Current
Research Interests
Updated
October, 2007
Resilience
of Social-Ecological systems
Human-Fire-Vegetation
Interactions
Climate-change Impacts on Ecosystem
Services and Use by Indigenous Communities
Long-Term
Ecological Research
Vegetation
Effects on Nutrient Cycling and Succession
The
central focus of my research is the study of the resilience of regional systems
in the face of directional changes in climate, economics, and culture. I
believe this is one of the most pressing challenges facing humanity: How do we
sustain the desirable features of Earth's ecosystems and society at a time of
rapid changes in all of the major forces that govern their properties? This
requires an understanding of the mechanisms that tend to maintain the system in
its current state vs. factors that cause changes to a new state. It also
requires an integration of natural and social sciences because many of the
drivers of change involve social-ecological interactions. As an ecologist, I
work mainly on the ecological aspects but also collaborate closely with social
scientists interested in similar issues. I address resilience mainly through a
graduate educational program in Resilience and Adaptation (http://www.rap.uaf.edu/) and through research on human-fire
interactions and successional dynamics of boreal forests. I am currently
writing a textbook with Gary Kofinas and Carl Folke on ÒPrinciples of
Natural Resource Stewardship: Resilience-Based Management in a Changing WorldÓ.
Human-Fire-Vegetation Interactions
Fire
is the dominant disturbance in the boreal forest and is becoming more frequent
as climate warms. Therefore one of the most profound ways in which human
activities might influence high-latitude ecosystems and their climate is by
altering fire regime. Fire also has large societal impacts through changes in
ecosystem services and economic costs and benefits to society. I work with a
group of ecologists, anthropologists, political scientists, and economists to
study the changing role of fire, particularly as affected by human activities,
on the forests of interior Alaska and its human residents. The aspects to this
research that I work on most directly are the effects of fire on ecological
processes and the ecosystem services (e.g., game animals, forest products,
recreational value, feedbacks to the climate system, and nutrient retention)
that it provides to society. I study how recent changes in the extent and
severity of fire influence the magnitude, spatial pattern, and timing of
recovery of these ecosystem services after fire. Both field work and
traditional knowledge provide important information in these studies. As a
research team we also study the effects of fire-related ecosystem services and
fire-fighting wages on rural communities, the effect of lightning and human
ignitions and of fire suppression on fire regime, and effects of national fire
policy and local public opinion on the formulation and implementation of fire
policy. We use conceptual and simulation models to integrate this information
to understand past and future trends in human-fire-vegetation interaction (http://www.hfi.uaf.edu/).
Climate-change Impacts on Ecosystem
Services and Use by Indigenous Communities
Climate
change is altering the physical environment and ecosystem services used by
rural indigenous communities in arctic and boreal Alaska. I work with these
communities to identify those critical ecosystem services about whose future
they are most concerned. These services include subsistence resources,
regulatory services (e.g., risk of fire spread), and the cultural services that
link people to the land and sea. We use simulation models to project future
trajectories of those critical ecosystem services that are of greatest concern
to communities as a basis for community planning efforts to plan strategies to
enhance ecological, economic, and cultural sustainability. This project is part
of the International Polar Year and coordinates with similar research in other
northern countries.
Long-Term
Ecological Research (Bonanza Creek)
I direct the Bonanza Creek Long-Term Ecological Research (LTER) program (http://www.lter.uaf.edu/), which conducts long-term ecological research in the boreal forest. There are some 25 investigators working on a spectrum of projects ranging from ecosystem processes to population dynamics to hydrology. This research program provides students with a wide range of opportunities for interdisciplinary research. The overall focus of the research program is on climate-disturbance interactions in the boreal forest. My research within this program addresses the controls over successional changes in vegetation and nutrient cycling (as described below) and the consequences for subsistence activities of rural Athabascan communities.
The
boreal forest is unusual in that all the tree species that occur throughout the
entire 100+ years of successional development colonize within the first 5-20
years. Therefore by documenting the patterns of initial tree establishment
after fire, you can predict the vegetational changes that occur during the next
century. You can also compare the species composition of the regenerating stand
with the pre-fire stand to directly measure the resilience of these forests
after disturbance (i.e., how likely it is to return to the pre-fire
composition). My research focuses on the mechanisms of resilience (e.g.,
post-fire seed supply) and the triggers for change (e.g., establishment of
different species under certain circumstances). I am also interested in the
mechanisms by which ecosystems change through succession. This involves studies
of tree growth and mortality, and the effects of vegetation on nutrient
cycling. My nutrient-cycling studies focus on the effects of vegetation and
environment on plant-microbial interactions, with the notion that plant traits
strongly determine many of the ecological properties of ecosystems.