applied science to inform conservation and restoration of a
TRANSCRIPT
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Applied science to inform conservation and
restoration of a threatened habitat type; the salt
marsh – upland ecotone
By: Cherie Crawford
California State University at Monterey Bay
May 2012 to February 2013
Advisor: Dr. Kerstin Wasson, Research Coordinator, Elkhorn
Slough National Estuarine Research Reserve
Submitted: March 15, 2013
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Table of Contents
Acknowledgements 3
Executive Summary 4
Project Objectives 5
Project Approach 6-7
Project Outcomes 8-9
Conclusions 10
Appendices 11-13
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Acknowledgements
This project was supported by Agriculture and Food Research Initiative
Competitive Grant no. 2011-38422-31204 from the USDA National Institute of
Food and Agriculture. Additionally, I would like to thank Dr. Kerstin Wasson,
research coordinator at the Elkhorn Slough National Estuarine Research Reserve
for giving me the opportunity participate in this project and Carla Fresquez
from UC Santa Cruz for allowing me to assist on her thesis project concerning
ecotones.
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Executive Summary
This project at the Elkhorn Slough National Estuarine Research Reserve
(ESNERR) has many tasks associated with ecotone habitats. The salt marsh –
upland ecotone is a threatened habitat type throughout the Elkhorn Slough and
there are many projects associated with determining the value this habitat has
as a transition zone. In the fall, I continued an ecotone wildlife monitoring
experiment begun that summer, which includes deploying cameras, sorting
through pictures, and drawing conclusions on habitat use based on animals
found in the habitat zones. In December, I gave a presentation summarizing
our findings of the ecotone wildlife monitoring project to a group of
stakeholders at ESNERR. Throughout the duration of my internship, I assisted a
Carla Fresquez, a graduate student at UCSC studying the effects of ecotonal
plant species in boundaries found above and below the ecotone transition zone.
This assistance involved analyzing soil samples, assisting with elevation
surveys, solitary data collection, and plant propagation and restoration. I also
assisted with an annual long-term monitoring project of ecotone zones as an
indicator of climate change.
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Project Objectives
The purpose of this project was to use applied science to improve
management of the salt marsh-upland ecotone at Pacific coast estuaries, with
emphasis on wetlands in the Elkhorn Slough. Ecotones are transition zones
between adjacent ecological systems that are sensitive to environmental
changes and may serve as indicators of global climate change. The marsh-
upland ecotone is only a few meters wide at Elkhorn Slough and is a highly
threatened habitat type important for ecosystem function. This project involved
assisting multiple aspects of slough management and had many specific tasks
associated with it, outlined below. While I assisted in each of the following
tasks, my primary task was to monitor wildlife corridors and conduct field
assessments to determine habitat value and level of use (Task A). This task was
very field intensive and did not allow for me to assist with restoration
experiments (Task B) as much as anticipated.
A. Determining wildlife corridor and habitat value of ecotone
B. Restoration experiments to enhance ecotone extent
C. Investigating factors setting ecotone boundaries
D. Correlation of plant community with environmental gradient
E. Long-term monitoring of ecotone as an indicator of climate change
F. A presentation to stakeholders
Following the completion of this project and graduation from California
State University at Monterey Bay, I am hoping to use the skills and experience I
have gained as an intern at ESNERR in a career with the Natural Resources
Conservation Service in natural resource management or with the United States
Forest Service.
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Project Approach
The methods used for achieve each of the tasks listed above are detailed
below.
A. Determining wildlife corridor and habitat value of ecotone: From August
2012 to December 2012, I deployed wildlife monitoring cameras at 10 sites on
and near Elkhorn Slough two weeks at a time to monitor wildlife use of the
ecotone, marsh, and upland zones (Appendix A). The sites were Azevedo,
Coyote marsh, Footbridge, Long Valley Dock/Tip, North Marsh, Packard, T
Dock, Whistlestop, Willowbend, and Yampah (Appendix B). At each site, I
conducted field assessments of plant species , percent cover, litter depth, and
canopy height for each zone, , and noted the presence or absence of trails to
determine whether any of these factors influenced wildlife use. We
hypothesized that the ecotone serves as a wildlife corridor and is more heavily
used than the lowland marsh or upland vegetation because of its transition
zone characteristics and lower canopy height, leading to higher species
richness and abundance.
B. Restoration experiments to enhance ecotone extent: The importance of
doing the other project did not allow me to participate in this experiment as
much as I had anticipated.
C. Investigating factors setting ecotone boundaries: I assisted Carla Fresquez
from UCSC on her thesis project, conducted at sites near and around Elkhorn
Slough. Her project involved transplanting ecotone specialists (Jaumea carnosa,
Frankenia salina, and Distichlis spicata) above, at, and below the ecotone
transition zone, both with and without the removal of competitors to determine
the role of physical and biological factors in setting ecotone boundaries. Some
of my duties were collecting soils samples and analyzing them for salinity, pH,
moisture content, and organic content, continued removal of competitors in
each of the transects, and data collection for each transect.
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D. Correlation of plant community to environmental gradients: I assisted Carla
Fresquez with the collection of plant community data across elevational
gradients of the marsh-upland ecotone and conducted elevational surveys with
RTK GPS and a surveyor's auto-level for the same project.
E. Long-term monitoring of the salt marsh-upland ecotone as an indicator of
climate change: I assisted ESNERR in an annual long-term monitoring of
ecotone dynamics at permanent transects throughout Elkhorn Slough, as part of
a ten year monitoring program, to determine whether landward migration of
the ecotone is continuing as an apparent response to sea-level rise. Data
collection included analyzing plant composition measuring specific species
growth.
F. Presentation of ecotone wildlife monitoring to stakeholders: Following the
conclusion of the ecotone wildlife monitoring for the fall and using data
collected during the previous summer, I gave a presentation about ecotone and
habitat use by mammals to stakeholders informing them of this project
occurring at Elkhorn Slough and potential implications from the results.
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Project Outcomes
The following project outcomes are results of my primary task involving
ecotone wildlife monitoring. I assessed the following potential correlates to
determine if the hypothesis that ecotone serves as a wildlife corridor and is
more heavily used than the lowland marsh or upland vegetation is supported:
vegetation transects (plant cover, bare ground, litter depth), physical
(precipitation, fog, moon), and the season (summer vs. fall). Appendix C is a
summary of all the animal species detected across all sites. The ecotone wildlife
monitoring for the fall and subsequent analysis of pictures taken at each site
and zone lead to the following outcomes, by zone:
animals did not show a preference between zones (marsh, ecotone,
upland)
total number of animal species did not differ across zones
deer and coyote, the most abundant species, did not show a preference
for a zone, although the highest abundance for both was the ecotone.
When comparing season and zones:
a higher diversity of species was seen in the fall vs. the spring in all
zones
significantly more deer were present in the fall across all zones
coyote abundance was higher in the fall (though not significantly)
more than 50% of the deer sightings in the fall were between sundown
and sunrise while less than 50% of sightings in the summer were
between sundown and sunrise.
When investigating the impact of a trail on animal abundance, there
seemed to be no effect of total animal species seen, but there was a higher
trend for deer and coyote abundance in the presence of a trail. Neither trend
was significant however.
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A cursory analysis of the impact of environmental variables on corridor
use revealed:
deer foraging was more common in the ecotone than the marsh, but it
was not significant
total animals species seen was best explained by the combination of
more bare ground and less moon
deer abundance shows a positive relationship with rain and bare ground.
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Conclusions
The following are conclusions from the primary task of the project:
there is a high diversity of animal species using the Reserve and other
neighboring properties
deer was the most common animal seen, followed by coyote
more animals were seen in the fall than in the summer (more species and
more deer)
there was huge variation between sites, with sites on the Reserve peaking
in abundance and other sites off the Reserve had little or nothing.
We rejected the hypothesis that the ecotone was used more heavily than
adjacent habitat types. Other sources of error include inadequate sampling
design, and the zones we monitored at each site were too close together (we
need a larger spatial scale). However, there was no evidence of a barrier to
movement or habitat use and animals were able to move freely between each
zone.
Future research could include: having a different sampling design (marsh
and upland zones further from ecotone), how different sites and properties are
used by animals, and the role of topography and barriers influence their use,
comparison of habitats further away from the marsh, and achieving a better
understanding of wildlife trails, connectivity, and movement.
Overall, this internship at ESNERR has given me the experience and skills
necessary to further my goal of working with either the National Resources
Conservation Service or the United States Forest Service, specifically pursuing
habitat and wildlife management and soil conservation.
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Appendix A
Coyote marsh on Elkhorn Slough National Estuarine Research Reserve and the
three zones where monitoring cameras were deployed.
Marsh Ecotone Upland
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Appendix B
Fall 2012 wildlife monitoring sites. Sites on Elkhorn Slough National Estuarine
Research Reserve included: Coyote marsh, Footbridge, Long Valley Dock/Tip,
North Marsh, T Dock, Whistlestop, and Willowbend.
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Appendix C
Summary of all animal species seen at various sites, both on and off Elkhorn
Slough National Estuarine Research Reserve.