Lizard diversity on a rainforest - savanna altitude gradient in north-eastern Australia

2011 ◽  
Vol 59 (2) ◽  
pp. 86 ◽  
Author(s):  
A. S. Kutt ◽  
B. L. Bateman ◽  
E. P. Vanderduys
Keyword(s):  
Canopy Cover ◽  
Radiant Heat ◽  
Natural Experiments ◽  
Lizard Species ◽  
Altitudinal Distribution ◽  
Altitude Gradient ◽  
Lower Altitude ◽  
Diverse Range ◽  
Eastern Australia ◽  
North Eastern

Mountain ecosystems act as natural experiments for investigating the relationship between environmental heterogeneity and species diversity. A review of the global altitudinal distribution of reptiles identified a diverse range of patterns driven by climate and taxonomy. No Australian examples were included in this analysis. We addressed this gap by surveying the reptile assemblage along an altitude gradient from upland rainforest (~1000 m) through to open savanna woodlands (~350 m) in north-eastern Australia. Reptiles were sampled on four separate occasions between May 2006 and November 2007. Thirty-six species, representing seven families, were recorded along the gradient. As we used only diurnal active searching, snakes and nocturnal geckoes were probably under-sampled; thus we considered only lizards in the analysis of altitude pattern. Lizard species richness peaked at the mid-altitudes (600–900 m, 11–12 spp.) and abundance highest at the lower (<500 m) and higher (>800 m) zones. This pattern is likely a factor of both the increase in radiant heat sources (reduced canopy cover) and increased species packing due to the diversity of niches available (presence of rock cover and increase in saxicolous species). In the lower-altitude sites the high abundance of few species seems linked to the dominance of disturbance-tolerant species. We conclude that lizard richness and abundance patterns on this transect are not necessarily exhibiting a mid-domain effect, but instead are a function of species-specific ecological and habitat requirements.

Altitudinal distribution and abundance of microhylid frogs (Cophixalus and Austrochaperina) of north-eastern Australia: baseline data for detecting biological responses to future climate change

2004 ◽  
Vol 52 (6) ◽  
pp. 667 ◽  
Author(s):  
L. P. Shoo ◽  
Y. Williams
Keyword(s):  
Climate Change ◽  
Altitudinal Gradient ◽  
Baseline Data ◽  
Future Climate Change ◽  
Altitudinal Distribution ◽  
Biological Responses ◽  
Eastern Australia ◽  
North Eastern ◽  
Wet Tropics ◽  
Impacts Of Climate Change

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.

The effects of vegetation structure on the birds in a tropical savanna woodland in north-eastern Australia

2006 ◽  
Vol 28 (2) ◽  
pp. 139 ◽  
Author(s):  
A. L. Tassicker ◽  
A. S. Kutt ◽  
E. Vanderduys ◽  
S. Mangru
Keyword(s):  
Bird Species ◽  
Canopy Cover ◽  
Aerial Photographs ◽  
Woody Vegetation ◽  
Bird Species Richness ◽  
Widespread Species ◽  
Savanna Woodland ◽  
Bird Richness ◽  
Eastern Australia ◽  
North Eastern

Management of the dynamics of woody vegetation in Australia’s tropical savannas is a vexing issue for both pastoralists and conservation biologists. In savanna regions around the world, increasing density of woody vegetation contributes to declines in pastoral productivity, but its effects on native fauna are largely unknown. In this paper we examine the avifauna in savanna woodlands of varying structure in the Desert Uplands bioregion, Queensland. Vegetation cover maps derived from aerial photographs were used to choose 60 sites, across 4 cattle stations. We sampled sites mapped at 30–45% and 45–60% foliage cover, and areas which previously had these levels of cover but had been mechanically modified, both by broad scale clearing and selective thinning. Between May and June 2004, we measured a range of habitat variables and sampled the birds at each site. Bird species composition varied significantly between treatments. Bird richness and frequency was greatest in intact vegetation. Thirteen species of birds were most frequently encountered in sites with 30–45% canopy cover, compared with 10 species in the 45–60% cover sites, 4 species in the thinned sites and 7 in the cleared sites. Our results suggest that increasing density of woody vegetation in savanna woodland may be to the advantage of some savanna bird species. Mechanical modification to reduce woody vegetation appears to also benefit some common, widespread species, but has a generally negative overall effect on bird species richness.

Selection of sap feed trees by yellow-bellied gliders (Petaurus australis) in north-eastern Queensland, Australia – implications for site-specific habitat management

2018 ◽  
Vol 40 (1) ◽  
pp. 10
Author(s):  
S. R. Heise-Pavlov ◽  
T. Chizinski ◽  
N. E. Walker
Keyword(s):  
Resource Selection ◽  
Habitat Management ◽  
Species Conservation ◽  
Canopy Cover ◽  
Structural Features ◽  
Site Specific ◽  
Eastern Australia ◽  
North Eastern ◽  
Petaurus Australis ◽  
Selection Of

Knowledge of site-specific ecological factors affecting a species’ resource selection is essential to assist in habitat management for a species’ conservation, particularly for species with narrow resource width. This study aimed to assess whether microhabitat variables affect the selection of Eucalyptus resinifera sap feed trees by yellow-bellied gliders (Petaurus australis) in north-eastern Australia. Microhabitat variables were measured in a simplified way around glider-selected and -non-selected Eucalyptus resinifera trees. Canopy cover and percentage of burnt trunk below breast height were identified as influential on feed tree selection, with feed trees showing a higher percentage of burnt trunk and a lower surrounding canopy cover. While the direct effect of fire on a potential feed tree remains to be clarified, fire may affect the structural composition of vegetation leading to lower surrounding canopy cover around potential feed trees. Thus, any forest management, such as logging and grazing should be practiced with great caution since they affect structural features of the vegetation that may contribute to the selection of feed trees by this species and may also affect its alternative food resources.

Freshwater Cyanobacteria of North-Eastern Australia: 2. Chroococcales

Phytotaxa ◽  
2013 ◽  
Vol 133 (1) ◽  
pp. 1 ◽  
Author(s):  
GLENN B. MCGREGOR
Keyword(s):  
Light Microscopy ◽  
Natural Populations ◽  
Northern Territory ◽  
Detailed Account ◽  
Ecological Data ◽  
Eastern Australia ◽  
North Eastern ◽  
Rivers And Streams ◽  
Original Illustrations ◽  
Freshwater Habitats

This volume provides the first detailed account of the Chroococcales of north-eastern Australia. It provides keys, morphological and ecological data for 6 families, 33 genera and 112 species, and photomicrographs and original illustrations to enable the identification of natural populations based on stable and recognizable characters observable with the aid of light microscopy. Distributional data are based on extensive surveys at 270 sites representing the major freshwater habitats including rivers and streams, palustrine and lacustrine wetlands, thermal springs, and man-made reservoirs in Queensland and the Northern Territory as well as a review of the Australian phycological literature. 

Some physical and chemical features of two upland crater lakes in tropical north-eastern Australia

1999 ◽  
Vol 50 (2) ◽  
pp. 159 ◽  
Author(s):  
D. Walker
Keyword(s):  
Thermal Stability ◽  
Meteorological Data ◽  
Euphotic Zone ◽  
Open Water ◽  
Crater Lakes ◽  
Ground Temperatures ◽  
Eastern Australia ◽  
North Eastern ◽  
Physical And Chemical ◽  
Continuous Deposition

Lakes Barrine and Eacham, ~1.0 and 0.5 km2 area, 67 and 63 m depth respectively, lie at ~740 m a.s.l., ~17°S in north-eastern Australia. Seasonal changes in their volumes modelled from meteorological data correspond well with observations at Eacham. Temperature profiles through 6 years show summer stratification with a metalimnion at 20–30 m; in winter, near isothermy is usually attained. At Barrine, thermal stability varies between winter and summer (<500 and >4000 g-cm cm-2 respectively). Mixing is related to low ground temperatures during periods of generally low thermal stability; exceptionally it penetrates to >60 m. Oxygen saturation decreases from the surface to ~20% at the base of the euphotic zone (15–21 m) but oxygen is carried lower by mixing after which anoxia commonly rises to ~40 m. At Barrine, Fe-reducing redox (<200 mV) usually occurs below 50 m, but during mixing this boundary falls to within 1 m of the mud–water interface. The Barrine solution is dilute (total dissolved solids 55–58 mg L-1), and that of Eacham is more so. A concentrated monimolimnion has developed in the lowermost 2–3 m at Barrine but not at Eacham. Sedimentation at the middle of each lake results from the continuous deposition of open-water products punctuated by the redistribution of coarser detritus from the ‘shallows’ at times of deep mixing. The resultant laminations are preserved only at Barrine, protected by the chemical stability of the monimolimnion.

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