<p> Green roofs are an established best management practice (BMP) for storm water mitigation because of their ability to retain precipitation runoff. The purpose of this study was to quantify storm water retention of <i> Sedum</i> and native plant green roof systems at three substrate depths (10, 15, 20 cm). Survival of plants on green roof systems is dependent on how quickly they can establish themselves. This study also determined native and <i>Sedum</i> plant roof surface coverage at three green roof growth media depths (10, 15, 20 cm). A mixture of six <i>Sedum</i> species (<i>S. spurium, S. sexangulare, S. album, S. Immergrunchen, S. kamtschaticum</i>, and <i>S. reflexum</i>) and four native species (<i>Sporolus cryplandrus, Boutelous curtipendula, B. gracilis </i>, and <i>Penstamen pallidus</i>) were planted into the built-in-place systems (BIPs) on June 20, 2014. </p><p> There were 137 precipitation events totaling to 158.2 cm during the entire (June 20, 2014-June 30, 2015) study period and there were 87 precipitation events with a total precipitation of 108.1 cm during storm water collection (Oct. 31, 2015 until June 30, 2015). During the study period, mean storm water retention of green roof systems planted with native (>58%) and <i>Sedum </i> (>53%) species were identical regardless of growth media depth. Mean storm water retention in green roof systems planted with native and <i> Sedum</i> species in all growth media depths were greater than mean storm water retention of non-vegetated roof models (32%). </p><p> Green roof plant surface coverage plays an important role in water retention of storm water runoff. During the dormant period (January 23, 2015), roof coverage by <i>Sedum</i> plants was greater than roof coverage by native plants. In addition, green roof surface coverage by <i>Sedum</i> plants was the same regardless of depth (>89%). Green roof surface coverage of native plants in 10 cm depth achieved less coverage than native plants in 15 and 20 cm depths. These results differ from the plant-growing season (June 30, 2015). Green roof surface coverage by native plants in green roof systems with 15 and 20 cm growth media depth were identical to the roof coverage by <i>Sedum</i> plants in green roof systems with 10, 15, or 20 growth media depth. Green roof surface coverage by native plants in green roof systems with 10 cm growth media depth was less than the roof coverage in all green roof systems in this study. </p><p> Analysis of covariance was used to determine if green roof surface coverage by native and <i>Sedum</i> plants affected mean storm water retention. During the study period green roof surface coverage by native and <i> Sedum</i> plants did not affect storm water retention regardless of growth media depth. </p><p> This green roof research demonstrates that green roof systems planted with native plant species are effective tools for retaining storm water in the mid-western region of the United States. After 9 months, there was no difference in storm water retention between native and <i>Sedum</i> species planted in 10, 15, and 20 cm growth media depth. Each green roof module retained more storm water than the traditional, non-vegetated roof model. Both native and <i>Sedum</i> species planted on green roofs in 10, 15, and 20 cm media depth achieved more than 69 percent green roof surface coverage after nine months.</p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:10111534 |
| Date | 23 June 2016 |
| Creators | Schuchman, Rachel |
| Publisher | Southern Illinois University at Edwardsville |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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