Joanie Ball
Background
I received a B.S. in Environmental
Studies from Emory University in 2005, and then worked for three years as
an environmental scientist at a consulting and engineering firm. My work
involved evaluating and remediating environmental contamination for urban
redevelopment and industrial sites. I conducted historical environmental
site assessments, and led groundwater monitoring projects for several
sites throughout California. I also developed best management practices
for construction sites, and managed storm water monitoring programs to
assess nonpoint pollution sources to the San Joaquin River, San Francisco
Bay, and Monterey Bay.
Research Interests
I am interested in the effects of
historical and current habitat alterations on groups of aquatic
macroinvertebrates with different life history traits. My research
involves: 1.) using a microhabitat approach to develop indicators of
sedimentation, 2.) determining how macroinvertebrate communities change as
ephemeral ponds and streams dry out in California, and 3.) assessing the
effects of landscape composition and pattern on the distribution of
dragonflies with varying dispersal abilities.
Cobble-Dwelling
Macroinvertebrates as Indicators of Sedimentation
Sedimentation alters
benthic habitat by homogenizing the streambed, and eliminating important
microhabitats that macroinvertebrates and fish need to find food and
refuge. Multi-scale studies have demonstrated that the impacts of
increased fine sediment on macroinvertebrate communities are more
significant on patches of varying sediment type than for individual
streams or reaches. This is likely because benthic macroinvertebrates,
which are small and relatively sessile, select habitat on a fine-scale.
Microhabitat sampling underneath large cobbles may therefore be an
effective and reliable method for developing macroinvertebrate indicators
of sedimentation. I am currently evaluating the relative sensitivity of
individual macroinvertebrate taxa and metrics to high cobble embeddedness
to develop biological indicators of sedimentation.
Macroinvertebrates in Non-Perennial Streams
Climate change and
intensive water use are creating increasingly dry conditions in arid
regions, making the study of intermittent and ephemeral freshwater habitat
more important than ever. Seasonal habitat transitions from flooding to
drying extremes in non-perennial streams are associated with
characteristic changes in macroinvertebrate taxa-composition, richness,
average tolerance values, and functional feeding groups. Relatively few,
and spatially-limited, studies have explored seasonal changes in
macroinvertebrate life history traits during these extreme hydrologic
transitions. I am evaluating whether characteristic changes in
macroinvertebrate taxa and their life history traits occur as streams
transition to intermittency in six Southern California non-perennial
streams.
Dragonfly distribution
in the San Francisco Bay Area
Urbanization has
impaired water quality, eliminated critical buffer vegetation, and in many
cases has resulted in complete channelization or burying of streams and
ponds. As a result, freshwater habitats have some of the highest
extinction rates of all ecosystem types worldwide. However, we know
relatively little about the distribution of freshwater organisms,
particularly distribution changes that that have occurred over time. I am
working with data from biological assessment samples, museum specimens,
enthusiast group sightings, and additional field collections to determine
how landscape alteration and climatic variables have affected the
distribution of dragonflies in the San Francisco Bay Area.
Contact
Information
Joanie Ball
Dept. of Environmental Science, Policy & Management
University of California, Berkeley
137 Mulford Hall #3114 (Resh Lab)
Berkeley, CA 94720
Phone: 510.642.5913
Fax: 510.642.7428
jball@nature.berkeley.edu
