Soil Moisture Patterns in Sierra Nevada Mixed Conifer Forest, Sequoia National Park, CA

EPA Grant Number: MA916307
Title: Soil Moisture Patterns in Sierra Nevada Mixed Conifer Forest, Sequoia National Park, CA
Investigators: Lopez, Ryan P.
Institution: California State University - Fresno
EPA Project Officer: Zambrana, Jose
Project Period: January 1, 2004 through December 31, 2006
Project Amount: $56,728
RFA: GRO Fellowships for Graduate Environmental Study (2004) RFA Text |  Recipients Lists
Research Category: Fellowship - Natural and Life Sciences , Academic Fellowships , Biology/Life Sciences


The objective of this research project is to quantitatively describe temporal (seasonal) and spatial (horizontal and vertical) variation in soil moisture content of forest soils in Sequoia—Mixed Conifer forests within Sequoia National Park, CA. Soil moisture is an important factor in determining overstory and understory species richness, density, and pattern within these forests. Soil moisture will be measured in both canopy gaps and along linear transects that cross through the range of canopy cover found in these forests (closed canopy to open gap).


Soil moisture will be sampled using rods installed at permanent sample points with Time Domain Reflectometry (TDR). Six canopy gaps (three < 0.3 ha and three > 0.5 ha) will be established at 2,200 m elevation with TDR rods installed at four depths (10, 30, 60, and 100 cm) in a series of plots located on radial arrays crossing the plot N-S, W-E, NW-SE, and NE-SW. A total of thirty 50-m long transects with TDR sample points at 5-m intervals have been established in six plots (five transects per plot) at 1,600 and 2,200 m elevation. Soil moisture will be measured in the transects and in the canopy gaps every 2 weeks throughout the snow-free season. In addition, hemispherical photos will be taken at all sample points in gaps and transects for characterization of canopy cover and light availability. This experimental design allows testing of a variety of hypotheses concerning the patterns of soil moisture availability and use in forest gaps and in the forest understory and how these patterns are related to solar radiation and canopy cover. Results from this project will improve the understanding of forest dynamics in the middle and southern Sierra Nevada and will be useful to forest managers and many research collaborators attempting to preserve this resource.

Supplemental Keywords:

fellowship, forest gaps, hemispherical photography, Sierra Nevada, mixed conifer forest, soil moisture, time domain reflectometry, California, CA, Sequoia National Park, species richness,, RFA, Scientific Discipline, ENVIRONMENTAL MANAGEMENT, ECOSYSTEMS, Ecosystem Protection/Environmental Exposure & Risk, Ecosystem/Assessment/Indicators, Ecosystem Protection, Resources Management, Forestry, Environmental Monitoring, Ecological Monitoring, Ecology and Ecosystems, Ecological Indicators, ecosystem assessment, forest canopies, forest ecosystems, conservation, forest land cover, ecological assessment, changes in species composition, changes in forest cover, spatial and temporal patterns, Sequoia National Park, Time Domain Reflectometry, ecological research, forest conservation

Relevant Websites:

2004 STAR Graduate Fellowship Conference Poster (PDF, 1p., 143KB, about PDF)

Progress and Final Reports:

  • 2004
  • 2005
  • Final