A Preliminary Exploration of Different Planting Combinations of Extensive Green Roof in Warm Temperate Semi Humid Climate Zone

Abstract

The construction methods of extensive green roof are different in different regional climate conditions, which are directly affected by weight load bearing capacity, planting substrate, plant species and other factors. In order to explore the planting types of extensive green roof suitable for warm temperate semi humid region, 12 plant species and 5 planting substrates were selected to conduct the experiment on the roof of the Architectural Art Museum (36°40'37"N, 117°11'25"E) of Shandong Jianzhu University, Licheng District, Jinan City, Shandong Province, China in March to October in 2019, and each plant species was planted on 5 planting substrates on the roof, respectively. By measuring the basic foundation layer load parameters, substrate bulk density and plant unit weight in the process of construction, the increase of planting weight load bearing capacity was calculated. After 4 weeks, the plant physiological indexes were tested. Finally, based on fuzzy mathematics subordinate function value method, combined with the plant physiological indexes, all combination types were comprehensively evaluated. The results showed that the unit weight of 12 plant species was divided into three categories, and the change trend of the weight load bearing capacity increase of each plant combined with the five planting substrates was similar to that of the five planting substrates. According to the comprehensive evaluation, 12 planting combinations were considered to be suitable for application on the extensive green roofs in warm temperate semi-humid areas. Compared with the plant weight, in the early stage of extensive green roof construction, the weight of planting substrate is the main factor leading to the change of weight load bearing capacity increase.