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What is sustainability?
The idea of sustainability is far from having a clear and agreed definition.
Although the core of the vision seems simple --- a lasting and nondestructive
way to live on this Earth --- the questions are many. Probably the simplest
widely used definition of sustainability is meeting the needs of today’s
population without diminishing the ability of future populations to meet their
needs.
In the landscape, beginnings and endings overlap. Healthy landscapes
are ecosystems, and they survive by constant change. In a self-sustaining
landscape, marsh becomes meadow becomes forest, then returns to meadow after
fires, or even to marsh after floods. Individual plants and animals die,
but the community --- the landscape --- lives on through a constant “recycling”
process. The sustainable landscape does not exclude human presence or
even human engineering; however, it does not blindly glorify human intervention
nor equate gentle human influence with massive human domination.
For those of us who love landscapes, it is troubling and confusing to
think that our creations damage the environment. How can a green growing
place hurt the Earth? The question can be answered both in a technical way
and in terms of attitudes and cultural trends. First of all, the choice of
materials and process of landscape construction can be crucial factors which
cause ecological problems. For example, materials like PVC that is highly
valued while in use but cause serious disposal problems. Also, ignoring site
and habitat protection limits the ability to transform construction into
more environmentally friendly forms. This implies that without site protection
as a goal, green building can become a little like fat-free cookies --- an
excuse to consume more because it is better than the other brands.
Besides appropriate techniques and materials, site
protection relies on positive attitudes toward the landscape. Designers
and construction workers often get great satisfaction from their power to
change and rearrange the site. In many cases, designers choose to limit
the plant species permitted in a particular landscape; contractors install
paving to control mud and dust. How much control, and how formal or controlled
a style, depends on the individual’s unconscious respond to the land. Similarly,
some construction workers view site and materials as adversaries to be overcome.
This combative attitude is expressed when existing trees are hacked unnecessarily,
or equipment is driven carelessly, or construction scrap is thrown around
the site.
As one can start to realize, landscape-making is a
complex activity. It requires collaborative effort from not only landscape
professionals but also their clients and their communities. It is certainly
possible for one person to build an entire landscape beautifully, if the
site is small enough and the time for building is quite long. For larger
landscapes, for those that are ecologically complex, or for ones that must
be built in a hurry, teamwork is inevitable. The general principles that
one should be aware of when working on a sustainable landscape project are
as followed:
• Site and soil protection
• Using local / renewable / recycled materials
• Efficient irrigation
• Pervious paving
• Managing construction waste
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Turn barren roof spaces into
Ecoroofs
Conventional roofs are impervious to water and exposed to high wings;
they cause severe microclimates by absorbing or reflecting heat. No wonder
they are nearly barren of life and resistant to environmental improvement.
Every square foot of sterile roof corresponds to a square foot of life missing
from the ground surface.
Conventional roof gardens do not adequately address
the problem of sterile roof expanses. In fact, constructing a roof garden
requires very high energy inputs and costs. Beefing up the structure of
a building to withstand the added weight of soils, shrubs, and even trees;
imported soil that must be lifted to great heights; extra irrigation and
maintenance for plantings to withstand exposure and drying winds. Conventional
roof garden may be delightful to the favored few who have access to them,
but they do little for the urban environment as a whole.
The ecoroof, a concept pioneered in Europe, offers
new possibilities for integrating buildings into the living environment. These
ecological roof gardens require little or no modification to a building’s
structural system and hardly any irrigation or maintenance, but covered
urban roofs with a living carpet of vegetation. The requirements of an ecoroof
are relatively modest, yet the environmental benefits are considerable:
• Improves the building’s thermal insulation.
• Reduces the urban “heat island” effect, by absorbing
less heat.
• Produces oxygen, absorbs carbon dioxide, and filters
air pollution.
• Stores carbon.
• Provides wildlife habitat, especially for birds.
• Absorbs up to 75 percent of rain falling on it, thus
slowing stormwater runoff.
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What is Permaculture?
According to Bill Mollison, who coined the term, permaculture is a
design system for creating sustainable human environments. The word
permaculture was derived from “permanent agriculture” and also “permanent
culture”. The sustainable design system focuses on the interrelationship
between humans, plants, animals and the earth.
Permaculture principles focus on considerate designs for small-scale
intensive systems which are labor efficient and which use biological resources
instead of fossil fuels. For example, the use of certain types of
natural materials such as bales of straw (see Casa de Paja, New Mexico)
to create thermal mass at a cost effective. Designs stress ecological connections
and closed energy and material loops. The core of permaculture is design
and the working relationships and connections between all things. Each component
in a system performs multiple functions, and each function is supported by
many elements. Key to efficient design is observation and replication of
natural ecosystems, where designers maximize diversity with polycultures,
stress efficient energy planning for houses and settlement, using and accelerating
natural plant succession, and increasing the highly productive "edge-zones"
within the system.
Permaculture is a response to caring for the earth and being sensitive
to limited energy resources. Furthermore, it is a means of finding ways
to mutually benefit the environment humans live in as well as benefiting
the earth.
Below are some principles and ethics behind permaculture: (Taken from
http://www.thefarm.org/permaculture/ethics#
System yield is the sum total of surplus energy produced by, stored,
conserved, reused, or converted by the design. Energy is in surplus once
the system itself has available all its needs for growth, reproduction and
maintenance. Unused surplus results in pollution and more work.
• Permaculture is not limited to plant and animal
agriculture, but also includes community planning and development, use of
appropriate technologies (coupled with an adjustment of life-style), and adoption
of concepts and philosophies that are both earth-based and people-centered,
such as bioregionalism.
• Many of the appropriate technologies advocated
by permaculturists are well known. Among these are solar and wind power,
composting toilets, solar greenhouses, energy efficient housing, and solar
food cooking and drying.
• Due to the inherent sustainability of perennial
cropping systems, permaculture places a heavy emphasis on tree crops. Systems
that integrate annual and perennial crops-such as alley cropping and agroforestry-take
advantage of "the edge effect," increase biological diversity, and offer
other characteristics missing in mono- culture systems. Thus, multi-cropping
systems that blend woody perennials and annuals hold promise as viable techniques
for large-scale farming. Ecological methods of production for any specific
crop or farming system (e.g., soil building practices, biological pest control,
composting) are central to permaculture as well as to sustainable agriculture
in general.
• Since permaculture is not a production system,
per se, but rather a land use and community planning philosophy, it is not
limited to a specific method of production. Furthermore, as perma-culture
principles may be adapted to farms or villages worldwide, it is site specific
and there-fore amenable to locally adapted techniques of production.
• As an example, standard organic farming and gardening
techniques utilizing cover crops, green manures, crop rotation, and mulches
are empha-sized in permacultural systems. However, there are many other
options and technologies avail-able to sustainable farmers working within
a permacultural framework (e.g., chisel plows, no-till implements, spading
implements, compost turners, rotational grazing). The decision as to which
"system" is employed is site-specific and management dependent.
• Farming systems and techniques commonly associated
with permaculture include agro- forestry, swales, contour plantings, Keyline
agriculture (soil and water management), hedgerows and windbreaks, and integrated
farming systems such as pond-dike aquaculture, aquaponics, intercropping,
and polyculture.
• Gardening and recycling methods common to permaculture
include edible landscaping, keyhole gardening, companion planting, trellising,
sheet mulching, chicken tractors, solar greenhouses, spiral herb gardens,
bioswales, and vermicomposting.
• Water collection, management, and re-use systems
like Keyline, greywater, rain catchment, constructed wetlands, aquaponics
(the integra-tion of hydroponics with recirculating aquaculture), and solar
aquatic ponds (also known as Living Machines) play an important role in
permaculture designs.
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Infiltrate road and parking
lot runoff in Bioswales
Beyond (or instead of) the curb, install grassed or vegetated areas
called bioswales --- linear, planted drainage channels. A typical bioswale
moves stormwater runoff as slowly as possible along a gentle incline, keeping
the rain on the site as long as possible and allowing it to soak into the
ground --- contrary to conventional engineering practice. At the lowest point
of the swale there is usually a raised drain inlet that empties any overflow
(during particularly heavy storms) into the nearest waterway. Since well-designed
bioswale are capable of infiltrating most or all of the rain from normal
showers. Along with the infiltrating function, bioswales cleanse runoff via
their plants and soil microbes.
Bioswales function particularly well in parking lots, which generate
runoff laden with pollutants that drip from cars and collect on the parking
lot surface. It is important that the “first flush” of rain off a parking
area go to a grassed or vegetated area. If stormwater is routed first to a
bioswale, and enters a drain system only if pounding is deep enough to reach
an overflow outlet, most of the first-flush pollutants will be contained
in the bioswale.
Whether or not a road or parking area incorporates a bioswale or similar
system, it is a good idea to break up paved areas so that they drain directly
to an unpaved area rather than to a storm drain. Directly connected impervious
areas should be minimized in design.
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Use pervious paving materials
Another way to decrease the stormwater impacts of paving is to make
the pavement more permeable so that infiltration occurs through the surface
of the paving itself. Pervious paving combines surface stability with permeability.
Since the 1970s, landscape professionals have been pioneers in its development
and use. These materials are gaining acceptance, but unfortunately are not
as well known as they deserve to be. Considering how often the professional
is involved in (and frustrated by) pavement design, familiarity with these
materials is a must for being part of the solution rather than part of the
problem.
Porous asphalt and porous concrete are two commonly used materials for
pervious paving system. Both materials are strong enough for parking, pedestrian
use, and some road surfaces. The asphalt version was originally developed
for airport runways, where it prevents dangerous surface ponding.
In addition to porous asphalt and porous concrete, among the most permeable
parking surfaces are grassed paving systems that allow turfgrass to grow
through an open cell of concrete or plastic that transfers the weight of vehicles
to an underlying base course. A variety of commercial products is available,
including large sheets of plastic mesh, precast open concrete blocks, and
form systems for casting concrete cells in place. The environmental benefits
of grassed paving can be considerable. Every 1000 square feet of grass paving
infiltrates nearly 7000 gallons per 10 inches of rainfall, which would otherwise
be runoff; converts enough carbon dioxide to oxygen to supply twenty-two
adults for a year; provides significant cooling, and recycles more than 400
pounds of plastic in the product itself.
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Some recommendations…
“The edges” are defined as the planes where different types of vegetation
meet. For example, at the place where forest meets an open field,
“the edge” condition is created. The “edge effect” is the effect that occurs
at these meeting points of different landscape where different ecosystems
can occur simultaneously. This creates a richness of diversity that
can occur in these places where there exists a multiple of mutual environment
beneficiary resources.
Because of these already existing conditions, it would be better to further
improve these conditions rather than changing what has been established
by nature.
Consider the possibility of creating ‘edges’ around the landscape. On the
rear of the site, there are two different types of vegetation. On the side
of the rocky wall, there are rushes that line the entire foot of the cutaway
rock wall. The rushes also line the path that is currently unused
for several reasons (e.g., not well lit, overgrown with rushes and also
water collected on the surface.) The other side of the path has a
row of deciduous trees, creating a different type of vegetation that meets
the path. The trees are a lot smaller because of the shallow depth
of the soil. By using the idea of bioswale to design a better drainage system
along the path, the path can be turned into a beautiful ……..which stays dry
for most of the time and allow pedestrians to observe ……….from both side
while walking through it.
When dealing with a large open field, wind direction and wind velocity
are always important considerations for the landscape designer. In reference
to the wind direction that comes through the site, perhaps there is a need
for a ‘windbreak’ from the south west corner of the song along the edge of
the reservoir to the pump house. Although the gradual sloping of the boundary
around the site creates an already existing wind barrier against the winds
from the south west, the access ‘path’, on the corner of McTavish and Doctor
Penfield is exposed to the wind from that direction. Trees could be planted
there perhaps to slow down the air velocity.
To incorporate and use the indigenous plants that grow on the site for
the new proposal could also be a thoughtful design strategy. There
was an abundance of wild daisies of different colors on the site, especially
along the path. In these shallow soil conditions, plant life
can exist. Although some of these plants do not have popular names, they
are as valuable and natural as the ones you can find in the forest. The landscape
designer should look at the existing plants and somehow, find a way to “reveal”
their beauty and value instead of trying to “manipulate” and “cultivate”
them to beautify the landscape.
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