Bryophyte species composition over moisture gradients in the Windmill Islands, East Antarctica: development of a baseline for monitoring climate change impacts

Abstract

M. (2012). Bryophyte species composition over moisture gradients in the Windmill Islands, East Antarctica: development of a baseline for monitoring climate change impacts. Biodiversity,, 257-264. Bryophyte species composition over moisture gradients in the Windmill Islands, East Antarctica: development of a baseline for monitoring climate change impacts AbstractExtreme environmental conditions prevail on the Antarctic continent and limit plant diversity to cryptogamic communities, dominated by bryophytes and lichens. Even small abiotic shifts, associated with climate change, are likely to have pronounced impacts on these communities that currently exist at their physiological limit of survival. Changes to moisture availability, due to precipitation shifts or alterations to permanent snow reserves, will most likely cause greatest impact. In order to establish a baseline for determining the effect of climate change on continental Antarctic terrestrial communities and to better understand bryophyte species distributions in relation to moisture in a floristically important Antarctic region, this study surveyed finescale bryophyte patterns and turf water and nutrient contents along community gradients in the Windmill Islands, East Antarctica. The survey found that the Antarctic endemic, Schistidium antarctici, dominated the wettest habitats, Bryum pseudotriquetrum distribution spanned the gradient, whilst Ceratodon purpureus and Cephaloziella varians were restricted to the driest habitats. These patterns, along with knowledge of these species relative physiology, suggest the endemic Schistidium antarctici will be negatively impacted under a drying trend. This study provides a model for quantitative finescale analysis of bryophyte distributions in cryptogamic communities and forms an important reference site for monitoring impacts of climate change in Antarctica. AbstractExtreme environmental conditions prevail on the Antarctic continent and limit plant diversity to cryptogamic communities, dominated by bryophytes and lichens. Even small abiotic shifts, associated with climate change, are likely to have pronounced impacts on these communities that currently exist at their physiological limit of survival. Changes to moisture availability, due to precipitation shifts or alterations to permanent snow reserves will most likely cause greatest impact. In order to establish a baseline for determining the effect of climate change on continental Antarctic terrestrial communities and to better understand bryophyte species distributions in relation to moisture in a floristically important Antarctic region, this study surveyed finescale bryophyte patterns and turf water and nutrient contents along community gradients in the Windmill Islands, East Antarctica. The survey found that the Antarctic endemic, Schistidium antarctici, dominated the wettest habitats, Bryum pseudotriquetrum distribution spanned the gradient, whilst Ceratodon purpureus and Cephaloziella varians were restricted to driest habitats. These patterns, along ...

The spatial structure of Antarctic biodiversity

“…Analogous enrichment also occurs tens and up to several hundred kilometers ''inland,'' associated with bird colonies on nunataks (Ryan and Watkins 1989) or the influence of burrowing petrels in the sub-Antarctic (Smith and Froneman 2008). At much smaller scales, the importance of fertilization is demonstrated by the development of specific lichen or microbial communities around isolated bird perches (Øvstedal and Smith 2001), mummified seal carcasses (Nelson et al 2008), and on the sites of ancient penguin colonies (Wasley et al 2012).…”

“…The vegetation changes from extensive moss beds in the lower-lying regions to lichen-dominated communities toward the summits (Melick and Seppelt 1997). Opposing resource gradients accompany the vegetation change, with water decreasing and plant nitrogen content increasing with elevation (Wasley et al 2006a(Wasley et al , 2012.…”

“…The mosses and lichens that dominate the limited continental Antarctic flora and survive in extremely xeric environments, such as rock surfaces, can avoid light stress by drying out rapidly, becoming inactive and increasingly tolerant of radiation including UV-B (Schlensog and Schroeter 2000, Kappen and Valladares 2007). Interspecific differences in the response of mosses to desiccation and UV radiation (Smith 1999, Robinson et al 2003, Dunn and Robinson 2006, Wasley et al 2012, determine both their spatial distribution on small scales, and their likely different future response to changes in the pattern and/or magnitude of stresses experienced. On exposed surfaces that dry quickly, lichen development is limited to crevices, interstitial spaces, or south-facing surfaces that offer shade but also where a reliable water supply is present.…”

Spatial Co-Registration of Ultra-High Resolution Visible, Multispectral and Thermal Images Acquired with a Micro-UAV over Antarctic Moss Beds

“…Established in 2003, this monitoring system comprises a set of 30 permanent quadrat locations, across 10 transects spanning a water gradient across three community types: from the wettest community dominated by mosses (Bryophyte community) to the driest community dominated by moribund moss encrusted with lichens (Lichen community), with a Transitional community between [39]. For each quadrat, the percentage of live bryophytes was evaluated from 9 small samples, each containing approximately 20-50 moss shoots, at 9 intersections within a 20 × 20 cm grid.…”

“…For each quadrat, the percentage of live bryophytes was evaluated from 9 small samples, each containing approximately 20-50 moss shoots, at 9 intersections within a 20 × 20 cm grid. For a more detailed description of moss ground monitoring see Wasley et al [39] and Lucieer et al [25] and for a description of spectral properites of Antarctic moss see Lovelock and Robinson [40]. To replicate the ground based sampling scheme, a grid of 3 × 3 pixels was extracted from the MTVI2 map and averaged per sampled quadrat.…”