Dynamics of temperate rainforest from fine resolution pollen analysis, Upper Ringarooma River, northeastern Tasmania

Abstract

The relationship between sclerophyll forest and temperate rainforest in Tasmania is believed to be driven by climate, soils and fire regime; however, this has been tested infrequently on time frames relevant to the longevity ofthe major forest trees involved. This study uses sediments in four small hollows from within a rainforest stand in the Upper Ringarooma valley in northeastern Tasmania, Australia, to analyse vegetation dynamics and disturbance over the last 1000 years. Pollen-vegetation relationships were investigated by comparing pollen rain and current vegetation, and the chronology was established by radiocarbon and lead-210 dates. The lead-210 data indicate that the two Sphagnum humus profiles were not always closed systems for inorganic inwash; however, the pollen and charcoal records are generally consistent indicating that a mixed Eucalyptus-Nothofagus forest shifted to a Nothofagus dominated rainforest as fire became a less prominent component of the environment. About 400 years ago Lcptospermum laiiigcrum invaded the community as canopy gaps developed, possibly as the older Nothofagus cuiintnghamit trees died. There is no strong evidence of invasion hy Atherosperma moscliatum as suggested by some models of forest dynamics in these forests in Tasmania. In this stand of forest, fire and erosion following flooding have been the major causes of disturbance.

Altered Ecologies: Fire, climate and human influence on terrestrial landscapes: Terra Australis 32

“…Colhoun 1996) seem to be futile except at sites where independent evidence allows one or both variables to be excluded. Such ideal sites may occur within rainforest stands (see Macphail 1984;Dodson et al 1998), but this is improbable in buttongrass moorland. Reasons include: (1) it is highly likely that mean and seasonal rainfall and air temperatures greatly exceeded the minimum requirements for buttongrass (and most forest species) throughout the late Holocene; (2) general agreement exists that the regeneration of Gymnoschoenus and other moorland species depends on frequent burning; and (3) modern observations indicate that, at the community level, rainforest and buttongrass are not constrained by regolith geology, although floristic diversity and growth rates (and presumed competitive abilities) of individual taxa will vary with different substrates.…”

“…Small hollows in outwash fans on the margins of the Arthur, Lake Pedder and Loddon Plains and at Cradle Mountain may be suitable sites (cf. Macphail 1984;Dodson et al 1998). Whether management concerns justify research across the range of communities making up buttongrass moorland in southwest Tasmania is unknown, but modelling by King (2008) indicates that if boundaries are found to be geographically stable through time at a number of sites located away from Aboriginal trails, this would indicate at least 10% of the buttongrass moorland in southwest Tasmania had been burned on an annual basis.…”

Reconstruction of long‐term successional dynamics of temperate woodland in Białowieża Forest, Poland

“…This is in contrast to similar investigations in America and Tasmania (Davis et al . 1994; Macphail 1984; Dodson et al . 1999).…”

Dynamics of North Patagonian rainforests from fine-resolution pollen, charcoal and tree-ring analysis, Chonos Archipelago, Southern Chile

“…1997). Such records have proven very useful in studies of climate change and natural and anthropogenic disturbance in the southern temperate rainforests of Tasmania, Australia (Dodson et al . 1998;Dodson 2001), and the northern temperate and boreal forests of the United States (e.g.…”