The Rubenstein School of Environment and Natural Resources The University of Vermont

The Rubenstein School of Environment
and Natural Resources
The University of Vermont
THIRTY-SECOND ANNUAL
GRADUATE RESEARCH SYMPOSIUM
Friday, October 9th, 2015
4:45 – 7:45 PM
George D. Aiken Center
Please recycle this program.
4:45pm
Welcome by Dean Nancy E. Mathews in Aiken 103
5:00 pm
Marcella Dent
The Facilitative Role of Government
and Science Communication in a
Collaborative Conservation Network
5:15 pm
Alison Adams
Thirty Years of Forest Conversion in
the Northeast: Historical Patterns,
Carbon Storage Impacts and Future
Projections
5:30 pm
Jessica Griffen
Connecting Guests to the Landscape at
Kripalu: Ecological Inventory,
Interpretation and Education
5:45 pm
Alexandra Millar
The Functionality of Metaphor Use in
Motivating Behavioral Responses
6:00 pm
Nathan Fry
The Ala Archa Ecological Leadership
Project: Evaluating the Efficacy of
Outdoor Education in Operationalizing
Ecology and Conservation in the
Kyrgyz Republic
6:15 pm
Break
6:30 pm
Carrie Kozel
Can Early Feeding in Lake Trout Fry
Ameliorate Thiamine Deficiency?
6:45 pm
Hana Aronowitz
Investigating Cryptic Speciation
among Allopatric Populations of
Hemlock Woolly Adelgid, Adelges
tsugae (Hemiptera: Adelgidae)
7:00 pm
Choki Gyeltshen
Fire Risks in Bhutan's Blue Pine
Forests: Anticipating and Adapting to
Climate Change
7:15 pm
Aviva Gottesman
Regeneration Responses to
Management for Old-Growth
Characteristics in Northern HardwoodConifer Forests
7:30 pm
Sam Talbot
Wildlife Habitat Linkages
Surrounding Lake George and
Southern Lake Champlain
Thanks to Ariana Cano for moderating this session and Emma Sass for providing technical assistance.
Reception to follow in the Aiken Solarium
Oral Presenter Abstracts
(in alphabetical order)
Thirty Years of Forest Conversion in the Northeast:
Historical Patterns, Carbon Storage Impacts and Future Projections
By: Alison Adams
Advisor: Dr. Jennifer Pontius
The ability to monitor and assess changes in forest cover and the services they provide is critical
to sustainably managing forested land in an era of unprecedented environmental change.
However, current land cover products covering the northeastern United States provide neither the
spatial, informational, or temporal resolution necessary to perform comprehensive longitudinal
analyses of changes in forest cover and carbon stored in the region. Additionally, whether it is
important to capture forest heterogeneity in landscape-scale carbon calculations is an empirical
question that remains largely unexplored. Here I present 1) a novel method to quantify historical
forest change in the Northern Forest region using maps of tree species basal area, 2) a method to
predict future changes in forest cover and composition given historical changes mapped in (1),
and 3) comparative regional-scale carbon storage calculation methods using varying levels of
input data specificity.
Investigating Cryptic Speciation among Allopatric Populations of
Hemlock Woolly Adelgid, Adelges tsugae (Hemiptera: Adelgidae)
By: Hana Aronowitz
Advisor: Dr. Kimberly Wallin
The hemlock woolly adelgid is one of the most devastating non-native invasive forest insects in
the eastern U.S. because it threatens the long-term sustainability of two ecologically and
economically important native trees species, eastern and Carolina hemlock. The adelgids
introduced to the eastern U.S. originated from Japan, however, previous research has determined
that there are genetic lineages of hemlock adelgids associated with hemlock species in China,
Taiwan, Japan, and western North America. Currently, all adelgids that occur on the nine known
species of hemlock around the world are classified as a single species, which does not accurately
reflect this diversity. This project aims to use multivariate morphometrics to identify
morphological differences in individuals from five allopatric populations of A. tsugae. We
hypothesize that a cryptic subspecies exist for each of the different lineages of Tsuga, potentially
co-evolving with the host. The findings of this project will provide taxonomic designation of
Adelges linages. This will influence policies on regulation and biological control.
The Facilitative Role of Government and Science Communication
in a Collaborative Conservation Network
By: Marcella Dent
Advisor: Dr. Clare Ginger
Natural resources rarely conform to social and political boundaries; ecosystems are often subject
to many competing management goals and decisions. The goal of my research is to better
understand the roles that government and science communication play in landscape-scale,
collaborative conservation efforts that transcend political boundaries. The Landscape
Conservation Cooperative Network is a facilitative branch of the U.S. Department of the Interior
that provides science information and tools to natural resource managers to encourage local
conservation decisions that contribute to regionally shared conservation goals. The networks
links regional decision-makers across scales of governance from local to international and tribal,
both public and non-profit. I will explore the North Atlantic LCC as a case study, and ask how
the Department of the Interior and the U.S. Fish and Wildlife Service facilitates collaboration
across scales and sectors of governance in this network. I will ask what challenges exist in
facilitating natural resource management collaboration across the network and how the agency
addresses these challenges. I will also explore the roles that science communication plays in
network collaborations. I expect my results to provide insights into how government agencies
can facilitate collaboration across political boundaries, and how science communication can
support these efforts.
The Ala Archa Ecological Leadership Project:
Evaluating the Efficacy of Outdoor Education in Operationalizing Ecology and
Conservation in the Kyrgyz Republic
By: Nathan Fry
Advisor: Dr. Joshua Farley
In 2012, the Kyrgyz Republic formed a National Council for Sustainable Development that
shortly thereafter issued a strategic plan on Sustainable Development for the next five years –
2013-2017. Although the plan met general praise, critics noted that the plan’s flaws included a
failure to inspire specific projects to meet the country’s sustainable development goals. The Ala
Archa Ecological Leadership Project (ELP) attempts to address this issue by using an applied,
interdisciplinary approach to teaching the concepts of Social-Ecological Systems, ecosystem
services, leadership, and strategic planning to Kyrgyz student-ecologists in Bishkek, Kyrgyzstan.
In partnership with the American University of Central Asia (AUCA), the ELP will combine best
practices from experiential leadership programs in the United States with current research on
human-environment interactions into a two-week long experiential education program in the
Tian Shan Mountains of Ala Archa National Park, Kyrgyzstan. In addition to examining the
educational methods by which to best “operationalize” ecological education, the project also
aims to inspire a practical vision in its Kyrgyz students for how they can each use their postgraduation career fields to practically address the issues highlighted in the Kyrgyz National
Sustainable Development Strategy towards a progressive, ecologically balanced future in the
Kyrgyz Republic.
Regeneration Responses to Management for Old-Growth Characteristics
in Northern Hardwood-Conifer Forests
By: Aviva Gottesman
Advisor: Dr. William S. Keeton.
Multiple sources of variability interact with forest management to influence regeneration trends
in northern hardwood forests. The Vermont Forest Ecosystem Management Demonstration
Project is a long-term study testing the hypothesis that a silvicultural approach called “Structural
Complexity Enhancement”(SCE) can promote accelerated development of late-successional
forest structure and function, sustaining a broader array of ecological functions and biodiversity.
However, there is uncertainty whether such low-intensity selection harvesting techniques, will
result in adequate and desirable tree regeneration. Therefore our objective is to understand the
regeneration dynamics following three uneven-aged forestry treatments modified to increase
postharvest structural retention: single-tree selection, group selection, and SCE. Research
questions include: 1) what are the effects of treatment on regeneration densities and composition;
and 2) how do other factors such as light availability, competition, substrate, and herbivory
interact with treatment effects? Statistical analyses will include generalized linear modeling and
multivariate tests evaluating the relative predictive strength of multiple controls on regeneration.
SCE results in overall high seedling densities diversity (H-index) based on preliminary analyses,
but prolific beech sprouting dominates the understory in patches. Variants of uneven-aged
systems that retain or enhance stand structural complexity, including old-growth characteristics,
generally show resilience to regeneration limitations depending on site conditions.
Connecting Guests to the Landscape at Kripalu:
Ecological Inventory, Interpretation and Education
By: Jessica Griffen
Advisors: Dr. Marla Emery and Dr. Deane Wang
Sweeping views of the Berkshires and miles of trails await guests at Kripalu Center for Yoga and
Health in western Massachusetts, yet surprisingly few visitors venture outside. I am collaborating
with Mass Audubon to transform Kripalu's grounds from a beautiful backdrop viewed through
the windows to an essential part of the guest experience. This summer, I conducted an ecological
inventory of the 125-acre property and mapped the trails. I also developed and piloted natural
history programs, including sunrise birding and a pollinator citizen science project. My inventory
will serve as a basis for ecologically-informed management decisions. I am creating trail maps to
enable guests to easily navigate the extensive trail network, and interpretive materials that
Kripalu will use to share the property’s natural history with guests. Finally, my pilot natural
history programs will serve as a basis for continued collaboration between Mass Audubon and
Kripalu.
Fire Risks in Bhutan’s Blue Pine Forests:
Anticipating and Adapting to Climate Change
By: Choki Gyeltshen
Advisor: Dr. William Keeton
Forest fire risks are increasing in many parts of the world, often in conjunction with increased
drought related to climate change. In the central Himalayan Mountain region, anecdotal
evidence suggests similar trends, but no empirical research is available. Climate data indicate
that timing and dynamics of the summer monsoon season, as well as intensification of the winter
dry season, may already be occurring. In Bhutan, alteration of fire dynamics poses direct threats
to human life and property, as well as ecosystem services, such as flood control, landslide
prevention, and carbon sequestration. The most fire-prone system – Himalayan blue pine (Pinus
wallichiana) – occupies the Wildland-Urban-Interface at mid-elevational zones surrounding
major towns and villages in the northwestern part of the country. Our study investigates
relationships between intra and inter-annual climate variability and forest fire intensity and
extent in Bhutan’s blue pine forests. Field data on fuel profile, burn intensity, vegetation
impacts, and other variables were collected at 12 study sites. The design paired areas burned
within the last 5 years with adjacent, unburned areas indicative of pre-burn conditions. Detecting
a climate signal is challenging because fire activity is strongly affected by human land-use and
ignition, as well as structure, age, management history, and site-variability within the forest
ecosystem. Consequently, we are building a multivariate model predictive of fire risks that
includes all of these sources of variation. The results will help inform adaptive management,
including urban growth planning, fire management, and conservation efforts.
Can Early Feeding in Lake Trout Fry Ameliorate Thiamine Deficiency?
By: Carrie L. Kozel
Advisors: Dr. Jacques Rinchard, Dr. Allison Evans, Dr. J. Ellen Marsden
Recruitment failure of lake trout (Salvelinus namaycush) in the Great Lakes has been attributed
to the consumption of alewife (Alosa pseudoharengus) by adult lake trout, eventually leading to
Thiamine Deficiency Complex (TDC) in alevins. Thiamine deficiency results in early mortality
and is likely hindering successful restoration. Prior studies found that wild fry begin feeding
before yolk-sac absorption but in hatchery-reared fry first feeding does not occur until after yolksac absorption. We postulated that wild-hatched alevins could mitigate thiamine deficiency
through early feeding on natural prey. Eggs were collected from 53 adult lake trout from Lake
Champlain. Upon fertilization each family was split in half; one group was treated with thiamine
and the other was untreated. Eggs were reared until hatching; then each group was split again
into fed and unfed groups. Fry groups were kept under similar conditions; the fed group was fed
a mixture of zooplankton daily. Fry were sampled weekly and thiamine levels were quantified
using HPLC in summer 2015. To date, thiamine analysis has only been run on samples from
weeks one and six, but no evident trends in thiamine concentration over the experimental period
emerged from the four treatment groups.
The Functionality of Metaphor Use in Motivating Behavioral Responses
By: Alexandra Millar-House
Advisor: Dr. Adrian Ivakhiv and Dr. Christine Vatovec
Mitigation and adaptation efforts for environmental problems are increasingly reliant on the
voluntary actions of individuals. Success, therefore, requires communication strategies that
effectively motivate environmentally-desirable behavior. While metaphors are commonly
applied in environmental discourse to guide perceptions and actions towards the environment,
recent research suggests that the utility of metaphor use is dependent on whether a concept is
construed as psychologically distant or close to the self. As a result, there is a need to assess
whether situationally introducing a metaphor affects the construed psychological distance of a
concept, or the perceived psychological approachability of a concept. From a communication
perspective, the former suggests the possibility of using metaphor to frame behavior, while the
latter implies the potential to raise awareness without immediate behavioral implications.
Therefore, the central question of this research is: can situational metaphor use affect the
construed psychological distance of a concept, thereby impacting behavioral responses? To
answer this question, this research will apply a mixed-methods approach, focusing on two
objectives: 1) to compare the role of values in guiding intentions toward a psychologically
distant situation with and without metaphor use, 2) to determine if feasibility concerns are
equally predictive of an individual’s intentions towards a distant situation with and without
metaphor use. The results of this study will provide necessary insights into the functionality of
metaphor use as a tool in environmental communication.
Wildlife Habitat Linkages Surrounding Lake George and Southern Lake Champlain
By: Sam Talbot
Co-Advisors: Dr. Matthew Kolan and Dr. Jennifer Pontius
Not all land is created equal for wildlife on the move. Furthermore, wide ranging species, such as
black bear, bobcat, and fisher, don’t always give us concrete information on where they live and
travel. Since habitat connectivity is an important feature of the landscape, Sam Talbot used
computer modeling to reveal potential wildlife corridors. His two ArcGIS toolkits of choice
include Corridor Design and Linkage Mapper. His study focused on the region surrounding Lake
George and southern Lake Champlain – an area rich in rolling forests, prime agricultural soil,
and recreational opportunities. Given this landscape’s value to both wildlife and humans,
modeling habitat connectivity will guide future land conservation decisions that allow wildlife to
move unencumbered by barriers, such as roads and high-density development. Sam will employ
sensitivity analysis and model validation to be as transparent as possible of how well this model
depicts potential movement across the landscape.
PhD Poster Abstracts
(in alphabetical order)
Poster presenters will be on hand to discuss their research
in Aiken 103 at the noon hour on Friday, October 9th.
Machine Learning Methods for Acoustic Monitoring and Wildlife Occupancy Modeling
By: Cathleen Balantic
Advisor: Dr. Therese Donovan
Landscapes are shifting rapidly due to climate and land use change, requiring efficient methods
for monitoring and modeling wildlife species responses across vast spatial scales. Automated
detection methods using an acoustic monitoring system for vocal species can improve detection
probabilities and subsequent inferences about occupancy, enhancing understanding of wildlife
responses to land use patterns within the context of climate change. The efficacy of an automated
detection method varies based on vocalization habits and properties of any given focal species.
This early-stage research uses a U.S. Bureau of Land Management Solar Energy Zone in the
southeastern California desert as a pilot acoustic monitoring effort to develop the following
methodology: 1. Multi-species, multi-season occupancy models that account for false positive
and false negative acoustic detections, 2. Sampling schedules that maximize acoustic detection
probability of weather-driven, seasonally active desert amphibians, and 3. Effective automated
detection and occupancy modeling of the acoustically diverse and wide-ranging Common Raven.
Machine learning tools currently under investigation for these purposes include artificial neural
networks and template-based matching algorithms embedded within a Bayesian update system.
This research will contribute to wildlife monitoring knowledge and provide decision-making
tools for land management entities.
Agricultural Greenhouse Gas Emissions in Vermont:
Assessing the Impacts of Field Management Strategies and Environmental Conditions
By: Lindsay Barbieri
Advisor: Dr. E. Carol Adair
Agricultural greenhouse gas (GHG) emissions contribute to ~10-12% of global anthropogenic
emissions. Accurately quantifying and understanding emission rates from agricultural landscapes
is crucial to develop optimal mitigation strategies. This study assesses soil emission rates from
various field management strategies, and examines environmental conditions to better
understand how emission rates may be altered considering a changing climate. This study
combines field GHG emissions monitoring from May-September with soil cores emissions
monitoring during a week-long laboratory simulation of potential spring thaw conditions in
April. A No Till corn field in Alburgh, Vermont was managed with varying manure
incorporation methods. This study monitored three Injected plots, three Broadcast plots, and
three Plow plots weekly using in-field static chambers. Incubation study: four 10cm frozen soil
cores were extracted from nine plots. Three soil cores from each plot were subjected to simulated
environmental conditions; one frozen, one freeze-thaw and one core warming. Carbon dioxide
and nitrous oxide emissions were measured using a Photoacoustic Gas Sensor. This study shows
that management strategies and environmental conditions have important implications for GHG
emissions, and with climate change imminent, closely examining and assessing the effects and
benefits of fertilization strategies is a crucial next step in agricultural management.
A Novel Approach to Mapping Forest Cover: Coupling Spectral Unmixing and Objectbased Classification of Multitemporal Landsat TM Imagery across the Northern Forest
By: David Gudex-Cross
Advisor: Dr. Jennifer Pontius
Developing rapid, cost-effective methods to accurately classify forest cover is essential for
sustainable forest management. Spatially-explicit distribution maps of individual tree species are
increasingly valuable to forest managers and researchers, particularly in light of the anticipated
effects of climate change and invasive pests on forest resources. Yet, our ability to predict
changes in carbon dynamics, timber stocks, and other ecosystem services is limited by the coarse
detail of current regional and national forest cover maps. Thus a clear need exists to develop
more accurate methods of classifying forests to species-level. Advanced remote sensing
techniques such as spectral unmixing and object-based image analysis (OBIA) enable more
precise forest cover mapping. Spectral unmixing outperforms traditional pixel-based classifiers
by decomposing (“unmixing”) mixed pixels and assigning tree species classifications at the
subpixel level. This is particularly useful in northern forests where species composition is often
mixed. Here, we develop an integrated pixel-based and OBIA method for classifying tree species
using multitemporal Landsat TM imagery. Spectral unmixing is used to map and quantify perpixel basal area for 12 key tree species. This information is then included in an OBIA workflow
incorporating multitemporal spectral data, vegetation indices, and ancillary environmental data to
refine each classification.
Comparative Growth of Five Northern Hardwood and Montane Tree Species Reveal
Differing Trends and Responses to Weather and Deposition
By: Alexandra Kosiba
Advisors: Dr. Paul Schaberg and Dr. E. Carol Adair
Two notable tree species in the northeastern US have undergone decline in the 20th century: red
spruce (Picea rubens Sarg.) and sugar maple (Acer saccharum Marsh.). Recently, red spruce has
shown a dramatic and synchronous increase in growth. However, it is unclear how co-occurring
species have responded to both the declines of sugar maple and red spruce, and the latter’s recent
increase. We examined the growth of five key tree species in Mt. Mansfield State Forest,
Vermont: sugar maple, red spruce, red maple (Acer rubrum L.), yellow birch (Betula
alleghaniensis, Britton), and balsam fir (Abies balsamea, [L.] Mill.). We found baseline
differences in growth; with red maple and yellow birch having the highest mean basal area
increment growth, balsam fir the lowest, and sugar maple and red spruce intermediate. When
growth was converted into a Z-score that compares recent growth (2008-2012) to mean growth
since 1925 for each species, red spruce, at both mid and high elevations, had growth above their
respective means, while for the other species recent growth was indistinguishable from the mean.
Although many year-to-year declines in growth were likely associated with specific stress
events, protracted patterns in growth may be associated with climate and/or deposition trends.
Reconsidering Assumptions about Diel Vertical Migration
Using an Omnivorous Macroinvertebrate
By: Brian O’Malley
Advisor: Dr. Jason Stockwell
Diel vertical migration (DVM) is a widespread behavior among aquatic organisms whereby
individuals migrate between deep and shallow habitats from day to night, respectively. DVM
theory predicts this strategy to be optimal when predation risk (µ) and growth potential (g) are
high priorities. While a substantial body of evidence suggests DVM evolved to minimize the
“µ/g” ratio in holoplanktonic species (pelagic-only life history), few studies have attempted to
evaluate DVM theory using species which can use both benthic and pelagic habitats (i.e.
meroplanktonic). Objectives of this study were to quantify diel habitat use by Mysis diluviana, a
native benthic-pelagic omnivore, across seasons in Lake Champlain using standard pelagic net
tows, benthic sled tows, and continuous video monitoring day and night. As expected, day/night
comparisons of pelagic sampling generally revealed higher abundance at night, consistent with
DVM behavior. Contrary to prior assumptions about Mysis DVM behavior, however, both
benthic sled sampling and video monitoring recorded a substantial portion of the mysid
population on or near bottom during night. Comparisons using benthic sled tows revealed little
difference in day/night catches. Our results point to further evaluation of DVM theory to
compare benthic and pelagic tradeoffs when considering optimal migration strategies.
Forest Regeneration and Biodiversity Following Wind Disturbance
and Salvage Harvest in Northern Mixed Deciduous Forests
By: Sarah Pears
Advisor: Dr. Kimberly Wallin
Stand-replacing disturbances due to severe weather have historically been rare in northern mixed
deciduous forests; however, the frequency of extreme storms in the region is projected to
increase. A 2010 windstorm severely damaged trees in northwestern Vermont. Forest managers
salvage harvested storm-impacted stands, removing trees blown over or otherwise injured. This
proposed research will quantify cumulative impacts of windstorm and salvage harvest on
ecosystem services in northern mixed deciduous forests. Across a range of disturbance intensities
I will quantify regeneration and factors that influence tree recruitment including coarse woody
debris abundance and remnant canopy tree species, size and density. I will also quantify
disturbance impacts to species richness and diversity of herbaceous plants and ground-dwelling
invertebrates along a gradient of disturbance intensity. This biodiversity data will serve as a test
of the Intermediate Disturbance Hypothesis, which predicts that highest biodiversity results from
moderate intensity or frequency ecosystem disruptions. I expect to find forest recovery rates
highest at sites subjected to wind disturbance and moderately intense salvage harvest, and
biodiversity highest in sites where salvage harvest was moderate. I will share results and
conclusions via peer-reviewed publications, professional and academic conference presentations,
press releases, and public workshops for Vermont forestland managers.
Cityscape Connections: Assessing the Relationships among Urban Populations and
National Park Service Parks, Partnerships, and Programs
By: Elizabeth E. Perry
Advisor: Dr. Robert E. Manning
The National Park Service (NPS) protects vital natural, cultural, historic, and recreational
resources and uses these resources to tell many of America’s most iconic stories. Although all
NPS sites provide engagement opportunities, the ability to engage large, diverse, and proximate
communities is unique to urban NPS sites. The NPS has responded innovatively to this
opportunity for enhanced park-people connections, such as with its landmark Urban Agenda.
This initiative aims to expand the NPS’ relevancy to all Americans, emphasize its entire
portfolio, and deepen its collaborative culture. A program of research to elicit perceptions about
the NPS’ urban presence is currently underway. The intent is to understand community and
NPS (1) park perspectives; (2) partnership networks; (3) programmatic interactions; and (4)
evaluations of areas of impact for the Urban Agenda in these complex systems. A multi-method,
developmental evaluation approach is being used, combining qualitative interviews with
quantitative social network analysis. Case study sites span the NPS-identified cityscape
typology: embedded parks (Boston), proximate parks (Tucson), and programmatic-only
presence (Detroit). Results will aid in site-specific and overall successful implementation of the
Urban Agenda, contribute to enhanced NPS management coordination across cityscapes, and
highlight means by which park-people relevancy and resiliency may be strengthened.
A Socio-Ecological Analysis of Salvage Logging in Vermont: Landowner Motivations,
Forest Succession Modeling, and Ecosystem Service Trade-Offs
By: Eduardo Rodriguez
Advisor: Dr. Jon Erickson
Forests provide us with countless benefits, from carbon storage, to timber products,
wildlife habitat, water filtration, and recreational opportunities. Given that the vast majority of
Vermont forestland is held by private landowners (80%), their management decisions have
significant effects on the ability of Vermont’s forests to continue providing these essential
ecosystem services. This research uses methods from both social and natural sciences to
investigate how salvage logging that follows severe wind events affects the long-term provision
of ecosystem services in the northern forest. I employ a mixed methods approach that marries
quantitative and qualitative data to identify determinants of forest management decisions, and
describe motivations for salvage logging. I simulate forest succession that follows disturbances
and salvage logging using a forest landscape model (LANDIS II). Finally, I analyze trade-offs in
ecosystem service provision depending on salvage logging intensity. This multi-faceted
approach combines socio-ecological tools and methods to enhance our understanding of the
current state of Vermont forests, and to demonstrate how different management paths may affect
their ability to provide us with valuable ecosystem services in the future.
Understanding Sediment Sourcing and Erosion Controls from 10Be Measurements in
Fluvial Sediments from Yunnan, China
By: Veronica Sosa-Gonzalez
Advisor: Dr. Paul R. Bierman
Widespread deforestation in southwestern China is thought to have increased short-term erosion
rates, but sediment yield data do not reflect this. We tested anthropogenic effects on denudation
by comparing long-term erosion rates derived from in-situ 10Be concentration and modern
sediment yield of 22 watersheds in Yunnan. We found that in most watersheds, the modern
sediment yield is 2-3X higher than long-term. We examined the relationship between erosion and
topography for 39 watersheds. We found a statistically significant, positive relationship between
erosion rates and both area (R2 = 0.653, p < 0.0001) and mean basin slope (R2 = 0.324, p =
0.0003). We found a significant, negative relationship between erosion and rainfall (R2 = 0.564,
p < 0.0001). We tested two assumptions of the method that uses in-situ 10Be to quantify
background erosion rates: 1) erosion is constant over different integration times and 2) sediment
sourcing is steady throughout the watershed. To test the first assumption, we re-sampled sites
previously analyzed for 10Be, and found that in most sites the concentration is lower. To test the
second assumption, we compared isotopic concentration of active channel and overbank
material. We found no significant concentration differences, implying no seasonal bias in
sediment sourcing.