Nick is a molecular ecologist with research interests in the biogeography and population dynamics of aquatic invertebrates. He is specifically interested in using genetic patterns that have been shaped by population isolation and connectivity in the past to make predictions about the future. In addition, he uses next generation DNA sequencing to undertake metabarcoding studies of entire communities to improve the taxonomic resolution of biomonitoring and better understand community connectivity and the dynamics of assemblages. In the alpine region he is particularly interested in the diversity and evolution of endemic headwater specialists, as well as studying population connectivity and isolation of aquatic taxa in alpine environment to better understand the likely impacts of habitat fragmentation. Research in this area (undertaken with PhD student Jude Hatley) is uncovering an incredibly diverse and undocumented crustacean fauna, with headwater springs resembling isolated islands, despite the clear aquatic connectivity amongst these sites.
Species on the Move: an international conference on climate change held in Hobart
RCAAE members Keith McDougall, John Morgan, Neville Walsh and James Shannon presented a Poster at the Conference titled: Hitching a Ride into the Australian Alps: roadsides as conduits for native plant movements. Using the distribution of native species found on 13 roadsides in the Alps (260 quadrats), and comparing this distribution to the distribution of species in their native habitat in mountain regions (from 2596 quadrats), they show that three native species - Bothriochloa macra (Poaceae), Helichrysum luteoalbum (Asteraceae) and Hydrocotyle laxiflora (Apiaceae) – are moving upslope into new thermal niches (colder) and that roads likely facilitate this movement. Indeed, they conclude that this range expansion could be considered a ‘realized niche expansion’. The range expansion to colder environments might be an early indicator of native species responding to changing climates, and highlights that native species are taking advantage of the dispersal and establishment opportunities afforded by roadside verges (just as many weeds do).
Shrubs trap windblown snow
The 2015 winter was Susanna Venn's first season testing out her new Federal Snow Corer. Susanna is investigating how alpine shrubs trap windblown snow, and whether this will partly facilitate shrub expansion in the alpine zone. New data suggests that the biggest shrubs, like Orites lancifolia on the Bogong High Plains and Nematolepis ovatifolia in the Snowy Mountains, create the biggest snow drifts, accumulate more snow-water equivalent units (SWE) and that snow lasts much longer behind a big shrub like this, compared to the surrounding landscape, or even a smaller shrub. This will have implications for soil moisture, soil nutrient availability and leaf litter decomposition in and around shrubs. Over this summer season, Susanna will be measuring other shrub canopy properties in order to elucidate which types of shrubs, based on morphological characters, have the most influence on snow drifting patterns and snow accumulation in the landscape.