Advisor Information

Timothy Dickson

Location

UNO Criss Library, Room 231

Presentation Type

Oral Presentation

Start Date

3-3-2017 9:15 AM

End Date

3-3-2017 9:30 AM

Abstract

Disturbances are drivers of spatial change in the plant communities of the tallgrass prairie ecosystem. Fire and large herbivore grazing are prevalent disturbances that maintain the vegetation structure and create spatial heterogeneity in vegetation at various scales. The fire-grazing disturbance interaction occurs when areas that have been recently burned are followed by intense grazing due to the high quality of forage regrowth. This interaction has been managed in tallgrass prairies in a homogenous method using uniform burning and grazing and a heterogeneous method using patch-burn-grazing (PBG). Vegetation heterogeneity at a large scale has been studied in PBG and uniformly managed tallgrass prairie. However, no work has been done on quantifying vegetation heterogeneity at a small scale within “patches” between PBG and uniform treatments. I examined small scale vegetation heterogeneity in a PBG managed system, compared to uniformly burned and grazed systems, by using remotely sensed data and biomass samples. I used the coefficient of variation between biomass sampled at a 10 meter scale and the normalized difference vegetation index (NDVI) values from multispectral imagery as a metric of small scale heterogeneity in PBG and uniform treatments. PROC MIXED was used in SAS to run a two-way ANOVA on a blocked split-plot design of the whole plot treatments (PBG and uniform) and the split-plot treatments (patch year since burn). The results indicate that PBG does not significantly produce more small scale heterogeneity as a function of the CV in biomass and NDVI multispectral data.

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COinS
 
Mar 3rd, 9:15 AM Mar 3rd, 9:30 AM

Small Scale Heterogeneity in Vegetation Structure in a Patch-Burn-Grazing Landscape

UNO Criss Library, Room 231

Disturbances are drivers of spatial change in the plant communities of the tallgrass prairie ecosystem. Fire and large herbivore grazing are prevalent disturbances that maintain the vegetation structure and create spatial heterogeneity in vegetation at various scales. The fire-grazing disturbance interaction occurs when areas that have been recently burned are followed by intense grazing due to the high quality of forage regrowth. This interaction has been managed in tallgrass prairies in a homogenous method using uniform burning and grazing and a heterogeneous method using patch-burn-grazing (PBG). Vegetation heterogeneity at a large scale has been studied in PBG and uniformly managed tallgrass prairie. However, no work has been done on quantifying vegetation heterogeneity at a small scale within “patches” between PBG and uniform treatments. I examined small scale vegetation heterogeneity in a PBG managed system, compared to uniformly burned and grazed systems, by using remotely sensed data and biomass samples. I used the coefficient of variation between biomass sampled at a 10 meter scale and the normalized difference vegetation index (NDVI) values from multispectral imagery as a metric of small scale heterogeneity in PBG and uniform treatments. PROC MIXED was used in SAS to run a two-way ANOVA on a blocked split-plot design of the whole plot treatments (PBG and uniform) and the split-plot treatments (patch year since burn). The results indicate that PBG does not significantly produce more small scale heterogeneity as a function of the CV in biomass and NDVI multispectral data.