biodiversity

Climate Change, Nitrogen and Biological Diversity

By Chris Clark, Ph.D.

When I visit our national parks, hike in the woods or backpack in the mountains, one of the things I enjoy most is the natural beauty that surrounds me—especially the plants. I’m a plant person, which is hard for some people to understand. (“They don’t do anything” many of my friends quip.) But, to me, that couldn’t be further from the truth.

Prairie scene

Three of the most prevalent dangers to plant biodiversity are habitat loss, climate change and nitrogen deposition.

Plants form the foundation for all robust ecosystems, supporting healthy biogeochemical cycles (how materials—for example, fallen leaves—move through systems and are chemically altered by both biological and geological forces), clean air and water, and all higher life forms. To me, this gives plants a quiet kind of majesty that is beautiful to witness.

All the different types of plant species in an ecosystem, from the largest trees to the tiniest wildflowers, play a role in the healthy functioning of that system. In the systems that I studied as a graduate student, the grasslands of Minnesota, it blew me away how many different species co-existed in one square meter of space. What once was just “green grass” became a teeming system of life to me.

Three of the most prevalent dangers to plant biodiversity nationwide are habitat loss, climate change and nitrogen deposition. These stressors can lead to changes that may reduce plant biodiversity, which can cascade through systems and affect other processes and services.

The work I do at EPA is important because it can help preserve ecosystems. I look at different stressors, like climate change and nitrogen deposition, and their impacts on ecosystems. I identify the types of changes that occur and the rate at which the changes are happening. If we understand this, we will be better poised to support and inform policy decisions that enhance the sustainability of our natural resources and avoid irrevocable damages.

For a recent project, I looked at how nitrogen deposition impacts plant biodiversity on land nationwide.  My collaborators and I examined “critical loads” (the upper limit of nitrogen an ecosystem can handle) from different regions of the U.S.  We then used computer modeling to estimate when deposition was too high and what the effect might be.

The results showed that many regions had nitrogen deposition amounts that may be too high, with losses of species ranging from one to 30 percent using a “worst-case scenario” approach.  When we used a “best-case scenario” approach, we estimated minimal losses. We had to use both of these scenarios because scientists don’t know exactly where in this range the critical loads are, and for which systems.

Before our study, no one knew what the ramifications could be of such a range. Refining these estimates of critical load thus is a very important area of future research.

Our results were recently published in the journal Ecology. Future work will build on this project to look at different aspects of the climate change-nitrogen relationship.  As a whole, the research will help promote a better understanding of how climate change and nitrogen deposition may impact our natural environment; this, in turn, will help policy makers mitigate these impacts. That’s important to me, and probably to anyone, who enjoys walking in the woods, backpacking or any other outdoor activity.

About the Author: EPA research scientist Chris Clark, Ph.D., works on a diversity of issues related to climate change, including biodiversity, biofuels, and urban resilience.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Studying Plant and Insect Response to Environmental Change: A Love Story

By Jessica Dawn Pratt

EPA Fellow Jessica Pratt examines sagebrush.

EPA STAR Fellow Jessica Dawn Pratt

As a native Midwesterner, I was not impressed with the brown and shrubby coastal sage scrub ecosystem that covered hillsides around my new home when I moved to southern California in September of 2005. It was drab, short and prickly compared to the northern hardwood forests to which I was accustomed.

But, as an ecologist, I was excited to live in a “biodiversity hotspot,” a place that rivals the species diversity of many tropical forests and is home to numerous endemic and endangered plant and animal species.

I quickly learned that September was the end of the summertime drought that characterizes California’s Mediterranean climate. As I watched the brown and shrubby hillsides come to life with the winter rains, I fell in love with the coastal sage scrub ecosystem.

In addition to being incredibly diverse and unique, the coastal sage scrub ecosystem also faces many threats, including development, habitat fragmentation, pollution, climate change, invasive species, and wildfire. So, in 2008 when I began the Ph.D. program in Ecology & Evolutionary Biology at the University of California, Irvine, I was determined to work on questions related to its conservation and restoration. A Science to Achieve Results (STAR) Fellowship from EPA allowed me to do just that.

My graduate research examines how California sagebrush (Artemisia californica), an icon of the coastal sage scrub ecosystem, is responding to environmental changes like climate change and nitrogen pollution, and how the response of this important plant species affects the animals that depend on it.

It is my hope that understanding how important species respond to environmental change – and how those responses “scale up” throughout the ecosystem to affect other species – will help us predict and mitigate the impacts.

The first part of this work, published online in Global Change Biology and summarized on UC Irvine’s web site, shows that sagebrush in the southern part of its range will adjust better to climate change than sagebrush in the north.

To determine this, plants collected from a 400-mile stretch of coastal California were grown in experimental plots in Orange County where we tested their response to altered precipitation. Populations from southern sites, where year-to-year rainfall amounts have historically been rather variable, were more flexible to altered precipitation than populations from the north, where precipitation has been more predictable. The findings indicate that a species’ response to climate change won’t always be equal across its range.

Moreover, we saw that year-to-year variability in rainfall at weather stations across the species range is increasing more rapidly in the north, in the very regions where plants may be the least able to tolerate this effect of climate change. As such, including southern sagebrush in northern restoration plantings may be one way to ensure that we give this species an opportunity to adapt to our changing climate.

As we move forward with habitat conservation and restoration in this era of change, it may be prudent to consider the flexibility of the plants that we use in such endeavors so that the greening up of California’s shrubby hillsides each fall may continue long into the future.

About the Author: Jessica Pratt is a Ph.D. Candidate in Ecology & Evolutionary Biology at the University of California, Irvine. Her research examining plant and insect community responses to environmental change in Southern California is funded through the EPA’s STAR Fellowship Program.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Let’s Natuculture!

By Manny “The Mulch Hugger” Reyes

"The Mulch Hugger" in action.

For 20 years I have enjoyed working with awesome students at North Carolina Agricultural and Technical State University, where I am making myself known as the ‘mulch hugger.’ 

I grew up in the Philippines totally unconcerned with nature.  I vividly remember my enjoyment in shooting beautiful tropical birds and collecting their eggs and my vision of converting forests into monoculture agriculture. 

Well, my passion has turned 180 degrees. Today I am working to promote the integration of natural systems into urban landscaping. 

Thanks to funding provided by EPA’s People, Prosperity and the Planet (P3) program, my students and I have began natuculture.  What’s “natuculture,” you ask? The term, coined at North Carolina Agricultural and Technical State University (NCA&T), refers to any human-made system that mimics nature in “human disturbed landscapes,” such as your typical college campus.  We introduced the term at the 2011 EPA-P3 conference.

We ‘natucultured’ a typical lawn (that is a monoculture of turf grass) into a vibrant, chemical-free ecosystem with at least 150 flora and visited by multiple kinds of fauna.  I dare say that this place can be the coolest student hangout on campus.  Adjacent to it, the University recently razed a building and has designated the area to be a ‘green park,’ which we intend to landscape exclusively with native North Carolina flora. 

Image of "natucultural" landscape showing biodiversity

"Natucultured" landscape on campus.

We are actively spreading ‘natuculture’ in several K-12 campuses.  Yup!!!! We designed and built a raingarden in an elementary school and installed six rainharvesters in six high school campuses. We are now establishing biologically engineered experiments to help us learn how to improve soil health while producing chemical-free vegetables.  

Furthermore, we are developing lesson plans to integrate natuculture in K-12 science courses and organizing a natuculture scientific conference for high school students.  NCA&T faculty and students are actively partnering with K-12 faculty and are mentors to K-12 students.

About the Author: Guest blogger Manuel R. Reyes is a Professor of Biological Engineering at North Carolina Agricultural and Technical State University. He helped start Kingfisher Park, ‘a haven of biodiversity;’ in the Philippines, and works to advocate agroecology in Southeast Asia through agroforestry and conservation agriculture technologies.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

The Green Monster

By Brenda Reyes

“Mom there is a green monster in the patio.” The loud voices of my 5-year-old and 2-year-old neighbors made me run to the patio to see what was happening next door. As startled as I was, so was their mother and my gardener, who was working on my yard that day. The “green monster” was a gigantic 4-foot green iguana who was climbing on the power and electricity pole between our houses and eating avocados from a tree.

While one might think I live in a rural area, I live less than five minutes away from the CEPD office in a suburban/urban area which is next to Ft. Buchanan, a military facility with lush vegetation. This kind of iguana is also known as Iguana iguana. Native to Central and South America, it was introduced to Puerto Rico in the 1970s as a result of pet trade. It has been threatening native biodiversity and impacting infrastructure, agriculture and human safety for the last decade. There is no management program to control this reptile that is becoming more widespread and dominant in other areas around the island as they have no natural predators. The introduction of exotic species impacts biodiversity.

In urban and suburban areas-like the one in which I live-green areas have enormous economic and aesthetic value. Having these spaces help us maintain and support overall environmental health as humans have long depended on these for recreational and commercial activity. Just like the iguanas, there is a new frog in town menacing native biodiversity: the Cuban Frog. Bigger than our native Coqui and smaller than a regular toad or frog, this species is taking over our green spaces. It was about four months ago that I started noticing that our mixed breed dog, Chocolate, was leaving small dead frogs by the side yard. While frogs are deadly for dogs, I saw Choco playing with these almost daily. On a closer inspection with my 6-year old son, we discovered this was a different kind of frog. Three weeks later an article in a local paper identified this amphibian as the new invasive species.

Like iguanas and frogs we have also seen monkeys roam near our yard. They are known to steal fruits from the trees in the houses. We also have South American macaws that fly every morning making a lot of noise. Their population has grown in the Guaynabo area for the last 13 years. While they are quite a spectacle with their bright yellow and blue feathers, they have taken over the top of palms where other native birds also make their nests.

EPA belongs to the National Invasive Species Council, a working group of 13 federal agencies designed to prevent and control invasive species. For more information of what invasive species are in your area and what is being done about them please visit http://www.invasivespecies.gov/

About the author: Brenda Reyes has been a public affairs and community relations specialist out of EPA’s Caribbean Environmental Protection Division (CEPD) office in Puerto Rico since 2002.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Science Wednesday: Want more? Get Science Matters!

Each week we write about the science behind environmental protection. Previous Science Wednesdays.

By Aaron Ferster

Last year, we shared 64 separate blog posts on “Science Wednesday.”

Topics ranged from green chemistry and sustainability (11 posts), to biodiversity’s links to human health (3 posts), clean air science (20 posts, including several about Air Science 40 activities marking four decades of scientific achievements supporting the Clean Air Act), the U.S.A. Science & Engineering Festival (5 posts), and a host of other subjects too numerous to fit into a single blog post.

A special thanks to all our readers and commenters, who joined the science “Greenversation” to the tune of some 378 comments.
The award for the Science Wednesday blogger who generated the most comments goes to EPA scientist Jeff Morris, the National Program Director for Nanotechnology in EPA’s Office of Research and Development. Jeff’s February 10 post, Sheep, Goats, and Nanoparticles, not only provided a unique insight into nanotechnology research, but did so in a way that clearly sparked interest.

2011 promises to be another great year of sharing our science. Already in the works are regular Science Wednesday posts on green chemistry to help celebrate the International Year of Chemistry, and updates from the National Research Council’s efforts to help the Agency incorporate sustainability into all our programs. Stay tuned!

By now you’ve noticed that we shared more “Science Wednesday” posts than there were Wednesdays in 2010. We had to turn a few regular Tuesdays and Thursdays into Science Wednesday to share late-breaking or topical science news. And we still have much more to say! That’s why I’d like to invite everyone to sign up for our newsletter, Science Matters.

The January-February issue includes stories on near-roadway air pollution research, a project by EPA researchers exploring the impact of rain barrels and rain gardens on stormwater runoff, efforts to develop high-tech methods to monitor insect-resistant corn crops—and more.

To have the newsletter delivered right to your inbox, click on the link below and add your e-mail address to the box on the web site:

Subscribe to Science Matters

Thanks again for joining the Greenversations.

About the Author: Aaron Ferster is the lead science writer in EPA’s Office of Research and Development and the editor or Science Wednesday.

Editor’s Note: The opinions expressed in Greenversations are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Science Wednesday: EPA Helps Celebrate the International Year of Biodiversity

Each week we write about the science behind environmental protection. Previous Science Wednesdays.

As part of a series of United Nations (UN) events celebrating the International Year of Biodiversity (IYB), and to review progress towards the Millennium Development Goals, the UN Environment Programme organized an event on April 30 at New York’s American Museum of Natural History.

The event brought together scientists—including me—for a panel discussion on the important roles biodiversity and ecosystems play for children’s health and well-being.

We discussed the implications of continued biodiversity loss and ecosystem degradation for children, highlighting key concepts with case studies in Africa and Latin America. We also talked about actions we think would provide mutual benefit to both conserving biodiversity and protecting children’s health and well-being.

So what can be done to achieve mutual benefits for biodiversity and child health?

Erika Vohman, of the Equilibrium Fund, presented one great example from the Fund’s award-winning Maya Nut Program in Latin America. The program concentrates on helping rural women, acquire skills to produce and sell products made from Maya nuts they harvest from the rain forest.

The nuts are extremely nutritious, providing high levels of protein, fiber, calcium, potassium, folate, iron, zinc, and vitamins A, E, C, and B. Vohman’s team has documented a wide array of benefits from the program, including rising income levels, increased self-esteem and status for the women, food security for families, and better health and nutrition for mothers and their children. They even found an increase in infant birth weights.

The event gave me the opportunity to talk about EPA’s efforts to develop transdisciplinary studies linking ecosystems, biodiversity, and human health. One example, as I’ve blogged about previously, is our effort to explore the links between biodiversity and Lyme disease transmission (for which incidence rates are highest among children.) These studies are fostering partnerships among ecologists, epidemiologists, urban/suburban planners, and local and state governments to discuss scientific advances and new risk prevention/reduction strategies at the landscape and household scales.
It takes a community to engage in biodiversity and children’s health and to put results into action!

About the author: Montira Pongsiri, PhD, MPH, is an Environmental Health Scientist in EPA’s Office of the Science Advisor. She has blogged about her work exploring the links between biodiversity and human health for Science Wednesday.

Editor’s Note: A podcast of the event is available at: http://www.amnh.org/news/2010/05/podcast-childrens-health-ecosystems/. A brochure of key messages from the event will be publicized by partners and used during IYB, including for the General Assembly’s High Level Meetings on the IYB and progress towards the MDGs, and the 10th Conference of the Parties to CBD in Nagoya, Japan.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Science Wednesday: Biodiversity Loss Impacts Global Disease Ecology

Each week we write about the science behind environmental protection. Previous Science Wednesdays.
In this month’s Bioscience , we lead a team of ecologists, epidemiologists, an economist, and policy analyst on an article linking biodiversity decline and infectious disease transmission.

For the paper, the research team reviewed and compared seven case studies—malaria, schistosomiasis, Lyme disease, West Nile virus, Hantavirus Pulmonary Syndrome, enteric disease, and allergic diseases—and developed a typology of proposed mechanisms linking human health and biodiversity, from the level of genes to habitats.

What did we find? For one thing, the recent emergence and reemergence of infectious diseases appears to be driven by globalization and ecological disruption. We propose that habitat destruction and biodiversity loss can increase the incidence and distribution of infectious diseases affecting humans.

We think the article could have a major impact on our understanding of the relationship between biodiversity and human health, and the use of new environmentally-based strategies to protect both the environment and public health.

Protecting natural areas, such as national parks and refuges, is the focus of many conservation efforts, but this approach alone cannot prevent biodiversity loss. And since typically not very many people live near these areas, most people don’t realize how valuable they are.

We suggest that biodiversity protection may be just as important to people on a local scale, in their everyday lives, and that science-based management approaches can produce co-benefits for conservation and for human health.

Our paper is a truly interdisciplinary undertaking. While we have training in public health and conservation biology, our fellow contributors include ecologists, epidemiologists, an economist, and a policy analyst. As is the case with biodiversity protection, we believe that this interdisciplinary approach has multiple advantages. It allows us to explore biodiversity conservation, the history of disease, and to take an economic perspective (relevant to decision-making processes) on these disciplines.

The paper concludes with ways we think we can move forward in research and policy, but that will certainly involve more interdisciplinary work on our part. We’re looking forward to that!

About the Authors: Montira Pongsiri, PhD, MPH, is an Environmental Health Scientist in EPA’s Office of the Science Advisor, and Joe Roman, PhD, is a conservation biologist and a Fellow at the Gund Institute for Ecological Economics, University of Vermont, Burlington. He was previously at the EPA as a Science and Technology Policy Fellow with the American Association for the Advancement of Science.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Science Wednesday: Biodiversity, Mosquitoes, and Health, Oh My!

Each week we write about the science behind environmental protection. Previous Science Wednesdays.

It was 0630 and although the sun was beginning to rise, it was still very dark within the tropical forest. Following a 20 minute ride in a small boat, we had arrived at a remote trail on the island and were now navigating the trail to check the CO2/light traps set the night before. The illuminated traps were beacons in the sea of dark forest, and we hoped they’d be filled with mosquitoes. The forest was peaceful in the early morning light, except for the occasional bouts of grunting from the howler monkeys or an agouti crossing the trail.

I never imagined working at EPA would lead me to Barro Colorado Island (BCI), a former mountain top that became an island when the Panama Canal was created in the early 1900s. Now a natural monument, it was the setting of the inaugural sampling event for a joint project between EPA and the Smithsonian Tropical Research Institute (STRI).

The project explores the link between biodiversity, insect vectors (those capable of passing a pathogen one animal to another), and disease. The connection between biodiversity (the number and abundance of difference species) and disease is complicated, but we know that sometimes changes in biodiversity (specifically, the loss of structural diversity) can increase the abundance of certain disease-carrying vectors. In turn, this can increase the risk of humans coming into contact with the disease-transmitting vector. Human activities, such as encroaching into new areas to build houses or clear land for farming, can change local biodiversity.

The STRI-EPA project focuses on mosquitoes and how changing biodiversity in “natural” and anthropogenic landscapes affects vectors of public health importance.

Back at the lab, we began the monumental task of sorting through the traps’ contents. Thankfully, I was surrounded by insect experts who were able to show me exactly what to look for among the tiny copious critters. Microscope and forceps in hand, I started sorting and sorting…. Hours later, sorting complete, we separated mosquitoes and sandflies (another vector important to public health) by species into groups of 50 or fewer. Specimens were placed into vials and frozen. The samples will be analyzed later to see what kinds of pathogens the insects were carrying, if any.

image of author wearing orange lifejacket Over this next year, sampling will continue at BCI. We plan to expand sampling into nearby, land-disturbed areas inhabited by people so that mosquito diversity and disease risk can be compared with that of BCI.

About the Author: Meghan Radtke, Ph.D. is an AAAS Science and Technology Policy Fellow at EPA. Her fascination with biodiversity and tropical forests inspired her to join the Biodiversity and Human Health research effort.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Science Wednesday: Sustaining Tropical Forests

Each week we write about the science behind environmental protection. Previous Science Wednesdays.

The Amazon basin contains more than half the world’s remaining tropical rainforest, and is facing unprecedented changes that will have major impacts on biodiversity, regional hydrology and the global carbon cycle.

But the need for employment is causing tropical deforestation on a vast scale.

Stopping deforestation requires forest management strategies that provide jobs for people living in or near forests while also creating incentives for forest conservation. The andiroba tree (C. guianensis)– valued for the high-quality oil extracted from its seeds and for its mahogany-like timber—could provide this opportunity.

Collect the seeds, cut down the tree, or a little of both?

image of author standing on a root of a big tree over waterThrough my research, I am looking at the intersection of conservation and economics related to harvesting C. guianensis. I am using ecological models with an economic component to answer the question: Under what ecological and market conditions would the collection of C. guianensis seed oil be favored and, conversely, under what ecological and market conditions would C. guianensis timber harvest be favored?

Since 2004, I have been measuring growth, survival and reproduction of C. guianensis trees at my research site in the Brazilian Agricultural Research Institute’s 1,200-hectare research forest in Acre, Brazil.

Using these measurements, I plan to fine-tune models about future tree growth under various management scenarios, as well as identify how different life stages, such as seedlings, saplings, mature trees, etc., contribute to growth of the entire tree population. For example, it is possible that leaving a certain number of reproducing trees per hectare would maintain a growing population, leaving other, non-reproductive trees to be harvested?

I will use the new model to determine sustainable harvest limits for both timber and seed, and then incorporate the results into a financial assessment of these two competing strategies to manage the species. To ensure that the tree population is maintained and that it generates income, I plan to compare the relative compatibility of timber vs. seed harvest.

After I finish writing up my results, I will return to Brazil to give a series of training workshops and seminars on my results so they can be applied to forest management practices. In addition, I will compile materials (including comic-book-like illustrated pamphlets) that break down my results into tools that can benefit forest residents and local nongovernmental organizations. By sharing my research results in this way, I hope that I can provide important information to the local Brazilian government and play a part in helping people living near the forest find a sustainable way to create income based on a standing (or managed) forest.

About the author: Christie Klimas is a PhD student at the University of Florida in the department of Forest Resources and Conservation. A 2004-2006 EPA Science to Achieve Results (STAR) Graduate Research Fellowship supported her Master’s Degree research.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Year of Science Question of the Month: How Do You Think Biodiversity Affects You?

For each month in 2009, the Year of Science — we will pose a question related to science. Please let us know your thoughts as comments, and feel free to respond to earlier comments, or post new ideas.

The Year of Science theme for September is Biodiversity and Conservation. Biodiversity is a catch-all term that refers to the variety of life at all levels, from the range of genes within in a breeding population (more genetic diversity helps to prevent inbreeding problems), to how many different species there are, all the way to the variety of different ecosystems. EPA scientists are exploring how biodiversity is linked to human health and well being.

How do you think biodiversity affects you?

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.