Welcome! This blog is being created by students in the courses Population Ecology and Biological Diversity at the University of Oregon. It is one component of their work, and for each course will unfold throughout the term. +Jessica Green & Ann Womack
Professor Green gave a talk that revealed an entire
microscopic world that many of us forget exists. This forgotten world is essential for the function of this
planet and of our own bodies.
Microbes, microscopic organisms that blanket our bodies, inside and out,
and every surface and being we come in contact with, regulate the world we
know. Microbes get a bad wrap for
the ones that come to mind, and the ones most people know about, are the bad
ones: the pathogens. But, contrary
to popular belief, most microbes work for us, not against us.
Jessica’s research, and the subject of her presentation,
focus on where microbes come from, how our primary environment, buildings,
affects the composition of our microbes, and how our changing modern world
influences microbial composition and how our bodies react to these changes.
As technology grows, especially in the developed world,
sophisticated buildings have become the norm. These buildings are isolated, closely regulated and cut-off
from the outside world, thus controlling the microbes that enter, exit and
survive within these primary habitats.
We are essentially growing a monoculture of microbes. Additionally, these buildings are
limiting our exposure to other microbial populations.
Professor Green discussed the effects of the monoculture of
microbes and some of the consequences.
For one, she stresses that we do not understand the consequences these
changes in microbial composition.
Her data, which focused on hospitals and even buildings here on the UO
campus (i.e. Lillis), illustrated the completely different microbial
populations that live outside in the soil, within completely mechanically
ventilated buildings and within buildings with working windows. Some issues
that have arisen so far from reduced exposure to microbes and the reduced
diversity of those microbes are increased incidences of autoimmune disorders,
including asthma and allergies, as well as increased antimicrobial resistance,
which makes treatment more difficult and increases the spread of disease. These increase causes us to wonder if
our current practices are really the best for our health. While getting rid of the pathogens
makes logical sense, the rise of these health problems causes Jessica to pose
the question: are we getting rid of the wrong microbes? For more information on this issue
watch the following TEDtalk by Professor Green:
As we see these problems crop up, Jessica asks us to
consider a paradigm shift where instead of wiping out the microbial populations
within our buildings as much as possible, we learn to manage and promote
diversity of these organisms. This
would promote good microbes and help us to keep out the others. We need to be reminded that the
buildings we live in, the rooms we inhabit and even the computer on which you
are reading this blog on are entire ecosystems of microbes. Just as we want to try and preserve
biodiversity in the ecosystems that we see and understand, biodiversity is
important on the microbial level.
We must learn to protect and preserve microbial diversity before we have
to learn what the negative consequences are of its loss.
Jessica Green introduces
microbes in indoor environments by first listing out all the places that we get
the microbes that help us, ranging from our mothers to the foods we eat to our
primary habitat indoors. She talked about the four principles that have to
exist in an indoor microbial garden such as enclosed buildings and the
maintenance of homogeneous environments. Her main topic of discussion comes
into play when she discusses buildings as microbial ecosystems. Green and a
team of experimenters carried out a case study that revealed the microbial
diversity in hospital settings. They had 3 treatments: mechanical ventilation,
natural or window ventilation, and the outdoors. They found that with
mechanical ventilation, pollen/allergen concentrations were kept low
consistently but also had relatively lower bacterial diversity. Interestingly
enough, the bacteria found with mechanical ventilation, after running PCR
sequences, genetically resembled that of many known pathogens. And as expected,
mechanical ventilation bacteria consisted of more human-associated bacteria.
She also mentioned a case study performed more recently in the Lilis Business
Complex to observe the microbes that might be present on the U of O campus.
Results are still being processed. In concluding her lecture, she shows a video
that poses the ultimate question: are we unique individuals due to the genes we
possess or because of the microbes that live inside of us? To see the lecture, I have posted a link below: http://media.uoregon.edu/channel/2012/05/16/jessica-green-the-ecology-of-indoor-environments/
City
construction destroys the habitats of countless species, requiring them to
either relocate to another area of wilderness or adapt to the new urban
environment that has sprung up around them in order to survive. Plants, being unable to move, have neither of
these options, but there are a host of animals that have become ubiquitous to
the city landscape. Among these animals
are many species of birds, but although some of them may be thriving in their
new urban environments, others would benefit tremendously from a concerted
effort on the part of city dwellers to build as much habitat as possible into
their new surroundings. As cities
swallow up more and more of the land surrounding them, retaining urban bird
biodiversity is critically important to ensuring the continued survival of
these species.
What
makes the difference between birds that flourish in cities and birds that
struggle? One hypothesis is that birds
with bigger brains have the intelligence and mental flexibility to adapt to the
new environmental pressures—such as noise, traffic, lack of nesting sites, and
predatory cats and dogs— of the urban landscape, and to take advantage of its
benefits—such as increased warmth due to the “heat bubble” of cities and
readily available food in the form of garbage and road kill. Examples of a few such birds are the pigeon,
the peregrine falcon (which nests on the crossbeams of bridges), and the crow. Crows have been shown to be able to learn new
behaviors from other crows, and to be particularly innovative in figuring out
difficult problems for themselves. Crow
populations are increasing within cities, and they don’t seem to be in any
hurry to leave. Here is the link to"The Amazing Intelligence of Crows" a video of a TED
talk by Joshua Klein including, among
others, an example about how crows use traffic to crack nuts.
Most
birds, however, are threatened by urban sprawl and the destruction of their
natural habitats. Birds lose nest sites,
foraging cover, and food and water sources when their homes are turned into
buildings. Ground nesters are
particularly at risk in the city, as they require a lot of shrub growth under
which to hide their eggs, and dense bushes are less likely to be planted in
parks and yards than trees and ornamental flowers. Bird species that occupy small, specific ecological
niches are far less likely to be able to survive in the city than generalist
species. For this reason, native bird biodiversity is low within cities, as are
the numbers of native birds within a species that manage to live there; native
birds are much more likely to have their only food sources, the only trees on
which they nest, or even their entire habitats wiped out by urban sprawl. In general, one study found that birds that
do better in cities are those that include plant material in their diets, have
a large natural geographic range, are tree nesters, and are not long-distance
migrators. (Full paper found here)
Image from City Parks Blog
Parks
and leftover forested fragments are, perhaps unsurprisingly, the bird
biodiversity hotspots of cities. In
fact, even the “built” environment of a park—this being further within the
built environment of the city—can be home to a surprisingly large number of
bird species. What’s more, we can
continue to construct the park environment so that it benefits the greatest
number and diversity of birds. Increasing
the number and area covered by trees appears to be the most influential change
that can be made in order to positively affect bird biodiversity. The type of tree matters as well. It has been found that bird biodiversity in
parks is at its maximum when there is an even number of evergreen and deciduous
trees, providing the greatest variety of habitats. This, in addition to the planting of shrubs
of different heights, provides the vertical layering of plants that is
extremely important as foraging cover and nest hiding places, as well as “corridors”
that can conceal a bird as it travels between tree and ground. Comparatively small areas in which there is a
lot of vertical layering may have a greater effect on bird biodiversity than
larger areas in which there is no vertical layering (i.e. trees surrounded by
grass, as in the picture on the left). (Full paper found here)
The
shape of parks matters as well. Long,
thin parks have fewer bird species than do parks with a lower edge-to-area
ratio. Parks and inner-city forest
fragments with more edge habitat can only sustain the types of birds that are
able to live in an edge area, causing lowered biodiversity. Wooded streets may positively contribute to
biodiversity by essentially increasing the size of the park to which they may
be attached. By building parks with less edge and planting trees and shrubs
along the streets leading up to them, we can engineer an environment that is
more desirable to birds.
Image from Buzzle.com
City
residents’ yards are also possible bird nesting and feeding sites, however
there are several factors that affect the chances of a bird making its home in
one. The first is what types of plants
are present. Native birds are far more
likely to nest in someone’s yard if there is a wide variety of native plants
there, as well as plants of different heights.
A large expanse of lawn negatively impacts bird presence; by breaking up
the lawn with shrub and tree “islands,” birds will have less exposure to
predators while foraging for food.
Putting up nest boxes is also a good way to attract birds. Cities naturally have fewer trees than rural
environments, and if cavity-nesting birds struggling to find a site are able to
lay their eggs in a nest box, bird biodiversity will be preserved that much
more into the next generation. Bird
feeders, feeding tables, and water sources such as ponds or bird baths are
other ways to substitute for resources these birds would traditionally have
found in the wild. Finally, making sure
that pets are kept from hunting these birds is another way to promote bird
biodiversity within the urban environment.
Urbanization
is a great threat to bird biodiversity, but with the right strategies, cities
can be kept from destroying it altogether.
By constructing and modifying parks and yards to accommodate the
greatest number of species, and by preserving and protecting the forest
fragments and wetlands that remain undeveloped, we can “build” an environment
that imitates those lost to urban sprawl and keeps bird biodiversity as high as
possible.
Sources:
Dawson, Dan and M. Hostetler. "Forest Remants: Conserving and Observing Bird Biodiversity in Urban Settings." 2010. EDIS. http://edis.ifas.ufl.edu/uw343
Fontana, Simone, T. Sattler, F. Bontdina, and M. Moretti. "How to Manage the Urban Green to Improve Bird Diversity and Community Structure." 2011. Elsevier; Landscape and Urban Planning: pp. 278-285. http://www.sciencedirect.com/science/article/pii/S0169204611000995
Often times urban landscapes can seem like an endless expanse of skyscrapers and other man-made materials, with a horrific lack of wildlife for as far as the eye can see. One burgeoning trend in building planning and renovating is trying to change that. The trend is that of “green” or “living” roofs. Basically a green roof is where vegetation is planted on building rooftops and allowed to grow. Green roofs aren’t a new idea; they have been around for hundreds of years. Sod roofs, as well as roofs made from other living and growing vegetation, were quite common in Norway (and other parts of Europe) in the 18th century.
The relatively
recent popularity of living roofs was started in Germany in the 1960s, and
while the United States has greatly embraced the practice of green roofing, it
is still most popular in Europe.
Photo Credit: City of Chicago
Photo Credit: City of Portland
One of the largest living roofs in the world is in Dearborn, Michigan at Ford Motor Company’s Rogue River Plant. Over 42,000 square meters are covered in sedum and other plants.
Photo Credit: Ford Motor Company
At this point you may be thinking: “Sure, plants on top of buildings seems like a good thing, but is it worth the effort?” The answer is that numerous studies have shown very interesting and important benefits of living roofs.
The Pros:
All over the world corporations, cities, and nations have begun dealing in what is termed the “carbon economy.” This involves many global entities trying to lower, and cap, carbon emissions. Within the new carbon economy, these entities buy and sell their shares of “carbon” to show how Eco-conscious they are and to make an effort to lower and control carbon emissions. This economy also involves taking preventative measures that do lower carbon emissions, or that can at least help to combat carbon emissions in different ways. Living roofs are one such way to combat carbon emissions. Living roofs help to mitigate the negative effects of buildings’ carbon footprint by recreating green space at the roof level. Healthy, growing vegetation on rooftops can help store and retain CO2 and other pollutants in urban environments. Simply storing carbon is an asset to an urban environment, but living roofs provide even more ecosystem services. Along with filtering air and pollutants, green roofs are fantastic for storm water management. The roofs are designed to filter and sometimes retain storm water. When the water is released the runoff is far cleaner than if it had come off a regular city roof.
Another benefit of green roofs is that they help to combat the Urban Heat Island Effect. Studies have shown that most common materials in cities (metals, concrete, cement, asphalt, ect.) absorb UV radiation and heat during the day and make cities up to 4ºC hotter than surrounding areas. Even after the sun has gone down these urban materials continue to radiate heat, so cities do not cool down at night as much as they naturally should. Large scale studies in Chicago and Washington D.C. have shown that the microclimates of green rooftops are as much as 4.4ºC cooler than traditionally roofed buildings. Researchers even went as far as to estimate that if all roofs in a major city were greened, urban temperatures could be reduced by as much as 7ºC. That is a large difference in temperature, and not only can it have a significant effect on human comfort and well-being, but it can drastically affect wildlife within cities and near city limits. Changing temperatures is not the only affect living roofs have on wildlife. In cities throughout the world green roofs have become vital stopovers for migrating and local birds. Living roofs can provide important feeding and nesting habitats for endangered and displaced birds and other wildlife. Providing habitats for animals within the city helps to raise biodiversity within a usually sparse, human-made and human-dominated landscape.
Photo Credit: Earth Pledge. Green Roofs: Ecological Design and Construction (Atglen, PA: Schiffer Publishing), p. 77. Crerar SB419.5.G76 2005
There is even a
special kind of living roof, often referred to as a brown roof, which helps to
increase biodiversity even more. Brown roofs are important because they
specifically support rare species of plants, invertebrates, and animals. They
are made by taking locally sourced material and covering the flat roofs of new
developments, in an effort to somewhat mitigate the habitat loss caused by the
developments. The original idea was to allow the roofs to self-colonize with
plants, but they are sometimes seeded to increase their biodiversity potential
in the short term. In the UK, many of the roofs are being colonized by spiders
and insects (many of which are becoming extremely rare in the UK, especially in
developed areas) and provide a feeding site for insectivorous birds.
The Cons:
Perhaps the
largest drawback to living roofs is the start up cost. Nearly any building
(including residential homes) can be given a living roof, but some need certain
renovations to make this happen, and even when a building does not need
renovations, initial costs of these roofs can be quite high. All of the
materials needed for a green roof are highlighted in the figure below, and they
average costing about $15 per square foot on a perfectly flat roof. Costs only
increase for slanted and more complex roof designs. Then there is also the
added cost of watering and maintenance of green roofs.
On the plus side, once installed most of
these roofs require very little maintenance. They usually only need to be
watered sparingly for the first year and never after that. Also, they generally
only need to be weeded 3-4 times a year, unless the roof is actually being
cultivated for gardening, which then it will have to be maintained as any
garden would. These roofs have even been shown to produce more economic
benefits than first imagined. The studies in Chicago and other major cities
discovered that living roofs are actually great insulators so in the winter
when it was cold the roofs helped to keep the buildings warm, and in the summer
they helped to keep the buildings cooler. The roofs turned out to have a rather
substantial positive effect on the cost of heating and cooling the buildings
they were on.
Another
interesting benefit was that living roofs actually help to extend the life of
the actual rooftops of buildings. Since soil, vegetation, and other living roof
matter cover the roof of the building, the materials that make the building’s
roof are actually protected from natural damaging processes such as UV
radiation and storms. Green roofs in Europe have been shown to last as long as
50 years, which is a lot longer than the average shingle roof lifespan of about
20, so longer roof life is just one more thing to offset installation and
maintenance costs.
Green roofs can do great things for biodiversity in developed areas and they are economical. They should be implemented by more architects and city planners in the future.
Public commentary focusing more on green roofs can be found here.
References:
Czemiel Berndtsson, J., Emilsson, T. and
Bengtsson, L., 2006 The influence of extensive vegetated roofs on runoff
water quality, Science of The Total Environment, Volume 355, Issues 1–3, Pages 48–63
Fehrenbacher, Jill, and Sarah Rich. "Worldchanging: Bright Green: The Week in Green Design (11/12/05): Green Roofs." Worldchanging: Bright Green: The Week in Green Design (11/12/05): Green Roofs. 13 Nov. 2005. Web. 16 May 2012. <http://www.worldchanging.com/archives/003738.html>.
Gill, S.E., J.F. Handley, A.R. Ennos and
S. Pauleit. “Adapting Cities for climate Change: The Role of the Green
Infrastructure.” Built Environment Vol 33 No. 1, page 122-123.
Grant, G., Engleback, L., and Nicholson, B., Green Roofs: their existing status and potential for conserving biodiversity in urban areas [Report No. 498], Publisher: English Nature Reports (2003)
The Wayne L. Morse United States Courthouse is a federal courthouse located in Eugene, Oregon. The
groundbreaking ceremony of the project was held on April 7th, 2004
and construction was completed in November 2006. The building was designed to
be sustainable, with features such as a highly efficient HVAC (Heating,
Cooling, And Ventilation), a lot of natural lighting, a landscape designed to
reduce rainwater runoff, as well as the use of drought-resistant plants, which
greatly reduce water use in irrigation. The Courthouse achieved LEED Gold
status by the U.S. Green Building Council and was the first U.S. Federal
Courthouse to do so.
Sustainability is often talked
about on the news, in our communities, and even in our classrooms, but many of
us don’t understand the true reasons that sustainability is an important part
of species conservation and biological diversity. The rate of species decline
has been increasing. Many of the reasons and actions tied to species decline
can be linked to human actions, such as habitat degradation, pollution, and
construction. Sustainable building is a method of construction that is designed
to reduce energy, materials used, as well as the impact that the building has
on the environment.
In an effort to reduce the further
decline of our environment, we must make an effort to reduce our need for
energy. The continual and excess use of energy forces the mining and burning of
fossil fuels in an effort to replenish the used energy. Burning fossil fuels
also leads to increased pollution, as the fossil fuels are burned they release
Carbon Dioxide into the atmosphere. While many different corporations are
implementing the use of renewable and green energy such as solar panels, wind
turbines, and hydropower there is still a lot that needs to happen in order to
reduce our impact on the environment in order to obtain energy.
Prior to the construction of the
Wayne L. Morse United States Courthouse, the materials of a demolished building
which previously stood on the construction site was 90% recycled. Recycling
materials and using them in the construction of a sustainable building not only
reduces the need for harvest of our finite resources, but also removes the
materials from landfills. Although construction companies attempt to minimize
the disturbance of their presence on an environment, there is always some level
of negative impact that is present. Conservation of biodiversity in the built
environment attempts to combat these factors by encouraging the timing of
construction to avoid sensitive times of the year such as breeding seasons for
present species. Construction sites should also be highly monitored in an
effort to prevent pollution to the areas surrounding the construction site.
Migratory birds fly long distances
during their migration. The migratory pattern of many bird species often cross
a few large cities, where many birds lose their life by flying into glass
windows in large buildings. The birds cant see the glass as a barrier, and
flying into a window at high speeds often leads to the birds death. It is
estimated that around 1 billion birds are killed in the U.S. from flying into
glass panels. More and more sustainable buildings are being made with bird-friendly glass, it is seemingly normal to the human eye, but allow birds
to recognize it as a barrier. The U.S. Green Building Council, which determines
the sustainability of buildings in the U.S., offers credit for bird friendly
constructed buildings.The design
of thebird-friendly windows was inspired by the construction of a spider web.
There
are many types of sustainable designs that aid in biodiversity. Some buildings
have been designing rooftop gardens, which aid in removing carbon dioxide from
the environment and return oxygen to the atmosphere. These rooftop gardens also
help to keep he building cool during warm months by evaporative cooling from
the plants. The gardens also provide aesthetically pleasing environment with
could be used for relaxation and stress relief. Fly ash is a product of coal
burning, which is often recycled and used in the manufacturing of cement; this
recycling process reduces the need to make more concrete from new materials.
Rainwater runoff is a large concern to conservation biologists. Rainwater runoff often
picks up harmful contaminants such as chemicals, plant fertilizers, and oil
from automobiles and deposits them into streams, rivers and oceans. These
contaminants cause habitat degradation, and loss of life to aquatic species of
plants and animals. In an effort to minimize this, sustainable buildings are
often designed to minimize water run off in order to prevent the spread of
pollution to clean environments.
The
construction of a new building often disrupts the living environment of
surrounding wildlife. Many sustainable buildings often attempt to create a
suitable living environment for the surrounding wildlife in an area around
them, in an effort to reduce habitat disturbance.
Human
beings as a species have had a much larger negative impact on the persistence
of other living species more than any other organism. Our expansion and
construction causes stress on the surrounding environment. Building requires
resources from rivers, forests, and mines, which removes ecosystem services
from the environment. Harvesting timber removes the trees as a converter of
carbon dioxide to oxygen. With a limited supply of freshwater on our planet,
the pressure to reduce water usage is something that impacts human beings, but
also effects aquatic habitats, which are already largely effected by our
harvest of ocean species and pollution. While the expansion of human beings further
into uninhabited wilderness may be unavoidable, it is important to make as
little of a negative impact on the environment as possible, if we continue to
build without thought to the environment, there will be little biodiversity
which leads to fewer ecosystem services provided. We depend on ecosystem
services to purify our air, water, and to provide materials and energy needed
to survive.
Brendan Bohannan was the first of a series of 3 lectures that focuses on the idea of Microbes and the Modern World. As the first lecturer, his main point was to introduce microorganisms and our perspective of them throughout time.
Dr. Bohannan’s main topic of
discussion dealt with this new perspective of microbes in the modern world. In
the old perspective, microbes were portrayed as scary creatures that caused
disease and harm to the human health and were insignificant to the Earth’s
diversity. But as we learn new things about the lifestyle of more and more
microorganisms, we are starting to realize that not all microbes are harmful,
and in fact a great deal of them are very helpful to us and allow us to live
the life that we do. Instead of looking at them as our enemies, they’re more
like our allies. And as we uncover more about our phylogenic tree of life, we
are realizing that microbe diversity isn’t at all insignificant but actually
extremely significant. As Dr. Bohannan mentioned, its almost as if microbes
contribute about 95% of Earth’s diversity while the insects and everything else
only makes up about 5% of the planet’s diversity all together. The second part
of the lecture, Dr. Bohannan dedicated to talking about how instead of microbes
harming us, it was more like we are harming them. He gave an example about how
methanotroph diversity is being depleted from soil because of the increase of
methane in the atmosphere due to human activity.
To get a little taste of his lecture, I have attached a link below:
On May 8th I attended a public lecture on indoor microbial diversity by Jessica Green of the University of Oregon (lecture series found here). One of my favorite take away points from the lecture was about the similarity between microbes found on plans and in outdoor air, and microbes found on humans and those found in filtered air. The connections made between the built environment and natural microbial diversity brought to light aspects I had not thought about before. The final video that was shown was also very intriguing. If we share so many microbes with those we are around the most, are they making up are identity more than our cells are? This makes me think of the nature versus nurture argument, does out nature, our cells, or nurture, our microbes, decide who we are. I am of the mind that it is a mixture of both, As more research is done, as with the roller derby team and their microbes, it will be interesting to see how similar our microbes are. I would think that the people I spend more time with, I share more microbes with, it is almost sentimental.
The studies done in hospitals with also be interesting to follow up on. I have always been of the mind that fresh air can sure just about anything, but when it comes to air born infectious disease this may not be the case. Rooms studied that used mechanical air filter systems had lower pollen count and lower microbial diversity. This means less good microbes as wall as less bad microbes. If it is possible to use the “architectural yogurt” in hospitals how would the way we look at microbes change? I agree that the benefits of microbes are often overlooked and changing how people view them is an important aspect on education.
If you found Jessica’s lecture interesting you should check out the episode “Guts” by WNYC’s Radiolab which can be found here.
