scholarly journals Physical Characteristics of and Seed Germination in Commercial Green Roof Substrates

2015 ◽  
Vol 25 (2) ◽  
pp. 221-227 ◽  
Author(s):  
Derald A. Harp ◽  
Cheng Chen ◽  
Curtis Jones
Keyword(s):  
Seed Germination ◽  
Block Design ◽  
Green Roof ◽  
Chemical Properties ◽  
Green Roofs ◽  
Economic Benefits ◽  
Physical Characteristics ◽  
Internal Cooling ◽  
Pinto Bean ◽  
Expanded Shale

Green roofs provide multiple environmental and economic benefits, such as roof surface temperature reduction, reduced internal cooling needs, storm water management, and extended life span of roofing materials. However, green roof substrates must be relatively lightweight, so it is typically coarse with limited water holding capacity. We hypothesize the physical characteristics that make the substrates successful on a roof are likely to reduce seed germination. For this study, we tested the germination of three perennial species and one annual: shasta daisy (Leucanthemum ×superbum), yarrow (Achillea millefolium), and indian blanket (Gaillardia pulchella), and pinto bean (Phaseolus vulgaris) (as a control) across five different substrates: peat/perlite/large expanded shale, compost/sand/expanded shale, compost/black dirt/expanded shale, compost/expanded shale, and peat/perlite (control). Substrate physical and chemical properties were analyzed, and a germination test conducted using a randomized complete block design, with each species/substrate combination appearing once per block. Germination was defined as seedling emergence, and monitored every 7 days for 28 days. Pinto bean had the highest germination (76.2%) across all substrates, compared with 43.4% for indian blanket, 40.4% for yarrow, and 23.0% for shasta daisy. Seed germination, across all species, was lower in green roof substrates. Germination success was very strongly correlated with seed length, seed width, and seed area, while no relationship was found between seed germination and substrate pH or electrical conductivity (EC). Therefore, it is likely that the physical characteristics of green roof substrates create poor conditions for seed germination.

Green roof hydrologic performance and modeling: a review

2013 ◽  
Vol 69 (4) ◽  
pp. 727-738 ◽  
Author(s):  
Yanling Li ◽  
Roger W. Babcock
Keyword(s):  
Peak Flow ◽  
Green Roof ◽  
Field Measurements ◽  
Green Roofs ◽  
Economic Benefits ◽  
Design Parameters ◽  
Technical Literature ◽  
Factors Affecting ◽  
Model Soil ◽  
Runoff Volume

Green roofs reduce runoff from impervious surfaces in urban development. This paper reviews the technical literature on green roof hydrology. Laboratory experiments and field measurements have shown that green roofs can reduce stormwater runoff volume by 30 to 86%, reduce peak flow rate by 22 to 93% and delay the peak flow by 0 to 30 min and thereby decrease pollution, flooding and erosion during precipitation events. However, the effectiveness can vary substantially due to design characteristics making performance predictions difficult. Evaluation of the most recently published study findings indicates that the major factors affecting green roof hydrology are precipitation volume, precipitation dynamics, antecedent conditions, growth medium, plant species, and roof slope. This paper also evaluates the computer models commonly used to simulate hydrologic processes for green roofs, including stormwater management model, soil water atmosphere and plant, SWMS-2D, HYDRUS, and other models that are shown to be effective for predicting precipitation response and economic benefits. The review findings indicate that green roofs are effective for reduction of runoff volume and peak flow, and delay of peak flow, however, no tool or model is available to predict expected performance for any given anticipated system based on design parameters that directly affect green roof hydrology.

scholarly journals Growth of the Native Xerophyte Convolvulus cneorum L. on an Extensive Mediterranean Green Roof under Different Substrate Types and Irrigation Regimens

HortScience ◽  
2015 ◽  
Vol 50 (7) ◽  
pp. 1118-1124 ◽  
Author(s):  
Lamprini Tassoula ◽  
Maria Papafotiou ◽  
Georgios Liakopoulos ◽  
Georgios Kargas
Keyword(s):  
Green Roof ◽  
Photosynthetic Apparatus ◽  
Chemical Properties ◽  
Green Roofs ◽  
Irrigation Frequency ◽  
Soil Substrate ◽  
Grape Marc ◽  
Local Character ◽  
Shoot Number ◽  
Soilless Substrate

The possibility of using Convolvulus cneorum L., a native Mediterranean xerophyte, with compact dome-like canopy and extended blooming period, on extensive green roofs in areas with semiarid Mediterranean climate was investigated in a 27-month experimental period, which included three summers (the dry season of the year). The aim was to preserve the local character and biodiversity, as well as to reduce water consumption and construction weight. Convolvulus cneorum rooted cuttings were planted in the beginning of July 2011 in experimental modules on a fully exposed flat roof at the Agricultural University of Athens, with a green roof infrastructure (substrate moisture retention and protection of the insulation, drainage element, and filter sheet). Two types of substrate with 10 cm depth were used, one with soil, i.e., grape marc compost:perlite:soil:pumice (3:3:2:2, v/v) and a lighter one without soil, i.e., grape marc compost:perlite:pumice (3:3:4, v/v). Two irrigation frequencies were applied during the dry periods, i.e., every 5 days (normal) and 7 days (sparse) in 2011 and 2012 and every 4 days (normal) and 6 days (sparse) in 2013. The chemical properties of the two substrates were similar, while their physical properties differ slightly as the substrate that contained soil was holding more water at saturation and it had lower saturated hydraulic conductivity and higher easily available water (EAW). The substrate type affected growth since plant height and diameter, shoot number, and aboveground dry weight were promoted by the soil substrate. Irrigation frequency did not affect plant growth. However, plants cultivated on soil substrate and irrigated normally had the highest growth, particularly compared with plants in soilless substrate under sparse irrigation. Flowering was abundant in April (spring) and in the first year flower number was promoted by the soil substrate. During the dry periods, sparse irrigation resulted in increased stomatal resistance one day before irrigation, indicating that water availability was marginal for the plants, while normal transpiration rate was restored the day after irrigation. According to photosystem II photochemical parameters measured one day before and the morning after an irrigation event, no evidence of damage to the photosynthetic apparatus was recorded in any of the treatments. In general, after 27 months of culture, plant size and roof coverage was appearing more or less similar in all the experimental treatments, therefore the combination of the lighter soilless substrate with sparse irrigation is highly suggested for C. cneorum cultivation on Mediterranean green roofs.

scholarly journals Site Conditions, Maintenance Costs, and Plant Performance of 10 Extensive Green Roofs in the Research Triangle Area of Central North Carolina

2020 ◽  
Vol 30 (6) ◽  
pp. 761-769
Author(s):  
Julieta Trevino Sherk ◽  
Wenyan Fu ◽  
Joseph C. Neal
Keyword(s):  
North Carolina ◽  
Plant Cover ◽  
Green Roof ◽  
Green Roofs ◽  
Economic Benefits ◽  
Plant Performance ◽  
Site Conditions ◽  
Maintenance Costs ◽  
Research Triangle ◽  
Highly Correlated

Compared with traditional roofing, green roofs (GRs) have quantifiable environmental and economic benefits, yet limited research exists on GR plant survival, maintenance practices, and costs related to plant performance. The objective of this study was to assess plant cover, site conditions, and maintenance practices on 10 extensive GRs in the Research Triangle Area of North Carolina. Green roof maintenance professionals were surveyed to assess plant performance, maintenance practices, and maintenance costs. Vegetation cover on each site was characterized. Relationships among plant performance and environmental and physical site characteristics, and maintenance practices were evaluated. Survey respondents ranked weed control as the most problematic maintenance task, followed by irrigation, pruning, and debris removal. No single design or maintenance factor was highly correlated with increased plant cover. Green roof age, substrate organic matter, and modular planting methods were not correlated with greater plant cover. Results showed a trend that irrigation increased plant cover. Plants persisting on GRs included several species of stonecrop (Sedum sp.), but flame flower (Talium calycinum) and ice plant (Delosperma basuticum) were also present in high populations on at least one roof each. Green roof maintenance costs ranged from $0.13/ft2 to $3.45/ft2 per year, and were greater on sites with more weeds and frequent hand watering.

Research of Extensive Green Roof (Spring) for Create Comfortable Environment in Taiwan City

2015 ◽  
Vol 749 ◽  
pp. 420-424
Author(s):  
Chiou Chuan Chen
Keyword(s):  
Energy Saving ◽  
Air Conditioning ◽  
Room Temperature ◽  
Green Roof ◽  
Electricity Consumption ◽  
Green Roofs ◽  
Economic Benefits ◽  
Control Area ◽  
Building Roof ◽  
Extensive Green Roof

March to May at noon control area (exposed roof) temperature of 37.56°C, test below (green roofs) surface only 24.69°C, 24.79°C room temperature on the second floor, planting mean temperature of 27.6°C, effectively prevent the roof surface temperature rise, and thus reduce the interior roof of the second temperature 12.77°C . Building extensive green roofs to cooling, mainly to reduce the building room temperature of 3.76°C;reducing air conditioning electricity consumption , accomplish cooling and energy-saving benefits.March to May at noon (12:00-13:00), ANOVA analysis of cooling efficiency, the temperature difference between the building control area as the dependent variable, compare independent variables, and found that different monitoring areas of solar radiation cooling effect,2 floor indoor cooling temperature 13.9083°C, efficiency the most significant.Roofs of buildings spring will be applied as extensive green roof in spring, creating building roof thermal comfort (24.88°C) and Auliciems (1981) estimate room comfort temperature (24.55°C) are similar, significant benefits to achieve room thermal comfort.Buildings is applied for green roofs in the spring can reduce home power consumption (reducing air conditioning systems use frequency), to energy-saving (58.17%) of the economic benefits.

Green Roof Plant Responses to Different Substrate Types and Depths under Various Drought Conditions

2010 ◽  
Vol 20 (2) ◽  
pp. 395-401 ◽  
Author(s):  
Christine E. Thuring ◽  
Robert D. Berghage ◽  
David J. Beattie
Keyword(s):  
Green Roof ◽  
Green Roofs ◽  
Plant Responses ◽  
Ice Plant ◽  
Herbaceous Perennials ◽  
Central Pennsylvania ◽  
Drought Conditions ◽  
Expanded Shale ◽  
Influence Of Substrate ◽  
Substrate Depth

Plants suitable for extensive green roofs must tolerate extreme rooftop conditions, and the substrates in which they grow must fulfill horticultural and structural requirements. Deeper substrates may retain more water for plants during dry periods, but will also weigh more, especially when near saturation. A study in central Pennsylvania was conducted to evaluate the influence of substrate type and depth on establishment of five green roof plants. Two stonecrops [white stonecrop (Sedum album) and tasteless stonecrop (Sedum sexangulare)], one ice plant (Delosperma nubigenum), and two herbaceous perennials [maiden pink (Dianthus deltoides) and saxifrage pink (Petrorhagia saxifraga)] were planted in three depths (30, 60, and 120 mm) of two commercially available green roof substrates (expanded shale and expanded clay). Study flats inside a plasticulture tunnel received three drought treatments (no drought, 2 weeks early drought, and 2 weeks late drought). The two stonecrops performed well under most conditions, although tasteless stonecrop was stunted by early drought. Ice plant only grew well when provided with water. When subjected to any drought, the herbaceous perennials had the fewest survivors in the expanded shale. Saxifrage pink flowered profusely wherever it survived. The study plants were most affected by substrate depth, except for maiden pink, which responded solely to drought. When subjected to early drought conditions, the herbaceous perennials did not survive in 30 mm of either substrate, or in 60 mm of expanded shale. Although the stonecrops performed well in 60 mm of substrate when subjected to drought, their performance was superior in the expanded clay compared with shale.

Study on Landscape Design of Roof Garden

2013 ◽  
Vol 838-841 ◽  
pp. 2993-2996
Author(s):  
Ying Sun ◽  
Guang Lin Gao
Keyword(s):  
Green Roof ◽  
Complex Form ◽  
Green Roofs ◽  
Economic Benefits ◽  
Landscape Design ◽  
Garden Design ◽  
Performance Arts ◽  
And Performance ◽  
Roof Design ◽  
Roof Garden

The roof garden is a complex form of roofs landscape. Advanced green roof design played a huge ecological and economic benefits gradually being recognized for the significance of green roofs and classification, this paper study the roof garden design principles and key technologies for preliminary summary and discussion, proposed green roof functioning and performance arts beautiful landscape design methods.

INVESTIGATING THE ENVIRONMENTAL IMPACTS OF GREEN ROOF INSTALLATION

2015 ◽  
Vol 76 (1) ◽  
Author(s):  
Amir Mahdiyar ◽  
Arham Abdullah ◽  
Sanaz Tabatabaee ◽  
Leily Mahdiyar ◽  
Saeed Reza Mohandes
Keyword(s):  
Urban Areas ◽  
Green Roof ◽  
Environmental Issues ◽  
Green Roofs ◽  
Developed Countries ◽  
Economic Benefits ◽  
Environmental Benefits ◽  
Adverse Impacts ◽  
Increasing Trend ◽  
Rural Places

Green roof installation has been used as a sustainable approach for many years in order to reduce the adverse impacts of environmental issues all around the world. These environmental issues include: global warming, air pollution, flood, carbon footprint and so on. Green roofs are practical as a sustainable approach, especially in developed countries; however, there is an increasing trend of implementing green roofs in developing countries. This paper is reviewing the benefits of green roof installation and how green roof might contribute to reduce the negative environmental issues. The environmental problems that can be solved or reduced by these benefits are discussed separately in this paper. It is concluded that due to the environmental benefits of green roof installation, it leads to many economic benefits. Moreover, green roof implementation is beneficial in both urban areas and rural places.

scholarly journals Life cycle benefits and challenges of large – scale green roof implementation in a mediterranean compact city: the case of Thessaloniki

2021 ◽  
Vol 899 (1) ◽  
pp. 012010
Author(s):  
E Koroxenidis ◽  
T Theodosiou
Keyword(s):  
Life Cycle ◽  
Green Infrastructure ◽  
Urban Areas ◽  
Large Scale ◽  
Energy Savings ◽  
Green Roof ◽  
Green Roofs ◽  
Economic Benefits ◽  
Economic Life ◽  
Waste Production

Abstract Green roof installation is considered to be an effective practice in restoring green spaces to high – density urban areas, in an effort to mitigate environmental problems that arise from their growing expansion. The present study attempts to further investigate this claim by assessing the environmental and economic life cycle benefits and challenges of two extensive green roof large – scale implementation scenarios (on existing or on well – insulated roofs) in the compact mediterranean city of Thessaloniki, Greece. In both scenarios green roofs provided energy savings (13-19%), greenhouse gas emissions (22-29%) and waste production (57-60%) reductions but also led to a significant increase in water consumption (279-291%), with performance being better in the latter case. They also accrued significant public economic benefits in both a low and high discount rate scenario, although they were not an efficient choice for private owners in the second one. These results seem to imply that green roofs could potentially be a viable urban green infrastructure solution, if their water use is minimized in a sustainable way and additional state incentives are considered.

The ecosystem service benefits of green-roof as a part of smart ecosystem-based management: A case study in Dublin, Ireland

2021 ◽  
Author(s):  
Srikanta Sannigrahi ◽  
Bidroha Basu ◽  
Arunima Sarkar Basu ◽  
Francesco Pilla
Keyword(s):  
Ecosystem Service ◽  
Green Roof ◽  
Green Roofs ◽  
Well Being ◽  
Environmental Problems ◽  
Economic Benefits ◽  
Water Infiltration ◽  
Water Runoff ◽  
Ecosystem Based Management ◽  
Extreme Precipitation Events

<p>The concept of Ecosystem-Based Management (EBM) as part of Nature-Based Solutions (NBS) have frequently been adopted in different strategic planning as a cross-sectoral mechanism to manage environmental problems. The EBM combines all relevant approaches, methods, tools, and software that collectively provide key scientific and socioeconomic evidence and eventually address environmental issues more sustainably. The specific application of EBM in different environmental problems, including flooding, have been proven effective in many cases. This ensures the superiority of EBM approaches for designing collaborative programs for solving environmental problems. The EBM offers a variety of sustainable interventions such as reducing impervious surface through porous paving, green parking lots, brownfield restoration, and deployment of green-roofs, which collectively attenuates water runoff and peak discharge, and offers protection against extreme precipitation events by enhancing water infiltration. In addition to the targeted benefits and cost-effectiveness of EBM, the supply of potential ecosystem service co-benefits that usually comes with EBM can contribute substantially to generating environmental benefits and adds community well-being. In order to analyse the superior effects of green-roof as a part of a smart-EBM framework, which has been deployed in CHQ building in Dublin, Ireland, a conceptual upscaling scenario framework has been formulated for measuring the city scale impact of green-roofs in providing multiple-valued ecosystem services. The biophysical and economic benefits of smart green-roof EBM will be estimated using varied ecosystem service modelling and standard cost-benefit analysis. The proposed smart green-roof framework is expected to have a more significant impact in minimising the flooding problems in Dublin city and expected to provide multiple regulating, supporting provisioning, and cultural benefits that can collectively surpass the deployment cost of green-roofs in the long run.</p>

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Chemical Properties ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Physical And Chemical Properties ◽  
Total N ◽  
Randomized Complete Block Design ◽  
Physical And Chemical ◽  
And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

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