Plant functional traits and microbes vary with position on striped periglacial patterned ground at Glacier National Park, Montana

Abstract

The retreating snowfields and glaciers of Glacier National Park, Montana, USA, present alpine plants with changes in habitat and hydrology. The adjacent and relic periglacial patterned ground consists of solifluction terraces of green, vegetation-rich stripes alternating with sparsely vegetated brown stripes. We established georeferenced transects on striped periglacial patterned ground for long-term monitoring and data collection on species distribution and plant functional traits at Siyeh Pass and at Piegan Pass at Glacier National Park. We documented species distribution and calculated the relative percent cover (RPC) of qualitative functional traits and used 16S rRNA from soil samples to characterize microbial distribution on green and brown stripes. Plant species distribution varied significantly and there were key differences in microbial distribution between the green and brown stripes. The rare arctic-alpine plants Draba macounii, Papaver pygmaeum, and Sagina nivalis were restricted to brown stripes, where the RPC of xeromorphic taprooted species was significantly higher at the leading edge of the Siyeh Pass snowfield. Brown stripes had a higher percentage of the thermophilic bacteria Thermacetogenium and Thermoflavimicrobium. Green stripes were co-dominated by the adventitiously-rooted dwarf shrubs Salix arctica and the possibly N-fixing Dryas octopetala. Green stripes were inhabited by Krummholz and seedlings of Abies lasiocarpa and Pinus albicaulus. Prosthecobacter, a hydrophilic bacterial genus, was more abundant on the green stripes, which had 6,524 bacterial sequences in comparison to the 1,183 sequences from the brown stripes. While further research can determine which functional traits are critical for these plants, knowledge of the current distribution of plant species and their functional traits can be used in predictive models of the responses of alpine plants to disappearing snowfields and glaciers. This research is important in conservation of rare arctic-alpine species on periglacial patterned ground.

Geomorphological processes shape plant community traits in the Arctic

“…Our correlative methods do not prove causation, but our observational approach provides missing insights into trait–geomorphology relationships in Arctic ecosystems. Our results from the Arctic (Figure 5), together with existing literature from alpine ecosystems (Apple et al., 2019; Kopanina et al., 2020), provide evidence for the importance of geomorphological processes in trait ecology.…”

A complex patterned-ground ecosystem in the Sierra Nevada, California, USA supports unusual habitat for American pika

“…Comparing the species present at Kavanaugh to sortedcircle vegetation elsewhere is not especially informative given the different climatic and vegetation conditions of the studies. Though functional trait analysis could be of greater comparative value than taxonomy, studies using these are limited and have addressed vegetation on PG forms other than sorted circles (Mitchell, Lamarche, and Lloyd 1966;Apple, Ricketts, and Martin 2019). Apparent stability of the vegetation, high plant cover on the soil circles, and lack of vegetation-free zones further corroborate the relict nature of the Kavanaugh PG (Mitchell, Lamarche, and Lloyd 1966;J.…”

“…Examples range from dotted landscapes of soil mounds, such as the Mima Mounds of western Washington (Cramer and Barger 2014) to recurring patterns of termite "fairy circles" in Kenya, Zambia, and other hot desert regions (Bonachela et al 2015). In high-temperate mountains, spatially patterned vegetation can be associated with periglacial, spatially patterned features (Mitchell, Lamarche, and Lloyd 1966;Millar et al 2015;Apple, Ricketts, and Martin 2019) or with other aspects of mountain topography (Björk and Molau 2007).…”

On the impact of the COVID-19 pandemic on alpine research projects in Montana

“…of the Anaconda-Pintler Wilderness in southwestern Montana. It has late-lying snowfields, solifluction lobes, and periglacial-patterned ground where we study plant functional traits and species distribution (Apple et al 2019). Because Goat Flat is virtually inaccessible most of the year due to heavy snows and a steeply angled cirque, we are developing sensors and sensor networks to transmit soil moisture and temperature data remotely.…”