Two new camerate crinoid species from the Permian of eastern Australia

The habitat and habit of Australia's first recorded Tertiary marsupial species, Wynyardia bassiana, found some 130 years ago at Wynyard on the northwestern coast of Tasmania, remain enigmatic (Aplin 1987, Aplin &; Rich 1990). Fossil pollen and spores preserved in a rafted clast of estuarine silts from the same sequence of earliest Miocene marine sandstones as the skeletal remains indicate the local vegetation was Nothofagus-gymnosperm evergreen rainforest, probably with a cryptogam-rich rather than woody subcanopy stratum. Comparisons with present-day Nothofagus rainforests suggest that, although the subcanopy would have been sufficiently open to allow the passage of a large ground-dwelling herbivorous marsupial, limited food resources are more consistent with Wynyardia being a generalist arboreal herbivore.     

New views on an old forest: assessing the longevity, resilience and future of the Amazon rainforest

The aim of this paper is to investigate the longevity and diversity of the Amazonian rainforest and to assess its likely future. Palaeoclimate and palaeoecological records suggest that the Amazon rainforest originated in the late Cretaceous and has been a permanent feature of South America for at least the last 55 million years. The Amazon rainforest has survived the high temperatures of the Early Eocene climate optimum, the gradual Cenozoic cooling, and the drier and lower carbon dioxide levels of the Quaternary glacial periods. Two new theories for the great diversity of the Amazon rainforest are discussed – the canopy density hypothesis and the precessional-forced seasonality hypothesis. We suggest the Amazon rainforest should not be viewed as a geologically ephemeral feature of South America, but rather as a constant feature of the global Cenozoic biosphere. The forest is now, however, entering a set of climatic conditions with no past analogue. The predicted future hotter and more arid tropical climates may have a disastrous effect on the Amazon rainforest.     

Pits,mounds, and vernal ponds in a Tasmanian subalpine grassland

Falling trees commonly turbate soils in primary forest, creating characteristic edaphic patterns related to pit and mound topography. Vernal ponds with associated mounds were observed in mineral soils on a treeless plain in subalpine Tasmania, Australia. The hypothesis that paired ponds and mounds on the plain originated as pit and mound features in forests that were later destroyed by fire was tested by comparing the soils and landforms caused by recent tree falls in adjacent forest with those on the plain. The soil characteristics, orientations, and dimensions of the ponds and mounds were consistent with a tree fall origin, although rare secondary ponds on the tops of mounds may derive from the burrowing activities of the medium‐sized marsupial, Vombatus ursinus (common wombat). The characteristics of pond and mound soils suggested that most were hundreds to thousands of years old, with the ponds persisting because of differences in deflation, deposition, and organic matter formation between themselves and adjacent persistently dry land.     

Assessment of Riparian Rainforest Vegetation Change in Tropical North Queensland for Management and Restoration Purposes

Changes in riparian vegetation extent in northern Queensland, Australia were assessed using aerial photographs from 1944 and 2000. Change in riparian extent was recorded as vegetation gain or loss. Changes in density were recorded as vegetation thickening. Riparian forest coverage increased by 22 ha during this time period in the Mossman River catchment. A total of 124 ha of riparian forest were gained, while 101 ha of riparian forest were lost. A further 59 ha of forest increased in density over this time period. Clearing, changes in farm management practices and natural stream channel movement have been identified as three potential causes for these changes. Areas with little or no riparian vegetation were identified and categorised into priority levels for potential revegetation efforts.     

Securing Landscape Resilience to Tropical Cyclones in Australia's Wet Tropics under a Changing Climate: Lessons from Cyclones Larry (and Yasi)

Tropical cyclones are part of the ecosystem dynamics of rainforests in the Wet Tropics of Australia, and intact forest areas show remarkable ability to recover from cyclonic disturbance. However, forest remnants, littoral rainforests, and riparian vegetation have been shown to be particularly susceptible to cyclonic winds and post‐disturbance weed invasion with consequences for their long‐term conservation values. I evaluate the frequency and intensity of tropical cyclones impacting the Wet Tropics region since records began in 1858. The recent Category 4 cyclones featured in this study, Larry and Yasi, had return intervals of about one in 70 years. I then discuss the natural resource management (NRM) lessons from Cyclone Larry and put forward practical recommendations on how authorities should deal with natural resources in the clean‐up and recovery phases. I argue that natural resources must be treated as valuable commodities by including their protection and rehabilitation in the same way that human livelihoods, infrastructure and industry are covered in disaster management planning. This requires NRM issues to be included in disaster response policy and legislation, together with ensuring that structures are in place to mitigate the effects of cyclones on natural resources. There is a general consensus that tropical cyclone intensity will increase under climate change while frequency will decrease slightly. This has profound implications for the long‐term sustainability of ecosystems in the Wet Tropics. There is a real risk of a phase shift to vegetation types dominated by disturbance species, including weeds, at the expense of cyclone intolerant species. It is therefore important that we begin to build more cyclone resilient landscapes to reduce the vulnerability of our remaining rainforest habitats and primary production systems. Securing landscape resilience requires greater NRM investment in key areas, including landscape connectivity, river repair, protecting coastal assets and cyclone resilient farms. While climate change poses a long‐term threat to the rainforests of the region, we need to focus on more immediate pressures affecting our remaining biodiversity, notably clearing of native habitat, habitat fragmentation and degradation, and biosecurity issues.