简单式屋顶绿化基质厚度筛选研究

薄层基质技术是降低屋顶负荷的关键，筛选满足简单式屋顶绿化植物生长和快速覆盖的最 小基质厚度显得尤为必要。通过蓄水盆栽培试验，研究了基质厚度2，4，6，8 cm 对八宝景天(Sedum spectabile)、佛甲草(Sedum lineare)、长寿花(Kalanchoe blossfeldiana)、吊竹梅(Zebrina pendula)、铺地锦 竹草(Callisia repens) 地被植物生长及覆盖效率的影响。结果表明：基质厚度越大，植物长势越好；基质 厚度为 8 cm 时，直立生长型植物八宝景天株高、根系体积、最长根长、地上部和地下部生物量均显著高 于其它厚度处理（P<0.05）；吊竹梅在基质厚度6 cm 时最快36 d 达到100% 覆盖，铺地锦竹草则在基质 厚度6，8 cm 时最快45 d 达到100% 覆盖；佛甲草、长寿花则生长较慢，基质越薄、成活率越低。综合 分析植物生长指标，建议八宝景天、吊竹梅、铺地锦竹草可选择最小基质厚度分别为 8，6 ，4 cm；佛甲 草、长寿花最小基质厚度则需要继续开展试验研究。

Screening on the Suitable Substrate Thickness for Extensive Roof Greening

The screening and using of thin-layer substrates contributes a lot to fast vegetation?coverage of extensive roof greening plants and reduces the load of green roof. Planting experiments with Sedum spectabile, Sedum?lineare, Kalanchoe blossfeldiana, Zebrina pendula?Schnizl and Callisia repens in water storage containers were performed to study the effects of different substrate thickness (2, 4, 6 and 8 cm) on plants growth and coverage efficiency. The results showed that the plants grew better with the increase of the substrate thickness. When the thickness of the substrate was 8 cm, the plant height, root system?volume, the longest root length, the overground and underground part biomass of S. spectabile were all significantly higher than the other three thickness treatments (P<0.05). The 100% vegetation?coverage of Z. pendula?Schnizl need 36 days growing when the substrate thickness was 6 cm and that of C. repens need 45 days both in 6 cm and 8 cm thickness substrate. S. lineare and K. blossfeldiana grew slowly and a lower survival rates were observed as the decrease of substrates thickness. A comprehensive analysis of plant growth indexes suggested that the minimum cultivation substrate thickness for S. spectabile, Z. pendula?Schnizl and C. repens were 8 cm, 6 cm and 4 cm, respectively.