Pollen fall-out from a tropical vegetation mosaic

Pollen fall-out into 60 Oldfield traps set in 11 localities and a variety of vegetational contexts on an upland in tropical northeast Australia, range from 0.5k to 20k (mean 3.5k) gr cm⁻² a⁻¹. The ranges attributable to the four major vegetation types in which the traps were situated overlap to such an extent as would make it virtually impossible to allocate an ‘unknown’ pollen count to a vegetation type on the basis of total pollen influx alone. Nevertheless, the composition of the pollen clearly differs according to the vegetation in which it is trapped and the amounts of other vegetation types within at least 100 m. Substantial variations in catches from closely placed traps suggest the influence of very local site, including meteorological, conditions on the results. Pollen is carried between vegetation types, much less far from rainforest than from sclerophyll forest and woodland, regrowth scrub or herbaceous vegetation, but there is no numerically significant ubiquitous ‘background’ fall-out in the region. The data impose some constraints on the interpretation of fossil pollen spectra but also potentially permit a greater precision in some aspects of such applications.     

Comparative phylogeography and the history of endemic vertebrates in the Wet Tropics rainforests of Australia

We examine the effects of historical climate change on vertebrate differentiation in tropical rainforest by comparing phylogeographic patterns in six species of widespread rainforest-restricted herpetofauna from throughout the Wet Tropics of Australia. Qualitative and quantitative comparisons of phylogeographic structure reveal strikingly similar patterns of pre-Pleistocene vicariant population differentiation on either side of a previously identified biogeographic break (variously referred to as the Black Mountain Barrier or Corridor; BMC). While divergence across the BMC antedates the Pleistocene, the impact of Quaternary climate change is apparent in populations on either side of the BMC. Consistent with palaeoclimatological reconstructions for the region, the distribution and degree of mtDNA diversity suggests that populations were fragmented and reduced to multiple refugia during Pleistocene glacial periods, with expansion following Holocene rainforest recovery. This pattern is repeated on both sides of the BMC, but substantial differences in the amount and distribution of mtDNA diversity within species indicate the importance of species-specific ecological characteristics. The historical processes of extinction and (re)colonization revealed by the comparative phylogeographic analysis of mtDNA sequences substantiate earlier suggestions that current regional patterns of species distribution and diversity in the Wet Tropics are largely determined by local extinctions and subsequent recolonization driven by Quaternary climate changes.     

Assessing biodiversity 'sampling packages': how similar are arthropod assemblages in different tropical rainforests?

Arthropod sampling protocols have been applied to four areas of undisturbed rainforest in Australia and Borneo at sites located between 28° S and 4° N. Seven different trapping methods have been used in each case following a strictly comparable protocol applied during single wet-season surveys at each location. A number of large scale patterns across sites correlated with latitude, altitude and/or biogeographical history are evident at the ordinal level. The results are used to evaluate two key ideas in biodiversity survey. The first tests questions of the constancy of particular trap types in terms of the target animals. The second attempts to design an efficient multiple method sampling 'package' for rapid biodiversity assessment. Across all sites similar traps behaved in a similar manner in terms of the profile of arthropods that they caught although Malaise traps and pitfalls are particularly 'constant' in this regard. Subsets of both trapping methods and target taxa are identified which will maximise the opportunities for detecting between site differences.     

Revision of the rove beetle genus Antimerus (Coleoptera, Staphylinidae, Staphylininae), a puzzling endemic Australian lineage of the tribe Staphylinini

The genus Antimerus Fauvel, 1878, endemic to eastern Australia and Tasmania and a phylogenetically enigmatic member of the large rove beetle tribe Staphylinini, is revised. The genus and each of its four previously known species are redescribed, and a lectotype is designated for Antimerus punctipennis Lea, 1906. Five species are described as new: Antimerus metallicussp. n., Antimerus jamesrodmanisp. n., Antimerus gracilissp. n., Antimerus bellussp. n. and Antimerus monteithisp. n., so that the number of known species in this genus now totals nine. For the first time Antimerus larvae are described, tentatively identified as Antimerus smaragdinus Fauvel, 1878, Antimerus punctipennis and Antimerus metallicus. Available distributional and bionomic data are provided for each species and summarized in the discussion. Adult and larval morphology of Antimerus and its distribution patterns are discussed in the broader context of new data on the evolution of the entire tribe Staphylinini, and with respect to the formation of the Australian fauna of this tribe. The phylogenetic position of Antimerus within Staphylinini remains unresolved pending a targeted formal study. However, a majority of currently available data suggests that it could be a basal member of the recently recovered monophyletic clade of Staphylinini tentatively called "Staphylinini propria".     

From ratites to rats: the size of fleshy fruits shapes species' distributions and continental rainforest assembly

Seed dispersal is a key process in plant spatial dynamics. However, consistently applicable generalizations about dispersal across scales are mostly absent because of the constraints on measuring propagule dispersal distances for many species. Here, we focus on fleshy-fruited taxa, specifically taxa with large fleshy fruits and their dispersers across an entire continental rainforest biome. We compare species-level results of whole-chloroplast DNA analyses in sister taxa with large and small fruits, to regional plot-based samples (310 plots), and whole-continent patterns for the distribution of woody species with either large (more than 30 mm) or smaller fleshy fruits (1093 taxa). The pairwise genomic comparison found higher genetic distances between populations and between regions in the large-fruited species (Endiandra globosa), but higher overall diversity within the small-fruited species (Endiandra discolor). Floristic comparisons among plots confirmed lower numbers of large-fruited species in areas where more extreme rainforest contraction occurred, and re-colonization by small-fruited species readily dispersed by the available fauna. Species'' distribution patterns showed that larger-fruited species had smaller geographical ranges than smaller-fruited species and locations with stable refugia (and high endemism) aligned with concentrations of large fleshy-fruited taxa, making them a potentially valuable conservation-planning indicator.     

Effects of herbivory on growth and survival of seedlings of a rainforest tree,Alphitonia whitei (Rhamnaceae)

This study examined the effects of insect herbivory on growth and mortality of seedlings of a mid- successional rainforest tree, Alphitonia whitei Braid. Two experiments were conducted in which seedlings were exposed to 0% and 50% natural defoliation by insect herbivores and placed in light gaps in simple notophyll vine forest at Paluma, near Townsville, North Queensland. In the first experiment, insect herbivory significantly increased mortality of 2-month-old seedlings. Smaller seedlings had significantly greater mortality rates than larger seedlings, irrespective of herbivory. A significantly greater proportion of smaller seedlings died from being smothered by fallen leaves and soil as a result of digging by vertebrates than for larger seedlings. In the second experiment, the effects of seedling age were examined by comparing 2-month and 4-month-old seedlings. Mortality rates were significantly influenced by seedling age, with eight times greater survival of older seedlings than of younger seedlings. Although insect herbivory was correlated with a significant decrease in shoot mass and a significant increase in root:shoot ratio, there was no effect of insect herbivory on seedling survival in the second experiment. Thus, mortality rates were greater for seedlings if they were young or small (which indirectly results from insect herbivory), because small, young seedlings were more susceptibile to other mortality factors, such as burial by fallen debris and digging by vertebrates.     

Euastacus morgani sp. n., a new spiny crayfish (Crustacea, Decapoda, Parastacidae) from the highland rainforests of eastern New South Wales, Australia

Euastacus morgani sp. n., is described from a highland, rainforest site in Bindarri National Park, in eastern New South Wales, Australia. Euastacus morgani is found living sympatrically with two more common species, Euastacus dangadi Morgan, 1997 and Euastacus neohirsutus Riek, 1956. Systematically, the species belongs in the 'simplex' complex of the genus that includes Euastacus simplex Riek, 1956, Euastacus clarkae Morgan, 1997, Euastacus maccai McCormack and Coughran 2008 and E. morgani. This new species differs from its nearest congenor, Euastacus simplex, in having three mesial carpal spines. A key to the 'simplex' complex is presented.     

Postdispersal survivorship of north Queensland rainforest seeds and fruits: Effects of forest,habitat and species

Abstract Diaspore (seed and/or fruit) survivorship of 12 species of North Queensland rainforest trees was monitored over a 4 week period in two rainforests on the Atherton Tableland, north Queensland, Australia, with replicated sites in forest interiors, canopy gaps, forest edges and adjacent pastures. General linear modelling was used to estimate the relative importance of forest site, habitat, species and diaspore type on survival. The probability of survival varied significantly among species, between habitat, forest and diaspore types. Survival averaged 41.2% at day 28, was greater in one forest (Curtain Fig, 56.1%) than the other (Lamins Hill, 25.3%) and was apparently inversely related to the abundance of rodents. In both forests, survival declined in the order: pasture ≥ forest edge ≥ forest interior = canopy gap. A lack of significant difference between the forest interior and canopy gap is consistent with findings in other rainforest sites within Australia, but contrasts with most results from other continents. The study also indicated that diaspore weight was an important intrinsic variable affecting survival, the predators (mostly rodents) taking small to moderately large diaspores rather than the very large ones.