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Satellite image of the Taylor Valley, Antarctica (location shown in inset). Locations of algal mat transects analyzed in this study are marked. Circles indicate locations of stream discharge gages.
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In the McMurdo Dry Valleys of Antarctica, stream biota is limited by the brief availability of liquid water. The benthic microbial mats harbor diatoms that have adapted to hydrologic stresses, including numerous endemic species. We found a strong relationship between diatom community composition and flow intermittency in a data set including seven...
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... McMurdo Dry Valleys are among the coldest and dri- est habitats on the planet and are representative of the ice- free areas along the Antarctic coast. The Dry Valleys are lo- cated between mountain ranges that extend from the Ross Sea to the Polar Plateau (Fig. 1). Glacial meltwater streams flow during the austral summer through desiccated stream channels, and numerous abandoned and relict channels that do not regularly flow are also evident on the landscape. Flow extremes occur regularly and include cold and cloudy periods when flow ceases (desiccation) and episodic high flows following warm ...
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... mat samples were collected from orange mats in seven glacial meltwater streams in Taylor Valley (Fig. 1). Sampling was conducted at long-term algal monitoring trans- ects on Von Guerard Stream, Canada Stream, Delta Stream, Green Creek, and Bowles Creek, where the channels consist of a stable stone pavement. Canada Stream, Green Creek, and Bowles Creek drain from the Canada Glacier, and while they exhibited large differences in total ...
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... Relict Channel was an abandoned channel that had not received major flow since 1969 until flow was experi- mentally reactivated in January 1995. Flow was diverted from the uppermost reach of Von Guerard Stream onto a dry playa area and from there into a reach of the channel with high banks (Fig. 1). A detailed description of the Relict Channel is presented in McKnight et al. (2007). Briefly, nine transects were established along the channel between 1995 and 1997 as flow reached progressively farther downstream, with the uppermost sites 1-3 receiving flow almost every season. At sites 5 and 6 the channel became narrower and ...
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... MDV microbial mats and sediments host a well-described flora of about 50 diatom species, many of which are endemic to Antarctica (Esposito et al., 2008;Kohler et al., 2015b;Sakaeva et al., 2016;Kociolek et al., 2017). Diatom communities here are structured by physical processes, including intra-and inter-annual hydrology (Esposito et al., 2006;Stanish et al., 2011Stanish et al., , 2012Kohler et al., 2015a), as well as historical processes such as dispersal (Sakaeva et al., 2016;Sokol et al., 2020;Schulte et al., 2022). Furthermore, MDV diatom species seem to have preferences for some mat types over others (Schulte et al., 2022) which makes it possible to use diatoms as tracers for the mobilization of different mat types. ...
Flow pulses mobilize particulate organic matter (POM) in streams from the surrounding landscape and streambed. This POM serves as a source of energy and nutrients, as well as a means for organismal dispersal, to downstream communities. In the barren terrestrial landscape of the McMurdo Dry Valleys (MDV) of Antarctica, benthic microbial mats occupying different in-stream habitat types are the dominant POM source in the many glacier-fed streams. Many of these streams experience daily flow peaks that mobilize POM, and diatoms recovered from underlying stream sediments suggest that mat-derived diatoms in the POM are retained there through hyporheic exchange. Yet, ‘how much’ and ‘when’ different in-stream habitat types contribute to POM diatom assemblages is unknown. To quantify the contribution of different in-stream habitat types to POM diatom assemblages, we collected time-integrated POM samples over four diel experiments, which spanned a gradient of flow conditions over three summers. Diatoms from POM samples were identified, quantified, and compared with dominant habitat types (i.e., benthic ‘orange’ mats, marginal ‘black’ mats, and bare sediments). Like bulk POM, diatom cell concentrations followed a clockwise hysteresis pattern with stream discharge over the daily flow cycles, indicating supply limitation. Diatom community analyses showed that different habitat types harbor distinct diatom communities, and mixing models revealed that a substantial proportion of POM diatoms originated from bare sediments during baseflow conditions. Meanwhile, orange and black mats contribute diatoms to POM primarily during daily flow peaks when both cell concentrations and discharge are highest, making mats the most important contributors to POM diatom assemblages at high flows. These observations may help explain the presence of mat-derived diatoms in hyporheic sediments. Our results thus indicate a varying importance of different in-stream habitats to POM generation and export on daily to seasonal timescales, with implications for biogeochemical cycling and the local diatom metacommunity.
... One well-documented landscape that exhibits similar biotic diversity to plot 09 is the Wormherder Creek wetland in western Taylor Valley on the south side of the west lobe of Lake Bonney (Harris et al., 2007;Simmons et al., 2009b;Nielsen et al., 2012). Unlike the soil biocrusts documented here (e.g., plot 09), which are fed by the melt of relatively small snowpacks (<60 m in diameter), the Wormherder Creek wetland is fed intermittently by the melt of large snowpacks on the southern valley wall which create melt-water drainages that have contributed to saturated soils and overland flow on at least 3 documented occasions (sufficiently warm and sunny summers) in the last thirty years (Lyons et al., 2005;Nielsen et al., 2012;Wlostowski et al., 2019;Stanish et al., 2012;Harris et al., 2007). Abundant microbial mats hosting diatom and invertebrate communities have been described in Wormherder Creek Stanish et al., 2012;Simmons et al., 2009b). ...
... Unlike the soil biocrusts documented here (e.g., plot 09), which are fed by the melt of relatively small snowpacks (<60 m in diameter), the Wormherder Creek wetland is fed intermittently by the melt of large snowpacks on the southern valley wall which create melt-water drainages that have contributed to saturated soils and overland flow on at least 3 documented occasions (sufficiently warm and sunny summers) in the last thirty years (Lyons et al., 2005;Nielsen et al., 2012;Wlostowski et al., 2019;Stanish et al., 2012;Harris et al., 2007). Abundant microbial mats hosting diatom and invertebrate communities have been described in Wormherder Creek Stanish et al., 2012;Simmons et al., 2009b). Both these snowpack-fed meltwater environments are examples of biological hotspots in an otherwise arid terrestrial landscape physically separated from the diverse communities within the annual ephemeral streams. ...
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.
... Disturbance events at dryland sites, such as wildfires, floods, and dust storms, are the result of broadscale climate patterns and dynamics interacting with the landscape and can have a large negative impact, as was shown in studies at US LTER sites (figure 1; Stanish et al. 2012, Abraha et al. 2015, Ratajczak et al. 2019, Collins et al. 2020, Collins et al. 2021. The frequency and intensity of landscape-scale disturbance events are projected to increase with global warming (IPCC 2021) while being region (USGCRP 2018) and site dependent. ...
... Cooler temperatures in earlier decades (1986Doran et al. 2002) resulted in drought conditions that lowered stream flows, reducing total microbial mat biomass in streams, but increasing mat biodiversity (Kohler et al. 2015) as habitat heterogeneity increased. Streamflow variability also influenced the relative abundance of diatoms and diatom diversity in microbial mats (Stanish et al. 2012). Local pockets of soil moisture from snow melt promote the increased abundance and distribution of nondominant soil fauna (Andruizzi et al. 2018) but have a negligible impact on primary production. ...
Long-term observations and experiments in diverse drylands reveal how ecosystems and services are responding to climate change. To develop generalities about climate change impacts at dryland sites, we compared broadscale patterns in climate and synthesized primary production responses among the eight terrestrial, nonforested sites of the United States Long-Term Ecological Research (US LTER) Network located in temperate (Southwest and Midwest) and polar (Arctic and Antarctic) regions. All sites experienced warming in recent decades, whereas drought varied regionally with multidecadal phases. Multiple years of wet or dry conditions had larger effects than single years on primary production. Droughts, floods, and wildfires altered resource availability and restructured plant communities, with greater impacts on primary production than warming alone. During severe regional droughts, air pollution from wildfire and dust events peaked. Studies at US LTER drylands over more than 40 years demonstrate reciprocal links and feedbacks among dryland ecosystems, climate-driven disturbance events, and climate change.
... Diatom communities of Continental Antarctica have recently been studied in several regions: the Larsemann (Sabbe et al. 2003), Bunger (Gibson et al. 2006), and Vestfold (Bishop et al. 2020) Hills in Princess Elizabeth Land, the McMurdo Dry Valleys in Victoria Land (Stanish et al. 2012(Stanish et al. , 2013Sakaeva et al. 2016), and the Skarvsnes icefree area along the Sôya Coast (Ohtsuka et al. 2006). Nevertheless, these studies were focused mostly on sediments or benthic algal mats from continental Antarctic lakes and streams, which are predominantly composed of cyanobacteria, chlorophytes, and diatoms . ...
... The McMurdo Dry Valleys in Victoria Land constitute the most well-studied Continental Antarctic area. found 50 diatom taxa in the sediment core of Lake Hoare, while Sakaeva et al. (2016) identified 43 diatom species in microbial mats of 25 ponds, Stanish et al. (2012) reported 41 species from meltwater streams, and Stanish et al. (2013) recognized 29 diatom taxa in cryoconite holes as a subset of the species found in streams. Finally, Ohtsuka et al. (2006) observed 21 species in freshwater lake algal mats from the Skarvsnes ice-free area. ...
Diatoms constitute an important and diverse component of terrestrial protist communities but remain poorly studied, especially in the Antarctic realm. Here, we investigated the diversity and community structure of the terrestrial diatom flora from the Ulu Peninsula, James Ross Island (Maritime Antarctic Region) using a morphology-based dataset and physico-chemical measurements. A total of 97 taxa belonging to 27 genera was identified in 59 samples from terrestrial environments, including soils and rock walls. The flora was dominated by the genera Hantzschia, Luticola, and Humidophila. Eight distinct diatom assemblages could be distinguished and were mainly structured by differences in environmental characteristics such as vegetation coverage, moisture, conductivity, pH, and nutrient concentrations. In general, James Ross Island harboured a unique diatom flora as evidenced by very low similarity values with other (sub-)Antarctic localities. Only 16% of the taxa have a typical cosmopolitan distribution, whereas 70% showed a restricted Antarctic distribution, supporting previous indications of high species-level endemism in environments characterized by harsh abiotic conditions. In addition, several of the cosmopolitan species uncovered in this study might harbour substantial levels of hidden diversity, including endemic taxa, as previously revealed for the Pinnularia borealis species complex on James Ross Island. Taken together, the present study improves our knowledge and understanding of the diversity, ecology, and community structure of the terrestrial diatom flora of Ulu Peninsula and highlights that soils and wet rock walls represent important terrestrial habitats in this transitional zone between Maritime and Continental Antarctica.
... The Shannon index was calculated according to Weaver and Shannon (1963) and the difference of diatom community composition was represented by the first dimension of non-metric multidimensional scaling (NMDS). The NMDS could be used to visualize differences in composition with Bray-Curtis similarity index (Stanish et al., 2012). In our study, we simplified it and chose the first ordination number to present the similarity of the community composition in temporal point of view. ...
With the growing demand of assessing the ecological status, there is the need to fully understand the relationship between the planktic diversity and the environmental factors. Species richness and Shannon index have been widely used to describe the biodiversity of a community. Besides, we introduced the first ordination value from non-metric multidimensional scaling (NMDS) as a new index to represent the community similarity variance. In this study, we hypothesized that the variation of diatom community in rivers in an agricultural area were influenced by hydro-chemical variables. We collected daily mixed water samples using ISCO auto water samplers for diatoms and for water-chemistry analysis at the outlet of a lowland river for a consecutive year. An integrated modeling was adopted including random forest (RF) to decide the importance of the environmental factors influencing diatoms, generalized linear models (GLMs) combined with 10-folder cross validation to analyze and predict the diatom variation. The hierarchical analysis highlighted antecedent precipitation index (API) as the controlling hydrological variable and water temperature, Si²⁺ and PO4-P as the main chemical controlling factors in our study area. The generalized linear models performed better prediction for Shannon index (R² = 0.44) and NMDS (R² = 0.51) than diatom abundance (R² = 0.25) and species richness (R² = 0.25). Our findings confirmed that Shannon index and the NMDS as an index showed good performance in explaining the relationship between stream biota and its environmental factors and in predicting the diatom community development based on the hydro-chemical predictors. Our study shows and highlights the important hydro-chemical factors in the agricultural rivers, which could contribute to the further understanding of predicting diatom community development and could be implemented in the future water management protocol.
... Studies of diatom community diversity in the MSR have shown that streams generally have higher diatom morphospecies richness (a = 18-25) than cryoconite, pond mat, or lake mat communities (a = 10-15; Stanish et al. 2011). Furthermore, diatom community composition and diversity in streams is most strongly associated with climatedriven flow intermittency (Stanish et al. 2012), whereby more intermittency leads to higher abundances of endemic taxa and more mesic conditions favor cosmopolitan taxa (Esposito et al. 2006). Additionally, macronutrient availability ) and water temperature (Esposito et al. 2006, Darling et al. 2017) also alter diatom growth rates and community structure. ...
Diatom metacommunities are structured by environmental, historical, and spatial factors that are often attributed to organism dispersal. In the McMurdo Sound region (MSR) of Antarctica, wind connects aquatic habitats through delivery of inorganic and organic matter. We evaluated the dispersal of diatoms in aeolian material and its relation to the regional diatom metacommunity using light microscopy and 18S rRNA high‐throughput sequencing. The concentration of diatoms ranged from 0 to 8.76 * 106 valves · g‐1 dry aeolian material. Up to 15% of whole cells contained visible protoplasm, indicating that up to 3.43 * 104 potentially viable individuals could be dispersed in a year to a single 2 cm2 site. Diatom DNA and RNA was detected at each site, reinforcing the likelihood that we observed dispersal of viable diatoms. Of the 50 known morphospecies in the MSR, 72% were identified from aeolian material using microscopy. Aeolian community composition varied primarily by site. Meanwhile, each aeolian community was comprised of morphospecies found in aquatic communities from the same lake basin. These results suggest that aeolian diatom dispersal in the MSR is spatially structured, is predominantly local, and connects local aquatic habitats via a shared species pool. Nonetheless, aeolian community structure was distinct from that of aquatic communities, indicating intra‐habitat dispersal and environmental filtering also underlie diatom metacommunity dynamics. The present study confirms that a large number of diatoms are passively dispersed by wind across a landscape characterized by aeolian processes, integrating the regional flora and contributing to metacommunity structure and landscape connectivity.
... Consequently, at a given location, the quantity of diatom frustules may be indicative of the quantity of POM retained and processed over timescales of years to centuries. Similarly, the community assemblage of hyporheic diatom frustules may reveal the source of the POM, because different mat types contain distinctive assemblages of widespread and endemic diatom taxa well-documented in the Antarctic Freshwater Diatoms database (Spaulding et al., 2020) of the McMurdo Dry Valleys Long Term Ecological Research (MCM LTER) project and other publications (Esposito et al, 2006(Esposito et al, , 2008Stanish, 2011;Stanish et al., 2012). For other streams and rivers in North America, detailed descriptions of diatom floras are available via Diatoms of North America (diatoms.org) ...
In low‐nutrient streams in cold and arid ecosystems, the spiraling of autochthonous particulate organic matter (POM) may provide important nutrient subsidies downstream. Because of its lability and the spatial heterogeneity of processing in hyporheic sediments, the downstream transport and fate of autochthonous POM can be difficult to trace. In Antarctic McMurdo Dry Valley (MDV) streams, any POM retained in the hyporheic zone is expected to be derived from surface microbial mats that contain diatoms with long‐lasting silica frustules. We tested whether diatom frustules can be used to trace the retention of autochthonous POM in the hyporheic zone and whether certain geomorphic locations promote this process. The accumulation of diatom frustules in hyporheic sediments, measured as biogenic silica, was correlated with loss‐on‐ignition organic matter and sorbed ammonium, suggesting that diatoms can be used to identify locations where POM has been retained and processed over long timescales, regardless of whether the POM remains intact. In addition, by modeling the upstream sources of hyporheic diatom assemblages, we found that POM was predominantly derived from N‐fixing microbial mats of the genus Nostoc. In terms of spatial variability, we conclude that the hyporheic sediments adjacent to the stream channel that are regularly inundated by daily flood pulses are where the most POM has been retained over long timescales. Autochthonous POM is retained in hyporheic zones of low‐nutrient streams beyond the MDVs, and we suggest that biogenic silica and diatom composition can be used to identify locations where this transfer is most prevalent.
... This hydrological pattern configures temporary streams amongst the most dynamic and diverse freshwater ecosystems (Larned et al., 2010;Acuña et al., 2014). Within temporary streams elsewhere (Stanish et al., 2012;Veselá and Johansen, 2009;Piano et al., 2019), those under Mediterranean climate show characteristically regular occurrence and high intensity of non-flow events (Leigh et al., 2016;Colls et al., 2019). ...
Flow cessation affects river ecosystems submitted to low precipitation and increased water demand and creates unfavourable conditions to aquatic biological communities. Diatoms are amongst the most sensitive biological groups to hydric stress, making them good indicators of preceding hydrological conditions. We here analyse the response of diatom assemblages to the duration and frequency of non-flow periods in 23 Mediterranean temporary streams. All of them experienced a strong decrease in water flow during summer, leading to a period of flow cessation. In addition, other ten permanent streams (zero dry days during the study period) were included in the study for comparative purposes. Temporary and permanent streams showed similar diatom species richness, evenness, and alpha diversity. However, beta diversity was higher in temporary than permanent streams, regardless rare taxa (< 1% occurrence) had similar numbers in the two types of streams. Alpha diversity, richness, and evenness of diatom assemblages in the temporary streams changed with the duration of the non-flow period. Durations of 50-100 days were associated to higher alpha diversity, richness, and evenness, but longer non-flow periods caused their decrease. Diatoms thriving under the most extreme conditions were mostly aerophilic, pioneer, and motile taxa. The proportion of aerophilic diatom taxa increased beyond 100 dry days, particularly in those sites receiving more intense solar radiation. Overall, the taxonomical and functional composition of diatom assemblages mostly responded to the duration of the non-flow period, irrespectively of these being consecutive or not. This study shows that diatom assemblages from temporary streams contain taxa adapted to non-flow conditions, but remain vulnerable to further reductions of water flow associated to climate or global change. ‘Unimpacted’ watercourses in the Mediterranean region, independently of their flow regime, should be urgently protected and used as taxonomical and functional early indicators of climate change.
... In MDV streams, several aspects of the flow regime appear to be dominant environmental filters for diatom communities. Specifically, the occurrence of flood pulses and periods without flow during the austral summer, as well as the interannual frequency of flow, have been linked to diatom assemblage composition (Esposito et al., 2006;Stanish et al., 2011Stanish et al., , 2012. Laboratory and field experiments indicate that optimal growth temperatures (Darling et al., 2017) and nutrient concentrations may also influence species composition, but these factors are also strongly influenced by stream hydrology (Wlostowski et al., 2018). ...
... Laboratory and field experiments indicate that optimal growth temperatures (Darling et al., 2017) and nutrient concentrations may also influence species composition, but these factors are also strongly influenced by stream hydrology (Wlostowski et al., 2018). Thus, there is strong support that hydrology is a master environmental variable for understanding diatom assemblage structure in the MDV (Esposito et al., 2006;Stanish et al., 2012). In addition, dispersal dynamics can also influence benthic diatom community composition (Soininen et al., 2004;Verleyen et al., 2009;Heino et al., 2010;Sakaeva et al., 2016;Chen et al., 2019). ...
... Simulations that best maintained initial biodiversity levels were considered the most plausible. provide an excellent model ecosystem for integrating community assembly theory and models with patterns of diatom distribution observed in the field because the diatom metacommunity presents a tractable number (∼50) of taxa (Esposito et al., 2008) whose distribution and ecological preferences have been rigorously described in streams since 1994 by the McMurdo Dry Valleys Long Term Ecological Research (MCM LTER) program (Esposito et al., 2006;Stanish et al., 2011Stanish et al., , 2012Kohler et al., 2016;Darling et al., 2017). ...
Diatoms are diverse and widespread freshwater Eukaryotes that make excellent microbial subjects for addressing questions in metacommunity ecology. In the McMurdo Dry Valleys of Antarctica, the simple trophic structure of glacier-fed streams provides an ideal outdoor laboratory where well-described diatom assemblages are found within two cyanobacterial mat types, which occupy different habitats and vary in coverage within and among streams. Specifically, black mats of Nostoc spp. occur in marginal wetted habitats, and orange mats (Oscillatoria spp. and Phormidium spp.) occur in areas of consistent stream flow. Despite their importance as bioindicators for changing environmental conditions, the role of dispersal in structuring dry valley diatom metacommunities remains unclear. Here, we use MCSim, a spatially explicit metacommunity simulation package for R, to test alternative hypotheses about the roles of dispersal and species sorting in maintaining the biodiversity of diatom assemblages residing in black and orange mats. The spatial distribution and patchiness of cyanobacterial mat habitats was characterized by remote imagery of the Lake Fryxell sub-catchment in Taylor Valley. The available species pool for diatom metacommunity simulation scenarios was informed by the Antarctic Freshwater Diatoms Database, maintained by the McMurdo Dry Valleys Long Term Ecological Research program. We used simulation outcomes to test the plausibility of alternative community assembly hypotheses to explain empirically observed patterns of freshwater diatom biodiversity in the long-term record. The most plausible simulation scenarios suggest species sorting by environmental filters, alone, was not sufficient to maintain biodiversity in the Fryxell Basin diatom metacommunity. The most plausible scenarios included either (1) neutral models with different immigration rates for diatoms in orange and black mats or (2) species sorting by a relatively weak environmental filter, such that dispersal dynamics also influenced diatom community assembly, but there was not such a strong disparity in immigration rates between mat types. The results point to the importance of dispersal for understanding current and future biodiversity patterns for diatoms in this ecosystem, and more generally, provide further evidence that metacommunity theory is a useful framework for testing hypotheses about microbial community assembly.
... In ice-free terrestrial systems of Antarctica, microorganisms are thought to be sentinel organisms: organisms that rapidly respond to climate-driven changes in water, nutrient or sunlight availability in this oligotrophic cold desert environment (Stanish et al. 2012, Tiao et al. 2012, Lee et al. 2018, Niederberger et al. 2019. Strong climate-organism connections are inferred because the physical characteristics of stream habitats are thought to determine the occurrence of the different microbial mats to a greater extent than differences in water quality (McKnight et al. 2013). ...
The reflectance spectroscopic characteristics of cyanobacteria-dominated microbial mats in the McMurdo Dry Valleys (MDVs) were measured using a hyperspectral point spectrometer aboard an unmanned aerial system (remotely piloted aircraft system, unmanned aerial vehicle or drone) to determine whether mat presence, type and activity could be mapped at a spatial scale sufficient to characterize inter-annual change. Mats near Howard Glacier and Canada Glacier (ASPA 131) were mapped and mat samples were collected for DNA-based microbiome analysis. Although a broadband spectral parameter (a partial normalized difference vegetation index) identified mats, it missed mats in comparatively deep (> 10 cm) water or on bouldery surfaces where mats occupied fringing moats. A hyperspectral parameter (B6) did not have these shortcomings and recorded a larger dynamic range at both sites. When linked with colour orthomosaic data, B6 band strength is shown to be capable of characterizing the presence, type and activity of cyanobacteria-dominated mats in and around MDV streams. 16S rRNA gene polymerase chain reaction amplicon sequencing analysis of the mat samples revealed that dominant cyanobacterial taxa differed between spectrally distinguishable mats, indicating that spectral differences reflect underlying biological distinctiveness. Combined rapid-repeat hyperspectral measurements can be applied in order to monitor the distribution and activity of sentinel microbial ecosystems across the terrestrial Antarctic.
