Post-Glacial Spatial Dynamics in a Rainforest Biodiversity Hot Spot

Abstract

Abstract:Here we investigate the interaction between ecology and climate concerning the distribution of rainforest species differentially distributed along altitudinal gradients of eastern Australia. The potential distributions of the two species closely associated with different rainforest types were modelled to infer the potential contribution of post-glacial warming on spatial distribution and altitudinal range shift. Nothofagus moorei is an integral element of cool temperate rainforest, including cloud forests at high elevation. This distinct climatic envelope is at increased risk with future global warming. Elaeocarpus grandis on the other hand is a lowland species and typical element of subtropical rainforest occupying a climatic envelope that may shift upwards into areas currently occupied by N. moorei. Climate envelope models were used to infer range shift differences between the two species in the past (21 thousand years ago), current and future (2050) scenarios, and to provide a framework to explain observed genetic diversity/structure of both species. The models suggest continuing contraction of the highland cool temperate climatic envelope and expansion of the lowland warm subtropical envelope, with both showing a core average increase in elevation in response to post-glacial warming. Spatial and altitudinal overlap between the species climatic envelopes was at a maximum during the last glacial maximum and is predicted to be a minimum at 2050. OPEN ACCESSDiversity 2013, 5 125

Intraspecific Divergence Associated with a Biogeographic Barrier and Climatic Models Show Future Threats and Long-Term Decline of a Rainforest Conifer

“…2) suggests that the two population groups respond differently to climate change, and that both are subjected to expansion/contractions cycles indicative of community turn-over [20,25]. This emphasizes the sensitivity of this species to climatic fluctuation and, when considering its fragmented distribution along a broad latitudinal range, the likelihood that this species may survive climatic cycles within dispersed refugia and microhabitats, e.g.…”

“…While similar findings have been repeated across northern hemisphere species [23,24], the constraints of Australian fossil deposits have made detailed documentation of analogous changes along southern latitudes difficult. The use of climatic models has proved to be an informative alternative in predicting the turn-over of rainforest habitats differentially distributed along altitudinal gradients of eastern Australia [25].…”

“…Here we refer regularly to, and build upon, these previous works [17,35] to understand the deeper evolutionary history and to compose appropriate conservation strategies for the species. We have sub-sampled the genetic data from these previous works [17,35] and generated an additional HapSTR marker for a coalescent-based analysis to infer demographic history and splitting time, and have projected the current climatic envelope [17] onto an ensemble of future climate scenarios [25].…”

“…This correlative approach provides a robust method, based upon climate envelope models and a novel AOGCM ensemble, to predict the future distribution of species [25]. Climatic models for Podocarpus elatus inferred that the current geographic separation of the northern and southern envelopes corresponds to the genetically differentiated population groups [17].…”

Species turnover of corticolous bryophyte assemblages over 15 years in an Australian subtropical cloud forest

“…Microphyll fern forests are confined to cool, moist areas at high elevations where frequent cloud immersion provides a regular and important source of moisture (Floyd 1990b;Hutley et al 1997). Climate models indicate that N. moorei and corresponding cool-moist microclimates have steadily contracted to higher elevations since the Last Glacial Maximum (21 000 years ago) (Mellick et al 2013). Climate models indicate that N. moorei and corresponding cool-moist microclimates have steadily contracted to higher elevations since the Last Glacial Maximum (21 000 years ago) (Mellick et al 2013).…”