02394nas a2200301 4500008004100000022001400041245012200055210006900177260001200246300001100258490000800269520142600277653001501703653002401718653001901742653001901761653003401780653002301814100002801837700002001865700002501885700002401910700002201934700002101956700001901977700002101996856007502017 2025 eng d a0012-965800aRemote sensing for species distribution models: An illustration from a sentinel taxon of the world's driest ecosystem0 aRemote sensing for species distribution models An illustration f c02/2025 ae700350 v1063 a

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.

10aAntarctica10aMcMurdo Dry Valleys10amicrobial mats10aremote sensing10aspecies distribution modeling10aspecies occurrence1 aThapa‐Magar, Khum, B.1 aSokol, Eric, R.1 aGooseff, Michael, N.1 aSalvatore, Mark, R.1 aBarrett, John, E.1 aLevy, Joseph, S.1 aKnightly, Paul1 aPower, Sarah, N. uhttps://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecy.7003503255nas a2200277 4500008004100000022001300041245011100054210006900165260001200234300001100246520240400257653001502661653001302676653001102689653002902700653000902729653001702738100002102755700002402776700002002800700002102820700002502841700001702866700002202883856007202905 2024 eng d a2666017200aRemotely characterizing photosynthetic biocrust in snowpack-fed microhabitats of Taylor Valley, Antarctica0 aRemotely characterizing photosynthetic biocrust in snowpackfed m c02/2024 a1001203 a

Microbial communities are the primary drivers of carbon cycling in the McMurdo Dry Valleys of Antarctica. Dense microbial mats, consisting mainly of photosynthetic cyanobacteria, occupy aquatic areas associated with streams and lakes. Other microbial communities also occur at lower densities as patchy surface biological soil crusts (hereafter, biocrusts) across the terrestrial landscape. Multispectral satellite data have been used to model microbial mat abundance in high-density areas like stream and lake margins, but no previous studies have investigated the lower detection limits of biocrusts. Here, we describe remote sensing and field-based survey and sampling approaches to study the detectability and distribution of biocrusts in the McMurdo Dry Valleys. Using a combination of multi- and hyperspectral tools and spectral linear unmixing, we modeled the abundances of biocrust in eastern Taylor Valley. Our spectral approaches can detect low masses of biocrust material in laboratory microcosms down to biocrust concentrations of 1% by mass. These techniques also distinguish the spectra of biocrust from both surface rock and mineral signatures from orbit. We found that biocrusts are present throughout the soils of eastern Taylor Valley and are associated with diverse underlying soil communities. The densest biocrust communities identified in this study had total organic carbon 5x greater than the content of typical arid soils. The most productive biocrusts were located downslope of melting snowpacks in unique soil ecosystems that are distinct from the surrounding arid landscape. There are similarities between the snowpack and stream sediment communities (high diversity of soil invertebrates) as well as their ecosystem properties (e.g., persistence of liquid water, high transfer of available nutrients, lower salinity from flushing) compared to the typical arid terrestrial ecosystem of the dry valleys. Our approach extends the capability of orbital remote sensing of photosynthetic communities out of the aquatic margins and into the drier soils which comprise most of this landscape. This interdisciplinary work is critical for measuring and monitoring terrestrial carbon stocks and predicting future ecosystem dynamics in this currently water-limited but increasingly dynamic Antarctic landscape, which is particularly climate-sensitive and difficult to access.

10aAntarctica10abiocrust10acarbon10areflectance spectroscopy10asnow10asoil ecology1 aPower, Sarah, N.1 aSalvatore, Mark, R.1 aSokol, Eric, R.1 aStanish, Lee, F.1 aBorges, Schuyler, R.1 aAdams, Byron1 aBarrett, John, E. uhttps://www.sciencedirect.com/science/article/pii/S266601722400004X02186nas a2200313 4500008004100000022001400041245009000055210006900145260001200214300001800226490000700244520123000251653002201481653002401503653002001527653001701547653001501564100002201579700002101601700002101622700002201643700002201665700002401687700002101711700002501732700002101757700002501778856006901803 2024 eng d a2328-427700aResponse of a terrestrial polar ecosystem to the March 2022 Antarctic weather anomaly0 aResponse of a terrestrial polar ecosystem to the March 2022 Anta c08/2024 ae2023EF0043060 v123 a

Record high temperatures were documented in the McMurdo Dry Valleys, Antarctica, on 18 March 2022, exceeding average temperatures for that day by nearly 30°C. Satellite imagery and stream gage measurements indicate that surface wetting coincided with this warming more than 2 months after peak summer thaw and likely exceeded thresholds for rehydration and activation of resident organisms that typically survive the cold and dry conditions of the polar fall in a freeze-dried state. This weather event is notable in both the timing and magnitude of the warming and wetting when temperatures exceeded 0°C at a time when biological communities and streams have typically entered a persistent frozen state. Such events may be a harbinger of future climate conditions characterized by warmer temperatures and greater thaw in this region of Antarctica, which could influence the distribution, activity, and abundance of sentinel taxa. Here we describe the ecosystem responses to this weather anomaly reporting on meteorological and hydrological measurements across the region and on later biological observations from Canada Stream, one of the most diverse and productive ecosystems within the McMurdo Dry Valleys.

10aatmospheric river10aclimate variability10aextreme weather10apolar desert10asoil biota1 aBarrett, John, E.1 aAdams, Byron, J.1 aDoran, Peter, T.1 aDugan, Hilary, A.1 aMyers, Krista, F.1 aSalvatore, Mark, R.1 aPower, Sarah, N.1 aSnyder, Meredith, D.1 aWright, Anna, T.1 aGooseff, Michael, N. uhttps://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023EF00430602051nas a2200253 4500008004100000245010800041210006900149260001200218520110900230653001201339653001401351653002401365653001701389653001901406653001701425100002401442700002501466700002201491700002001513700002101533700002101554700001601575856020601591 2020 eng d00aRemote characterization of photosynthetic communities in the Fryxell basin of Taylor Valley, Antarctica0 aRemote characterization of photosynthetic communities in the Fry c03/20203 a

We investigate the spatial distribution, spectral properties and temporal variability of primary producers (e.g. communities of microbial mats and mosses) throughout the Fryxell basin of Taylor Valley, Antarctica, using high-resolution multispectral remote-sensing data. Our results suggest that photosynthetic communities can be readily detected throughout the Fryxell basin based on their unique near-infrared spectral signatures. Observed intra- and inter-annual variability in spectral signatures are consistent with short-term variations in mat distribution, hydration and photosynthetic activity. Spectral unmixing is also implemented in order to estimate mat abundance, with the most densely vegetated regions observed from orbit correlating spatially with some of the most productive regions of the Fryxell basin. Our work establishes remote sensing as a valuable tool in the study of these ecological communities in the McMurdo Dry Valleys and demonstrates how future scientific investigations and the management of specially protected areas could benefit from these tools and techniques.

10aecology10ahydrology10aMcMurdo Dry Valleys10amicrobiology10aremote sensing10aspectroscopy1 aSalvatore, Mark, R.1 aBorges, Schuyler, R.1 aBarrett, John, E.1 aSokol, Eric, R.1 aStanish, Lee, F.1 aPower, Sarah, N.1 aMorin, Paul uhttps://www.cambridge.org/core/journals/antarctic-science/article/remote-characterization-of-photosynthetic-communities-in-the-fryxell-basin-of-taylor-valley-antarctica/8576F6BB1BCFDCA8409F5EA96CA00C6F04273nas a2200193 4500008004100000022001400041245007400055210006900129260001600198300001400214490000700228520366500235100002203900700002103922700002503943700002203968700002403990856006504014 2015 eng d a0954-102000aRecovery of Antarctic stream epilithon from simulated scouring events0 aRecovery of Antarctic stream epilithon from simulated scouring e cJan-08-2015 a341 - 3540 v273 a

Microbial mats are common in polar streams and often dominate benthic biomass. Climate change may be enhancing the variability of stream flows in the Antarctic, but so far studies investigating mat responses to disturbance have been limited in this region. Mat regrowth was evaluated following disturbance by experimentally scouring rocks from an ephemeral McMurdo Dry Valley stream over two summers (2001–02 and 2012–13). Mats were sampled at the beginning and resampled at the end of the flow season. In 2012–13, mats were additionally resampled mid-season along with previously undisturbed controls. In 2001–02 rocks regained 47% of chlorophyll aand 40% of ash-free dry mass by the end of the summer, while in 2012–13 rocks regrew 18% and 27%, respectively. Mat stoichiometry differed between summers, and reflected differences in biomass and discharge. Oscillatoria spp. were greatest on scoured rocks and Phormidium spp. on undisturbed rocks. Small diatoms Humidophila andFistulifera spp. increased throughout the summer in all mats, with the latter more abundant in scoured communities. Collectively, these data suggest that mats are variable intra-annually, responsive to hydrology and require multiple summers to regrow initial biomass once lost. These results will aid the interpretation of long-term data, as well as inform Antarctic Specially Managed Area protocols.

1 aKohler, Tyler, J.1 aChatfield, Ethan1 aGooseff, Michael, N.1 aBarrett, John, E.1 aMcKnight, Diane, M. uhttp://www.journals.cambridge.org/abstract_S0954102015000024