Vegetation Composition in - PowerPoint Presentation

Slide1

Vegetation Composition in Niwot’s Riparian Tundra

Sean Race

Vegetation Ecology – Semester B 2014

Mountain Research Station. UC-BSlide2

IntroductionQuestion: Does proximity of riparian area in alpine tundra affect the composition of the vegetation found there? Are certain species exclusive to particular areas of the tundra?Slide3

HypothesisH0 : There is no relationship between proximity to riparian area and vegetation compositionAlternate Hypothesis: There is a significant relationship between proximity and vegetation compositionPrediction: Certain species will colonize the different parts of the tundra based on proximitySlide4

Proximity to water influences the plant diversity and topography of riparian zones compared to uplands (Elmore, Beschta 1987)

Species Richness increases as distance from stream increases,

then falls gradually

(Gregory et al. 1991)

Vegetation along arctic river systems is primarily determined by moisture content and pH

(Gould, Walker 1999)

Prior ResearchSlide5

MethodsSite 1 – Fourmile Creek tundra

Sites 2&3 –

Niwot

Ridge tundra

Elevation: 10961ft

Aspect: 120°SE

Slope: 2.5%

Elevation: 11041 and 11191ft

Aspect: 112 and 113°SE

Slope: 2% and 5%Slide6

Plotting techniques5 Daubenmire plots in 10x5m area 0-5m from stream and 10-15m from streamEach replicate had 10 plots totalMeasured avg. height, species, # individuals, and phenological stateSlide7

ResultsSpecies Richness did not vary greatly between the Riparian (25) and Off-Riparian (23) samplesMore significant were changes in phenological state and between individual species…Jaccard Index: 0.6# Common: 18# Different: 12

P-value: 0.0002Slide8

Erigeron vs. Snow Buttercup Chi-Square(s)Including all cover classes resulted in a p-value of .227.Removing cover class 1 (0-5%) resulted in a p-value of .0125, however

All Classes

Classes excl. 1Slide9

A strong relationship between cover class and Yarrow presence exists between the Riparian and Off-Riparian areasYarrow dominates the drier Off-Riparian areas while being largely absent from the

mesic

areas

Yarrow (

Achillea

millefolium

) Chi-SquareSlide10

Species Evenness T-TestNo significant relationship between location and species evenness was foundTwo-tailed p-value: .846Riparian Mean: 82Off-Riparian Mean:83Slide11

DiscussionDifferences in species richness and species evenness were minimal between sitesHowever, vegetation composition based on phenological state and individual presence/absence showed significant trendsResults of Chi-Square tests and Jaccard Index suggest that individual species composition is heavily influenced by proximity to water sourceSlide12

Limits and Future ResearchMajor limits of this study included lack of 3 distinct replicatesMore replicates for future studiesT-test on bounded dataPossible ranking system? A future study could survey larger areas to perhaps see the affect of further distance (>15m) on vegetation compositionPotentially look into differences between native and exotic grass species…Slide13

Gould, W. A. and Walker, M. D. (1999) “Plant communities and landscape diversity along a Canadian Arctic river.” Journal of Vegetation Science, 10: 537–548.Gregory, Stanley V and Swanson, Frederick J et al. “An Ecosystem Perspective of Riparian Zones” Bioscience, Sep 1991: 41, 8. Research Library Core pg. 540Elmore, Wayne and Beschta, Robert L. “Riparian Areas: Perceptions in Management” Rangelands, Dec 1987: 9, 6: 260-265.References