The Functional Role of Biodiversity

Biodiversity is broadly defined as the “degree of variation of life.” Biodiversity arguably adds great intrinsic value to our planet, but biodiversity is also important because it’s indicative of ecosystem health, function, and service. For example, high levels of biodiversity can point to a resilience from disturbance, presence of complex wildlife habitat, and effective air and water purification. Tilman (2014) summarized 100 biological studies and found that biodiversity was positively correlated with productivity, indicating a strong relationship between biota and ecosystem processes. Because of the strong connection between wildlife and our environment and natural resources, changes in biodiversity frequently lead to shifts in ecosystem processes and services that we all rely on. Focus on biodiversity therefore is vital for promoting a healthy human population and world.

Biodiversity is most commonly measured and discussed using taxonomic diversity (e.g., species identity), however, there are several other ways biodiversity can be assessed. One such axis is functional diversity. A variety of functional categorizations have been used such as behavioral habits (e.g., activity mode; Merritt, 2008), morphological features (e.g., body size; Hein, Hou & Gillooly, 2012), habitat occupation (e.g., littoral zone), life history traits (e.g., reproduction events per year; Olden, Poff & Bestgen, 2006), and feeding groups (EPA, 2014). Overall, this trait-based research focus came about as ecologists realized that not all species affect ecosystem processes equally or in the same manner; therefore, attention to what species do ecologically, instead of simply what species are taxonomically, has become a key component of biodiversity studies.

Such functional assessments can capture features of the biotic assemblage that would not be acknowledged with only taxonomic evaluations (Giller et al., 2004; Setala, 2002). Functional diversity has offered various benefits for researching specific aspects of community investigation, including assemblage structure and composition, chemical breakdown and accumulation, and non-native invasion. For example, assessing functional diversity of fishes according to their feeding groups (e.g., piscivore, insectivore, parasite, etc. [EPA, 2014]), such as shown in Figure 1 can indicate level of competition, resource availability, niche availability, and habitat characteristics. When assessing the degree of variation of life, unique axes of assessing organisms and plants, such as functional diversity, can give unique and informative insights of the community which lead to effective investigations of biotic communities.

Figure 1. Examples of Lake Erie fish species categorized according to their functional feeding groups: Bowfin (Amia calva) Piscivore; Pumpkinseed Sunfish (Lepomis gibbosus) Insectivore; American Brook Lamprey (Lampetra appendix) Parasite; White Sucker (Catostomus commersonii) Omnivore.


EPA. 2014. 2014 Updates to Biological Criteria for the Protection of Aquatic Life. In: Users Manual for Biological Field Assessment of Ohio Surface Waters. Ohio Environment Protection Agency: Division of Surface Water.

Giller P.S., Hillebrand H., Berninger U.G., Gessner M.O., Hawkins S., Inchausti P., Inglis C., Leslie H., Malmqvist B., Monaghan M.T., Morin P.J. & O'mullan G. 2004. Biodiversity effects on ecosystem functioning: emerging issues and their experimental test in aquatic environments. Oikos, 104, 423-436.

Hein A.M., Hou C. & Gillooly J.F. 2012. Energetic and biomechanical constraints on animal migration distance. Ecology Letters, 15, 104-110.

Merritt R.W., K. W. Cummins, and M. B. Berg (Editors). 2008. An introduction to the aquatic insects of North America, Kendall/Hunt Publishing Company, Dubuque, Iowa

Olden J.D., Poff N.L. & Bestgen K.R. 2006. Life-history strategies predict fish invasions and extirpations in the Colorado River Basin. Ecological Monographs, 76, 25-40.

Setala H. 2002. Sensitivity of ecosystem functioning to changes in trophic structure, functional group composition and species diversity in belowground food webs. Ecological Research, 17, 207-215.

Tilman D. 2014. Biodiversity and Ecosystem Functioning: Annual Review of Ecology Evolution and Systematics. (Ed I. Forest), pp. 471-493. Annual Review of Ecology, Evolution, and Systematics.

-- Jenna Odegard, Wildlife Specialist

Unseasonal Weather Triggers Unseasonal Activities in Ohio

For those of you reading in Ohio and a good portion of the Midwest, you know that this has been one strange winter. While the average temperature this time of year (historically) is 40.8⁰F, we've recently traded our winter coats and gloves for light layers and even short-sleeved shirts, with temperatures in the mid-high 60's! This stretch of warm weather has many of us feeling like spring has sprung in February instead of April. And we're not the only ones confused by this warm spell. Several spring ephemeral species, such as Spring Beauty (Claytonia virginica), False Mermaid Weed (Floerkea proserpinacoides), and Harbinger-of-Spring (Erigenia bulbosa), have started pushing through the leaf litter. These plants typically don't emerge until late-March and begin blooming in April, when ambient temperatures exceed 50⁰F. This is timed so that native pollinators will be out looking for pollen and nectar when the blooms appear. The potential temporal disconnect between pollen-producers and their pollinators is one concern that ecologists have regarding our changing climate.

Harbinger-of-Spring and Spring Beauty starts photographed in Hamilton County by Daniel Boone on February 11, 2017. Daniel reported seeing Spring Beauty in bloom February 23, 2017.

Skunk Cabbage (Symplocarpus foetidus) in bloom. Photographed by Jenny Adkins in a Crawford County vernal pool on February 22, 2017.

In addition to early-sprouting plants, many amphibian species have been spotted on their annual migrations towards vernal pools and wetlands throughout the state and region. MAD Scientist Associates field teams have observed Jefferson Salamanders (Ambystoma jeffersonianum), Northern Dusky Salamanders (Desmognathus fuscus), Redback Salamanders (Plethodon cinereus), Wood Frogs (Lithobates sylvatica), Spring Peepers (Pseudacris crucifer crucifer), and Western Chorus Frogs (Pseuadcris triseriata). Many of these species have been known to emerge from their subterranean burrows and begin their journey to a breeding pool by late-February, however, they're used to much cooler temperatures during this mating trek.

Western Chorus Frog (likely a male), retrieved from a Crawford County vernal pool by Mark Dilley, February 22, 2017. These frogs often call in tandem with Spring Peepers and even look similar. They can be distinguished by the dark band extending from their nose to their abdomen.

Red eft, the terrestrial juvenile form of the Red-Spotted Newt, photographed by Aaron Laver in Vinton County, February 23, 2017.

Two varieties of the lungless Redback Salamander. On the left is the red-striped phase, and the right, the leadback phase. Both found near a Crawford County vernal pool by Daniel DeBruler, February 22, 2017.

One of many Jefferson Salamanders (this one is a male), photographed by Aaron Laver near a Vinton County vernal pool on January 19, 2017.

Year to date weather records for Columbus, Ohio, from NOAA.

Research is unclear on the effects of mild winters regarding reproductive success and mortality of adult and larval amphibians. One study found that mild winters had positive effects on hibernating adults, such as limited change in body mass (Üveges et. al., 2016). Other studies suggest that adequate precipitation is a more important factor in survivorship than temperatures (Ficetola and Maiorano, 2016). Based on the year to date information collected by the National Oceanic and Atmospheric Administration (NOAA) for Columbus, Ohio, we are unseasonably warm, but right on point with expected precipitation. Hopefully we continue to see rain accompanying these temperatures for the sake of our native amphibians venturing out for early spring activities!



Ficetola, G.F. & Maiorano, L. (2016) Contrasting effects of temperature and precipitation change on amphibian phenology, abundance and performance. Oecologia. 181: 683. doi:10.1007/s00442-016-3610-9

National Oceanic and Atmospheric Administration. (2017, February 24, 2017) Year to date graph for Columbus, Ohio. Retrieved from:

Üveges, B., Mahr, K., Szederkényi, M., Bókony, V., Hoi, H., & Hettyey, A. (2016). Experimental evidence for beneficial effects of projected climate change on hibernating amphibians. Scientific Reports6, 26754.

-- Jenny Adkins, Botany Specialist

MAD staff help Environmental Science students put GIS mapping into action

In March of this year, MAD Scientist Associates was approached by Chad Schwinnen and Ali Laughbaum of the New Albany High School (N.A.H.S.) Environmental Science Program to discuss the feasibility of graphically cataloguing (i.e. mapping) the natural resources located in and around the school campus. If such an endeavor were to gain enough momentum and support, this initiative would serve as the first of many phases to holistically develop a Land Management Plan for the campus and its surrounding natural areas.

In order to be successful on all fronts, the mapping effort would need to integrate sound scientific prowess while providing a gateway for student education and development. In other words: MAD and N.A.H.S. sought to develop a plan that not only had real-world applications, but also presented opportunities to teach students real-world skills—skills that are often used in the field of environmental science. If this could be successfully accomplished, efforts could go beyond the education opportunities. The maps produced during the effort could later be used to develop land management strategies and secure funding for future land enhancement projects, thus providing a gateway for environmental education and habitat enhancement to continue for years to come. The school would be well on its way toward providing students with an improved eco-learning space while simultaneously giving students a first-person view of the world as an environmental professional. As one could guess, such a plan would require a great amount of student involvement in the data collection and mapping process, and so the team began to develop a plan that would fit the bill.

MAD kicked off the campaign by having their GIS Specialist, Aaron Laver, conduct training sessions for the program’s students and staff. The focus of these sessions was to provide students with the appropriate tools and knowledge to conduct as much of the collection and mapping work on their own as possible. In addition to technical, hands-on exercises where students learned how to operate GPS units and mapping applications, the sessions were intended to help the students realize the importance of their role in the land management process. Aaron covered the fundamentals of data collection, demonstrated how data collection relates to the world of natural resources, and stressed the importance of precision and accuracy when conducting GPS activities. 

With the training under their belt, exceptional Environmental Science Program leadership in place, and a motivation to dive into “something real” that could be used for years into the future, students at N.A.H.S. now had all the tools and resources necessary to begin changing their campus for the better. Under the leadership of Ali, Chad, and retired Environmental Science teacher Bill Somerlot, the students began, and have just recently completed, the first of two large-scale mapping events. Using MAD’s training and professional-grade GPS units in the field, the students have logged more than 21,000 GPS positions and generated over 1,400 features—all of which locate and describe the campus’s natural resources. Students are currently in the process of using this data to develop an informative catalog of geographically represented features, such as trails, streams, large-diameter trees, and wildlife habitat. 

MAD’s Education Specialist and Botanist, Jenny Adkins, will visit New Albany in a few weeks to kick off the program’s second large-scale mapping event. Here, she’ll venture out into the field with students to identify priority resources and fine-tune the mapping efforts, enabling students to effectively and efficiently put a close to their field activity in the mapping phase. Following the second event, the students should have everything they need to develop an accurate and informative graphical representation of the campus natural resources. 

So where does all of this fit into the grand scheme of things? As of now, the Land Management Plan is in a constant state of evolution, and we aren’t sure how it’s going to pan out in the long run. However, what we DO know is that once the data has been collected, maps have been made, and students have had a healthy dose of the environmental field life—the Environmental Science Program efforts will have set the stage for positive ecosystem change within their community, provided stakeholders with an accurate readout of the natural resources at their doorstep, and empowered more than 130 students to change their community for the better, which is something impossible to ignore. 

Maps are like campfires — everyone gathers around them...
― Sonoma Ecology Center, GIS/IS Program Web Site

-- Aaron Laver, GIS and Water Resources Specialist

Part 2 of a 3-Part Series: Phosphorus in the Environment: The Great Water Resource Threat

Conceptual diagram comparing a healthy system with no or low eutrophic condition to an unhealthy system exhibiting eutrophic symptoms. From Bricker et al., 2007. 

As discussed in our last blog post, Phosphorus in the Environment: Conception, Cycling, and Fate in an Ecosystem, the greatest mechanisms for Phosphorus (P) loss from an ecosystem are erosion and run-off. Once lost from an ecosystem, where does it go? What is the fate of this lost P and what does it mean for Ohio and its waterways if the P makes its way to a stream or lake?

Once in water, the P is generally bound to sediment, which means that it is not readily available for use by plants and microbes. Some of the P, however, is dissolved in water and ready for biological uptake. The P ready for uptake is often called bioavailable P (BAP). BAP provides necessary nutrients for waterborne plants and microbes to grow. When there is too much BAP for plants (water willow, cattail, duckweed, etc.) to utilize, algae and other microorganisms will proliferate due to the excess nutrients that are readily available. This hyper-enriched condition is referred to as eutrophic, and the process of its formation is eutrophication.

Algae thrives in water with high nutrient content, warm conditions, and moderate sunlight. Under normal circumstances, algae is consumed by grazers (macroinvertebrates and fish). These grazers are in turn consumed by predatory fish, many of which are valued as “sport fish.” In this way, algae makes up an invaluable part of the food chain in many waters as a primary producer. There are, however, many kinds of algae with varied modes of survival. As you could probably guess, different species of algae thrive under specific environmental conditions. Under most circumstances, available nitrogen (N) is far more prevalent in ecosystems than BAP, and therefore it is common to have high N:P ratios in plants, soil, and water. Most microorganisms have specific N:P ratios similar in magnitude to the ecosystems in which they thrive. Green algae, the stringy algae with which most people are familiar, has a relatively high N:P ratio and is likely to dominate in most environments. However, with high P inputs from surrounding areas, the N:P ratio tends to decrease, favoring microorganisms with lower N:P ratios (typically lower than 10:1) or organisms that are more competitive for N.

One kind of algae, cyanobacteria (the blue-green algae), can fix nitrogen (N), meaning it can pull N from the atmosphere and turn it into a form usable for itself. This gives cyanobacteria an advantage in those environments with lower N:P ratios because they can counter-balance the excess of BAP. Once cyanobacteria-laden waters receive an excess of BAP due to inputs from surrounding lands, the cyanobacteria can dominate the system and the grazers that consume the algae simply cannot keep up. This is the beginning of a blue-green algae bloom. Once algae begins to bloom, it quickly outcompetes other waterborne microorganisms because of the thick mats they tend to form. Algae often covers entire ponds and streams from bank to bank. Once covered, algae has preferential access to nutrients, sunlight, and even physical space. Additionally, a byproduct of cyanobacteria is a set of compounds called cyanotoxins. These toxins are what turn algal blooms into harmful algal blooms (HABs).

There are many different compounds exuded, and some target a number of different human organs. Microcystins are the main group of compounds used to determine if cyanotoxins are present. These compounds were measured at levels found to be harmful to humans in 2014 in Lake Erie near Toledo, OH. Cyanotoxins can cause liver damage, contact dermatitis, and gastro-intestinal illness. Additional effects are likely to occur, but these have not been well studied. Cyanobacteria in a bloom eventually reach a point in the season when resources, length of daylight, or drops in temperature cause a dieback. The bloom recedes and much of the bacteria die or go into a suspended state forming a cyst which lies in the sediment until conditions are favorable again.

The large, now dead, algal mats left over from the bloom continue to have consequences on water quality long after the bloom has subsided. Like any digestive process, the decomposition of these algal mats by aerobic bacteria requires a large amount of oxygen, creating what is known as a biologic oxygen demand (BOD). Since aerobic bacteria require oxygen to decompose the algae, dissolved oxygen (DO) concentrations can be depleted to levels far below the 2 parts per million (ppm) minimum needed for many macroinvertebrates and fish to survive. This consequence of eutrophication, is a common cause of fish kills around the country. These effects can occur naturally, but are often exacerbated by anthropogenic inputs of nutrients (fertilizers, sediment disturbance, etc.) into these aquatic systems.

It takes time for balance to return to an ecosystem after a large bloom. Often, water flow and dropping temperatures eventually raise DO to a point where populations of macroinvertebrates, fish, and other heterotrophic organisms can recover. If HABs are patchy and more widely distributed, this can occur within 6 months. However, if the HABs are relatively ubiquitous throughout the lake or stream, population recovery could be slow, since fish and macroinvertebrates will need to migrate in from further away. Recovery of these systems can be slow, but nearby, healthy, and resilient systems can help to ensure the eventual recovery of even highly impaired water bodies.

Although aquatic systems can improve after becoming eutrophic, protecting our lakes and streams from eutrophication is critically important.  How do we prevent HABs in our aquatic systems, and avoid the associated loss of ecologic function and human and animal health risks? What can be done to limit the frequency and severity of HABs? In our next blog, we will discuss what we, as stewards of the land, can do to keep phosphorus where it belongs: in the soil and not in our waterways!  Watch for this in another few weeks!

For additional information on HABs see the Ohio EPA HAB webpage, the Army Corps of Engineers HAB webpage, or the National Oceanic and Atmospheric Administration Great Lakes Environmental Research Laboratory webpage.


Part 1 of a 3-part series: Phosphorus in the Environment: Conception, Cycling, and Fate in an Ecosystem

By now, most of us have heard about at least one water quality crisis within the country. These events receive especially abundant media attention whenever water quality reaches a point where citizens can no longer utilize their nearby water source. Recently, two events in particular have generated substantial amounts of press: Lead contamination of Flint, MI, and harmful algal blooms in Toledo, OH. The latter of these two events is the result of excessive nutrient loading. But what does that mean? From a dietary perspective, aren’t nutrients a good thing? Furthermore, what nutrients are “bad?” All of these questions do not come with easy, black-and-white answers, but over the next few weeks, we plan to release an informative series about the way one nutrient in particular, Phosphorus, moves through an ecosystem. In doing so, we will discuss how Phosphorus is generally a good (great, rather) thing, and we’ll also cover what conditions need to exist for this “great thing” to turn so bad that can deprive humans of one of the most important resources essential for life: clean, safe drinking water.

Phosphorus (P) primarily originates in rocks as the mineral apatite, which comprises approximately 0.1% the mass of the Earth’s crust. Rocks weather over time and form soil containing nutrients from this rock, including P. Phosphorus is also a plant essential nutrient that,once weathered and solubilized in the soil solution, is available for uptake by plants and microbes.  Within the plant, P is central to energy transfer by adenosine tri-(di-, and mono-) phosphates (ATP, ADP, and AMP, respectively). Phosphorus is also a component of nucleic acids (DNA and RNA) as a phosphate-sugar “backbone.”

The total amount of P in an ecosystem includes many different forms, some which can be easily taken up by plants or microbes and some which cannot be utilized as readily (within the next several growing seasons). Available forms include phosphates, soluble and easily dephosphorylated organic P compounds (ATP and phosphate sugars), and P that is very loosely bound to soil or sediment surfaces. Unavailable forms include P which is tightly bound to mineral surfaces, unweathered P still existing in minerals, organic P in recalcitrant(resistant to decomposition) compounds, and P that is physically segregated or buried. Over time P can become available through dissolution, decomposition, ligand exchange (the exchange of one molecule for another), and upheaval. Available forms can also be converted to unavailable forms through precipitation reactions, inner sphere complexation, and burial. Internal cycling of P is dependent on the microbial communities which decompose the organic matter and release ligands to exchange for phosphate, chemical equilibrium of the different forms of P, and the weathering rates of primary minerals containing P. In this soil environment, plants and microbes must aggressively compete for the small amounts of available P resources.

From this point, P can mobilize through runoff, erosion,leaching through the soil profile,or it be directly removed from the site through harvest or consumption. Inputs to most natural systems are very minor and include dust settling, run-on from adjacent sites, and direct inputs from animals. Because these inputs are small relative to the loss of P (dominated by erosion and run-off), over time TP will likely decrease. This is in truth what is observed in most sites throughout the world. As a site develops and ages, there is a gradual loss of P from the system. The rate of loss depends heavily on the climate, parent material, organisms, and topography. No matter the rate, most systems tend toward loss of total P with the most developed and weathered sites being more P deficient.

As P decreases or available sources begin to deplete, deficiency symptoms in plants can be observed. When P is in low supply, gene expression and protein synthesis suffer and,as a result,plant growth slows or dieback occurs. As the nutrient capital of the site diminishes, only stunted plants will remain with off-colored foliage and smaller-than-normal fruiting bodies. Very developed and old locations with low levels of macronutrients such as P can develop unique communities of plants specifically adapted to low nutrient concentrations. These plants must access nutrients through mycorrhizal symbiosis (a relationship between plants and fungi that is beneficial for both), complex or deep rooting systems, or by employing carnivory to provide nutrients(like in the Venus fly trap). Many other plants in these systems simply grow very slowly, similar to bonsai trees. While these systems lack the growing vigor and biomass of younger sites, they still represent beautiful, diverse, and important ecosystems.

So what happens with the Phosphorus that gets carried away from one ecosystem to the next? And if many systems are Phosphorus deficient, then why is everyone talking about Phosphorus-rich systems? Both of these questions will be answered in our next blog, where we will examine the fate of Phosphorus which has left a site through erosion and the effects of P loading into eutrophic waters.

Work with environmental students rewarding for all involved

We, at MAD Scientist Associates, are always delighted when we’re asked to participate in or provide expert knowledge on student projects. It’s a great way to stay connected to the community, hear different and fresh perspectives on ecological issues, and provides a great platform for us to show students ecological problems and solutions from a real-world perspective. This week, the MAD team participated in two education events: one at New Albany High School and the other with the Wetland Ecology class at The Ohio State University

At New Albany HS, we were asked to listen to student presentations regarding the harmful algal blooms at Grand Lake Saint Marys and provide expert advice to catalyze meaningful discussion regarding the subject.  After nearly three weeks of research, student groups each presented the solution that they thought would be most suitable to alleviate the problem.  Solutions ranged from expanding riparian buffer zones, changing the components in fertilizer applications and applying chemicals like alum to the water.  They quickly discovered that each solution came with its own set of financial, social, environmental, and political problems and that there is no one “silver bullet” to fix the issue. The MAD team was impressed by the complex ideas presented by these young scientists/students and know that they will do great things for the environment in the future.

At OSU, part of the MAD team listened to wetland restoration plans developed and presented by undergraduate students as part of their final project. Students were asked to identify a location best suited for a restoration project by identifying areas with appropriate soils and an adequate buffer. They were then asked to develop a construction plan to help restore the hydrology as well as a planting plan to restore proper vegetation—the same thing we at MAD do every day! We were captivated by their ability to use sophisticated software and the concepts they learned in the classroom to develop such great plans!

We think it’s great for students to be exposed to real-world environmental issues and to be able to try their hand at developing solutions—after all, they are our future. No matter what age or at what level, there is always something that can be learned. It’s a pleasure to interact with these bright minds, and we look forward to doing more in the future!

--Lindsey Korfel, Environmental Technician & Wildlife Specialist

Wetland Management

A wetland manager’s activities can range from wastewater treatment to waterfowl population management.

Importance of Wetland Management

Agricultural enterprises and ever-expanding urban areas pose a constant threat to wetland ecosystems. A wetland manager obtains the skills to identify boundaries of wetlands to help prevent unnecessary degradation of these valuable ecosystems. This process is known as wetland delineation.

Wetland delineation establishes the existence and physical limits of a wetland for the purpose of federal, state and local regulations.

Before wetlands were regarded as unique and valuable ecosystems, they were frequently viewed as wastelands. They were unable to be farmed or built upon because of their inherent ability to sustain water. Once they became recognized for their natural water-cleansing abilities and critical habitat for many forms of wildlife, governing agencies took measures to encourage their general preservation.  In 1988, a federally sponsored National Wetland Policy Forum raised public awareness of wetland loss and recommended a policy known as “No Net Loss.”

In 1992, the National Research Council set a goal of gaining ten million acres of wetlands by the year 2010, through creating and restoring wetlands.

Wetland restoration is the process of returning hydrology (flooding) to areas of land by reversing drainage. Wetland creation, the process of developing a wetland where there was not one previously, is a growing area in wetland management that is expected to help counter the loss of wetlands to agriculture and urban sprawl.

Wetland Management Goals

Maintain water quality
Buffer stormwater
Reduce erosion
Control insect populations
Produce and sustain wildlife populations
Provide a natural system to process pollutants
Maintain a diverse gene pool of native hydrophytic vegetation
Provide habitat for fish spawning and other food organisms
Provide aesthetic and psychological retreats for humans
 Further scientific knowledge and inquiries

For more information about wetland management or if you are working on a project which requires environmental consulting, please feel free to contacts us.


Mitsch, William J., Gosselink, James G. (1993) Wetlands. New York, NY: Van Nostrand Reinhold

An Overview of Constructed Wetlands

Green infrastructure is becoming more widely used to manage stormwater runoff, providing a natural means of limiting or eliminating combined sewer overflows and improving overall water quality.  Constructed wetlands and systems that mimic wetlands (for example bioswales, bioretention areas, and rain gardens) provide a cost-effective and environmentally conscious option that can result in an efficient and aesthetically pleasing wetland.  Additionally, constructed wetlands can provide valuable habitat for wildlife, including many amphibians, songbirds, and small mammals.  Constructed wetlands are classified according to their designed water flow; three common wetland designs are horizontal subsurface flow (HF), vertical flow (VF), or free surface wetlands (FSW).

Regardless of the type of treatment wetland used, each utilizes a process known as the root zone method (RZM) for removing bacteria, and excess nutrients, that negatively affect water quality.  The RZM can be summarized as follows: Influent (incoming) water passes horizontally or vertically through the soil and percolates the wetland bed.  The roots of wetland plants provide a pathway for the water to flow, and as the wastewater and solids move through the system they are treated by microbes that are contained near the plants’ roots.  The leaves of the plants absorb oxygen and transport it to the roots through their stems, which are hollow, and act as a bio-pump.  In the soil, or filter layer below the roots, anaerobic digestion treats the influent wastewater as well.  The type of substrate and plants included in the wetland design will vary depending on what the wetland has been designed to control.  Depending on the specific use of a treatment wetland, it may be necessary to pre-treat wastewater and remove large solids to prevent clogging of the substrate, which will reduce the effectiveness of the system.

In horizontal subsurface flow wetlands, water passes through emergent plants, and the RZM removes bacteria and excess nutrients at very high rates in a well functioning system.  After construction is complete, HF wetlands do not require significant maintenance, and many can function several years without maintenance.  Vertical flow wetlands utilize the RZM with a planted filter bed to treat wastewater as it flows through the system.  Typically the top layer is planted gravel above a layer of sand.  The deepest portion of the system is another layer of gravel that contains drainage pipes to collect and transport the filtered water as it percolates through the system.  VF wetlands are designed to be most effective when wastewater is applied in discrete intervals at a rate of 4-12 doses per day, and the wastewater is allowed to slowly percolate through the unsaturated layers of soil and sand.  Intermittent dosing is necessary to allow adequate oxygen transfer, which is necessary for aerobic degradation by the resident microbes.

Free surface wetlands are the most natural-looking treatment wetland option.  In these systems, water flows above ground and plants are rooted in the soil layer at the base of the wetland.  Typical design includes a basin lined with an impermeable layer, such as clay.  The substrate consists of rocks, gravel, and soil.  The basin is usually planted with native plants, and floating wetland islands can be used to supplement the plant coverage and increase system efficiency.  FSW wetlands are usually flooded with wastewater to a depth of 3-18 inches above ground level.  As the water slowly flows through the wetland and percolates into the soil, excess nutrients are taken up by the plants and potentially harmful bacteria may be trapped and degraded by microbial communities in biofilms on and near the plant roots.

Each type of treatment wetland has advantages and drawbacks that need to be carefully considered before developing blueprints and planning construction.  MAD Scientist & Associates has a proven track record with wetland design and construction, so if you are considering a constructed wetland for treatment or mitigation, we can help from the initial planning stages through construction and monitoring to make sure your wetland is a success.

Diagrams for Horizontal Flow and Vertical Flow Wetlands credited to:

Morel, A.; Diener, S. (2006): Greywater Management in Low and Middle-Income Countries, Review of different treatment systems for households or neighbourhoods.    Duebendorf: Swiss Federal Institute of Aquatic Science (EAWAG), Department of Water and Sanitation in Developing Countries (SANDEC). [Accessed: 19.02.2013].

Bats of Ohio: Benefits, endangered species, and how you can help

According to the Ohio Department of Natural Resources, there are 11 species of bats (out of about 1,200 worldwide) found in Ohio. All are insectivores and the most common are the big brown and little brown bats. While bats may have a bad reputation among the general public, they are an important part of our environment and provide humans with many benefits. Unfortunately, bats face many human-caused challenges that threaten their future. Several species of bats are experiencing declining populations due to various factors, but there are opportunities to help turn around this unfortunate trend.

Why should you care about bats?

A colony of insectivorous bats can consume thousands, even hundreds of thousands, of insects over several weeks of feeding. This is beneficial to many people: from the teen at soccer practice who doesn’t want to be bitten by insects, to the local farmer who wants his crops to grow healthy and free of pest invasions. Recent research estimates that the loss of bats in North America could lead to agricultural losses estimated at more than $3.7 billion/year (crop loss & pesticide use) (Boyles et al., 2011). Bats are also important pollinators and seed dispersers. Nectar-feeding bats are critical pollinators for a wide variety of plants of great economic and ecological value. In North America, giant cacti and agave depend on bats for pollination. A few commercial products that depend on bat pollinators include: bananas, peaches, durian (a fruit), cloves, carob (a chocolate substitute) and balsa wood. Fruit-eating bats disperse seeds that help to restore forests, including rainforests that have been cleared. Because they are night foragers, they are not as wary of crossing the clear-cut areas as diurnal birds may be.

The Indiana Bat

The Indiana bat (Myotis sodalis) is a migratory tree-roosting bat that is listed as endangered at the state and federal levels. It spends winters in communal hibernacula, such as an old mine site, and migrates to forested areas in the summer, where individuals live under the bark of trees with peeling bark. These trees can be live trees with loose “peely” bark (like a Shagbark Hickory) or standing dead/dying trees of any species (called a snag) with loose bark or cavities that provide small hiding places. Males will often roost alone or in a small “bachelor colony.” Male Indiana bats have been observed roosting in trees as small as 3 inches dbh (diameter at breast height) (USFWS, 2013). Females, however, roost in maternity colonies that can number in the hundreds. Because of the high numbers, the maternity colonies require a larger tree (typically >9” dbh) that receives sun exposure for at least half of the day (USFWS, 2007). Maternity colonies will use multiple trees in an area and the proportion of bats using a specific tree determines if it is a primary or alternate roost tree. The colony will usually use 10–20 different trees each year, but only 1–3 of these are primary roosts. Proximity to water, such as streams or wetlands, is another important factor these bats will look for when selecting a roost site.

The population decline for this species is related to several main causes: white-nose syndrome (WNS), wind turbines, and summer habitat loss/fragmentation. WNS is caused by a whitish fungus (Geomyces destructans) that appears on the bats muzzle, hence the name. It spreads rapidly in communal hibernacula where individuals live in very close proximity. It is believed that humans brought the disease over from Europe and spread it around the country during caving activities. Stress from the fungus causes the bats to come out of hibernation too early. They do not have enough fat reserves and due to the time of year there is not a substantial food source.  Wind turbines pose a different threat. With the push for sustainable energy, large wind farms are being built. While these developments provide many benefits, the wind turbines can harm bats. The force of the spinning blades creates a change in pressure that ruptures capillaries along the edges of their lungs (Baerwald et al., 2008). Researchers are looking into this phenomenon and some believe that bats may be somehow attracted to the turbines. Solutions are being sought to reduce the potential for bat mortality around these installations. A third factor, summer habitat loss and fragmentation, removes or disconnects bats from areas they would use.  The removal of trees with sloughing bark or snags effectively reduces the amount of habitat available to bats within their summer range, creating greater competition for the available resources.  Tree removal and forest fragmentation also removes corridors that bats use while foraging. Indiana bats have been shown to exhibit site fidelity, returning to the same forested areas year after year, so removing forested areas and corridors can create an issue.  Not much is known yet as to how Indiana bats react to the loss of habitat in areas where they have exhibited site fidelity. Additional sources of population decline can be linked to pesticide use and cave alterations.

How can you help?

  1. Think before cutting. Bats may be living in your dead/dying trees or any live trees with peeling bark. Just because you think it no longer looks nice doesn’t mean it isn’t important. If it poses a safety issue or you really must remove it then try to cut it during the winter when bats are at their hibernacula.
  2. Install a bat box. Bat boxes provide bats with somewhere to live. This is especially helpful if you must cut trees down or remove bats that may have gotten into your house.
  3. Remove bats from your house safely. When bats get in your house it is often by mistake. Shutting off the lights and opening your doors and windows may help guide the bat outdoors. If bats are living in your attic the best way is to exclude them so they cannot regain entry. For more information visit Bat Conservation International’s site on Bat Removal.
  4. Volunteer! MAD Scientist & Associates recently volunteered with the Ohio Department of Natural Resources to complete acoustic surveys.  The data collected from this project will be helpful to develop an understanding of the range and preferred habitats types for bat species in Ohio.
  5. If you need to conduct a bat habitat evaluation as part of a project, please call MAD Scientists & Associates  and we can help you understand the regulations, survey your site, and assist you every step along the way.


Literature Reviewed:

Baerwald. E.F., G.H. D’Amours, B.J. Klug, R.M.R. Barclay. 26 August 2008. Barotrauma is a significant cause of bat fatalities at wind turbines. Current Biology.

J.G. Boyles, P. Cryan, G. McCracken and T. Kunz. 1 April 2011.  Economic importance of bats

in agriculture. Science.

USFWS Ecological Services. January 2007. Indiana Bat – Summer Life History Information for Michigan.

USFWS Great Lakes-Big Rivers Region. April 2007. Indiana Bat Draft Recovery Plan First Revision.

USFWS Midwest Endangered Species Program. April 2013. Revised Range-wide Indiana Bat Summer Survey Guidelines.