Santa Clara University

Department of Environmental Studies and Sciences

News and Events


Environmental Studies and Sciences News & Events

  •  Virginia Matzek awarded funding for restoration study in France

    Saturday, Feb. 7, 2015

    ESS assistant professor Virginia Matzek has been awarded a grant to study carbon credits associated with forest management strategies along the Rhône River in France. Virginia Matzek, along with colleagues John Stella of the State University of New York and Hervé Piégay of the École Nationale Supérieur de Lyon, will receive 10,000€ from the Institut Écologie et Environnement in France to perform the study.

    The Rhône is a highly altered and channelized river, having a long history of use for navigation between inland France and the Mediterranean sea, and, more recently, for hydropower. Combined with land-clearing for agriculture, there is very little of the native riparian forest left along the main river channel. However, some stretches of the former main channel, known as the Vieux Rhône, still support riparian forest and experience some of the dynamism of flooding and sediment deposition typical of riverine vegetation.  Previous work done by Stella and Piégay has characterized the forest vegetation structure at sites along the Vieux Rhône. The new project will examine to what extent the growth of forest on sediments deposited in the old channel has increased carbon stocks in soil. Together, these data will allow the group to calculate the carbon credits that could be earned by management strategies that encourage periodic flooding and vegetation growth in the non-navigable reaches of the river.
    Matzek most recent paper on this topic, “Can carbon credits fund riparian restoration?” appeared in January in the journal Restoration Ecology. That paper found that carbon credits earnable by riparian forest restoration on the Sacramento River in California were sufficient to pay back most or all of the cost of planting. Click here for a link to the abstract.
    Photo courtesy of Rama. Licensed under CC BY-SA 2.0.
  •  Cold-water fish habitat affected by warmer climate in the Columbia River Basin

    Saturday, Jan. 17, 2015

    Researchers and water managers have wondered how much heat the fish will have to take.

    The Columbia River Basin is a network of streams that spans the states of Washington, Oregon, Montana, Idaho and British Columbia (see first Figure below) and that provides water for public water supplies, irrigation, and for important salmon runs and other species adapted to its cold and forceful waters.

    Water temperature in a stream is an important physical factor that regulates which fish and other aquatic species can not only survive, but thrive.  With warmer temperatures attributed to climate change, that have been observed in the western U.S. mountains there is concern that not only air temperatures, but also stream temperatures will continue to warm up - beyond levels that cold-water native species can tolerate. Stream temperatures are to a large degree determined by air temperatures and by the temperatures of the various waters that mix in a stream, such as water coming from precipitation, water entering a stream from other tributaries or from upslope portions of a watershed, from groundwater, from flow through the soil layer, and from snowmelt. When temperature and precipitation patterns change, the interactions between physical processes shift in ways that affect stream flow and stream temperature regimes. For example, with warmer temperatures, less precipitation is deposited as snow,and snow melts earlier in the year, but warmer air temperatures affect a stream at the same time as the colder water from snowmelt enters it.

    The century is still young, but several years have already broken records, and 2014 was recently declared the warmest year on record on the global scale.

    And air temperatures are expected to rise further in the coming decades, with concurrent changes in precipitation. Thus accurate assessments of the thermal habitats in freshwater systems are critical for predicting aquatic species' responses to changes in climate and for guiding adaptation strategies. For this project, ESS faculty member Iris Stewart and CE faculty member Ed Maurer and their colleagues used a hydrologic model, coupled with a stream temperature model they developed, and output from global climate models (called general circulation model or ‘GCMs’) that are adapted to the local climate patterns (or ‘downscaled’) to explore the spatially and temporally varying changes in stream temperature for the late 21st century at the scale of both small watersheds (sub-basins) and ecological provinces for the Columbia River Basin.

    They found that, on average, stream temperatures are projected to increase 3.5 °C for the spring, 5.2 °C for the summer, 2.7 °C for the fall, and 1.6 °C for the winter, which are significant changes for such a large system as is the Columbia River Basin. At the ecological province scale, the largest increase in annual stream temperature was within the Mountain Snake ecological province, which is home to migratory cold water fish species. The hydrologic models captured the important, and often ignored, influence of hydrological processes on changes in stream temperature on the local scale. Their work shows, that decreases in future snow cover will result in increased thermal sensitivity within regions that were previously buffered by the cooling effect of flow originating as snowmelt. The largest increases in stream in all ecological provinces are forecast for the spring and summer, already a critical time for water supplies and aquatic habitats. 

    A pdf of the paper, which appeared in the open acess journal Hydrological Earth System Science (HESS) can be downloaded from here: PDF

    Citation: Ficklin, D. L., Barnhart, B. L., Knouft, J. H., Stewart, I. T., Maurer, E. P., Letsinger, S. L., and Whittaker, G. W.: Climate change and stream temperature projections in the Columbia River basin: habitat implications of spatial variation in hydrologic drivers, Hydrol. Earth Syst. Sci., 18, 4897-4912, doi:10.5194/hess-18-4897-2014, 2014.

    Photo of Columbia River by Iris Stewart-Frey

  •  Nicaraguan smallholders thin shade trees, but maintain high species diversity

    Friday, Jan. 9, 2015


    The majority of the world’s coffee producers are smallholder farmers, managing land in tropical regions globally recognized for high levels of biodiversity and capacity for carbon sequestration. Though researchers have recognized the potential for coffee smallholders to conserve biodiversity by maintaining a layer of shade trees and using low-input farming methods, studies have by and large remained at the landscape scale and we know little about long-term species diversity and sequestration patterns in these systems. A recent study published in  Agriculture Ecosystems and the Environment was conducted in partnership with the same cooperative that has worked with ESS faculty member Chris Bacon since 2001. The research tracked changes in shade trees, epiphytes, and carbon stocks in smallholder coffee farms in northern Nicaragua over a 10-year period, offering insight in response to this pressing question.
     Authors Chris Bacon (Department of Environmental Studies and Sciences Santa Clara University), Katie Goodall (Wellesley College), and Ernesto Mendez (University of Vermont) found that tree density and carbon stocks declined over the decade-long study, but diversity of tree species remained unchanged

    Epiphytic plants increased over the ten-year period despite decreasing host tree densities, suggesting either a change in farmer management or improved habitat conditions for epiphytes.  The authors also found that farmers who individually managed coffee farms maintained a greater tree density than collectively managed farms, but that species diversity and carbon stocks were no significantly different.
    This research not only highlights the contribution of smallholder coffee production to the conservation of shade tree diversity and epiphyte communities, but also the pressure smallholders may experience to cut shade trees in order to increase coffee yield.  You can taste the coffee by asking for the Nicaraguan coffee at the Sunstream Café in the Learning Commons. 
    Full citation: Goodall, K. E., Bacon, C. M., & Mendez, V. E. (2015). Shade tree diversity, carbon sequestration, and epiphyte presence in coffee agroecosystems: A decade of smallholder management in San Ramón, Nicaragua. Agriculture, Ecosystems & Environment, 199, 200–206. doi:10.1016/j.agee.2014.09.002



  •  Scientists and land managers at odds on invasive species research

    Friday, Dec. 19, 2014

    Invasion ecologists study the phenomenon of invasive species—plants, animals, and other organisms that have been moved around the globe and established outside their native range, often with disastrous results. Well-known invaders in California include that prickly pest of the state’s rangelands, yellow starthistle, and the quagga mussel, a tiny mollusk that clogs water pumps and pipes, threatening the state’s water infrastructure.

    Research on invasive species is in great demand by natural resource managers who protect the state’s wilderness, agricultural lands, and waterways from pests. But how much of the research done is actually aimed at serving managers’ needs? And are scientists taking care to make their findings can be easily accessed and used by managers outside academia?

    Santa Clara University professor Virginia Matzek set out to answer these questions by comparing the output of research scientists, published in scientific journals, with the needs land managers had identified in an earlier survey. With the help of two Santa Clara undergraduates, Sophia Cresci ’13, and Maile Pujalet ’14, she searched through all the articles on invasive plants relevant to California that were published in top scientific journals from 2007-11. The contents of the articles were then compared to what managers had said they needed to be more effective at controlling plant invasions. Articles were also rated for their usability to managers (e.g., if costs were detailed); how long it took for the findings to be published; and whether the article could be accessed online without a subscription to a university library.

    Matzek, Pujalet and Cresci found that researchers published far more basic science, and far less applied science, than managers would prefer. A handful of invaders got the lion’s share of research, while many other troublesome species were virtually ignored. The usefulness of published research was also hampered by the small scale and short timeframe of research studies, and by lengthy delays between the end of work and the publication of the results. However, with the advent of Google Scholar and “open-access” journals, articles were relatively easy to find online, with about 2/3 being available online with no subscription.

    In the paper’s conclusion, Matzek and colleagues lay out several ways scientists could be more responsive to managers’ research needs while working within the constraints of the academic system. The work was published in Conservation Letters in September 2014; click here to read the full text. Matzek’s previous study, which first identified managers’ needs, was also published in Conservation Letters and is available here.

  •  Carbon credits can pay for ecological restoration in California

    Friday, Dec. 19, 2014

    Since California passed a law to reduce greenhouse gas emissions in 2006, people have been wondering how well AB32’s financial incentives and penalties would work.

     Now research performed at Santa Clara University confirms that the state’s brand-new carbon credits market can pay back the costs of restoring native forest along California rivers. Carbon credits are earned by people engaging in emissions-reducing activities, like planting trees, and purchased by industries, like power plants, that are emitting more than their share of greenhouse gases. Ecological restoration is a particularly attractive way to earn carbon credits because it not only soaks up carbon dioxide, but also provides wildlife habitat and recreational benefits to humans.  In work funded by the US Department of Agriculture’s Climate Change program, Virginia Matzek and colleagues Cedric Puleston and John Gunn found that riverbank forests planted on land owned by public agencies could recoup as much as 109% of the cost of planting, measuring, registering, and verifying the carbon in such a forest after only 20 years of accruing carbon credits.  However, they also found that the credits by themselves were unlikely to persuade farmers on private lands to switch from growing lucrative orchard crops to farming carbon.  


    The findings were published in December in the leading ecological restoration journal, Restoration Ecology ; click here for the abstract. Santa Clara undergraduate students did the field surveys for the study along the Sacramento River in the summer of 2012.  

    Photo of Sacramento River restoration area courtesy Geoff Fricker. Photo of field crew by Virginia Matzek.

  •  ESS and Political Science Alum Aven Satre-Meloy ’13 wins prestigious Rhodes Scholarship

    Tuesday, Nov. 25, 2014


    The Department of ESS congratulates Aven Satre Meloy on being selected as one of the 2015 Rhodes Scholarship recipients. Rhodes Scholarships are the oldest and most celebrated international fellowship awards in the world.  Recipients are chosen for outstanding leadership potential, scholarly achievements, character, and

     commitment to others and the common good. They receive funding to study at Oxford University in Great Britain.

    While at SCU, Aven majored in Environmental Studies and Political Science with a minor in International Studies. He worked with the Office of Sustainability , in Associated Student Government, and with One in Four, a sexual assault prevention peer education group.  Aven won a Hackworth Fellowship from the Markkula Center for Applied Ethics to work on issues of academic integrity. He was awarded the Nobili Medal on graduation .

     Since leaving SCU, Aven has won a Fulbright grant to research and teach in Turkey. He is currently a White House Intern working in the Office of Energy and Climate Change. At Oxford, Aven plans to pursue graduate studies in Geography and the Environment. 


  •  New Assessment of the Uneven Distribution of Environmental Burdens and Benefits for Santa Clara County

    Monday, Oct. 27, 2014

    ESS faculty members Iris Stewart-Frey and Christopher Bacon, together with SCU undergraduate researcher William Burke investigated the uneven distribution of environmental benefits and burdens in Santa Clara County.

    Who lives close to toxic waste sites, freeways, or areas where pesticides are applied, and who has acess to parks and open spaces? Inequalities in the exposure to environmental burdens and access to environmental benefits are an environmental justice concern and have been shown to exist in several urban areas. Although several Superfund sites, many freeways, truck routes, farmlands, and open spaces exist right here in Santa Clara County (SCC), no research to date had investigated how their impacts and benefits are distributed among more and less wealthy neighborhoods, people of different ethnic and racial background, and people of different ages. Documentation of potential inequalites is a first step to address the issues through urban and regional environmental planning. 

    Similar to studies conducted elsewhere, Stewart, Bacon, and Burke assessed the exposure of different populations to a combination of environmental hazards using Geographic Information Systems (GIS). GIS is a software that allows for mapping and overlaying several layers of infomation and to conduct spatial analysis. For example, in Figure 1 here, all types of environmental hazards are mapped together. The resulting GIS-based asessments are termed Cumulative Environmental Impact Assessments (CEIA). The new aspect of the Stewart et al. study is that is explicitly incorporates the impact of freeways and transportation and that it takes the beneficial aspects of parks and open spaces into account.

    The results show that social vulnerability, cumulative environmental hazards, and environmental benefits exhibit distinct spatial patterns in SCC. High environmental hazard values are found along freeway and railroad corridors with substantial industrial legacies, as shown in Figure1, while environmental benefit scores are generally higher in the suburban periphery, as shown in Figure 2. Taking all burdens and benefits into account leads to cumulative scores, which are shown in Figure 3.

    Statistical correlations indicate, that socially vulnerable populations in SCC are predominantly hispanic and are more likely to be exposed to environmental hazards, while white and wealthier populations are more likely to have access to environmental benefits. The results from this study could be used to develop community-based initiatives for neighborhood improvement and environmental-justice-based regional planning and public health policy reform.

    The research was published in the Journal of Applied Geography: Stewart, I. T., Bacon, C. M., & Burke, W. D. (2014). The uneven distribution of environmental burdens and benefits in Silicon Valley's backyard. Applied Geography, 55, 266-277.




  •  Lucy Diekmann awarded USDA postdoctoral grant to study urban agriculture

    Monday, Oct. 27, 2014

    ESS congratulates Lucy Diekmann, who has been awarded a postdoctoral fellowship from the National Institute for Food and Agriculture! Over the next two years, Lucy will be working with Associate Professor Leslie Gray on a study of urban agriculture in Santa Clara County. Lucy is an environmental social scientist with a PhD in Environmental Science, Policy, and Management from the University of California, Berkeley.

    This research project will produce a comprehensive assessment of the benefits, costs, and challenges associated with Santa Clara County's home gardens, community gardens, urban farms, and farmer's markets. One of the project’s goals is to better understand how the benefits and costs of urban agriculture are distributed across the county, with particular attention to low-income communities.

    In addition, Lucy is working with a national Cooperative Extension group for people interested in local, community, and regional food systems. Through her participation in this group, Lucy aims to foster learning and information sharing among Extension educators involved in urban agriculture and to create research-based educational content for a broad audience.

  •  Ancient sediments point to rising mountains as origin of arid Central Asia

    Tuesday, Oct. 14, 2014

     Scientists have long debated the topographic and climatic history of Asia. What were the forces behind the creation of expansive arid regions? How and when did the uplift of Asia’s great mountain ranges occur? While the Himalaya and Tibetan Plateau have received much attention in the tectonics and paleoclimate communities, the history of mountain ranges and deserts to the north of Tibet have remained largely overlooked. Hari Mix and his colleagues at Stanford University and Rocky Mountain College set out to examine the evolution of Mongolia’s Gobi Desert, Hangay and Altai Mountains. In order to track changes in aridity and uplift over the past 80 million years, the team collected and analyzed the chemistry of hundreds of ancient soil, stream and lake sediment samples.

    Many previous explanations for the origin of an arid Central Asia invoked the uplift of the Himalayas and Tibetan Plateau over the last 45 million years. By examining the carbon isotope composition of these ancient sediments, the team was able to quantify the productivity of ancient plants, and in turn the amount of ancient rainfall. These data point to the importance of moisture from the west, not Tibet to the south, as the dominant control on the climate of Mongolia. Sediments from central and southern Mongolia document a 50-90% decrease in rainfall over the past 30 million years. The group’s findings, published in this month’s American Journal of Science, suggest that the uplift of Mongolia’s Altai and Hangay Mountains created rain shadows leading to the expansion of the Gobi Desert. Hari hopes to return to Mongolia and Kazakhstan to continue examining the evolution of moisture transport in Asia

    You can find the article at:


  •  ESS welcomes new faculty member Hari Mix

    Monday, Sep. 15, 2014

    Hari comes to us from Stanford University, where he received degrees in Geology (B.S.) Environmental Earth System Science (PhD). Hari reconstructs ancient continental environments analyzing isotopes in soil, river and lake sediments. His research addresses questions involving the topographic evolution of mountain ranges, the role of plants in continental water vapor recycling, and the response of the climate system to elevated atmospheric CO2 concentrations.


    At SCU, Hari will teach courses in climate science, introductory earth science, and GIS, and conduct research on the topographic and climatic evolution of the Alaska Range, western US and Central Asia. He is establishing a laboratory facility to measure stable isotopes in water, with the intent to study a range of topics in modern climate change and the hydrologic cycle. Hari is passionate about the mountains. His adventures have taken him on numerous expeditions to the high peaks of the greater Himalaya, but he finds himself most at home in California’s High Sierra.


    ESS is delighted to have new assistant professor Hari Mix on board the faculty team!