A new early pleistocene species of Nothofagus and the climatic implications of co-occurring Nothofagus fossils

A new species of Nothofagus, N. pachyphylla, is proposed based on fossils from Early Pleistocene sediments at Regatta Point, western Tasmania. This extinct species occurred for some time with its sister species, N. cunninghamii, which is still extant in Tasmania. The fossil leaves of N. cunninghamii in the Regatta Point sediments are all very small and are only consistent with leaves from cold climate extant populations of this species. The fossil leaves of other taxa in these sediments are also mostly at the small (and cool climate) end of the range of the leaves of their extant relatives. These data provide corroborating evidence for floristically based inferences of colder than modern palaeoclimates for this fossil site. The co-occurrence of small and large leaved sister species is paralleled in a number of modern Tasmanian rainforest genera

Macrofossils as indicators of Plio-Pleistocene climates in Tasmania and Antarctica

Plant macrofossils can be used as proxy palaeoclimatic indicators, since both the taxa present at a site and the form ofleaves depend on the climate, and macrofossils are rarely transported far. In the simple case of the Sirius Group Nothofagus leaves and wood in Antarctica, the fossils provide data on climate that suggest temperatures at the time of deposition were in the order of> 10°C warmer than at present. While the age of the fossils is still debated, the climatic signal is not. However, in more subtle cases, where the climatic differences are smaller and the fossil evidence is more complex, it is critical to interpret the evidence cauriously. Macrofossils from Pleistocene localities in Tasmania provide a clear signal on temperature and rainfall that is sometimes at odds with pollen-based reconstructions, bur the former is inherently likely to be more accurate

Genetic variation in the juvenile leaf morphology of Eucalyptus globulus Labill. ssp globulus.

The patterns of genetic variation in the length and shape of juvenile leaves of Eucalyptus globulus ssp globulus are described. Significant additive genetic variation occurred within populations for all traits. Leaf length was more heritable (h2 = 0.34) than most leaf shape traits (h2 = 0.19-0.34). Significant genetic differences also occur between populations in both leaf length and shape with the strongest differentiation occurring in leaf length. There were strong intra- and interpopulation genetic correlations amongst most of the leaf traits. Height and volume at two years of age were genetically independent of leaf length, but within populations, faster growth was genetically correlated with increased basal lobing and a shift of the widest point closer to the leaf base. The intra- and interpopulation genetic correlations were markedly different for some pairs of traits. Leaf length was genetically independent of the height of transition from the juvenile to the adult leaf form within populations, yet genetic differences between populations were highly correlated. Growth was more highly genetically correlated with different facets of leaf shape within populations than between populations. It is argued that correlated selection is the most likely cause of correlated genetic variation between populations when traits are genetically independent within populations

The macrofossil record of Proteaceae in Tasmania: a review with new species

About ten taxa of Proteaceae are known from the Early Eocene in Tasmania, one from a Late Eocene site, 22 from four Early Oligocene sites, one from a Late Oligocene/Early Miocene site, 12 or 13 from two Early Pleistocene sites, and five or six from the Middle and Late Pleistocene. Most of the Tertiary fossils are of extinct species, but the extant species Lomatia fraxinifolia and Telopea truncata have been recorded from the Early Oligocene as well as apparent close relatives of the subalpine rainforest species Orites milliganii, and the sub-tropical rainforest species, O. excelsa. None of the Early Oligocene species are known from more than one site, implying very high regional diversity, and floristic differentiation among the sites. High diversity of Proteaceae at some sites may be associated with oligotrophic soils. There is no evidence of any of the modern species-rich scleromorphic groups of Proteaceae except Banksiinae. Scleromorphy was well established in Oriteae, Embothrieae and Banksiinae by the Early Oligocene. The Early Eocene fossils have very small stomata, sparsely distributed on the leaf, which may have been due to elevated atmospheric CO2. All extant Tasmanian genera and many extant species were present by the Early Pleistocene as well as some extinct species. The specific diversity within the region was probably higher than it is now. In order to resolve a nomenclatural problem with the genus Proteaciphyllum, Euproteaciphyllum G.J.Jord., R.J.Carp. & R.S.Hill, gen. nov. is proposed and this name is applied to 10 previously described species. The Tasmanian fossil taxa include three new records, and nine new species: Euproteaciphyllum brookerensis G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., and E. tasmanicum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov. from Early Eocene sediments; and Orites milliganoides G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., O. scleromorpha G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., E. papillosum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., E. polymorphum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., E. microlobium G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., E. falcatum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., and E. serratum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov. from Early Oligocene sediments

Susceptibility of Eucalyptus globulus ssp. globulus to sawfly (Perga affinis ssp. insularis) attack and its potential impact on plantation productivity

Sawflies (Perga species) are leaf-damaging pests of the major plantation tree species Eucalyptus globulus ssp. globulus. This work describes the patterns of quantitative genetic variation in susceptibility to attack by Perga affinis ssp. insularis, based on data from a large open-pollinated trial containing genetic material from throughout the geographic range of E. globulus ssp. globulus. Forty three percent of the trees in the trial exhibited damage from sawflies in either their sixth or seventh growth seasons. The incidence of damage was genetically based, with significant variation between geographic races of E. globulus ssp. globulus and highly heritable (h2 = 0.43 +/- 0.05) variation in damage incidence within races was observed. Susceptibility to sawfly damage significantly affects plant fitness with both genetic and environmental correlations demonstrating that that sawfly damage causes slow growth and increased mortality of trees. Mild and severe sawfly damage resulted in 16 % and 31 % reduction in the basal area of surviving trees, and the effect was consistent across races and families. Based on this data, we propose a model predicting relative plantation productivity of races of different susceptibility under different infestation regimes