Project Summary:
The overall objective of this program of research and intensive monitoring
is to provide a mechanistic understanding of soil foodweb dynamics related
to changes in below ground indicators of ecosystem integrity, specifically
the production of dissolved organic carbon (DOC) and dissolved organic
nitrogen (DON). We believe changes in the quantity and quality of root
and mycorrhizal carbon © can be used to predict changes in soil biota
- the gatekeepers of nitrogen (N) availability. Soil biota, intimately
linked to plant roots, regulate C and N transformations and provide
a critical linkage at the landscape level to aquatic environments through
their role in the production of DOC and DON. We will link variation
in below ground processes to spatial and temporal environmental gradients
that control the export of DOC and DON from terrestrial environments
to streams and lakes.
A nested, hierarchical sampling strategy will be used to assess the
effects of climatic variation and N addition on DOC and DON production
and transport in Olympic National Park. This will consist of 1.) measurements
of vegetation, temperature, soil moisture, and soil solution DOC and
DON at a network of sites covering dominant vegetation types along elevation
and precipitation gradients, and 2.) intensively studied soil processes
within major vegetation types on a subset of plots located along the
broad moisture and temperature gradients. Plot level studies will be
used to quantify how temporal soil climatic variation and N addition
alter soil C inputs, food web C transformations, and the production
of various DOC and DON precursors and fractions. Existing and newly
established weather monitoring stations will be used in conjunction
with vegetation, elevation, aspect, and soil temperature and moisture
information to predict DOC and DON export at the landscape scale.
This study addresses all three PRIMENet objectives. The research emphasizes
spatial and temporal variation in ecological response to stress, especially
from atmospheric N deposition and climate change. The research is proposed
for a national park with an existing long-term monitoring and research
program. This will help place the study in a broader ecosystem context.
Soil biota are intimately linked to plant roots and they regulate C
and N transformations. Through the production of DOC/DON, soil biota
provide a critical connection with aquatic environments at the landscape
level.
Summary
of Project Results
2002
Olympic PRIMENet Meeting Presentation
Distributions
of Airborne Agricultural Contaminants Relative to Amphibian Populations
in the Southern Sierra Nevada, California Research Plan
Trudell et al., 2004.
Patterns
of nitrogen and carbon stable isotope ratios in macrofungi, plants and
soils in two old-growth conifer forests. New Phytologist 164:317-335.
