Red River Gorge, KY

Red River Gorge, KY

Friday, August 7, 2015

2015 Summer Research: Wintercreeper and Arthropods

Wintercreeper forms dense monocultures on the forest floor. 
Summer always tends to fly by, and before you know it classes have begun and the field research season is nearly at an end! It's valuable to spend time reflecting on research as things wind down, so the focus of this post will be the first of three projects I've spent time on this summer. 

It's well known that invasive plants can be detrimental to native plant and animal communities. For example, invasive plants like broomsedge and wintercreeper can outcompete native grasses and flowers, reducing plant biodiversity. They can also reduce the quality of the habitat for animals, such as ground nesting birds, small mammals, and even insects. These invasive plants are able to grow and reproduce very rapidly, thus potentially altering local biodiversity of native organisms quite quickly. However, this is a broad statement - how some invasive plants specifically affect local biodiversity is often unknown! This is especially true of wintercreeper (Euonymus fortunei), an invasive evergreen vine which can form dense mats within the understory of forests, and is widely marketed by the horticulture industry and used in landscaping. 

Top: a wintercreeper dominated plot.
Bottom: A removal plot.
My friend and colleague at Transylvania University, Dr. Sarah Bray, has been studying the effects of wintercreeper on soil microbial communities. Last year, her ecology class spent some time collecting insects within wintercreeper removal plots and comparing those communities to those found within wintercreeper dominated plots. One of those students, Caitlin Raley, was interested in continuing this research and was awarded a summer stipend from the Kenan Fund for Faculty and Student Enrichment at Transylvania University to that end. 

Since June, Caitlin has collected arthropods via pitfall traping and sweep netting on a weekly basis from wintercreeper dominated and removal plots at the Arboretum Woods in Lexington, KY. There are a ton of arthropod samples to sift through, and Caitlin is in the process of identifying all of them! I haven't been able to find a published study on arthropod communities associated with wintercreeper that comparable to Caitlin's, so it will be very exciting to see what she finds! She is initially focusing her investigation on the spiders captured over the course of the summer, and plans to present that portion of her research at the Kentucky Academy of Science meeting this November. 

Caitlin installing pitfall traps in wintercreeper dominated plots.
Next time: Restoring native grassland habitat by removing invasive grasses with herbicides!

JA

Wednesday, October 22, 2014

The Tale of The Bluegrass Savanna-Woodland


Griffith Woods, Kentucky. Photo by J. Cox. Used without permission

The Inner Bluegrass region of Kentucky is an area well known for its gently rolling hills, fertile cropland, bourbon, and Thoroughbred horses. Much of the region is dominated by agriculture and horse pasture land, while Lexington continues to expand its borders into the surrounding landscape. That the region's native biological communities are no longer completely intact is a widely known fact. However, upon closer investigation, it becomes very difficult to say specifically what the local plant communities may have once looked like in the Bluegrass region.

It has been noted time and again that the prominent botanist E. Lucy Braun described the Bluegrass region as the "most anomalous vegetation area in the eastern United States." Many early explorers wrote short depictions of the vegetation that they experienced as they passed through the area. Several of these observations depict great herds of large ungulates, such as bison and elk, grazing on an understory comprised of wild ryes, running buffalo clover, and an abundance of cane found growing in open, park-like savanna-woodlands.
"There are many canebreaks so thick and tall that is is difficult to pass through them. Where no cane grows there is abundance of wild rye, clover, and buffalo grass, covering vast tracts of country, and affording excellent food for cattle. The fields are covered with abundance of wild herbage not common to other countries."
                    -John Filson, 1784. The Discovery, Settlement, and Present Site of Kentucke
“On the north-west and south-east sides of the Ohio, below the great Kanhaway river, at a little distance from it, are extensive natural meadows, or savannas. These meadows are from 20 to 50 miles in circuit. They have many beautiful groves of trees interspersed as if by art in them, and which serve as shelter for the innumerable herds of buffalo, deer, etc. with which they abound.” 
-Thomas Hutchins. 1778a. A Topographical Description of Virginia, Pennsylvania, Maryland, 
and North-Carolina.
“In all the fertile parts covered by the forests the soil is completely barren; no herbage is seen except a few plants, scattered here and there; and the trees are always far enough apart that a stag may be seen a hundred or a hundred and fifty fathoms off. Prior to the Europeans settling, the whole of this space, now bare, was covered with a species of the great articulated reed, called arundinaria macrosperma, or cane, which is in the woods from three to four inches [check units] diameter, and grows seven or eight feet high...”
-Francois Andre Michaux. 1805. Summarizing geography of central Kentucky

The concept of the Bluegrass savanna became widespread after gaining prominence through the research of Dr. Mary Wharton, professor of botany at Georgetown College. Dr. Wharton's work finds its basis in Lucy Braun's supposition that pre-European Inner Bluegrass forests could not have been dense, and were likely open and park-like. In an article published in the September 1980 issue of the  journal Castanea, William Bryant and Dr. Wharton along with William Martin and Johnnie Varner found blue ash, bur oak, Shumard oak, and chinquapin oaks in upward of 395 years in age. In particular, they note that the bur oaks are not known to be species of closed canopy forests, which suggests that the forests in the Bluegrass during the mid to late 1700's had relatively open canopies. These pre-European Bluegrass savanna-woodlands would have included a dense herbaceous understory comprising of cane, clover, and cool season grasses such as Elymus spp. They assert that open conditions could have been maintained by large herds of buffalo and other ungulates rather than fire. The loss of this natural disturbance coincides with the displacement of native grasses and forbs by Kentucky bluegrass and fescue around the time of the earliest intensive settlement of the area by Europeans. This viewpoint of the Bluegrass savanna-woodland is best captured by the 1991 book "Bluegrass Land and Life" by Wharton and Barbour. It is also very commonly found in the descriptions of the region found on state agency website such as the Kentucky State Nature Preserves Commission, and in books about Kentuckys biota, such at "Kentucky's Last Great Places" by the late Thomas G. Barnes.

In a 2008 article published in the Journal of Biogeography (PDF), Ryan McEwan and Brian McCarthy present data that calls into question the extent of the Bluegrass savanna prior to European settlement. Using dendrochronology, or the scientific method of dating trees by counting their annual growth rings, these researchers found evidence of very slow growth of these large "savanna indicator" species prior to European settlement. After European settlement, McEwan and McCarthy found that the rings in these savanna indicator trees are wider, perhaps as a result of tree removal by Europeans in the forests of the Bluegrass region which could have released the remnant "savanna" trees from competition for light and increasing their growth rate.  Indeed, the very notion of the savanna as a widespread component of the Bluegrass region of Kentucky is questioned by these results.

I have not been able to find any other more recent research on the topic, although Julian Campbell has compiled a great deal of research on his website, which can be found here.  It would appear that the issue of pre-European settlement vegetation in the Bluegrass region of Kentucky continues to be something of a controversy - an interesting one that is at the heart of conservation and restoration ecology, and one that bears much more discussion as well as more research!

Until next time!

JA

Friday, October 3, 2014

Pollinator Decline and Citizen Science - How Can I Help?


In BIO 1164: Biology and Human Concerns, we have been discussing the importance of conservation, and what one could do to help the environment given the dire condition of our planet's biodiversity. At times, I fear my students look at the state of the world and see no hope. What is a concerned, conscientious person to do? One option might be to become involved in a citizen science program!

During lab on Thursday, 2-Oct-14, my students participated in a pollinator count on campus at Transylvania University. TU is situated very close to downtown Lexington, KY. It seems imperative to understand how pollinators use any available resources in this urban setting. 

Transylvania University in Lexington KY. 
Though autumn is quickly approaching (low temperatures this weekend should approach the upper 30's!) goldenrod is still in bloom in the campus rain gardens. And, there are still pollinators out there!

A carpenter bee foraging on goldenrod
The students paired up, and took turns making pollinator visit counts on the goldenrod for five minutes at two spots on campus. One location was more centrally located and the flower garden was smaller, while the other was larger and on the edge of campus. I have two lab sections: one early, the other later in the morning. My students made predictions about whether they'd see more pollinator visits early or late, and in the middle of campus versus the edge. 

Then the pollinator visit counts began!


Above: Tim focuses on pollinator visits while Katie records data
Below: Joey and Teddy recorded their pollinator visits

As the students suspected, the late lab section saw greater pollinator activity than the morning group. Temperatures rose 17 degrees between the two lab sections. However, we anticipated greater activity on the edge of campus. Instead, we saw greater numbers of pollinators on the interior of campus. However, one thing we did not take into consideration was the composition of the pollinators across the two locations. In the campus interior, we saw greater numbers of small, solitary Halictid bees, whereas on the edge larger bodied bees such as honey bees and carpenter bees were dominant.

This was just one day of sampling, but as a pilot study it raises a number of questions. Which pollinators take advantage of the flowers on campus at Transylvania University throughout the year? How could the campus community more effectively use native flowers in our landscaping to benefit pollinators? Early next year, I hope to organize more pollinator counts on campus, in order to answer some of the questions raised by this short lab project.

If you would like to become involved in local pollinator counts, or would like to learn more about using native plants to enhance pollinators in your yard, there are lots of resources available for you! Check out the Xerces Society's bumblebee watch page, and take part in the search for bumblebees! The University of Kentucky has publications covering a range of topics  that might be of interest as well, such as landscaping with wildflowers, how to attract butterflies with native plants, and more. 

Finally, there is a smartphone app called iNaturalist which looks very interesting. This might be a great way to collaborate on a city-wide or regional pollinator study and share the results in real time. I plan to download and try this app out soon, and will post later about how it works!  

Knowledge, concern, and collaboration are key to effective conservation programs. Recently, there have been some indications that the hole in the ozone layer is beginning to shrink. This was a result of a massive, international collaborative effort to reduce CFC emissions. So long as concerned, knowledgeable people care about the environment, there is hope! 

Until next time!

Wednesday, September 24, 2014

Invasives and Natives - Emerald Ash Borer and Blue Ash

Last week I posted an introduction to the emerald ash borer (EAB: Agrilus planipennis), an exotic invasive wood-boring beetle that since 2002 has been spreading throughout the landscape of the eastern United States and Canada. As the name implies, EAB targets ash trees (genus Fraxinus) and infestations can lead to tree mortality very quickly.

Ash trees are important components of urban and suburban ecosystems, as they are very popular street trees. In central Kentucky, however, one species of ash represents much more than the ash trees used for ornamental landscaping. Blue ash (Fraxinus quadrangulata) is a major component of woodlands in the Bluegrass region. These large, impressive trees have narrow range restrictions, and are most often found in association with limestone-based soils, such as those found in the Bluegrass. This species, along with chinquapin oak (Quercus muehlenbergii), is indicative of an anomalous (and controversial!) vegetative community, the Bluegrass savanna-woodland. (Note: I hope to spend some time discussing that controversy sometime soon! Was the Inner Bluegrass made up of savanna-woodlands with sparse tree canopy cover and understories comprised of cane and clover? The answer is tricky, and none too clear!)

Blue ash and chinquapin oaks at Griffith Woods WMA, near Cynthiana, KY. Photo by Neil Pederson
Regardless of the precise pre-European vegetative composition of the Inner Bluegrass, these large, ancient (many date to the late 1600's/early 1700's!) blue ash trees are irreplaceable components of Kentucky's native biota. The emerald ash borer represents a dire challenge to the fitness of these stately trees, and a threat to overall biodiversity. What can you do to help? Next time, I plan to discuss ways in which interested naturalists and citizen scientists can play a huge role in the fight to preserve native ash trees and monitor the spread of EAB.

We are starting to discuss plants in more detail in BIO 1164: Biology and Human Concerns. On Thursday, 9/25/2014 we'll have lab outside, and we'll begin learning to identify some trees common to our region. There are many examples of native trees on campus at Transylvania University, so we'll have plenty of specimens to practice with! Beyond learning some tree ID skills, I hope that my students will become familiar with the ins and outs of using dichotomous keys. That's an important skill for any naturalist to have, one that will make identifying other groups such as birds or insects much easier for them!

Until next time!

JA

Tuesday, September 16, 2014

Backyard Ragnarök: The Emerald Ash Borer

Naturalists of all ages know that trees are cornerstones of the environment. Trees provide food and habitat for wildlife, play a major role in global oxygen and carbon cycles, help to stabilize soils and prevent erosion, and perform many other ecological tasks.

"The Ash Yggdrasil" (1886) by Friedrich Wilhelm Heine
Trees can also hold great emotional, aesthetic, and cultural value. From the ancient Babylonian and Greek societies to Native American tribes, many cultures revere trees to some extent. Trees were central in many tales of the Norse. According to the Prose Edda compiled by Snorri Sturluson, the nine worlds were held within the boughs of Yggdrasil, the World Tree. Yggdrasil was a giant ash tree where the gods held court. This immense, cosmic tree was a link that served as connective tissue for the Norse cosmology. Although the fate of Yggdrasil after Ragnarök, the Norse end-times, is never explicitly stated it is surmised that the survival of humankind rests solely upon this gigantic tree1.


I find this legend especially interesting given the serious threat that native ash trees face throughout the eastern United States. An exotic invasive insect called the emerald ash borer (Agrilus planipennis) has been rapidly dispersing throughout the eastern and midwestern United States, aggressively attacking native ash (Fraxinus) species. As adults, these beetles are metallic green, and feed on ash foliage. They do most of their damage as larvae, burrowing through the vascular tissue and disrupting the tree's ability to transfer food downward from the leaves.


Top: Emerald ash borer larva.
Bottom: Emerald ash borer adult.
Images from Bugwood.org

There are confirmed populations of emerald ash borer in Kentucky, and according to the Kentucky Division of Forestry, there are approximately 130 million individual ash trees in the Commonwealth. How might this invasion affect Kentucky? Native ash trees support a number of native insect species, mostly Lepidopterans (butterflies & moths) which subsist on ash foliage as caterpillars2.  Localized mortality of native ash trees in forests can cause canopy gaps to open, changing light levels within those forests, leading to increased temperature and reduced moisture on the forest floor. This can affect the composition of the forest floor plant community. One ash species, the blue ash (Fraxinus quadrangulata) is a tree indicative of a functionally extinct ecotype found only in Kentucky - the Bluegrass Savanna. The emerald ash borer invasion leads to an overall net reduction in biodiversity in our forests.

From an economic standpoint, Louisville Slugger baseball bats are made from northern white ash grown in Pennsylvania. Emerald ash borer is moving closer to these trees, and the company is evaluating other woods to use for bat production. Ash is also a popular urban tree in Kentucky, and is planted in neighborhoods and along roadsides to improve local aesthetics. Loss of these trees and the associated cost of removal represents an economic loss as well.

Recently, we have been discussing the importance of biodiversity in BIO 1164: Biology & Human Concerns. The threat that invasive species pose to native biota is alarming, and I will explore this topic in more detail later. But for now, let's return to our Norse myth. Each native species, from plants to insects to vertebrates, could each be represented by a branch on the World Tree, Yggdrasil. Since human society cannot be separated from nature, do we have an obligation to protect and conserve biodiversity to ensure a higher quality of life for future generations? If so, the parallel of the old Norse myth is an effective one, and it is in our best interest to protect Yggdrasil, or biodiversity, and stave off ecological Ragnarök for as long as we can!

For more information on emerald ash borer in Kentucky visit http://pest.ca.uky.edu/EXT/EAB/welcomeeab.html

Until next time!

JA

1. Larrington, Carolyne (Translator) (1999). The Poetic Edda. Oxford World's Classics. ISBN 0-19-283946-2
2. Wagner DL. 2007. Emerald ash borer threatens ash-feeding Lepidoptera. News Lepid Soc 49:10–11

Tuesday, September 9, 2014

What is Nature?

A recent topic we've been discussing in BIO 1164 is the idea of the place and role of humans in the scope of nature. What do we think of when we think of nature? Large tracts of unbroken forest, streams, and meadows? Hilltops and hollows, and ancient gorges carved into the rock by the wind and rain over millions of years? Certainly no one would argue with those descriptions.

Pine Mountain, Pineville, KY
Is there a problem with referring to nature as a place removed? Is nature a destination to which you need to pack up the car and travel, burning fuel on your way to enjoy a day hike? What does this separation signify about how we view our place in the world? Clearly, each of us lives within an ecosystem. If you open the door, no matter where you are, you can observe plant and animal species along with sunlight, soil, and water. It may be that you live in an urban area, with parks scattered around the city. On the other hand, you might live in a rural area and an idealize view of nature isn't far from you. Regardless, a view of nature that does not include humans and the large influence that we have on our environment is rather incomplete. Wendell Berry writes in the foreword to our textbook, "Kentucky's Natural Heritage" about the value of  knowing and observing local biota. This knowledge can tell us much about the health of the local environment that we all share. These are ideas that my students and I will develop and explore throughout the semester.

What is a naturalist? The role of the naturalist has changed throughout history, from ancient Greek philosophers to wealthy Victorian era plant and animal collectors and enthusiasts. We are discussing the history of natural history, and the interesting ways in which the field has been intertwined with philosophy, faith, and the arts. We have also been discussing what it means to be a naturalist, and the contributions that naturalists have made to science throughout history. Of course, the focus has been on Darwin, but soon we will delve into the writings of other important figures like John Muir, Aldo Leopold, and Rachel Carson. But, more importantly, we'll be spending some time outside on campus at Transylvania University, sharpening our plant and insect identification skills (= the fun stuff!)

Until next time!

Monday, September 1, 2014

It's a Brand New Semester!

Hello, I'm Josh, and I'm an entomologist.

Let's start over.

I'm Josh, and I'm a Kentuckian. I speak for the trees. I have interests which are wide and varied, but one of them is the natural world that surrounds us. Often, this world seems invisible, as though it's just beyond what we can see as we drive to work or walk to class, spend the day inside, and make our way back again. Yet this world can easily be seen if we take time from our routines and allow ourselves to see it, even if we are surrounded by an urban environment. This may sound a bit flowery, but I think it's vital that we each slow down and begin to pay attention to, and understand, local biodiversity.

The Fall 2014 term at Transylvania University gets underway on Tuesday, September 2! I feel a sense of great anticipation and eagerness for the semester to begin. In addition to coordinating labs in the Biology department, I'll be leading a non-majors course called BIO 1064: Biology and Human Concerns. Since I have some latitude in designing the course, we'll spend the semester discussing natural history, biodiversity, and conservation issues in Kentucky. We'll use Kentucky's Natural Heritage, edited by Abernathy, White, Laudermilk, and Evans.

You can find it on Amazon.com

This book is beautiful, and could easily pass as a coffee table book. However, many knowledgeable local ecologists, biologists, and naturalists contributed to this book, and as a result it provides the best holistic view of Kentucky's natural history, physical geography, and biodiversity out there.

My hope is that this course will provide my students some basic naturalist skills, an understanding of how natural history has been important to the development of the biological sciences, and why conservation and wise use of natural resources continues to be of critical importance. I also plan to spend as much time as possible outside, learning to identify native trees, birds, and insects! 

Finally, the students will be blogging this semester, and I look forward to reading their posts and seeing what topics they're interested in. I plan to post the links to their blogs as soon as they're set up, so you should be able to check them out as well! 

This should be a great semester!