Criteria for plant selection in green roofs design

Abstract

Green roofs are a modern technology in landscape architecture, which is constantly developing. The main reason is the lack of space for landscaping at a ground level, especially in highly urbanized areas. This practice has been used expansively in many cities in Bulgaria. One of the most important tasks in the design and con¬struction of green roofs is the plant selection. The selection of appropriate species is main factor for achieving the objectives in this investment construction activity. Plant selection for vegetated roofs is a subject of number of publications. Some of them, as a result of particular studies, make recommendations on the use of a limited range of investigated species, others – give general guidelines, based on the specifics of the microclimatic roof conditions and the thickness of the substrate. This study is an attempt to formulate the criteria and to develop a methodological approach for plant selection for different types of green roofs. A detailed analysis of all factors and their influence was made. The basic principles for achieving optimal results were outlined. A model species composition was suggested. The methodology will find practical application in the green roofs design.