도심에 녹지공간 확보를 위한 방안으로 저관리 경량형옥상정원이 많이 조성되고 있으나 토심이 낮아 활용할 수 있는 식물종이 매우 제한되어 있다. 따라서 중부지방의 저관리 경량형옥상정원에 활용할 수 있는 다양한 식물자원을 선발하기 위하여 곤달비와 금낭화 등 초본성 자생식물 82종에 대한 생육 및 월동특성, 지피특성, 적용 후 온도 및 토양수분 등의 변화를 조사하였다. 실험결과 생육특성, 생존율, 월동전의 생육상태, 지피특성 등을 고려하여 잔대, 산부추, 두메부추, 벼룩이울타리, 참당귀, 개미취, 참취, 범부채, 섬초롱꽃, 패 랭이, 금낭화, 윤판나물, 용머리, 원추리, 붉은단풍취, 비비추, 흰줄무 늬비비추, 옥잠화, 꽃창포, 붓꽃, 노랑꽃창포, 곤달비, 맥문동, 하늘나 리, 참나리, 꽃무릇, 돌단풍, 강활, 수호초, 작약, 수크령, 도라지, 둥굴레, 무늬둥굴레, 양지꽃 물싸리, 할미꽃, 오이풀, 황금, 기린초, 애기기린초, 섬기린초, 세잎꿩의비름, 산비장이, 섬백리향을 선발하 였다. 또한 식물이 식재된 후의 콘크리트 표면과 토양의 온도편차는 여름철 최고 20 ~ 35οC이였으며, 토양습도는 6월과 9월 비가 많이 내리지 않는 건조기에는 5%미만으로 떨어지는 기간이 1주 이상 지 속되어 자생 초본식물의 도입시 관수를 필요로 하였다.

This study was carried out to assess the covering of 11 Sedum species on an extensive green roof system under the urban climate of South Korea for 2 years. The 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. The plants were planted in the extensive green roof system with the substrate of porous glass+bark+field soil (v:v:v, 3:2:5) and then evaluated. The covering area of the Sedum species were about 72㎠ at the start after the establishment. 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. Most covering area 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.

This study as a part of an extensive green roof system development was carried out to assess the heat tolerance of 11 species Sedum spp. on the extensive green roof system: S. kamtschaticum, S. oryzifolium, S. polystichoides, S. sarmentosum, S. acre, S. album, S. reflexum, S. rupestre, S. sexangulare, S. spurium, and S. telephium. Electrolyte leakage evaluation was used to estimate the heat tolerance level of each Sedum at 40°C, 45°C, 47.5°C, 50°C, 52.5°C, 55°C, and 57.5°C. The critical temperatures at the midpoints of sigmoidal curves fitted through electrolyte leakage (EL) were predicted with the range of 54.0°C to 65.2°C. S. album, S. telephium, and S. sexangulare were more tolerant of high temperature than the others. In field condition, the heat tolerance of 11 species Sedum spp. applied to the suggested extensive green roof system was also estimated by EL evaluation. The EL (%) values of 11 species Sedum spp. subjected to maximum temperature (46.7°C) recorded during the experimental periods were lower than 50% except S. kamtschaticum and S. spurium. Especially, S. album, S. rupestre, and S. telephium were ranked higher than the others in heat tolerance. The most Sedum spp. would show good heat tolerance on the extensive green roof system if the maximum temperature on rooftop was below 50°C in summer season.

This study investigated the effects of soil depths and soil organic fertilizer application on the growth characteristics of Spiraea bumalda ‘Gold Mound’ in a extensive green roof system. The treatments were 3 soil depths (10, 15 and 25 cm) and 5 soil types in mixture of artificial soil and organic fertilizer. We measured plant height, leaf width, leaf length, number of flowers, visual quality and survival rate from March to October in 2011. The growing medium of 10 cm soil depth showed the highest plant growth in A1 (amended soil 100%), and the lowest plant growth in O1A4 (organic fertilizer 20% + amended soil 80%) treatment. In case of 15 cm soil depth, Spiraea bumalda ‘Gold Mound’ showed a high leaf length and visual quality in O1A2(organic fertilizer 33% + amended soil 67%) treatment and high leaf width and number of flowers in O1 (organic fertilizer 100%) treatment. A1 treatment without organic fertilizer showed the lowest leaf length and poorest visual quality, and O1A4 treatment showed the lowest plant height and lowest number of flowers. At soil depth 25 cm, O1A1 (organic fertilizer 50% + amended soil 50%) treatment showed greater plant height, visual quality and number of flowers than other treatments. The leaf length and leaf width were more effective in O1 treatment. A1 treatment showed a relatively low leaf length, leaf width and visual quality. The higher the organic conditioner, the better the plant growth. And, survival rates of Spiraea bumalda ‘Gold Mound’ showed 92%, 88% and 76% at soil depths of 25 cm, 15 cm and 10 cm, respectively, in this a extensive green roof system. Therefore, the results showed that the growth of Spiraea bumalda ‘Gold Mound’ was affected by both soil quality and soil depth. Different optimal mixtures of organic fertilizer and amended soil were determined, depending upon soil depth.

This study is the development to standard for evaluation performance of the waterproofing and root resistance combined membrane layer on the green roof system, and it is especially to evaluate to chemical resistance of it

본 연구는 무관수 옥상녹화시스템 식재기반 차이에 따른 돌나물의 생육 변화를 살펴보고, 적합한 토심과 토양배합비를 제시함으로써 무관수 옥상녹화 식물소재로 활용성을 높이고자 수행하였다. 토심(15㎝, 25cm)과 토양배합비(SL, P7P1L2, P6P2L2, P5P3L2, P4P4L2)를 각각 다르게 실험구를 조성하였으며, 내건성이 뛰어난 돌나물을 식재한 후 초장, 녹피율, 엽록소 함량, 생체중과 건조중 등 생육변화를 측정하였다. 토심 15㎝처리구에서 토양배합비에 따른 돌나물의 초장은 인공배합토가 자연토보다 높았으며, 인공배합토 중 P5P3L2에서 초장이 가장 길었다. 토심 25㎝처리구도 같은 경향을 나타내었다. 녹피율과 엽록소함량은 경우 자연토보다 인공배합토에서 대체로 높았으나, 토심에 따른 차이는 뚜렷하지 않았다. 생체중과 건물중은 토심 25cm가 토심 15cm보다 높았으며, 인공배합토가 자연토에 비해 높았다. 이상의 결과에서 무관수 옥상녹화시스템에 돌나물을 적용함에 있어, 토양배합비는 피트모스함량을 높인 인공배합토가 자연토보다는 바람하고 토심은 15cm가 토심 25cm보다 초장, 녹피율, 엽록소 함량 등 외형적인 생육상태가 양호하였다. 하지만, 토심 25cm에서는 생체중 및 건조중 등과 같이 현존량(Biomass)을 향상시킬 수 있어 조성목적에 따라 구분적용하는 것이 바람직하다. 이는 무관수 옥상녹화시스템에서 단기적인 녹피율을 높이고자 할 때 토심 15cm가 25cm보다 바람직하나, 장기적인 생육을 고려해볼 때, 토심 25cm가 15cm보다 유리함을 보여준다고 하겠다. 추후, 토양수분변화 및 각 옥상녹화시스템의 요소들과 생육요소들 간에 상관성 및 요인분석에 대한 분석이 좀 더 조사되어야 할 것으로 보인다.

This study proposes a guideline of a green roof system suitable for the local environment by verifying the growth of Zoysia japonica in a shallow, extensive, green roof system under rainfed condition. The experimental soil substrates into which excellent drought tolerance and creeping Z. japonica was planted were made with different soil thicknesses(15cm, 25cm) and soil mixing ratios(SL, P7P1L2, P6P2L2, P5P3L2, P4P4L2). The plant height, green coverage ratio, fresh weight, dry weight and chlorophyll contents of Z. japonica were investigated. For the soil thickness of 15cm, the plant height of Z. japonica was significantly as affected by the soil mixing ratio and it was shown in the order SL= P4P4L2 < P7P1L2 = P5P3L2 < P6P2L2. For the soil thickness of 25cm, the plant height was increased in order to SL < P7P1L2, P6P2L2, P5P3L2 < P4P4L2. The green coverage ratio was not observed by soil the mixing ratio or soil thickness. However, the green coverage ratio was 86∼90% with a good coverage rate overall. The chlorophyll contents of Z. japonica were not significantly affected by the soil mixing ratio in the soil thickness of 15cm, but were higher in the natural soil than in the artificial soil at 25cm soil thickness. The fresh weight and dry weight of Zoysia japonica were heavier in the 25cm thickness than in the 15cm thickness and in the artificial soil mixture than in the natural soil. The result indicated that the growth of Zoysia japonica was more effective in the 25cm soil thickness with artificial soil than in the 15cm soil thickness with natural soil in the green roof system under rainfed condition.

The objectives of this study were to compare growth of Pllioblastus pygmaed and soil characteristics as affected by difference of soil thickness and mixture ratio in shallow-extensive green roof module system, and to identify the level of soil thickness and mixture as suitable growing condition to achieve the desired plants in green roof. Different soil thickness levels were achieved under 15cm and 25cm of shallow-extensive green roof module system that was made by woody materials for 500×500×300mm. Soil mixture ratio were three types for perlit: peatmoss: leafmold=6:2:2(v/v/v, P6P2L2), perlit: peatmoss: leafmold=5:3:2(v/v/v, P5P3L2) and perlit: peatmoss: leafmold=4:4:2(v/v/v, P4P4L2 ). On June 2006, Pllioblastus pygmaed were planted directly in a green roof module system in rows. All treatment were arranged in a randomized complete block design with three replication. The results are summarized below. In term of soil characteristics, Soil acidity and electric conductivity was measured in pH 6.0∼6.6 and 0.12dS/m∼0.19dS/m, respectively. Organic matter and exchangeable cations desorption fell in the order: P4P4L2> P5P3L2> P6P2L2. P6P2L2 had higher levels of the total solid phase and liquid phase, and P4P4L2 had gas phase for three phases of soil in the 15cm and 25cm soil thickness. Although Pllioblastus pygmaed was possibled soil thickness 15cm, there was a trend towards increased soil thickness with increased leaf length, number of leaves and chlorophyll contents in 25cm. The growth response of Pllioblastus pygmaed had fine and sustain condition in order to P6P2L2 = P5P3L2 > P4P4L2. However, The results of this study suggested that plants grown under P4P4L2 appear a higher density ground covering than plants grown under P6P2L2. Collectively, our data emphasize that soil thickness for growth of Pllioblastus pygmaed were greater than soil mixture ratio in shallow-extensive green roof module system.

This study focused on the characteristics of change soil water with respect to soil thickness and soil mixture ratio, in order to effectively carry out an afforestation system for a roof with a low level of management and a light weight. Soil hardness tended to increase as sand particle was increase regardless soil thickness and soil porosity had more higher artificial soil than natural soil mixture. In case of soil pH, natural soil mixture had between 6.7 and 7.4, and artificial soil mixture had 6.0∼6.8. Organic matter, electrical conductance and exchangeable content were highest in L10, which it had the highest leafmold ratio. Soil moisture tension(kPa) in 15cm soil thickness was observed natural soil mixture had a considerable change but artificial soil mixture had a gradual change when non-rainfall kept on. In the experimental L10, S10, S7L3 and S5L5 object, the amount of moisture tended to rapidly decrease. However, in the experimental P7P1L2, P6P2L2, P5P3L2 and P4P4L2 objects, which contained pearlite and peat moss, the amount of moisture tended to gradually decrease. As a result, the use of a artificial soil mixture soil seems to be required for the afforestation of a roof for a low level of management.

본 연구는 다양한 옥상의 환경조건을 감안해 볼 때 지속적인 생장과 생존이 가능한 범위 내의 토양 토심 및 토양배합비에 따른 토양수분변화를 검토함으로써 현재 일률적으로 규정되어 있는 토심을 줄여 하중을 줄이고, 최소한의 관수만으로도 적정수준의 생육에 필요한 토양층 조성을 도출하고자 하였다. 또한 순비기나무 생육에 효과적인 관리방법과 토양조건의 조합형을 탐색제안함으로써 설계 및 시공관리기술의 개발에 필요한 기초자료와 정책에 반영할 수 있는 방안을 모색하고자 하며, 다음과 같은 결론을 얻었다. 대체적으로 모든 실험구에서 토양수분함량이 점점 감소하는 경향을 보이다가 관수를 포함한 강우 시 수분함량이 올라갔으며, S10, S7L3, S5L5 실험구의 경우에는 강우 후 수분함량이 급격히 떨어지는 경향을 나타내었다. 이에 비해 피트모스와 펄라이트가 포함된 P7P1L2, P6P2L2, P5P3L2, P4P4L2 실험구는 완만하게 감소하여 저관리를 위한 옥상에서의 인공토양 사용은 불가피할 것으로 판단된다. 인공토양을 이용한 적정토심 및 토양 배합비는 관수시점 및 강우와 밀접한 관련이 있다고 판단되며, 7㎝ 토심의 경우 잦은 수분관리가 필요할 것으로 판단된다. 15㎝ 실험구의 14일 무관수에서도 충분히 순비기나무가 생육한 점과 P6P2L2 이상의 피트모스 배합비에서 왕성한 생육이 이루어진 점에서 미루어 볼 때 15일 이상의 저관리에 필요한 인공토양의 배합비는 펄라이트 피트모스 부엽토가 6:2:2, 5:3:2, 4:4:2가 될 것으로 판단된다. 다만, 펄라이트가 많이 배합된 토양에서는 토양이 물을 흡입하는 힘인 토양수분장력(kPa)이 높은 수치로 올라가 추후 순비기나무가 활발히 성장할 수 있는 수분장력의 범위를 설정하는데 연구가 지속되어야 할 것이다. 토심 및 토양배합비에 따른 순비기나무의 광합성특성을 살펴보면 수분함량이 적은 7㎝ 실험구에서는 거의 이루어지지 않았으며, 15cm나 25㎝ 실험구 중 인공토양이 배합된 곳에서 활발하게 이루어진 것으로 나타났다. 또한 통계적으로 살펴볼 때 수분함량이 1%씩 증가할 때 광합성률은 2.82%씩 증가하는 것으로 나타났으며 99%의 유의수준을 보였다. 추후 연구에서는 순비기나무의 생육에 필요한 최소한의 수분함량을 판단하고 그에 따른 토양토심별 적정 관수시점을 찾아내 저관리 옥상녹화와 더불어 식물소재 개발에 이바지 하고자 한다. 또한 순비기나무 이외에 옥상녹화에 적합한 목본을 선정하고, 도시열섬현상 완화 효과를 규명하며, 이를 바탕으로 우리나라 중부지역에 알맞은 저관리형 옥상녹화시스템을 구축하고자 하는 연구가 진행되어야 할 것이다.