Ying Xu, Zhongtang Liao, Jialin Liu, Can Liu, Yufei Li
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引用次数: 0
Abstract
Low-maintenance extensive green roofs hold the potential for adapting to climate change, but there is a limited understanding of their effective design in humid subtropical regions. In this study, we aimed to investigate low-maintenance green roof ecosystems capable of thriving under heat stress. Plant growth performance was evaluated in the second year of an experimental green roof in southwest China. This green roof was unirrigated and involved two plant communities (forbs and grasses) cultivated in four substrate types. Metrics of growth performance, including plant survival, green coverage, visual appearance, leaf stomatal conductance, and substrate volumetric water content were used to analyze the impact of substrate on plant growth. ESP substrate, comprising 30 %v (percent of volume) expanded shale, 25 %v perlite, 25 %v vermiculite, and 20 %v compost, featured the highest porosity and optimal growth of forbs, achieving an average green coverage of 66.76 % and average visual appearance value of 3.56 throughout the monitoring period. The high total porosity of this substrate could be critical in facilitating root development and drainage. Moreover, during the summer’s heat and drought, while substrate water content is not a limiting factor for the survival of some established forbs, it remains crucial for the growth of grasses. Additionally, the same substrate impacts different plant communities variably. Four particularly well-performing forb species, namely Lycoris chinensis, Tradescantia pallida, Liriope muscari, and Salvia farinacea, demonstrated survival rates closed to 100 % and an average visual appearance value exceeding 3 was noted, and thus, they are recommended as plant candidates for unirrigated green roofs. The distinguished performance of these species is attributable to their adaptation to heat and drought through specific physiological traits. Our findings provide insights into vegetation selection and substrate optimization for the successful establishment of extensive green roofs that could be feasibly developed without irrigation in the humid subtropical regions.
期刊介绍:
Urban Forestry and Urban Greening is a refereed, international journal aimed at presenting high-quality research with urban and peri-urban woody and non-woody vegetation and its use, planning, design, establishment and management as its main topics. Urban Forestry and Urban Greening concentrates on all tree-dominated (as joint together in the urban forest) as well as other green resources in and around urban areas, such as woodlands, public and private urban parks and gardens, urban nature areas, street tree and square plantations, botanical gardens and cemeteries.
The journal welcomes basic and applied research papers, as well as review papers and short communications. Contributions should focus on one or more of the following aspects:
-Form and functions of urban forests and other vegetation, including aspects of urban ecology.
-Policy-making, planning and design related to urban forests and other vegetation.
-Selection and establishment of tree resources and other vegetation for urban environments.
-Management of urban forests and other vegetation.
Original contributions of a high academic standard are invited from a wide range of disciplines and fields, including forestry, biology, horticulture, arboriculture, landscape ecology, pathology, soil science, hydrology, landscape architecture, landscape planning, urban planning and design, economics, sociology, environmental psychology, public health, and education.