Georgia Invasives Case Study

Georgia Invasives Case Study

Invasive species are a concern all over the U.S. and all over the world. Some invasive species are well known such as Lionfish or Kudzu in parts of the U.S. However, there are a multitude of other invasive species that can be just as harmful to the surrounding ecosystem, even if they aren’t well known. It’s important to raise awareness of invasive species to help prevent their spread to new areas. This post covers three invasive species that can be found in the state of Georgia.

NOTE: All three species presented below have been identified in some quantity in Lullwater Preserve at Emory University.

Chinese Lespedeza (Lespedeza cuneata)

Lespedeza cuneata is a notoriously invasive perennial on the east coast of the United States, most often found in old fields or prairies (Schutzenhofer et al. 2009). The species was introduced from Asia deliberately in 1895 for use in erosion control and as a forage plant for wildlife (Schutzenhofer et al. 2009). The species became further widespread with the passing of the Surface Mining Control and Reclamation Act in 1977, which listed L. cuneata as one of the acceptable ground cover species for reclamation of old mining sites (Bauman et al. 2015).  Old mining sites are often unproductive landscapes and provide more value in spreading invasives than for colonizing native species (Bauman et al. 2015).

L. cuneata is a successful invader of a range of habitat types due to several characteristics that increase the tolerance of the species. The species has a high seed production rate and high dispersal potential, increasing in abundance more than 20 fold in a single year(Schutzenhofer et al. 2009, Kibis and Buyuktahtakin 2017).Another feature of its survival is the large seed bank created, in which seeds can survive for decades (Kibis and Buyuktahtakin 2017). Plants also have a heteromorphic flowering system, producing flowers that can reproduce asexually in addition to flowers that are insect pollinated, which helps to increase the chances of successful reproduction (Schutzenhofer et al. 2009). L. cuneataalso engages in several behaviors that promote its survival over similar native species, such as L. virgnica: these include, shading of other vegetation, allelopathy, resistance to herbivory, and a greater efficiency of light harvesting (Allred et al. 2010).

Approaches to management of L. cuneatadepend on a variety of factors, but in most cases, it is preferable to apply treatment within the first two years of establishment to prevent the building up a sizeable seed bank (Kibis and Buyuktahtakin 2017). The species is most vulnerable in the early stages of its life, but has low rates of natural herbivory in the wild and thrives in disturbed habitats, which makes management strategies such as plowing not useful (Schutzenhofer et al. 2009, Bauman et al. 2015). The most successful treatments are ones involving herbicide and frequent monitoring (Bauman et al. 2015).

Alligator Weed (Alternanthera philoxeroides)

             Aternanthera philoxeroidesis a perennial, clonal plant originally from South America that has spread as an invasive species across multiple countries, in both aquatic and terrestrial ecosystems (Wu et al. 2017b). Since it is so widespread, little is known about the exact time and origin of the species within the United States. The species can effectively spread from aquatic systems to terrestrial systems, which may have played a role in its introduction (Wu et al. 2017a).

A. philoxeroidesis a major threat to a number of ecosystems, especially rivers, waterways, wetlands and a number of crops ecosystems, in which it has been linked to declines in crop yields (Tanveer et al. 2018). The species is fast growing, doubling its growth in less than two months and forming dense masses of underground root systems (Tanveer et al. 2018). Aquatic systems are more vulnerable to invasion by A. philoxeroides,but climate change is likely to increase the spread of the species onto land and to higher latitudes (Wu et al. 2017a, Wu et al. 2017b). The species reproduces vegetatively with efficient dispersal via stem fragmentation, and its high genetic variability allows it to occupy a number of niches enhancing its survival (Tanveer et al. 2018).A. philoxeroides inhibits other species through allelopathy and a greater ability to photosynthesize and capture water (Wu et al. 2017b, Tanveer et al. 2018). Its clonal integration also increases its competitive ability against natives and other species present in the habitat (You et al. 2016).

Management practices of this species are numerous, widespread and costly. China alone spends $72 million per year to manage its spread (Tanveer et al. 2018). Practices include physical removal, such as excavating roots, chemical management through herbicide use over a number of years, and biological control(Tanveer et al. 2018). The beetle, Agasicles hygrophila, has been shown to be successful in managing A. philoxeroidesand is used as a management practice in many countries (Tanveer et al. 2018).

Common Periwinkle (Vinca minor)

             Vinca minor is an evergreen vine originating from parts of Eurasia (Schulz and Thelen 2000). It is an edge forest species that was commonly used as a decorative plant (Panasenko and Anishchenko 2018). This particular type of periwinkle was introduced at the end of the 19thcentury, especially for its use as ground cover and an edge species in parks and other green spaces(Panasenko and Anishchenko 2018).

V. minor spreads prolifically through vegetative propagation and can form extensive curtains of vines when not controlled (Panasenko and Anishchenko 2018). The species thrives best in forest ecosystems such as pine forests, where it has been shown to greatly reduce forest biodiversity (Panasenko and Anishchenko 2018). Unlike other plants, V. minor grows well in shady regions helping to increase its spread into established forest ecosystems (Tatina 2015). It has been shown to exhibit high allelopathy to the point of inhibiting seed germination of neighboring species, which has greatly aided its survival in otherwise highly diverse forest ecosystems (Panasenko and Anishchenko 2018).

As a relatively new invasive species that has yet to cause the widespread removal efforts of more imposing species such as lespedeza and alligator weed, there is limited research on the successful removal and management of V. minor. The management practice of combined cutting and herbicide applications has been shown to be moderately effective, but further research into more aggressive means of management will be necessary as this species continues to spread and threaten diversity in forest ecosystems (Schulz and Thelen 2000). Herbicide impacts on surrounding native species is a concern in the management of periwinkle (Tatina 2015).

Works Cited

Allred, B. W., S. D. Fuhlendorf, T. A. Monaco, and R. E. Will. 2010. Morphological and physiological traits in the success of the invasive plant Lespedeza cuneata. Biological Invasions 12:739-749.

Bauman, J. M., C. Cochran, J. Chapman, and K. Gilland. 2015. Plant community development following restoration treatments on a legacy reclaimed mine site. Ecological Engineering 83:521-528.

Kibis, E. Y., and I. E. Buyuktahtakin. 2017. Optimizing invasive species management: A mixed-integer linear programming approach. European Journal of Operational Research 259:308-321.

Panasenko, N. N., and L. N. Anishchenko. 2018. Influence of Invasive Plants Parthenocissus vitacea and Vinca minor on Biodiversity Indices of Forest Communities. Contemporary Problems of Ecology 11:614-623.

Schulz, K., and C. Thelen. 2000. Impact and control of Vinca minor L. in an Illinois forest preserve (USA). Natural Areas Journal 20:189-196.

Schutzenhofer, M. R., T. J. Valone, and T. M. Knight. 2009. Herbivory and population dynamics of invasive and native Lespedeza. Oecologia 161:57-66.

Tanveer, A., H. H. Ali, S. Manalil, A. Raza, and B. S. Chauhan. 2018. Eco-Biology and Management of Alligator Weed Alternanthera philoxeroides) (Mart.) Griseb. : a Review. Wetlands 38:1067-1079.

Tatina, R. 2015. Effects on Trillium recurvatum, a Michigan Threatened Species, of Applying Glyphosate to Control Vinca minor. Natural Areas Journal 35:465-467.

Wu, H., J. Carrillo, and J. Q. Ding. 2017a. Species diversity and environmental determinants of aquatic and terrestrial communities invaded by Alternanthera philoxeroides. Science of the Total Environment 581:666-675.

Wu, H., M. Ismail, and J. Q. Ding. 2017b. Global warming increases the interspecific competitiveness of the invasive plant alligator weed, Alternanthera philoxeroides. Science of the Total Environment 575:1415-1422.

You, W. H., C. M. Han, L. X. Fang, and D. L. Du. 2016. Propagule Pressure, Habitat Conditions and Clonal Integration Influence the Establishment and Growth of an Invasive Clonal Plant, Alternanthera philoxeroides. Frontiers in Plant Science 7:11.

Science… Only Part of the Equation

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Category : Environment Blog

Every year, 2.7 million people die as a result of ambient, or outdoor, pollution. An even more astonishing fact is that close to double that number die from indoor air pollution.

photo from:

Photo of Professor Saikawa from:

This tragedy is the foundation of Emory University Professor Eri Saikawa’s research. I had the pleasure of interviewing her recently to discuss her work.

Professor Saikawa originally started her career as a modeler, studying the relationship between pollution and ambient emissions. When she learned that negative effects from indoor pollution are much worse than ambient, she wanted to explore it herself. She began a research project to study the impact of burning yak dung as a fuel for heating and cooking in Tibetan households.

Have you ever thought of culture as being an integral part of scientific research? It is what makes her work “interesting but challenging,” Saikawa says.

This study produced fascinating scientific results, and it also revealed a different side of science and the impact that culture can have. Science showed that purchasing chimneys, using alternative fuel sources, and improving ventilation would all help to decrease harmful indoor emissions in Tibetan households, but no one wanted to do it. Why? Culture.

Tibetans have been using yak dung as a fuel source for generations. Saikawa described that many families were aware of pollution within their homes but were not worried about the health impacts.

People often relate ambient pollution to its contribution to climate change, and Tibetans are very worried about climate change. There is a snowy mountain peak that the Tibetan people consider holy. They watch fearfully as the snow recedes further each year and disappears.

However, indoor pollution is a more serious and immediate issue for them than climate change. It is a problem of human health, and as a result should receive very different attention.

Photo by Qingyang Xiao

Photo of Tibetan household by Qingyang Xiao

Professor Saikawa described how one of her biggest challenges was getting the Tibetans to “perceive the environmental risk and see it as a problem.” Unlike the very visible cue of the mountain losing its snow, the impacts of indoor air pollution are not as easy for people to recognize as a problem.

In general, healthcare is not well promoted. When Professor Saikawa visited Tibet, she noted that the nearest healthcare facility was an hour drive from the rural villages. The people did not view it necessary to spend their time going to get healthcare.

The health risk caused by breathing in emissions from burning yak dung in their homes without proper exhausts and ventilation is immediate. In other countries having similar indoor air quality problems, scientists went in with fancy chimney and stoves but they have gone unused. People simply continued in the same ways they always had.

In addition to overseeing the research, Professor Saikawa has to balance her personal views of the situation with how Tibetans think and act. The difficulty resides in how much responsibility we have over the situation. It is important to protect people from negatives health effects while still respecting their culture.

In situations like these, it is not enough to rely on the science of the issue. Saikawa described this as one of the main problems facing the scientific community. She described her experience in Tibet as very positive and eye opening to their way of life and how “you can only understand how people live by going through what they do.” A good lesson for all of us!

Want to learn more about Professor Saikawa’s research? Check out this article on Emory’s eScience Commons:

Or read the full research article here:

The Water Cycle- Reclaimed


Prior to spring of 2015, Emory used about 1 million gallons of potable water every day, with nearly half of that put toward mechanical uses like heating and cooling. That’s a lot of drinkable water wasted—especially when California is experiencing a major drought and the Tri-State Water Wars are happening right here in Georgia.


WaterHub logo photo I took during my visit

What changed in 2015? Emory’s multi-award winning facility WaterHub began operation. WaterHub reduced potable water usage 40% on campus by recycling wastewater, providing an alternative source of water for use in mechanical systems. This facility provides an important role in reusing and reclaiming water.

The WaterHub is a triple win. Water entering the hub is routed directly from sewer lines, helping to reduce stress on wastewater treatment plants. Emory pays for the recycled water that is produced, generating profits to support the facility while saving money compared to water costs from other sources. The environment is the third beneficiary!

Let’s explore the process that creates such benefits!


Imagine the water you find in a sewer. It’s pretty gross right? The WaterHub process removes all the gross and leaves the water looking clean. A lot of your gross vision of sewer water was due to visible contaminants, most of which is some form of solid waste. Screening devices filter out those solids, and the cleaner—but probably still very discolored water—moves on to the next phase of the process.



Diagram of the Bio-Reactors at the WaterHub facility

The wastewater flows through a series of moving bed bioreactors (or MBBR for short). These four tanks contain small plastic discs with holes, designed to provide the largest amount of surface area possible. Microbes grow on these plastic pieces, and they remove small contaminants and chemicals from the water.

Surface area, surface area, surface area! That is a mantra you hear over and over in wastewater treatment. The greater the surface area, the bigger the number of microbes present, and the larger the amount of contaminants removed from a volume of water. The design of this system allows 400,000 gallons of water to be cleaned every day!



The “greenhouse” of the WaterHub. Photo taken during my visit.

The next component is the hydroponic system, which makes a visit to the WaterHub feel like a greenhouse stroll. The water tanks are housed underneath a variety of green plants, allowing their roots to extend into the water. These root systems contribute a lot of surface area and provide a great habitat for microbe growth.





Example of the reciprocating wetlands at the WaterHub

Emory’s WaterHub is especially unique because it is actually two different water treatment systems. The greenhouse with the MBBR is the main one processing most of the water. A second smaller unit called the reciprocating wetlands cleans around 1200 gallons of water each day.

Unlike the main system, the wetlands are outside and grow a different variety of plants. The plants still provide lots of surface area for microbial growth, but instead of continuous mixing like in the MBBR, the wetlands employ the concept of tides. There are two main basins using a series of 18 tides per day to move water throughout the process.


After passing through one of these systems, most of the large-particulate contaminants have been removed. Water then travels very slowly through a clarifier to filter out fine particles with the help of chemical treatment. And next through a disc filter to remove the smallest particles.

The water now passes the government’s test for being re-use quality! Just to be sure, the water moves through one last series of tanks where it is exposed to UV light, making it ultra clean.

The WaterHub’s state-of-the-art techniques create a huge difference in water usage at Emory! Every day, thousands of gallons of drinking water are saved from the fate of being used for operating mechanical systems. All thanks to reclaimed water that is distributed to campus for the steam and chiller plants, and even to residence halls for toilet flushing.

Recent news: the WaterHub team is exploring possibilities to expand the project to new sites and to apply the technology for other uses. For example, Matt, the senior project manager who led our great tour, described how the reciprocating wetlands model could be used in developing countries as an effective but cheaper wastewater treatment mechanism.

Check out plans and policies to advance sustainable water use at this government site:

Eager to learn more about the WaterHub? Visit its website explore the benefits and responsibilities of the WaterHub by clicking on an icon below.


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Energy Be(a)ware!

energy \ˈe-nər-jē\ noun  1a. ability to be active. b. the physical or mental strength that allows you to do things.
 2a. natural enthusiasm and effort.
 3a. usable power that comes from heat, electricity, etc.

You can look up the definition of energy but that doesn’t mean you entirely understand what it is and what contributes to it. And I don’t mean energy from eating healthy or getting a good night of sleep. I am talking about definition 3a.

Do you know where the energy that powers your home comes from?

Are you aware of how much energy that load of laundry really uses?

If not, then now is the perfect time to learn!

Why? October is National Energy Awareness Month.

If you are one of those people who needs an excuse to get active in sustainability issues, use this time to challenge yourself to make a change going forward. It’s never too late to start saving energy!

More information of the designation of energy awareness month can be found here:

What is the point of Energy Awareness Month?

While there are many residential communities, college campuses, workspaces and others who are working hard to reduce their energy consumption, the world is still burning fossil fuels at astronomical rates to meet energy demands, which continue to increase steadily.

The U.S. has only 5% of the world’s population, yet it consumes 5x as much energy—nearly 25% of world energy usage.

People are aware of renewable energy. But when put to the task, it seems the everyday citizen views the battle with energy consumption as taking place outside of their reality. They are wrong—There are many ways for individuals to reduce their energy usage on a daily basis, and it isn’t that difficult to do.

Energy Awareness Month definitely promotes large-scale energy projects, but also serves to educate the everyday consumer and make energy awareness more accessible.

Quick energy use statistics

What effect do people have on energy usage? Check out these energy stats on common practices:

  • Energy used by devices left on standby—computers, printers,…—account for 5-10% of the total electricity used in residential homes, and contributes to about 1% of the world’s carbon dioxide emissions. (Lawrence Berkeley National Laboratory)
  • Only 5% of the power drawn by a phone charger is used to charge the phone. The other 95% is wasted when your phone is left plugged in.
  • Turning off unneeded lights could remove 376 lb of CO2 emissions per year. (Energy Saving Trust)
  • Lighting a typical office overnight wastes enough energy to heat water for 1,000 cups of tea. (The Carbon Trust)
  • 90% of the total energy used by a typical washing machine is used just to heat the water. (Energy Saving Trust) Cold water wash is the best way to do your laundry!

Other fun facts can be found here:

Who can be involved in Energy Awareness Month?

One of the goals of Energy Awareness month is to make energy consumption issues more accessible for common consumers so everyone can participate!

Whether you want to be a lone warrior for the energy cause or you want to put together a team of energy savers in your school, workplace or home. Energy Awareness Month is a great incentive for you!

Many places establish a calendar of events and efforts specifically for this month, but you can build off these ideas at any time of the year—for school community service projects, office team-building events, even your New Year’s resolutions.

Emory University held an energy competition (read about it below).

Even the White House is getting involved! Specifically for this month, the Obama administration organized several clean energy events. You can learn more about White House efforts here:

Emory University- Campus efforts for Energy Awareness Month

Every year, Emory holds a competition during Energy Awareness Month to see who can reduce their energy consumption the most. Residence halls, classrooms and labs all participate in the competition, and for extra motivation, the grand prize is $1000! The competition setting is a fun way to get students involved and interested in energy issues. As the Sustainability Chair for my residence hall, I had many people asking me for tips on how they can reduce their energy consumption! By raising awareness now, we can work towards even more energy reduction in future campus events!

Another program for Emory students during Energy Awareness Month is No Power Hour, when dorms set a time for everyone to unplug their electronics and leave their residence hall to play games and socialize on the quad, all while saving energy! This gives students a fun example of ways they can reduce energy and is a very visible program to spread awareness throughout campus.

How can you decrease your energy consumption?

Hopefully, you have heard something here and want to get involved! Still not sure what you can do? Check out these helpful tips below:

  • Turn off your computer at night.
  • Unplug device chargers when not in use.
  • Adjust temperatures for air conditioning and heating when not at home.
  • Wash laundry when you have a full load, using cold water.
  • Take the stairs instead of the elevator.
  • Run your dishwasher with a full load or wash them by hand.
  • Don’t leave water running unnecessarily.
  • Turn off lights when you leave the room.
  • Use natural light whenever possible.

Do you have a great idea of how to decrease energy consumption or spread energy awareness to those who might not know? Please share your ideas!  

Remember, it’s never too late to save energy… Start now!

Emory’s Carbon Footprint


Sustainability is a buzzword in today’s society, and Emory University is a national leader among college campuses. However, arriving on campus and seeing a compost bin for the first time can be a little daunting for some first-year students. Being unaware of its toll, new students often take the elevator up and down when they could use the stairs in their dorm instead.

While I am thrilled that I have joined this community and enjoy being part of the sustainability movement, some first-years might feel a little overwhelmed. It is very important to educate students so they can understand and appreciate the sustainability initiatives on campus. I learned more about the program and Emory’s future goals from Kelly O’Day Weisinger, a coordinator with Emory’s Office of Sustainability, who presented on the university’s Climate Action Plan.

Emory’s first strategic plan in 2005 enacted steps to decrease energy and water use, and reduce carbon emissions and landfill waste. Even with those efforts, the reality today is that Emory still has a relatively large carbon footprint (~354,762 metric tons CO2 per year).



Luckily, Emory’s footprint has stayed fairly constant over the past few years despite increases in campus square footage and a growing student population. Changes in transportation—for example, shuttle buses that run on biofuels produced on campus—helped a lot, decreasing emissions 3% from 2005 to 2010.


Purchased electricity is responsible for the largest portion of Emory’s footprint totaling 55% of emissions in 2010. A lot of this is unfortunately because Georgia Power runs off coal and natural gas. The graph shows emissions from power are declining, but decreasing energy consumption continues to be a large issue on campus. I believe that pursuing alternative energy sources would be a great way to help achieve that goal. One suggestion is more power obtained from solar energy by expanding facilities on campus.

What is the most surprising part of Emory’s profile? The source of emissions that unfortunately increases annually is the contribution by students and faculty. Commuting, travel, and landfill waste are big examples of direct impacts that we have on Emory’s carbon footprint.

climateiconA new Climate Action Plan established last year with the help of students and faculty has set major goals towards reducing Emory’s impact on the environment, projecting a 20% reduction in overall carbon emissions by 2020 and shooting for 50% by 2050. Specific goals include reducing energy use by 50% per square foot, sourcing 75% of food locally or from sustainable means, and diverting 95% of wastes from landfills.


One of the things that stands out to me is how accessible sustainability is on campus. Through a combination of research, teaching, and community outreach, the Office of Sustainability Initiatives works to address issues that are within everyone’s reach.

recyclingiconStudents and faculty who have been at Emory for a while are pretty experienced on how to incorporate sustainable practices into their lives. However, one area that could use improvement is communication with the first-year class, especially considering that students come from such different experiences and not everyone knows about sustainable living.


I believe students are interested in sustainability but often just don’t know where to begin. Increased efforts to educate first-year students about sustainable practices—like hosting zero-waste events, taking shorter showers, and decreasing energy consumption from electronics—would be a great way to cut back on Emory’s footprint. Faculty and commuters can help decrease emissions by carpooling. Raising awareness, teaching practical methods, and encouraging students to be more accountable would start them on the right path for their four years on campus. An introduction to sustainability for new students can be found here:

To learn more about each of the sustainability practices mentioned in this blog click on the icon featuring the topic you wish to explore. Find general information on sustainability at Emory here: