옥상녹화를 위한 저토심·저관리형 시스템 개발 = Development of shallow-extensive green roof system for urban greening

다국어 초록 (Multilingual Abstract)

This study was carried out to develop a shallow-extensive green roof system for urban greening, which would require low maintenance in shallow soil depth and could be used for existing rooftops without risk of overload. To achieve this goal, plant species and system structures suitable for shallow-extensive green roof system were suggested and the suggested systems were evaluated for domestic use.
Through the literature review and plant growth observation, the criteria for choosing plants for shallow-extensive green roof system were proposed under category of growth type, environmental tolerance, construction and maintenance. Eleven Sedum species which came up to the criteria were selected; S. acre, S. album, S. kamtschaticum, S. oryzifolium, S. polystichoides, S. reflexum, S. rupestre, S. sarmentosum, S. sexangulare, S. spurium, and S. telephium.
Selected plants were planted in the green roof system applying field soil, perlite small grain, and crushed porous glass+bark+field soil(v:v:v, 3:2:5) and then evaluated. S. kamtschaticum, S. sarmentosum, and S. telephium ranked higher than the others in plant growth for all substrates. Perlite small grain was less effective for plant growth than the other substrates.
Electrolyte leakage evaluation and regrowth test were used to estimate heat and cold tolerance level of each Sedum species and the two procedures were in close agreement. The critical temperatures at the midpoints of sigmoidal curves fitted through electrolyte leakage were predicted with the range of 54.0℃ to 65.2℃ in high temperature treatments. S. album, S. telephium, and S. sexangulare were more tolerant of high temperature than the others. In low temperature treatments, the critical temperatures were predicted with the range of -19.9℃ to -27.2℃. S. rupestre and S. sexangulare were more tolerant of low temperature than the others.
The effects of substrate type, soil depth, and drainage type on the growth of S. kamtschaticum, S. oryzifolium, and S. sarmentosum were investigated to suggest a suitable system. For the effects of substrate type and soil depth, the growth of three Sedum species was higher in PGBF[crushed porous glass+bark+field soil(v:v:v, 3:2:5)] than in PGB [crushed porous glass+bark(v:v, 6:4)] and the highest in 10-15㎝ soil depth. The growth of S. kamtschaticum and S. oryzifolium was not significantly different in drainage type while the growth increment of S. sarmentosum was higher in the reservoir-drainage type than in the drainage type. Considering the permissible load on the existing rooftops and the effects of system structures on the plant growth, the system should adopted PGBF in substrate type and 10㎝ in soil depth. Though the effects of drainage type were obscure, the reservoir-drainage type which could keep a small quantity of water was expected to be helpful in dry season.
To evaluate drought resistance in the suggested systems, the eleven Sedum species were exposed to drought stress by withholding irrigation for 10, 15, and 20 weeks. As the growth quality of each Sedum species didn't remarkably decline until the drought stress continued for 15 weeks, the drought resistance of the eleven Sedum species applied to the systems would be enough to withstand dry season in domestic field. S. album, S. oryzifolium, and S. rupestre were superior in growth quality and the reservoir-drainage system was significantly effective in these plants. The shoot water content maintained at higher level in S. oryzifolim and S. rupestre. At the end of 20 week drought stress periods, the shoot water content of all became lower than 1g․g-1. The recovery after rewatering was high in S. acre, S. album, S. oyzifolium, and S. rupestre, but low in S. polystichoides. Substrate water content was about 1%(v/v) from the drought stress of 10 weeks.
In field condition, heat and cold tolerance of eleven Sedum species applied to the suggested system were estimated by electrolyte leakage evaluation. EL(%) values of the Sedum species subjected to maximum temperature(46.7℃) recorded during the experimental periods were lower than 50% except S. kamtschaticum and S. spurium. S. album, S. rupestre, and S. telephium were ranked higher than the others in heat tolerance. EL(%) values of the Sedum species subjected to minimum temperature(-9.8℃) recorded during the experimental periods were lower than 50% except S. oryzifolium. S. album, S. reflexum, and S. rupestre were ranked higher than the others in cold tolerance. The above-ground parts of S. kamtschaticum, S. polystichoides, S. sarmentosum, and S. telephium were not alive during the winter. These results were similar to those of laboratory condition.
The covering area of the Sedum species applied to the suggested system increased continuously for about two years and showed a large quantity of increment in summer season with the exception of S. kamtschaticum, S. polystichoides, S. sarmentosum, and S. telephium, whose above-parts were not alive in winter. When a year had passed since the systems were established, S. acre, S. oryzifolium and S. sexangulare maintained 200-500㎠/plant of covering area and the others maintained 800-1200㎠/plant.

목차 (Table of Contents)

• Ⅰ. 서론 = 1
• 1. 연구의 배경 및 필요성 = 1
• 2. 연구 목적 = 3
• Ⅱ. 연구사 = 4
• 1. 옥상녹화의 특성 및 동향 = 4
• 2. 옥상녹화 시스템 개발에 관한 연구 = 12
• 3. 식물의 환경 저항성 평가에 관한 연구 = 35
• Ⅲ. 재료 및 방법 = 52
• 1. 연구의 범위 = 52
• 2. 식물의 선정 = 52
• 3. 시스템의 구성 = 62
• 4. 제안된 시스템의 종합적 평가 = 68
• Ⅳ. 결과 및 고찰 = 74
• 1. 식물의 선정 = 74
• 1) 식물 선정 기준 및 적용 가능한 식물의 제안 = 74
• 2) 선정된 식물의 생육 평가 = 84
• 2. 시스템의 구성 = 120
• 1) 시스템의 개념적 모델 = 120
• 2) 시스템의 구조 평가 = 122
• 3. 제안된 시스템의 종합적 평가 = 147
• 1) 내건성 평가 = 147
• 2) 내서성 평가 = 166
• 3) 내한성 평가 = 168
• 4) 피복력 평가 = 171
• 4. 종합고찰 = 186
• Ⅴ. 적요 = 195
• 인용문헌 = 198
• ABSTRACT = 208