Spatially explicit moss microclimate observations - Windmill Islands, East Antarctica (ASPA 135 and Robinson Ridge) and Robert Island, Maritime Antarctica

Full description

Antarctic moss beds have complex micro-topography that results in spatial patterns of moss health that vary over centimetres across moss beds. As such, the underlying drivers of these patterns must also vary over centimetre distances.

The dataset includes data from Maritime Antarctica and East Antarctica. The dataset includes measured moss canopy temperatures and relative water content, and modelled direct radiation. Empirical data were measured at 3-4 points nested within 1x1 m plots of continuous moss cover, and the points were selected to capture different micro-topographic positions of the moss beds (north, east, south and west-facing micro-slopes, and micro-ridges and micro-valleys). Radiation was modelled at 1x1 cm resolution for the 1x1 m plots and extracted for the exact micro-topographic positions where empirical data were measured. Modelled radiation accounts for topographic shading from features outside of the plots, as well as shading from micro-topography within plots. The data were measured/modelled in a spatially explicit manner, with accurate reference to the micro-topographic position and associated slope and aspect.

Coppermine Peninsula, Robert Island, Maritime Antarctica:
Microclimate data were collected from 14th - 26th February, 2018 on the Coppermine Peninsula, Robert Island, located in the South Shetland Islands in Maritime Antarctica. Most of Robert Island is glaciated year-round, however the Coppermine Peninsula (-62.375701°, -59.711355°) is predominantly ice-free. Much of the peninsula is classified as an Antarctic specially protected area (ASPA No. 112) and recognised as a high conservation priority due to the vast and diverse moss turfs in the area (Management Plan for Antarctic Specially Protected Area No. 112, 2012). This study took place in a densely moss-covered area of the Coppermine Peninsula adjacent to, but outside of, the eastern boundary of ASPA 112.

Bailey Peninsula, Windmill Islands, East Antarctica:
On the Bailey Peninsula in East Antarctica (-66.282176°, 110.538666°), microclimate data were collected over two summer seasons: from 6th – 22nd February, 2022 and from 2nd January – 1st February, 2023. In both seasons data were collected from moss beds in ASPA 135, which lies approximately 400 m to the east of Casey Station on the Bailey Peninsula. The large moss beds and extensive lichen growth in ASPA 135 are considered the most lush and extensive vegetation communities in East Antarctica and are thus regarded as a high conservation priority.

Robinson Ridge, Windmill Islands, East Antarctica:
Robinson Ridge lies approximately 10 km south of the Bailey Peninsula (-66.367551°, 110.587481°) and also hosts large areas of lush moss beds. Microclimate data at Robinson Ridge were collected over two summer seasons: from 10th – 18th February, 2022 and from 3rd – 30th January, 2023.

Study design:
In this study, microclimate data were measured within the moss canopy at selected micro-topographic points nested within study plots of continuous moss turf. Across all locations and seasons, study plots were 1x1 m in size and were selected to capture a representative subset of the moss beds growing over the wider area at each site, including a range of slopes and aspects due to the landscape topography, wet sites close to melt water and drier sites away from water, as well as capturing a range of moss bed micro-topographic complexity. Each plot had continuous moss cover except where rocks were present. For the measurement of microclimate data, micro-topographic positions (MPs) were selected within each plot to capture as much variation in moss micro-topography as possible.

On the Coppermine Peninsula, seven plots were selected and microclimate data were measured at three MPs within each plot. All seven plots were dominated by moss species Sanionia uncinata, however, Polytrichastrum alpinum and Warnstorfia sarmentosa were also present in small patches. It should be noted that west-facing landscape scale slopes were not captured due to little-or-no moss growth in these areas.

On the Bailey Peninsula, five plots were selected in the 2022 season and five different plots were selected in 2023. At Robinson Ridge, six plots were selected in 2022 and five different plots were selected in 2023. In both seasons, data were measured at four MPs within each plot. Plots on Bailey Peninsula and Robinson Ridge were largely dominated by the endemic moss species Schistidium antarctici, while two cosmopolitan species, Ceratodon purpureus and Bryum pseudotriquetrum were also present.

The dataset consists of three Excel spreadsheets. Each contains a worksheet of data, and another worksheet with information on the column headings.

Lineage

Progress Code: onGoing

Statement: Data from malfunctioned sensors have been removed from the dataset.

Notes

Purpose
The data provide an accurate characterisation of the conditions that Antarctic mosses experience over the summer growing period, and the spatial and temporal variation of these conditions over biologically relevant scales. The data can go on to be used to ground truth high-resolution models of ground surface temperatures in ice-free areas of Antarctica, or to calibrate/constrain ecological models.