Ecological potentials of trees, shrubs and hedge species for urban green spaces by multi criteria decision making

In planning for sustainable development of urban green space at the macro and regional levels, it is imperative to examine plant species of urban green spaces and to introduce new species considering climatic conditions, environmental pollution, industrial lifestyle, and resource limitations. The present study employs multi criteria decision making techniques to assess the existing and recommended plant species (trees, shrubs, and hedge plants) in downtown and marginal parks of Rasht City, Iran. Twenty seven indicators were defined in the context of six criteria, namely regional adaptation, urban environment, aesthetics, maintenance, growth characteristics, and specific advantages. Weights were assigned to the criteria using the entropy method. They were subsequently ranked by Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), Combinative Distance-based Assessment (CODAS), Additive Ratio Assessment (ARAS), and Evaluation Based on Distance from Average Solution (EDAS) techniques. To provide a final ranking of the ornamental species, the results of these four techniques were integrated using average rank, Borda, and Copeland methods. Based on the results, Parrotia persica, Liquidambar styraciflua, Lagerstroemia indica, Pyracantha coccinea, and Ligustrum texanum were ranked highest and Aesculus hippocastanum, Koelreuteria paniculata, Crataegus microphylla, Viburnum opulus, and Berberis gagnepainii were ranked lowest. Based on the detailed results, the assessment of trees, shrubs, and hedge plants can help decision makers and planners of urban green space development.