A Comparison of Riparian Vegetation Structures Within City vs Outside City in Boulder, CO and Morrison, CO Dan Jackson Vegetation Ecology EBIO 4100-572 Summer 2014 Mountain Research Station, University of Colorado, Boulder

Riparian Habitats The land-water interface is of great importance to the riparian ecosystem (Gregory et al). Rivers carry nutrients through the ecosystem, which are taken up by vegetation along the banks. Disturbance of vegetation along the banks can damage the entire ecosystem.

Will vegetation structures differ between Riparian sites within the city and riparian sites outside of the city? Do the land management techniques of the two cities negate the effects of the city?

Hypotheses H0: There will be no difference in vegetation structures between within city and outside city sites. H1: The vegetation outside of the city will be greater in diversity, coverage, and evenness.

Methods Identification of site locations: Within city: area along creek that lies within city management areas but is not heavily affected by landscaping or human use Sites along trails but not too close to parks Outside city: area along creek outside of city management areas and has similar tree density to the within city site

Sites Boulder Morrison Within City Outside of City Map taken from google maps

Boulder County enlists strict regulations regarding habitat disturbance within the colored areas. https://www-static.bouldercolorado.gov/docs/vmp-maps-1-201304101623.pdf Map taken and cropped from OSMP website Boulder Sites

Jefferson County Open Space Parks are protected from unregulated hunting, fishing, and recreational uses. These areas are occasionally closed to visitors in order to protect the wildlife and allow for restoration. Map taken and cropped from JCOS website http://jeffco.us/parks/open-space/ Morrison Sites

Daubenmire Plots Five random points within a grid along and away from the creek (20m by 10m) At each point, collect Daubenmire data within a 20cm by 50cm rectangle

Daubenmire Plots Data Collected: Number of different species Percent cover of each species Number of individuals of each species Average height of each species Phenological State of each species

Species Richness P=0.34 Paired T-Test The species richness tends to be greater in the outside-city site than the within-city site for both Boulder and Morrison. The number of species doubled for both cities between the two sites. The insignificant p value indicates that more samples need to be taken, but this serves as a preliminary study that shows that some relationship between species richness and proximity to city may exist.

Evenness The evenness value for Morrison-within-city is non-existent, rather than zero. This is because only one species occurred in all of the Daubenmire plots at Morrison and evenness makes no sense with regard to a singular species. No Value

Percent Coverage P=0.018 Chi Squared Test for Independence using the Yates correction value Within the city, most of the species covered less than 5% of the Daubenmire plot. Outside of the city, most of the species covered more than 5%. This graph groups all within-city data together and all outside-city data together, ignoring which city the data came from.

Discussion Species Richness Evenness Percent Coverage Species Richness: The graph displayed a clear correlation between proximity to city and number of species, but the insignificant p-value indicates that more data needs to be collected before conclusions can be made. The indication of a correlation reveals that this question is worth pursuing further, but this study is not comprehensive enough to provide conclusions on the topic. Evenness: Ignoring Morrison, there is correlation between evenness and proximity to the city of Boulder. The higher level of evenness within the city disagrees with my hypothesis. Without the value from Morrison-within-city, no statistical test could be run. Therefore this data can only serve to provide indication of a correlation rather than to support any correlation. The percent coverage chart illustrates a trend between the proximity to a city and the amount of coverage by each species. Species within a city are more likely to have a low percent coverage than species outside of the city. The low p-value indicates that this correlation is significant.

Future studies Biases of site identification Greater amount of data Much more comprehensive study of entire areas before focusing on small scale Line intersects Greater amount of data Potential meaning for results on city management techniques Studies including sites of varying management

Works Cited An Ecosystem Perspective of Riparian Zones OSMP Map Gregory et. al. OSMP Map https://www-static.bouldercolorado.gov/docs/vmp-maps-1-201304101623.pdf JCOP Map http://jeffco.us/parks/open-space/ Google Maps