Responses of Non-volant Mammals to Late Quaternary Climatic Changes in the Wet Tropics Region of North-eastern Australia

1997 ◽  
Vol 24 (5) ◽  
pp. 493 ◽  
Author(s):  
J. W. Winter

It is generally recognised that the distribution of vertebrates in rainforest and wet sclerophyll forest of the Wet Tropics region of north-eastern Australia is profoundly influenced by the formation of two rainforest refugia at the height of Pleistocene glacial periods. Anomalies in the distribution of non-volant mammals indicate that other events may be equally important. In this paper, past geographical occurrence of non-volant mammals is examined by equating the mammals’ known temperature tolerance with palaeoclimatic temperature zones. It is hypothesised that dispersal and vicariant phases taking place since the most recent glacial period have had a profound influence on current patterns of distribution. A major dispersal phase of cool-adapted species occurred after the glacial period, and continuous populations were subsequently fragmented into upland isolates by expansion of warm rainforest during the late post-glacial period. These upland isolates remain substantially unchanged to the present day. Species shared either with New Guinea or south-eastern Australia arrived in the region during the most recent post-glacial period. Clarification of periods of vicariance and dispersal provides a conceptual framework for testing relative divergences of populations within and between regions.

2009 ◽  
Vol 60 (11) ◽  
pp. 1091 ◽  
Author(s):  
J. D. Armour ◽  
L. R. Hateley ◽  
G. L. Pitt

A long-term, annual-average catchment biophysical model (SedNet/ANNEX) was used to calculate sediment, nitrogen (N) and phosphorus (P) loads in the Tully–Murray catchment of north-eastern Australia. A total of 119 000 t year–1 of suspended sediment, equivalent to 430 kg ha–1 year–1, was calculated to be exported to the Great Barrier Reef (GBR). Most of the sediment (64%) was generated from hill-slope erosion. The modelled load of dissolved inorganic N (1159 t year–1 or 4.2 kg N ha–1 year–1) was similar to that from other wet tropics catchments in Queensland with similar areas of sugarcane. Sugarcane produced 77% of this load. The annual loads of total N and total P were 2319 t and 244 t, respectively. Simulations (scenarios) were run to evaluate the impact of improved land management on pollutant loads to the GBR. A combination of improved cultivation and fertiliser management of sugarcane and bananas (99% of cropping land) and restoration of the most degraded riparian areas reduced sediment by 23 000 t year–1 (18%) and dissolved inorganic N by 286 t year–1 (25%). However, this reduction is much less than the reduction of 80% that may be needed in the catchment to meet target chlorophyll loads in the marine environment.


2000 ◽  
Vol 48 (5) ◽  
pp. 651 ◽  
Author(s):  
Paul R. Williams

Details of plant regeneration, combined with soil seedbank data, are documented for a densely grassed wet sclerophyll forest in north-eastern Australia. The following two hypotheses were tested: (1) that established individuals of rainforest pioneer species are killed by low to moderate intensity fires and (2) that seedling recruitment of these species is evenly distributed throughout the intervals between fires. Both the sclerophyll and rainforest pioneer species displayed strong regenerative abilities as a response to low or moderate intensity fires. Most of the rainforest pioneer species were not killed by two recent fires but vegetatively regenerated. Alstonia muelleriana showed fire-enhanced vegetative expansion via root suckering. Both the sclerophyll and rainforest pioneer species were found to recruit seedlings primarily as a pulse in the first year or two after a fire, with limited recruitment after longer intervals between fires. This is consistent with suggestions that grass competition may limit tree recruitment. The germinable soil seedbank was dominated by rainforest pioneers, herbs and grasses, with heat treatment of the seedbank enhancing seed germination of two rainforest pioneer species. These results demonstrate the ability of rainforest pioneers to exploit the post-fire environment and indicate the complex nature of rainforest boundary dynamics. Further research into tropical rainforest expansion is required to examine the effects of fire regimes on vegetative and seedling regeneration across a range of sites.


2018 ◽  
Vol 189 (4-6) ◽  
pp. 17
Author(s):  
Smaine Chellat ◽  
Lotfi Toubal ◽  
Abderrezak Djerrab ◽  
Ahcene Bourefis ◽  
Belhadj Hamdi-Aissa ◽  
...  

The late Quaternary sequences of north-eastern Algeria composed of alternating dark and light layers, which are rich in molluscan fauna, could correspond to synchronous environmental phases. The facies variations of the Morsott Region deposits were systematically sampled as part of a sedimentological and malacological study in order to establish a palaeoenvironmental and climatic reconstruction of the late Quaternary. The alternation of sandy clayey silts levels, which contain abundant molluscan hygrophilous organisms, indicates an isostasis cycle followed, at the top, by a succession of rhexistasis and biostasis cycles. The molluscan record shows a dominant succession of xerophilous organisms in relation to the hygrophilous organisms. The faunistic richness in the fine levels is linked to sub-humid periods where the region has suffered numerous floods. The reduction in the number of species in the coarse levels comes is likely due to desiccation when the climate was semi-arid. This study is new in Algeria and will provide an insight into climatic changes. Further research will be required in order to understand the fluvial dynamics during the Quaternary.


2019 ◽  
Vol 41 (1) ◽  
pp. 99
Author(s):  
Fathimah Handayani ◽  
Ross L. Goldingay ◽  
Darren McHugh ◽  
Nicole Leslie

We used MaxEnt to model the current distribution of the yellow-bellied glider (Petaurus australis) and to predict the likely shift in the species’ future distribution under climate-warming scenarios in the Wet Tropics (WT) Bioregion in north Queensland and in the South-eastern Queensland (SEQld) Bioregion, which encompasses south-eastern Queensland and north-eastern New South Wales. Bioclimatic layers were used to generate models from 57 independent records in the WT and 428 records in SEQld. The modelled distribution of core habitat under current climate showed a good fit to the data, encompassing 91% and 88% of the records in each area, respectively. Modelling of future warming scenarios suggests that large contractions in distribution could occur in both bioregions. In the WT, 98% of core habitat is predicted to be lost under low warming (1°C increase) and 100% under high warming (2−3°C increase) by 2070. In SEQld, 80% of core habitat is predicted to be lost under low warming and 90% under high warming by 2070. These results suggest that this species is highly vulnerable to climate warming and highlight the importance of focusing conservation efforts at the bioregional scale. There is also a need to identify potential thermal refuges and ensure habitat connectivity.


Zootaxa ◽  
2009 ◽  
Vol 2063 (1) ◽  
pp. 64-68
Author(s):  
FAYE CHRISTIDIS

Riekophlebia crocina, a new genus and species, is described from Australia based on nymphs and adults. Riekophlebia belongs to a lineage that also includes the Australian genera Austrophlebioides, Kirrara, Manggabora and Tillyardophlebia.


Zootaxa ◽  
2010 ◽  
Vol 2391 (1) ◽  
pp. 33 ◽  
Author(s):  
STEPHEN J. RICHARDS ◽  
CONRAD J. HOSKIN ◽  
MICHAEL J. CUNNINGHAM ◽  
KEITH MCDONALD ◽  
STEPHEN C. DONNELLAN

The green-eyed treefrogs (Litoria eucnemis species-group) are found throughout New Guinea and some of its offshore islands, and in two geographically separated regions in north-eastern Queensland, Australia. We examine the genetic relationships among populations of the complex from across its range and find that populations fall into two major lineages: 1) specimens referable to L. genimaculata from New Guinea and its offshore islands, and L. exophthalmia, and 2) samples referable to L. eucnemis from New Guinea and northern Cape York, Australia, and two lineages from the Wet Tropics of north-eastern Australia that are currently assigned to L. genimaculata. Based on our molecular genetic analyses, morphological assessment of new collections and re-examination of type material, we retain L. eucnemis as currently recognised for northern Cape York populations but resurrect the name L. serrata for the Wet Tropics populations. The degree of reproductive isolation between the two Wet Tropics lineages is being studied currently and so at this point we refer both to L. serrata. The degree of genetic variation observed in L. genimaculata across New Guinea locations and possible paraphyly with L. exophthalmia suggest the presence of additional undescribed species. Reexamination of type material and collection of new specimens, allow us to reassess the status of several other names currently synonymised with L. eucnemis and L. genimaculata. Our observations support the present synonymy of Hyla rhacophorus with L. eucnemis and we remove Nyctimystes loveridgei from the synonymy of L. genimaculata and place it in the synonymy of L. eucnemis.


1996 ◽  
Vol 12 (4) ◽  
pp. 449-460 ◽  
Author(s):  
Christopher J. Hill

ABSTRACTTwo dung beetle assemblages from rainforest and open forest in the wet tropics of north-eastern Australia are described. The fauna was sampled using flight intercept traps, baited pitfall traps and light traps, with flight intercept traps being the most effective sampling technique. Dung beetle species were found to be highly habitat specific with a switch from rainforest to open forest assemblages occurring over tens of metres. The majority of the fauna was active at night. The most abundant species were attracted to a variety of food types but several species appeared to specialize on either dung or mushrooms.


2008 ◽  
Vol 22 (1) ◽  
pp. 29 ◽  
Author(s):  
Faye Christidis ◽  
John C. Dean

The mayfly genus Austrophlebioides Campbell & Suter, 1988 is endemic to Australia and is widely distributed in eastern Australia and Tasmania. Here, the phylogenetic relationships among species of Austrophlebioides are investigated using cladistic analyses based on morphological characters of the nymph and adult, and the first phylogenetic hypothesis for the genus is presented. The results from the phylogenetic analyses support the recognition of three monophyletic species-groups: the ‘rieki’, ‘pusillus’ and ‘marchanti’ clades. The ‘pusillus’ clade is the sister-group to the ‘rieki’ clade, and the clade comprising these two groups is sister to the ‘marchanti’ clade. Minimal overlap was observed in the geographic distribution of the three Austrophlebioides clades. The ‘rieki’ clade is confined to the Wet Tropics bioregion of north-eastern Queensland. The ‘pusillus’ clade is distributed from central-eastern Queensland to Victoria. The ‘marchanti’ clade occurs in southern New South Wales, Victoria and Tasmania. Distributional limits of the three clades correspond with the presence of recognised biogeographic barriers (Burdekin Gap, Hunter Valley and Bass Strait) suggesting that vicariance has been important in the differentiation of the group and in determining present-day distributions of species.


2004 ◽  
Vol 52 (6) ◽  
pp. 667 ◽  
Author(s):  
L. P. Shoo ◽  
Y. Williams

Extensive abundance surveys of microhylid frogs across altitudinal gradients within the Wet Tropics rainforests of north-eastern Australia were undertaken. Detailed patterns of abundance were resolved for nine microhylid species exhibiting differing associations within the altitudinal gradient. The position of altitudinal range boundaries was found to be largely consistent with previous accounts in the literature, providing confidence in established limits to species distributions. Microhylid frogs, in particular those species restricted to mountaintops, are considered among other endemic rainforest vertebrates within the region to be one of the groups most immediately threatened by climate change. The combined results establish important baseline data for assessing the impacts of climate change, including altitudinal shifts in distribution and localised declines in abundance, on microhylid frogs in the region.


Sign in / Sign up

Export Citation Format

Share Document