Theses and Dissertations at Montana State University (MSU)
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Item 'Hypertemporal' remote sensing of plant function: a comparison of phenocam and geostationary operational environmental satellite NDVI data products(Montana State University - Bozeman, College of Agriculture, 2019) Douglas, James Thomas; Chairperson, Graduate Committee: Paul C. StoyOngoing climate warming is changing the seasonality of plant canopy function, but common approaches to explore these changes via polar-orbiting satellites often miss rapid canopy transitions due to infrequent observations. I explored the ability of satellites designed for studying weather systems, namely The Geostationary Operational Environmental Satellite (GOES), to track plant canopy status on time scales of minutes. With new capabilities to remotely sense in the infrared, the GOES weather satellites now have the capability to detect photosynthetic activity. Satellite observations of the normalized difference vegetation index (NDVI) are compared against near-surface phenological camera ("PhenoCam") observations from the National Ecological Observation Network (NEON, Inc.) at six sites every 15 minutes for one week in April 2019. Diurnal trends across both observation platforms showed the expected diurnal parabolic structure in NDVI with critical differences in NDVI magnitude between PhenoCams and GOES observations. One tailed T-test results show that there is variability between methods when measuring NDVI, with P-values less than 0.05 in all cases. This was anticipated due to correction factors needed for PhenoCam NDVI observations. However, additional variability can be attributed to other areas such as cloud cover, plant type, and heterogeneity. My proof-of-concept study demonstrates that raw NDVI data from both methods are often comparable, which lends credit to the notion that NDVI can be accurately observed from space at high (up to five minute) temporal resolution. With current research underway on the topics of atmospheric corrections and further surface validation, GOES has the potential to observe land surface attributes at up to 5-minute intervals across entire hemispheres for identifying phenology, disturbance and other vegetation dynamics in real time. With two hypertemporal methods at different spatial scales recently introduced, the research is primed to move towards a real time understanding of plant canopy function across the United States.Item Soil restoration and invasive plants at the Block P Mill and tailings site, Montana(Montana State University - Bozeman, College of Agriculture, 2019) Massey, John Gant; Chairperson, Graduate Committee: Scott PowellMy case study considers the Block P Mill and Tailings Site (also, Block P or the Site), a derelict lead and zinc production facility in the Little Belt Mountains of Montana. Fifteen years after environmental restoration activities concluded at this heavily contaminated site, I analyzed whether the canopy cover of plant species correlates with soil pH conditions. Specifically, I investigated whether addressing acidic conditions during mine-site restoration encouraged the presence of oxeye daisy (Leucanthemum vulgare), a non-native invasive plant species. Fieldwork in June 2019 included collection of soil pH and vegetation canopy cover data from 36 quadrats (6 m x 6 m) arrayed across this 6.6-ha restoration site. A Canonical Correspondence Analysis (CCA) of these data shows no statistically significant relationship between soil pH and overall plant species' canopy cover values. Further, linear regression analysis shows no statistically significant relationship between soil pH and the canopy cover of oxeye daisy. Therefore, it is unlikely that differences in the soil pH across the Site unevenly affect the canopy cover of plant species or unduly encourages the presence of oxeye daisy. These results are a reminder, however, that if restoration returns fertility to a previously barren and inhospitable site, the presence of novel assemblages of non-native and native plant species also may be generally encouraged, including invasive species such as oxeye daisy. I therefore conclude that the treatment of invasive plants at restoration sites like the Block P are a required managerial choice, not a philosophical imperative.Item Snow accumulation and ablation under fire-altered lodgepole pine forest canopies(Montana State University - Bozeman, College of Letters & Science, 1994) Skidmore, Peter BrooksItem Factors influencing big sagebrush cover in Southwest Montana(Montana State University - Bozeman, College of Agriculture, 2010) Mendelsohn, Brittany Jennifer; Chairperson, Graduate Committee: Bok Sowell.The sagebrush steppe provides important habitat to many wildlife species. Conifer expansion of Douglas-fir and Rocky Mountain juniper into this area is a growing concern. Currently management focuses on the removal of Rocky Mountain juniper. The primary objective of this study was to determine the relationship between live sagebrush cover and aspect, slope, elevation, soil texture, soil depth and rock outcroppings. The second objective was to compare Douglas-fir and Rocky Mountain juniper's canopy areas at comparable ages. Percent cover of shrubs and conifers as well as the abiotic factors were recorded at forty Wyoming and forty mountain big sagebrush plots at each of three study sites in southwest Montana (Pipestone, Elkhorn, and Whitetail) (n = 240). The best-fit model utilizes the terms site, sagebrush subspecies, square root of conifer cover and site by sagebrush subspecies as the independent variables, with square roots of sagebrush cover as the dependent variable. The model found that abiotic factors had no correlation (p>0.05) with live sagebrush cover, but conifer cover had a negative effect on sagebrush cover. Equations were developed to predict canopy area of Douglas-fir and Rocky Mountain juniper thru time. Our findings suggest conifers should not be removed to increase sagebrush cover due to low response of sagebrush cover. Douglas-fir is the dominant conifer on these sites and has three times more canopy than Rocky Mountain juniper at similar ages (p<0.001). Rocky Mountain juniper is generally thought to have higher food and cover values for deer and elk and upland game birds compared to Douglas-fir (Gunderson 1990, Kufeld 1973). Therefore, the current practice of removing Rocky Mountain juniper to increase sagebrush cover should not be continued.