Beaver Dams at Santa Margarita Ecological Reserve:
An Experimental Ecology (354L) Class GIS Project.

Class Instructor: Alison Anderson Authors: Corrie Biggerstaff, Alaya Binder, Shelsea Boden, Cory Booth, Tal Haimovitch-Gal, Patrick McConnell, Susan Meier, Jessica Norton, Dawn Palumbo, Brian Polivka
Graduate field assistants: John Chalekian, Christian Manion, Gretchen Small
ArcView files and consultation: Bruce Nyden
Web Consultant: Jeanne Burch
Subject idea and background information: Robert Fisher
Field trip assistance and consultation: Kevin Contreras
Field trip assistance and consultation: Jim Zimmer
General support: Sedra Shapiro


Kevin Contreras


Start at lower field station


Chris and Tal at a pond

This page format is simply instructions/suggestions for writing the paper. You will fill in the text and references.  Next week we will meet to review our work, and our writing will be incorporated here as an on-line publication.

Introduction

Use beaver paper from Robert and other literature/web sites.

Objectives:
1) Collect descriptive baseline data, map dams & collect associated data.; 2) look for patterns in vegetation and topography that predict where beavers build dams. 3) Look for patterns in vegetation and associated wildlife that indicate an effect of beavers and dams on other species such as trees, crawdads, native and exotic fish, and birds.

Hypotheses:
1) Landscape-scale patterns in topography and vegetation can help predict where beavers will locate dams, and 2) Exotic lousiana swamp crawdads more abundant in beaver ponds than other pools.


American Beaver


Beaver Dam


American Coot

Beaver image from the Sevilleta Long-Term Ecological Research web site.
Coot image from Rick Cameron Photography

Methods

Section of river surveyed, site (SMER) info. Tools: GPS units (see photo/link below) maps: topographic (see photo/link below), aerial photos, digital geo-referenced hillshade, rangefinder, soil samples and analysis, PH/temp meter, diameter tape, counting crawdads (QuickTime movie), ArcView/GIS program (see photo/link below).


Topo Map, Dam 1


Reading G.P.S. Unit


Dam location data table
Geographic coordinates
Water pH above and below
Temperature above and below
Estimated river width

Results

 

GIS/ArcView maps of dam and coot locations. 3-D flyby of Santa Margarita Ecological Reserve. Observations: heron droppings full of crawdad parts (Quicktime movie), crawdad density, tree species cut by beavers (willow and sycamore), beaver slides and lodges, scattered flowering plants, frogs, butterfly species sited, Water PH and temp, jumping spiders, bobcat and other tracks, oak apple galls w/larvae. (Table of data, see ArcView photo/link above.)

Patterns to look for using GIS maps: 1) similarities in vegetation and topography associated with dam locations (and not with other locations).  2) similarities in vegatetion and dam location associated with coot locations (and not others).

Question I want you to answer: The location of dam 1 is in question.  The mark on the hillshade does not agree with the mark on the topographic map or the GPS unit coordinates (see above photos/links to hillshade map, topo map, and photo). Where is your best estimate of where the dam is actually located (use all available information)? Icons for dam and coot locations on the ArcView hillshade map (link in results section) may be offset from the actual location marked on the hardcopy hillshade map we used in the field (link in methods section) because the geographic coordinates on our hardcopy are plotted in "NAD 27" and the coordinates on the ArcView file are plotted in the more current "NAD 83" (Bruce Nyden & Kevin Contreras, personal communication). Check the geographic features and dam location on the scanned image of our hardcopy map against the features and location on the ArcView map to investigate this further.


Some natural history


Red Penstamen


Frog on Penstamen

Conclusions

Patterns you found, possible explanations for patterns (cite beaver, coot, and other literature), and hypotheses/questions for future research.

 

Literature Cited

Robert Fisher and (499 student). (In progress). Beaver activities and their effects on the ecosystem in the Santa Margarita River. San Diego State University Field Stations publication.

Include web sites.
 

Hot Links

SDSU Field Stations

InfoRain GIS Page
Experimental Ecology (354L) literature research page
Alison's Global Change page
Geographic System Information -- G.I.S.
G.I.S. Dictionary
Spacial Odyssey: G.I.S. Literature Database
Environmental G.I.S. Guide for the Neophyte
Yahoo G.I.S. Links

If you have comments or suggestions, email me at anderson@sunstroke.sdsu.edu