrastructure for the anthropocene’, Bulletin of the American Meteorological Society. American Meteorological Society, 99(9), pp. 1907–1924. doi: 10.1175/BAMS-D-16-0236.1.
-Demuzere, M. et al. (2019) ‘Mapping Europe into local climate zones’, PLOS ONE. Public Library of Science, 14(4), pp. 1–27. doi: 10.1371/journal.pone.0214474.
-Elmqvist, T. et al. (2015) ‘Benefits of restoring ecosystem services in urban areas’, Current Opinion in Environmental Sustainability. Elsevier, pp. 101–108. doi: 10.1016/j.cosust.2015.05.001.
-Gazal, R. et al. (2008) ‘GLOBE students, teachers, and scientists demonstrate variable differences between urban and rural leaf phenology’, Global Change Biology, 14(7), pp. 1568–1580. doi: 10.1111/j.1365-2486.2008.01602.x.
-Jochner, S. et al. (2013) ‘Using phenology to assess urban heat islands in tropical and temperate regions’, International Journal of Climatology, 33(15), pp. 3141–3151. doi: 10.1002/joc.3651.
-Jochner, S. and Menzel, A. (2015) ‘Urban phenological studies - Past, present, future’, Environmental Pollution, 203, pp. 250–261. doi: 10.1016/j.envpol.2015.01.003.
-Kotharkar, R. and Bagade, A. (2018) ‘Evaluating urban heat island in the critical local climate zones of an Indian city’, Landscape and Urban Planning, 169, pp. 92–104. doi: 10.1016/j.landurbplan.2017.08.009.
-Li, D. et al. (2019) ‘The effect of urbanization on plant phenology depends on regional temperature’, Nature Ecology and Evolution. Nature Research, 3(12), pp. 1661–1667. doi: 10.1038/s41559-019-1004-1.
-Stewart, I. and Oke, T. (2012) ‘Local climate zones for urban temperature studies’, Bulletin of the American Meteorological Society. Boston, 93(12), pp. 1879–1900.
-Wohlfahrt, G., Tomelleri, E. and Hammerle, A. (2019) ‘The urban imprint on plant phenology’, Nature Ecology and Evolution. Nature Research, 3(12), pp. 1668–1674. doi: 10.1038/s41559-019-1017-9.