@article {5017, title = {Remote sensing for species distribution models: An illustration from a sentinel taxon of the world{\textquoteright}s driest ecosystem}, journal = {Ecology}, volume = {106}, year = {2025}, month = {02/2025}, pages = {e70035}, abstract = {

In situ observed data are commonly used as species occurrence response variables in species distribution models. However, the use of remotely observed data from high-resolution multispectral remote-sensing images as a source of presence/absence data for species distribution models remains under-developed. Here, we describe an ensemble species distribution model of black microbial mats (Nostoc spp.) using presence/absence points derived from the unmixing of 4-m resolution WorldView-2 and WorldView-3 images in the Lake Fryxell basin region of Taylor Valley, Antarctica. Environmental and topographical characteristics such as soil moisture, snow, elevation, slope, and aspect were used as predictor variables in our models. We demonstrate that we can build and run ensemble species distribution models using both dependent and independent variables derived from remote-sensing data to generate spatially explicit habitat suitability maps. Snow and soil moisture were found to be the most important variables accounting for about 80\% of the variation in the distribution of black mats throughout the Fryxell basin. This study highlights the potential contribution of high-resolution remote-sensing to species distribution modeling and informs new studies incorporating remotely derived species occurrences in species distribution models, especially in remote areas where access to in situ data is often limited.

}, keywords = {LTER-MCM, Antarctica, McMurdo Dry Valleys, microbial mats, remote sensing, species distribution modeling, species occurrence}, issn = {0012-9658}, doi = {10.1002/ecy.v106.210.1002/ecy.70035}, url = {https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecy.70035}, author = {Thapa-Magar, Khum B. and Eric R. Sokol and Michael N. Gooseff and Salvatore, Mark R. and John E. Barrett and Joseph S. Levy and Knightly, J. Paul and Power, Sarah N.} } @article {4945, title = {Timing and duration of ephemeral Antarctic water tracks and wetlands using high temporal{\textendash}resolution satellite imagery, high spatial{\textendash}resolution satellite imagery, and ground-based sensors in the McMurdo Dry Valleys}, journal = {Arctic, Antarctic, and Alpine Research}, volume = {54}, year = {2022}, month = {12/2022}, pages = {538 - 561}, abstract = {

Antarctic water tracks and ephemeral wetlands are a primary location for biogeochemical soil processes driving cold desert soil formation. Though the spatial extent of water tracks and wetted soils has been mapped in the McMurdo Dry Valleys (MDV) on the basis of mapping darkened pixels in high-resolution commercial satellite imagery, the timescale over which water tracks and wetlands form and the duration of these biogeochemically active environments remain unknown. Here, we determine the start date and end dates and the duration of wetted soils at ten sites located across the MDV using a combination of in situ soil sensors and two complementary remote imaging platforms (Planet and WorldView) to understand the hydroclimatic processes that drive water track and wetland formation. Our remote sensing employs a terrain correction workflow that removes the contribution of differential direct illumination and small-scale shadowing on pixel brightness, reducing false positives (soils identified as wetted when in fact they are shadowed or darkened as a consequence of high phase angle). Our findings extend the water track and wetland hydroperiod by over a month, showing darkening occurring from November to March, suggesting hydrological contributions from ground ice thaw, snowmelt, and salt deliquescence and soil brine growth.

}, keywords = {LTER-MCM, Antarctica, hydroperiod, remote sensing, water track, wetland}, issn = {1523-0430}, doi = {10.1080/15230430.2022.2123858}, url = {https://www.tandfonline.com/doi/full/10.1080/15230430.2022.2123858}, author = {Kuentz, Lily C. and Joseph S. Levy and Salvatore, Mark R.} } @article {4691, title = {Episodic basin-scale soil moisture anomalies associated with high relative humidity events in the McMurdo Dry Valleys, Antarctica}, journal = {Antarctic Science}, year = {2021}, month = {08/2021}, pages = {1-15}, abstract = {

Outside of hydrologically wetted active layer soils and humidity-sensitive soil brines, low soil moisture is a limiting factor controlling biogeochemical processes in the McMurdo Dry Valleys. But anecdotal field observations suggest that episodic wetting and darkening of surface soils in the absence of snowmelt occurs during high humidity conditions. Here, I analyse long-term meteorological station data to determine whether soil-darkening episodes are present in the instrumental record and whether they are, in fact, correlated with relative humidity. A strong linear correlation is found between relative humidity and soil reflectance at the Lake Bonney long-term autonomous weather station. Soil reflectance is found to decrease annually by a median of 27.7\% in response to high humidity conditions. This magnitude of darkening is consistent with soil moisture rising from typical background values of \< 0.5 wt.\% to 2\–3 wt.\%, suggesting that regional atmospheric processes may result in widespread soil moisture generation in otherwise dry surface soils. Temperature and relative humidity conditions under which darkening is observed occur for hundreds of hours per year, but are dominated by episodes occurring between midnight and 07h00 local time, suggesting that wetting events may be common, but are not widely observed during typical diel science operations.

}, keywords = {LTER-MCM, deliquescence, hydrology, microclimate, micrometeorology, pedology, remote sensing}, issn = {0954-1020}, doi = {10.1017/S0954102021000341}, url = {https://www.cambridge.org/core/product/identifier/S0954102021000341/type/journal_article}, author = {Joseph S. Levy} }