HRT 460

Which country has the largest amount of green roofs/considered leader in the green roof industry

Germany

what are the professional organizations for green roofs?

Green Roofs for Healthy Cities World Green Infrastructure Network

which factor of a growing substrate has greatest influence on dissipation of available heat

water content/air space

what part of a green roof is only needed if it has shallow media

water retention fabric

what is the least important component of an intensive green roof?

water retention layer

what is WUE

water use efficiency: how much water a plant uses

what are the advantages of indoor green walls

wellness and quality of life biophilia air quality

what is a living wall

living roofs have substrate on them to hold plants for growing

what type of plants are sedum? c3, c4, cam?

CAM

stormwater management options

- drainage swales thru site - water retention ponds for storage - porous pavement - green roof

what does carbon sequestration depend on

- green roof design such as plants and substrates, species composition, density and diversity, ecosystem age - management techniques - climate - carbon emissions avoided

goals of stormwater runoff

- traditional goal: move it offsite - new goals: prevention, containment, deal with water on site

five steps of green roof planning

1. green roof design intent and performance requirements 2. installation schedule and site access 3. component staging and conveyance options 4. installation execution, detailing, and cleanup 5. post-installation documentation and education

how much do green roofs last for in comparison to traditional roofs

70 yrs, compared to 30 yrs

how many green roofs are present on MSU's campus

9-10

where are most green roofs installed in the US?

Washington D.C.

FLL

a set of standards created by Germany's green roof industry for green roofs

what is the main problem with indoor green walls

access to water and light

what are the four strategies climbing vines use to attach themselves

aerial roots suction cups twining tendrils

how does slope affect green roof building

affects which installation methods can be used, the growing medium, reinforcement systems, moisture levels

factors of a growing substrate

anchor plants, well drained, aerated, water holding capacity, nutrient retention, light weight, permanent, free of material which may degrade drainage or waterproofing system

green roof design goals

building stays up, no leaks, keep plants alive

disadvantages of pre-vegetated mats

cannot sit for long, more expensive, something must be under it, limits on media depth and diversity

What is the carrot and stick approach?

carrot: incentives to install green roofs stick: punishments for failing to install green roofs

what are factors influencing water balance

climate temperature irradiance wind velocity intensity and duration of rain events aspect roof slope plant selection substrate composition and depth irrigation

what are disdvantages/reasons not to water?

continuous cost decrease stormwater storage water waste increase of runoff maintenance plant dependency water availability less weeds nutrient leaching

types of green roof systems

conventional built-up system, modules, pre-vegetated mats

what can help carbon sequestration in green roofs

deeper growing substrates and greater species diversity used

structural loading capacity

design restraint that determines substrate composition and depth, plant selection, access, function

how do plants clean the air

directly: leaves intercept particulate matter, break down organic compounds in tissues and soil indirectly: lower surface temperatures create more transpiration and shade, which reduce reactions that form ozone

what factor is most important when choosing plants for an extensive green roof

drought tolerance

what are the advantages of outdoor green walls

energy conservation event enhancement urban food production accessible gardening logos and messages seasonal colors creation of green space

what changes over time to save more carbon than the loss it took to build it?

energy savings

what type of roofs do edge sensitive birds prefer - intensive or extensive and why?

extensive, because the plant canopy is more like a grassland/prairie

what is a green facade

facades do not have substrate, plants are mainly climbing vines attached to the wall or on trellises, rooted on ground

when is it best to install green roofs

fall or spring

what do green roofs need to provide for bird species?

food, shelter/cover, nesting

benefits of conventional system

greater plant diversity, more wildlife diversity

how do green roofs alleviate stormwater runoff flooding in terms of quantity

green roofs reduce the peak of stormwater and spreads it over time

what type of birds like extensive green roofs?

ground foragers

which substrates are typically used

heat expanded slate, shale, clay

what pertains to sensible heat as measured on a green roof?

heat that causes a change in temperature of an object (roof surface)

what are advantages of irrigating green roofs?

helps plant establishment more CO2 sequestration more UHI/energy more plant diversity healthier/more likely to survive aesthetic decreases erosion helps support intensive roofs protection of investment less evapotranspration

what is a possible negative of green roofs when it comes to holding heat from the sun

holds heat from the sun and radiates it down during the night causing more cooling to be needed

what should you do for green roof maintenance?

immediate after installation: irrigate 2 times per week for 6-8 weeks first growing season: spring: water once a week summer: water 2 times per week fall: water once a week second growing season: spring: water once a week summer: water 2 times per week fall: water once a week after growing season: summer: water once a month

what is the major barrier withholding green roof implementation in the USA

initial cost

what are the two main strategies to employ at time of installation to reduce the carbon payback period of a green roof?

install already established plants and the type of component used

benefits of modules

instant greenery, easy installation, easy to find a leak

advantages of pre-vegetated mats

instant greenery, good for steep slopes, relatively easy to install

what are potential problems for green walls

insufficient support desired height damp wall maintenance/removal environmental extremes

differences between extensive and intensive roofs

intensive roofs are more functional, more costly, more maintenance-involved, more flat, more weighted, more plant diversity, more slope limitations

is there a difference between installation methods regarding insects?

little difference

what accounts for the positive carbon equation after seven years?

it turns positive because of the energy savings the green roof creates over time due to less cooling needed for the building

what is the purpose of a filter fabric on green roofs

keep fines in the growing substrate from infiltrating the drainage layer

what are barriers to acceptance of green roofs?

lack of awareness data regarding benefits technical info cost public policy

what is the correlation between roof area and species richness?

larger area, more species richness

leaf factors that influence transpiration

leaf surface area, leaf cuticle, leaf pubescence, leaf boundary layer

extensive green roof

less than 6 inches of substrate

what are the three types of green walls substrates?

loose media mat media (substrate woven into felt mats, requires constant irrigation, typically indoors) structural media

what are flaws of prescriptive incentives?

mandates arbitrary depth of roof all substrate mixes aren't the same ignores other water holding green roof components de-incentivizes low-capacity load-bearing buildings

which of the following factors of a growing substrate has the greatest influence on dissipation of available heat

moisture content

deeper roofs are _____ energy savings efficient than shallow roofs

more

advantages and disadvantages of using organic trays

more environmentally friendly than plastic more expensive, short production window before it breaks down, harder to repair issues

Intensive Green Roof

more than 6 inches of substrate

why is stormwater runoff considered a problem in urban areas

most cities are nearly completely covered in impervious surfaces like concrete. rainfall that would normally be absorbed in the soil cannot absorb so it pools together and creates flooding

when are C3 plants most efficient

most efficient under cool and moist conditions and normal light levels

what is species abundance

number of individuals per species

what is the most efficient way to irrigate green roofs

overhead

what are the most important plant characteristics influencing heat transfer on green roofs

plant height leaf area index canopy coverage stomatal resistance

pre-vegetated mats

plant material grown off location and cut like sod and rolled onto roof

what is the easiest way to create biodiversity on a green roof?

planting different varieties of plants

modules

plastic trays of substrate with plant material that can be simply placed onto roof nestled within other modules to fit

disadvantages of modules

plastic use, empty spaces, not aesthetic initially

what is the purpose of green roofs in more southern climates?

reduce urban heat island effect

factors that influence transpiration

relative humidity temperature light wind velocity soil moisture

what are aerial roots

root hairs attach to rough surfaces

what plant type does best on green roofs in MI

sedum, second is allium

what are blue roofs?

shallow water pools on roof tops

what type of birds like intensive green roofs?

shrub and lower canopy and ground foragers

what influences substrate surface temperatures and heat flux

slope, aspect, albedo, percentage of plant cover

how does liveroof work?

soil elevators are placed in trays and then soil inserted with plants grown to maturity modules are then installed and soil elevators removed

what are horticultural considerations for green walls?

soil quality like foundation drainage pipes rain shadows suckers and aerial roots on young stems feet in cool, head in sun invasiveness

types of conventional system

spontaneous colonization, plugs, seeds, cuttings

benefits of green roofs

stormwater management, energy conservation, biodiversity, aesthetics, food, air pollution control, human health benefits, increases roof longevity, wildlife habitat, conserves money in long run, filters water, sound reduction, build insulation

what season of the year does a green roof provide most energy savings? why?

summer, because plants evapotranspirate more due to more solar radiation, which in turn creates less heat flux, meaning the building does not have to cool more due to extreme temperatures on the roof, which in turn means more energy savings

what are twining vines

tend to grow vertical, must be trained horizontally

what are suckers

tendrils attach to smoother surfaces

what part of a sloped roof has healthier plants

the bottom level due to drainage

what is the major negative aspect of using vermicompost

the impact of nutrient runoff like nitrogen and phosphorus

what is species richness

the number of different species in a community

what are the types of support structures for green walls

trellises or frameworks (wood, metal, cable and wire, plastic, glass fiber cable, rope) fixings and load bearing

components of a green roof

vegetation, growing medium, drainage layer and filter fabric, root barrier, waterproofing membrane, structural deck

what is the problem with carbon storage of green roofs

when mature, the carbon it holds at that moment is all the carbon it can ever hold, it cannot continuously be storing more and more carbon

why is organic matter kept to a minimum (<20% by volume) in green roof growing substrates

will eventually break down over time and lower height of total media height, which can cause problems for plants growing in the substrate

is there a difference between sedum and non-sedum roofs regarding insects?

yes

can you combine green roofs and solar panels

yes, just more care has to be given that panels do not shade out plants

do green roof trees live longer than street trees

yes, road salting, car compaction, heat from pavement are not problems