Category Archives: Student Guest Posts
The Pymatuning wetlanders discussed wetland restoration this morning, including an examination of the Florida Everglades Project, which is the largest wetland restoration ever attempted. We discussed the history of environmental degradation in South Florida and how it altered the hydrology and biogeochemistry of this unique wetland complex. The students were happy to apply their knowledge of Phosphorus cycling toward understanding some of the problems and challenges that the restoration effort is attempting to fix.
We had a short break, during which the students finished mounting a few labels on their plant collections and collectively cleaned the wet lab of peat, mud, dead macroinvertebrates, and various other byproducts of our recent explorations. We then briefly discussed treatment wetlands, highlighting the use of these created wetlands to treat things like municipal wastewater, non-point source pollution, and acid mine drainage. I then provided a brief overview of the course and its structure, highlighting what this hard-working group students has accomplished in only three weeks. Then we had one last bit of fun exploring some of the wetlands in the littoral zone of Pymatuning Reservoir via canoe. The students used the rest of the afternoon to study for tomorrow’s final exam.
This month I am highlighting some entries from the journals of EES-28 students. If students put together a particularly well-written and thoughtful entry, they are given the option of editing it and putting it here for others in the class (and the world) to see.
Given our recent focus on current conservation programs and ways people can get involved (in EES-028, Biodiversity & Conservation), I decided to look up news related to ecology and conservation in my home state, Oregon. I’ve always thought we were a fairly sustainably focused state, and other people I know share this opinion. We were one of the earliest states to implement recycling programs, and the first to pass a bottle recycling bill. Many people I know hike and spend a lot of time outdoors, and because of that many of us are invested in the environment around us. We tend to take a lot of pride in our abundance of evergreen trees, and are even fond of the drizzly rain. But I admit that I have not looked too deeply into the actual issues that concern my state, so I investigated what is happening right now. There were two recent stories that caught my eye, partly for their prominence and partly for their opposing tones.
Selling a portion of the Elliot State Forest
Recently, a controversial decision was made by the state to sell a 788-acre parcel of land in the Elliot State Forest to a timber company. In the past, the state has used money from selling timber rights on the land to fund state programs such as K-12 schools. However, environmental lawsuits put an end to that logging, and so with a budget shortfall, officials decided to test the feasibility of selling and privatizing parcels of the large Elliot State Forest. Very recently, the winning bid to Seneca Jones Timber Company was announced, although the papers have yet to be signed. Already environmental groups have launched a lawsuit against the sale of the land, citing a 1957 law that protects land that was state forest in 1913. Two more parcels were also sold, but no lawsuit has been leveled against those. Aside from the general desire to preserve habitats from the vagaries of timber company clear cutting, there is a specific population at risk. The marbled murrelet is a globally endangered species of bird and the Elliott State Forest has been classified as a critical habitat for the species, so reducing the forest may have extremely harmful effects on its population. Regardless of the outcome of the lawsuit, some of the groups opposing the land sale are hopeful that the results of this sale will discourage the State from selling more parcels. The recently sold parcels went for almost a fifth of their determined value, so perhaps state officials will not sell more land at such a poor price. But if looked at with a cynical eye, this sequence of actions could be interpreted as warning from the state land management that if environmentalist lawsuits make managing public land too expensive, the state will respond by selling it off to timber companies who likely have even less motivation for conservation.
Youth Ecology Corps
While the above story highlights struggles to protect the environment against degradation, this second news story focuses on some positive action being taken. As part of Portland’s 2013 parks and natural areas property tax levy, a new conservation initiative was begun in the form of a youth ecology corps. The main goal of this program is to get young people excited about nature and conservation. It especially focuses on underprivileged youth, with the assumption that poverty often prevents opportunities for activities like hiking and camping. Once accepted into the program, participants receive an education in botany, bird identification, wildlife tracking, salmon spawning, geology, and wilderness survival. Another facet of the program is that the students are also paid to participate in a youth conservation work crew, which is important because it gives the students the funds and freedom to participate. So not only does the program foster enhanced environmental education, it will also positively impact the environment through habitat restoration, trail maintenance, invasive species removal, and larger projects like side channel restoration to help spawning salmon. I really hope this program succeeds, because I believe that fostering a love of nature at an early age is critical to a lifetime of environmental awareness and engagement.
Over the next month, I hope to post some of the highlights from the journals of EES-28 students. If students put together a particularly well-written and thoughtful entry, they are given the option of editing it and putting it here for others in the class (and the world) to see.
Divestment from fossil fuels
College of the Atlantic, Foothill-De Anza Community College, Green Mountain College, Hampshire College, Naropa University, Peralta Community College, Prescott College, San Francisco State University, Sterling College, and Unity College. What do these schools have in common? These schools, along with numerous cities and foundations across the country, have boldly chosen not to invest in any of the 200 largest fossil fuel corporations over the next few years. The campaign for fossil-fuel divestment has been gaining steam since its start a few years ago, and the movement essentially calls for institutions to divest their endowments from the dirty and dangerous fossil fuel industry that has had catastrophic effects on the environment. The fundamental goal of the movement is to have universities and foundations invest in a safe, clean future for current students and generations to come. Nationwide there are approximately 300 colleges and universities engaged in divestment campaigns.
Divestment at Lehigh University
Experts agree that the burning of fossil fuels has and will continue to have catastrophic effects on environment, including climate change, ocean acidification, as well as extraction related disasters, and the recent IPCC report highlights the urgency of these problems.
In September of 2013, Lehigh University joined the nationwide divestment movement. The movement on campus is being led by Lehigh’s premier environmental advocacy group, Green Action. Green Action has called upon President Gast and Lehigh’s Board of Trustees to:
“immediately freeze any new investment in companies responsible for the extraction, refinement, and processing of fossil fuels, and any companies whose sole purpose is to support these aforementioned companies, completely divest within five years from direct ownership and from any commingled funds that include public equities and corporate bonds associated with the companies mentioned above and increase investments in renewable energy companies.”
The campaign has also specifically requested that the Board of Trustees ensures that the next university president is truly committed to sustainable development, and is willing to make Lehigh University a model university by divesting from fossil fuels. Currently many students are unaware of the movement at Lehigh, which is why Green Action is actively trying to generate awareness.
Lehigh University’s endowment totals over one billion dollars, and therefore how it choses to invest these funds should be based on BOTH economics and ethics. The university has recently emphasized sustainability on campus, implementing a nearly 30-page Campus Sustainability Plan that incorporates climate and energy, food and dining services, and building and land use. However, by continuing to invest in the fossil fuel industry instead of renewables, the present management of the endowment undermines these activities. Most arguments against divestment center on economics, although several analyses reveal that divestment has not resulted in lower returns on investment, and institutions of higher learning should certainly also consider the ethics of investments. If Lehigh were to successfully divest, they would set a strong example for other schools and become a leader in the effort to slow the rate of climate change. Although Lehigh’s current president, Alice Gast, is on the Board of Directors at Chevron, she will hopefully still be able to lend her support to this campaign.
There is also a petition that allows students to display their support for the divestment campaign. Please support the campaign by signing the petition: http://campaigns.gofossilfree.org/petitions/lehigh-university-go-fossil-free
“Couldn’t stay in bed so I went outside around 5am. No one was around so I had a chance to take a deep breath and enjoy the surroundings. I felt relaxed and appreciated the moment. The efforts made by Costa Ricans to conserve and protect these beautiful areas of nature must be a contributing factor to their culture of peace. Maintaining these areas not only protects biodiversity and the environment, but also serves as a symbol of the country’s national identity. Before this trip, whenever I told people that I was going to Costa Rica the inevitable response was “I’ve heard it’s beautiful there.”
It is. One of the reasons why it is so beautiful is that the people that live here make it a priority to keep it that way.”
Those excerpts from my journal encapsulate my feelings about Costa Rica. My trip was not for field study, nor was the main point of it to explore the amazing biodiversity and conservation ethic of the country. The trip was was part of a course entitled “Peace Studies and Conflict Resolution.” Part of the course was a 10-day trip to Costa Rica, which admittedly was the main reason I became interested in the first place. We explored aspects of Costa Rican society and listened to lectures from speakers from different disciplines and backgrounds (e.g., education, government, conservation, culture). We took field trips aimed at studying Costa Rica’s “culture of peace” and how it permeates virtually every aspect of their society, including the government. The trip to Monteverde, where I wrote the journal entry quoted above, was actually our time off: taking us out of San Jose for 2 nights and giving us a bit of a break from our long days in the classroom and buses. It was a wonderful respite from the bustle.
A few years prior, a friend of mine had taken a trip to Costa Rica for a field study in herpetology and all he could talk about was how amazingly GREEN everything was. I had not seen anything to fit that description. But all of that changed when we arrived in Monteverde – which literally means “green mountain.” I remember thinking: here is Costa Rica! Immediately I was struck by the diversity of plants, many of which were unlike anything I had ever seen before. Nearly 4% of the total number of species in the world are in Costa Rica!
But where were the animals? Where were these amazing technicolor frogs I had read so much about? The two things I looked forward to seeing most were spiders and frogs, and probably like most people, I had the mistaken impression that they would be everywhere; that you would practically have to avoid stepping on them. However, I was only able to catch a glimpse(I mean literally, a tiny peek) at a frog. A single solitary frog. And that wasn’t even on my morning hike on the trails around the lodge, but was on a night hike with a guide that had eagle eyes and knew the area like the back of his hand. However, I did get to see some really cool spiders and lots of other plants and animals. But I still secretly wondered: where were the frogs?
Not that my anecdotal “froglessness” should be interpreted as representative of frog populations sizes in Costa Rica, but it did get me thinking about extinction. Apparently even in Costa Rica, a place that is known for its efforts in conservation, reforestation, preservation, and any other environmentally conscious word ending in -“ation” that you can think of, they are losing species at an alarming rate. Deforestation has been primary cause of biodiversity in Costa Rica, but increasingly climate change is seen as a major biodiversity threat, particularly in mountainous areas. Among the most vulnerable organisms to climate change are the amphibians, as recent research has documented linkages between pathogen outbreaks and global warming. The golden toad. Gone. The Monteverde harlequin frog. Gone. And these extinctions are before the “escalator effect” even gets going. This NPR podcast is a nice summary of the situation.
“A few of us heard that there was a suspension bridge on one of the trails, so we went for a little hike before leaving Monteverde. I could have spent the whole day on that trail, just listening to the sounds of the birds and nothing else. We didn’t talk much, instead just thinking about how lucky we were to be there.”
And almost 2 years later, I still feel the same way. The remaining species of frogs probably do too.
I first read “Song of the Dodo” by David Quammen when I was beginning my graduate career. I had just started working toward my MS degree, and the book influenced my decision to pursue a PhD. Although the science of conservation has moved on from some of the ideas discussed in the book, it still provides a nice summary of the biodiversity crisis, the history and development of some major ecological and evolutionary ideas, a window into the diversity of scientific methods and approaches, and perhaps most importantly – manages to convey the excitement of ecology and infect the reader with the passion of the scientists involved. In five years of using the book in my non-majors course on conservation and biodiversity, the student responses have been overwhelmingly positive. Certainly there are a few students that dislike it, particularly because it is long and requires a big time investment, but most students find it interesting and each year a few students always find it tremendously inspiring. In fact, every year I have at least a few students that rank it among the best books they have ever read. Below are some selected thoughts of students after reading the book.
An exhaustive journalistic work
Quammen’s book struck the right note of hope in its final pages and did a service to readers by pointing them to research directed at answering the all-important “What can be done” question. As a journalist, Quammen is right to acknowledge that his job can only ever be descriptive, “diagnostic” as he calls it, and not prescriptive. The tough job of devising solutions to human-caused habitat degradation/fragmentation and extinction is best left to the field ecologists, researchers and modelers of the world, many of whom Quammen introduces us to in Dodo. It is comforting to know that such a colorful, impressive cast of characters is hard at work on behalf of the world’s endangered species and ecosystems, even if the particulars of their work remain a little fuzzy to non-scientists. The exhaustive journalistic work Quammen does in Dodo is valuable precisely because it brings the science into somewhat sharper focus for lay readers, who have a hand, to a greater or lesser extent, in informing the public policy and civil society decisions that affect biodiversity. This is, of course, the same reason it is valuable to offer a course like Biodiversity and Conservation to non-majors like me: to encourage intellectual curiosity and foster a concern for threatened biodiversity in those who are not immediate stakeholders. As someone who hopes to work in a university setting one day, albeit in a decidedly non-scientific field, I found it meaningful to see how science is practiced at the university level by taking this course at this late point in my academic career.
Looking past ourselves
The final section of David Quammen’s “The Song of the Dodo” has a very simple point: each and every species is going to go extinct. There is an inherent dynamism in the natural world that cannot be reversed. Humans, for better or for worse, are a part of something much greater than we personally can conceive. The implications of imagining our inevitable mortality are hard to swallow; the implications of imagining our way of life, our societies, our entire species going extinct are essentially impossible.
Our comparable intelligence allows us to know far more than we can readily perceive with our immediate senses. With this, we claim to know how ecosystems work and how species fit together. We grant ourselves the ability to control the environment in both positive and negative ways. We destroy species, so naturally we can save them. We envision that cloning will one day bring the thylacine back from extinction. We play God in an effort to avoid the realization that we one day will also fall.
This is not to excuse the immediacy of anthropogenic harm to the natural world. The Gaia hypothesis envisions the world as ever existing, before, during, and after human effects. The world functions as a whole, with humans as a major, but not sole part. Even if the world persists long after our inevitable decline, in the immediate realm – the realm that we as humans can actually conceive – we must act to minimize our impact. Granting rights and value to species for non-utilitarian purpose may be politically impossible, but morally it is necessary.
I doubt that we will see a major value shift any time soon. It will take major anthropocentric catastrophe to cause humans to change their motivations and stop consuming at such a rampant level. Conservation programs offer a glimpse into a world where nature, and the non-human, can be valued for something other than our own needs. We want to “Save the Whales” not solely for our own enjoyment and tourism, but because the whales deserve to be saved. In the short term, we appeal to human health and needs, but in the long term we must look past ourselves.
Trading a brotherly hug
I did it. I finished the entire book. I read all 628 pages and it didn’t disappoint. I really liked The Song of the Dodo. I was continuously surprised at how brave David Quammen was for a journalist/writer. I certainly would not be brave enough to climb a vine in order to get a story, but his passion/dedication was evident throughout the book. One of my favorite sections was when he went to Montes Claros to study the muriquis and got the chance to see firsthand and speak with scientists that were studying their reproductive habits. I was surprised to find that the female muriquis are dominant, and that there was little reproductive competition among the males. I had imagined the image that Quammen describes: males butting heads, growling. The image of the males instead “trading a brotherly hug” is much nicer! I definitely wouldn’t have wanted Strier’s job of collecting muriqui feces, however the dedication she had for this important form of data collection just reaffirms her passion – something evident in all of the scientists profiled in this book.
“So what?” begins the last chapter: a very simple question, but one that carries extreme weight. As we lose a large portion of the planet’s biological diversity, individual species are not all we are losing; we simultaneously lose “a large portion of our world’s beauty, complexity, intellectual interest, spiritual depth, and ecological health.” This section also examined the major effect that humans have played in extinctions and raised the strange concept that one day Homo sapiens might go extinct. It is a weird idea to think about. As Quammen mentions, extinction is natural, so why do we think that we are immune to it? It puts things in perspective for me.
Acquiring the evidence along with Quammen
With this final blog post comes a final reflection on David Quammen’s very lengthy book on island biogeography entitled, “The Song of the Dodo.” The last two sections of the novel focused on Quammen’s personal voyage through the islands of Aru, the reestablishment of the kestrels and the muriquis, and finally, how we are in the midst of a sixth mass extinction largely initiated by human influence.
What I really liked about the conservation efforts regarding the kestrels and the muriquis was that Quammen compared and contrasted active human involvement (kestrels) with passive, observatory human involvement (marquis) and the ensuing success in re-establishing viable populations. Quammen details a descriptive narrative of how the scientist’s involved in the campaign to revitalize the Mauritius Kestrel population went to great lengths to save this dwindling species. These scientists scaled mountains in order to “swipe” the kestrel clutches in order to propel the mother kestrel to produce more eggs to compensate for the missing ones. These extravagant efforts to save a dwindling species are contrasted with the case of the South American muriquis. The scientist involved in this effort holds the notion that humans should merely observe and facilitate the breeding and prosperity of these primates instead of becoming actively involved.
I was surprised by how much I really liked this book. It broke up the definitions, equations, and statistics with a humorous narrative and personal anecdotes. Quammen writes in such a way that you feel like you are learning about the development of these theories and acquiring the evidence along with him. The book ends with tones of both desperation and optimism, and the urgency of a call to action to salvage what little of our natural environment that we have left.
Honestly, the more I read this book, the more I want to be an ecologist. I came into the major not really knowing what job opportunities I would be able to pursue, but this book is certainly giving me some good ideas.
I’m also considering taking more English classes so I can more effectively “fight out [my] battles in the journal literature.” I’m not terrible at writing, but being able to compare my speech to others here at Lehigh has shown me that I really could use some improving. I thought it was funny how the scientists went back and forth in journals debating each other about the details of nature-reserve design (i.e., the SLOSS debate). Quammen pointed out that they even used exclamation points, which are apparently uncommon in scientific journals. Clearly the experiment itself is important, but I’m learning that it is equally important to effectively communicate your results and present your data in a clear and compelling fashion.
Biogeography and a burning boat
Is it a bad sign when the first word of a reading assignment, “biogeography,” is a word I have never seen before? Luckily, Quammen defines all the words he uses, and a second look at the spelling breaks the word down into two parts that are very familiar from high school (bio plus geography).
David Quammen’s personal style made the story of Alfred Wallace really engrossing. I was especially interested because it brought to life some of the more dry reading I have been doing for my museum studies class, particularly with respect to the changing usage of museums. Before Wallace left on his trip to Bali and other islands, he “boned up particularly on Malayan insects and reptiles at the British Museum” (p.29). At the time of Wallace, museums were primarily there for scientists to learn and study. It was not easy or practical for people to travel the earth to see specimens first hand. In fact, some biologists published works detailing the flora and fauna of continents they had never set foot upon, solely from visiting the museums of the day. Later in the chapter, Wallace was described as sending back many specimens for sale to collectors. In fact many of the collectors would, upon their deaths, donate their collections to the government and a new museum would be founded, or an existing museum expanded. In the high tech world we live in today, you think that it would be difficult to put yourself in Alfred Wallace’s shoes. However, Quammen brings the period to life.
As I was drawn into the story, I really felt for Alfred and his trip through the Amazon. At the end of his time there when he was returning to England I felt terrible for his loss. All that work lost when his boat sank. The poor caged animals – including his tame toucan – all perished. The loss seemed insurmountable. However, if the Helen hadn’t caught fire, and all of his work lost, would Wallace have ever gone to the Malay Archipelago? Or would he simply have gone home and sifted through all of his collections and notes for the rest of his life? He pressed on despite the loss, went to the Malay Archipelago and combined the patterns he saw on the islands with the patterns he saw in the Amazon with its natural boundaries – putting it all together to develop the greatest series of ideas in biology. What Darwin much more elegantly coined “natural selection.”
Birds of paradise
The end of The Song of the Dodo was approached very well. Quammen still introduced a number of terms and theories, but it wasn’t an overbearing amount of knowledge saved up for the end. His discussion of Population Viability Analysis and extinction vortices was a helpful depiction of the concepts and a good elaboration of the topics as discussed in lecture. He also provided good examples of the concept of insularization when applied to habitat fragmentation, almost as a summary of the book. I appreciated that he ended on an optimistic note by traveling to Aru and finding that the bird of paradise still exists, despite the level of ecological destruction in the rest of the world. This course was definitely one of the most enjoyable and informative classes of my entire freshman year. I liked the way the material was presented between lectures and the book; they complemented each other well, yet neither required the other and so both were effective on their own.
The Lehigh Canal was built in 1827 to transport coal from the upper Lehigh Valley. The canal was in operation until the 1940s, and it is now primarily used as a recreational trail for hiking, walking, and biking. Within the Bethlehem-Allentown-Easton area, it has all the problems of an isolated natural area surrounded by development (habitat degradation, invasive species, eutrophication of the canal), not to mention the legacies of once being a transportation corridor (e.g., even more invasive species). However, regardless of these problems, the area still provides considerable ecosystem services, including recreational opportunities, a great path for carbon-neutral commuting to work (for me!), and an easily accessible place to observe nature within the greater Bethlehem area.
Below are a few observations, made by students along the towpath this semester…highlighting the educational value of this interesting legacy of Lehigh Valley history.
Restoration at Sand Island
Last weekend, Dennis Scholl of the Delaware and Lehigh National Heritage Corridor led a group of volunteers in an effort to replant native species along the canal just east of Sand Island in Bethlehem, PA. I spent many hours of my youth exploring this area, visiting the playground, walking the bridge, and returning via the towpath adjacent to the canal. The area, and particularly the banks of the canal and river, were thick with vegetation. Although located in the center of the city of Bethlehem, as a child I really believed that we were walking deep in a magical forest. However, a few years ago most understory vegetation was cleared, giving it the appearance of a park. You could see through the trees all the way to the streets of Bethlehem. Of course, the intentions of this work were good – much of the understory vegetation was composed of invasive species, and native species were extensively planted in their place – but a lot bare ground remained. However, the removal of the vegetation didn’t just change the appearance of the area; without the thick vegetation the area became vulnerable to increased erosion, which was made worse by the unusual rain and flooding of last year. I hope the new restoration effort succeeds in reintroducing local plants to all of the areas of Sand Island, turning it back into a magical forest in the middle of the city of Bethlehem.
As I was on a bike ride near the Lehigh River, I came across something that we had just discussed in class – a fish ladder! To me, the ladder looked like a very difficult maze for the fish to navigate. The dam was originally constructed to help boats cross the river and was called the chain dam because there was a link chain across the river to prevent boats from falling over the edge of the dam. The entrance to the ladder was surprising small – only 2 meters or so wide. It is hard to believe that a fish could find it, let alone actually decide to enter it.
Apparently the ladder was added to the dam in 1992. One year fish tallies were made to assess how many fish actually use the ladder. 645 fish made it up the ladder from March 31-June 7. The tallies were achieved by using cameras that recorded the ladder 24 hours a day. The tapes were then looked through by interns, and the fish were each counted. Must have been about as exciting as counting sheep.
I observed a fish or possibly an eel that seemed to be stuck to one of the concrete walls. I wonder how many fish die in the ladder each year, or from injuries sustained while trying to navigate the maze? Perhaps another job for the interns….
Turtles, Turtles, and More Turtles
Today after class, I went for a run on the canal path. Usually I don’t pay much attention, but today I happened to look into the canal and saw a painted turtle basking in the sun! I continued to look for them while I ran. I saw another immediately…and then another right after! So I decided to count and by the end of my run I had seen 36 turtles! I have always assumed that the murky, algae-covered waters of the canal couldn’t possibly contain any life besides some bottom feeders. However, after a little research I discovered that painted turtles are extremely common in Pennsylvania, and they prefer slow-moving water and ditches where algae and insects are abundant. So in contrast to what I had thought, the canal is probably really good habitat for them.
It was a damp afternoon; it had been raining for most of the day and humidity was still in the air when I returned from my run and took some time to recover by stretching my legs. Seating myself on the driveway as I stretched, I noticed a six-inch-long earthworm winding its way slowly across the asphalt. I have often seen dead, desiccated earthworms on asphalt and concrete surfaces –my understanding of the phenomenon is that earthworms burrow up out of the ground during heavy rain to avoid being drowned as the soil becomes saturated. Usually, a few individuals seem to have the misfortune of ending up on impermeable asphalt or concrete surfaces and dying before they are able to find their way back to moist soil after the rain ends. I watched this particular earthworm as it progressed slowly across the porous surface of the asphalt, sticking its anterior end into each chink and crevice it came upon, apparently trying to burrow back down into the ground. Of course, each attempt at burrowing was thwarted by the impermeability of the asphalt. It was sad to watch the futility of the earthworm, guided by instinct, trying to burrow into this strange environment.
A quick Wikipedia search of earthworm physiology and behavior revealed the mechanism by which earthworms move through soil. These mechanisms appeared useless on asphalt—an environment the earthworm is not evolutionarily equipped to deal with. The earthworm’s slow pace brought to mind the issue of scale. The short distance of a driveway, traversable quickly in human terms, is for the tiny earthworm a much more formidable expanse. Watching the confused route the earthworm was taking, I couldn’t help but think it would probably live out the rest of its short life on that driveway, like so many of the poor, desiccated carcasses I had seen before. We often think of the effects that roadways and other manmade barriers have on larger animals like deer, but habitat destruction and fragmentation clearly operate at all scales, including the very small. By placing artificial barriers like roads or driveways in the middle of an earthworm habitat, could humans change the environmental conditions governing the evolution of earthworm populations? Islands of earthworm populations subject to the sorts of processes that take place on oceanic islands? Insular populations separated by concrete barriers?
A few days after my earthworm observations, we discussed the ecological role earthworms and other “soil biota” play in helping regulate soil health in my Science of Environmental Issues course. The soil is a habitat like any other, home to a diverse and extensive ecosystem of organisms – plants, fungi, arthropods, and microbes – that are linked to the aboveground ecosystem through the food web. By recycling nutrients like nitrogen and phosphorus and making them available to plants, soil biota help maintain soil quality and productivity. According to many sources, earthworms in particular help to increase water infiltration and water retention by soil through their tunneling and burrowing activities; they also mix and aerate the soil. These functions are thought to help to make soil more arable so that plant species to take root and develop more easily. But is this true? Apparently not all scientists agree.
Listening to the above NPR Science Friday podcast suggests a more nuanced perspective on the ecological significance of earthworms. It turns out that earthworms, like the one I saw exploring the topography of my driveway, may not be as innocuous or even as beneficial as I originally thought. Apparently, most earthworm species in the forests of the northeastern United States are non-native transplants from Europe and Asia and may be deteriorating soil quality in these ecosystems. It seems hard to believe, but the emblematic nightcrawler species, whose uses as bait and perceived importance in gardening make it such a visible part of American cultural life, is actually an invasive European species. Native North American earthworm species are not found in higher-latitude states because they were killed around 15,000 years ago when the land was glaciated. Considering that I live north of the glacial boundary, it is very likely that the earthworm I saw on my driveway was one of the interloper species.
Conventional wisdom among farmers and gardeners has long held that earthworms improve soil quality—exactly as I was led to believe from my previous class discussions. However, some scientists refute this claim, arguing that while the movement of earthworms has been observed to aerate compacted soil, leading to increased productivity, soil in most agricultural and forest systems is not compacted and receives adequate aeration without earthworm activity. Also, many studies that have attempted to show that earthworms enhance soil productivity in agricultural systems have been anecdotal. Although earthworm activity likely does help to accelerate the movement of water through soil, this may not always be a good thing for soil productivity, as too much earthworm activity can result in water leeching from the soil too quickly.
The main problem with non-native earthworm species in the forest ecosystems of the Northeast is that they consume the rich layer of organic matter that coats the forest floor. This organic “carpet” is essential for soil productivity and the health of the forest ecosystem, as it protects soil from erosion; provides proper environmental conditions for certain plant species, like spring beauty, trillium and trout lily, to take root; provides a habitat for certain animal species, like salamanders and beetles; and stores carbon and nitrogen, preventing the release of these elements into the atmosphere or nearby water systems. However, earthworm populations are extremely hard to remove once they’ve been established. Human efforts should probably be aimed at halting their spread rather than trying to eliminate existing populations. Education and outreach to people who use earthworms in different aspects of their daily lives, he said, is the most effective way to control the problem. Accidental transfer by humans is, of course, the way these organisms likely arrived in the non-native environment of North America to begin with–as is the case with so many invasive species.
All from watching a little earthworm trying to make its way through our world….
I think that one of the most salient aspects of conservation is its applicability to human life – a fact nicely highlighted by the above episode of NPR’s All Things Considered. While I personally value the natural environment in and of itself, I understand the necessity to recontextualize environmental protection in terms of human welfare in order to gain wider support. It is only through understanding that the environment provides human life with its sustenance and survival – even if we are active shapers – that large-scale policy shifts will occur to facilitate environmental protection.
One of the most frequently cited reasons for enacting environmental policy is just this: that the environment holds an enormous untapped wealth of resources that could, potentially, be used by humans. The NPR story highlights this; while often times the ocean might be overlooked by the everyday citizen, it does cover over seventy percent of the earth’s surface. With that large of a footprint, it seems obvious that it potentially contains numerous untapped human resources. For example, the drug Briostatin was originally derived from a type of marine moss animal (a species of Bryozoan, Bugula neritina) and has been tested as an inhibitor of cancer-cell growth, particularly in combination with other drugs. It is also currently being explored as a treatment for Alzheimer’s disease. How many other potential pharmaceuticals lie under the sea?
“It’s another example of how human activities alter the environment in unexpected ways that can often come back and bite us” reads the sign off to the above podcast from Scientific American entitled West Nile Virus and Bird Diversity. Ecological complexity underlies much of the study of biodiversity and conservation. Whether the end goal is land-use policy or pure wilderness preservation, this complexity must be considered when valuing natural ecosystems and the services they provide humans. The above podcast briefly highlights how the citification of previously rural land has reduced bird diversity, and in turn lower bird diversity has been linked to higher numbers of human incidences of West Nile virus. Mechanisms are unclear, but studies suggest that increased diversity within an ecosystem often reduces the proportion of suitable hosts for a disease. For example, a similar mechanism characterizes Lyme disease occurrence and transmission. Small (less than about 5 acres) forest fragments contain lower species diversity than larger forest tracts, and also harbor more Lyme-disease carrying white-footed mice. Smaller forest fragments have been shown to have a greater number of infected ticks – another unexpected consequence of human activities that is (literally) coming back to bite us.
Conservation efforts that seek to repackage issues in terms of human welfare will ultimately, in my opinion, be successful. Though I don’t personally see this as the only reason for protecting the environment, the pragmatic side of me understands its necessity. Whether it is the economic assessment of ecological services, or a more general understanding of the interconnectivity of humans and ecosystems, long-term conservation goals will only be met through appealing to the humanistic human. If not, the environment risks damage, and our own ignorance may again….come back to bite us.