A new map of mangroves for Kakadu National Park, Northern Australia, based on stereo aerial photography

2007 ◽  
Vol 17 (5) ◽  
pp. 446-467 ◽  
Author(s):  
Anthea L. Mitchell ◽  
Richard M. Lucas ◽  
Brian E. Donnelly ◽  
Kirrilly Pfitzner ◽  
Anthony K. Milne ◽  
...  
Keyword(s):  
Aerial Photography ◽  
National Park ◽  
Northern Australia

Fire regimes and interval-sensitive vegetation in semiarid Gregory National Park, northern Australia

2010 ◽  
Vol 58 (4) ◽  
pp. 300 ◽  
Author(s):  
Jeremy Russell-Smith ◽  
Cameron P. Yates ◽  
Chris Brock ◽  
Vanessa C. Westcott
Keyword(s):  
National Park ◽  
Fire Regime ◽  
Woody Species ◽  
Fire Regimes ◽  
Stem Density ◽  
Northern Australia ◽  
Juvenile Period ◽  
Climate Conditions ◽  
Fine Fuels ◽  
Ecologically Sustainable

Few data are available concerning contemporary fire regimes and the responses of fire interval-sensitive vegetation types in semiarid woodland savanna landscapes of northern Australia. For a 10 300 km2 semiarid portion of Gregory National Park, in the present paper we describe (1) components of the contemporary fire regime for 1998–2008, on the basis of assessments derived from Landsat and MODIS imagery, (2) for the same period, the population dynamics, and characteristic fine-fuel loads associated with Acacia shirleyi Maiden (lancewood), an obligate seeder tree species occurring in dense monodominant stands, and (3) the fire responses of woody species, and fine-fuel dynamics, sampled in 41 plots comprising shrubby open-woodland over spinifex hummock grassland. While rain-year (July–June) rainfall was consistently reliable over the study period, annual fire extent fluctuated markedly, with an average of 29% being fire affected, mostly in the latter part of the year under relatively harsh fire-climate conditions. Collectively, such conditions facilitated short fire-return intervals, with 30% of the study area experiencing a repeat fire within 1 year, and 80% experiencing a repeat fire within 3 years. Fine fuels associated with the interior of lancewood thickets were characteristically small (<1 t ha–1). Fine fuels dominated by spinifex (Triodia spp.) were found to accumulate at rates equivalent to those observed under higher-rainfall conditions. Stand boundaries of A. shirleyi faired poorly under prevailing fire regimes over the study period; in 16 plots, juvenile density declined 62%, and adult stem density and basal area declined by 53% and 40%, respectively. Although the maturation (primary juvenile) period of A. shirleyi is incompletely known, assembled growth rate and phenology data indicated that it is typically >10 years. Of 133 woody species sampled, all trees (n = 26), with the exception of A. shirleyi, were resprouters, and 58% of all shrub species (n = 105) were obligate seeders, with observed primary juvenile periods <5 years. Assembled data generally supported observations made from other northern Australian studies concerning the responses of fire-sensitive woody taxa in rugged, sandstone-derived landscapes, and illustrated the enormous challenges facing ecologically sustainable fire management in such settings. Contemporary fire regimes of Gregory National Park are not ecologically sustainable.

scholarly journals Spatial Dynamics of Invasive Para Grass on a Monsoonal Floodplain, Kakadu National Park, Northern Australia

2019 ◽  
Vol 11 (18) ◽  
pp. 2090
Author(s):  
Boyden ◽  
Wurm ◽  
Joyce ◽  
Boggs
Keyword(s):  
Satellite Imagery ◽  
Wild Rice ◽  
National Park ◽  
Fire History ◽  
Spatial Dynamics ◽  
Gradient Boosting ◽  
Native Vegetation ◽  
Northern Australia ◽  
Stochastic Gradient Boosting ◽  
The World

African para grass (Urochloa mutica) is an invasive weed that has become prevalent across many important freshwater wetlands of the world. In northern Australia, including the World Heritage landscape of Kakadu National Park (KNP), its dense cover can displace ecologically, genetically and culturally significant species, such as the Australian native rice (Oryza spp.). In regions under management for biodiversity conservation para grass is often beyond eradication. However, its targeted control is also necessary to manage and preserve site-specific wetland values. This requires an understanding of para grass spread-patterns and its potential impacts on valuable native vegetation. We apply a multi-scale approach to examine the spatial dynamics and impact of para grass cover across a 181 km2 floodplain of KNP. First, we measure the overall displacement of different native vegetation communities across the floodplain from 1986 to 2006. Using high spatial resolution satellite imagery in conjunction with historical aerial-photo mapping, we then measure finer-scale, inter-annual, changes between successive dry seasons from 1990 to 2010 (for a 48 km2 focus area); Para grass presence-absence maps from satellite imagery (2002 to 2010) were produced with an object-based machine-learning approach (stochastic gradient boosting). Changes, over time, in mapped para grass areas were then related to maps of depth-habitat and inter-annual fire histories. Para grass invasion and establishment patterns varied greatly in time and space. Wild rice communities were the most frequently invaded, but the establishment and persistence of para grass fluctuated greatly between years, even within previously invaded communities. However, these different patterns were also shown to vary with different depth-habitat and recent fire history. These dynamics have not been previously documented and this understanding presents opportunities for intensive para grass management in areas of high conservation value, such as those occupied by wild rice.

Bacteria in tropical floodplain soils are sensitive to changes in saltwater

2018 ◽  
Vol 69 (7) ◽  
pp. 1110 ◽  
Author(s):  
Tiffanie M. Nelson ◽  
Claire Streten ◽  
Karen S. Gibb ◽  
Anthony A. Chariton
Keyword(s):  
Bacterial Community ◽  
Bacterial Communities ◽  
Saltwater Intrusion ◽  
National Park ◽  
Wetland Soils ◽  
Rrna Gene ◽  
Northern Australia ◽  
Tropical River ◽  
16S Rrna Gene Pyrosequencing ◽  
Freshwater Habitats

Bacterial communities in floodplain and wetland soils cycle elements essential for flora and fauna. The coastal habitats of northern Australia are threatened with increasing saltwater intrusion (SWI) events that will destroy freshwater habitats. The effect of the impending SWI on bacterial communities is unknown. Here, we examined the bacterial communities of a tropical river floodplain located in World Heritage Kakadu National Park. Using 16S rRNA gene pyrosequencing, we measured the baseline bacterial communities from three morphologically distinct regions of the floodplain (lower, upper and backwater swamp), within three zones of the South Alligator River (upstream, cuspate and estuarine funnel or sinuous). Significant differences in the bacterial community were observed at each category of floodplain morphology and river zone. The greatest differences were due to pH and salinity. Large changes in bacterial compositions are predicted to occur with increases in salinity and pH. Saltwater intrusion is predicted to increase substantially in the next decades with sea-level rise, and is likely to cause large and significant changes to the bacterial community with unknown consequences for biogeochemical cycling. Kakadu National Park may benefit from incorporating bacteria into routine studies, because we have shown here that they are sensitive indicators of change, even across small ranges of abiotic variables.

National Parks and Native Peoples in Northern Canada, Alaska, and Northern Australia

1981 ◽  
Vol 8 (3) ◽  
pp. 207-215 ◽  
Author(s):  
J. E. Gardner ◽  
J. G. Nelson
Keyword(s):  
Land Use ◽  
National Parks ◽  
National Park ◽  
Northern Territory ◽  
Yukon Territory ◽  
Native People ◽  
The Arctic ◽  
Northern Australia ◽  
Native Peoples ◽  
Northern Canada

At the very general level, the aim of this paper is to compare the interaction of national parks and native peoples in Northern Canada (Yukon Territory), Alaska, and the Northern Territory of Australia. Currently these areas are subject to increasing land-use pressures from mining, industrial development, the creation of national parks and related reserves, and native attempts to maintain traditional wildlife and renewable resource use. The study focuses on the interactions between national parks and native peoples on the premise that experiences can be compared and problems encountered in one area but possibly avoided in another.The study begins by briefly describing native land-use issues, land-rights arrangements, and organizations, in the Yukon Territory, central Alaska, and Northern Australia. The national park agencies are described, compared, and shown to differ considerably in institutional character, field of management, control of land, and external links with interest groups such as native peoples. Case-studies of the national parks etc. named Kluane (Yukon), Gates of the Arctic (Alaska), and Kakadu (Northern Territory of Australia), are presented to provide more details on similarities and differences in planning, types of tenure, native subsistence activities, and other factors.In the Yukon Territory, neither the national parks agency nor the native people are highly motivated to interact. In contrast, the park agencies and native people in Alaska and the Northern Territory of Australia recognize mutual benefits from interaction—largely as a result of legislation and policies which encourage cooperation. Native involvement officers now facilitate coordination in the Yukon and Alaska. Park agency native employment programmes are proceeding in all three ‘hinterlands’, while native people can own land on which national parks are established in Alaska and the Australian Northern Territory. Only in Australia are native people known to be directly involved in upperlevel national park management. Potential limitations on native subsistence and associated use of national parks range from moderate to severe, and are only defined clearly in Alaska. Lack of definition leads to confusion in deciding upon native use, while exceedingly precise definition precludes flexibility at the park level.A number of aids to a more mutually satisfactory interaction can be identified. One is motivation, or recognition by both parties that there are advantages to consultation and cooperation. Another, not yet achieved in the Yukon, is a land-claims settlement, stating the legislated rights of native peoples in the ‘hinterlands’ and giving them a land-holding and bargaining status which is comparable with that of government agencies. A third aid is comprehensive systematic and regional planning efforts involving opportunities for informed input from all affected parties. Such planning would provide a forum for consideration of a variety of interests, including national parks and native peoples. Finally, satisfactory interaction on the park site could be assisted by clear yet flexible means of deciding upon acceptable native use of parkland, the conservation of wildlife, and associated economic and cultural factors.

scholarly journals Assessing ecological performance thresholds in fire-prone Kakadu National Park, northern Australia

Ecosphere ◽  
2017 ◽  
Vol 8 (7) ◽  
pp. e01856 ◽  
Author(s):  
Jeremy Russell-Smith ◽  
Jay Evans ◽  
Andrew C. Edwards ◽  
Anthony Simms
Keyword(s):  
National Park ◽  
Northern Australia ◽  
Ecological Performance ◽  
In Fire

scholarly journals Small mammals decline with increasing fire extent in northern Australia: evidence from long-term monitoring in Kakadu National Park

2015 ◽  
Vol 24 (5) ◽  
pp. 712 ◽  
Author(s):  
Michael J. Lawes ◽  
Brett P. Murphy ◽  
Alaric Fisher ◽  
John C. Z. Woinarski ◽  
Andrew C. Edwards ◽  
...  
Keyword(s):  
Small Mammals ◽  
National Park ◽  
Fire Regime ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Small Scale ◽  
Northern Australia ◽  
Fire Size ◽  
Burnt Area ◽  
Fire Extent

Small mammal (<2 kg) numbers have declined dramatically in northern Australia in recent decades. Fire regimes, characterised by frequent, extensive, late-season wildfires, are implicated in this decline. Here, we compare the effect of fire extent, in conjunction with fire frequency, season and spatial heterogeneity (patchiness) of the burnt area, on mammal declines in Kakadu National Park over a recent decadal period. Fire extent – an index incorporating fire size and fire frequency – was the best predictor of mammal declines, and was superior to the proportion of the surrounding area burnt and fire patchiness. Point-based fire frequency, a commonly used index for characterising fire effects, was a weak predictor of declines. Small-scale burns affected small mammals least of all. Crucially, the most important aspects of fire regimes that are associated with declines are spatial ones; extensive fires (at scales larger than the home ranges of small mammals) are the most detrimental, indicating that small mammals may not easily escape the effects of large and less patchy fires. Notwithstanding considerable management effort, the current fire regime in this large conservation reserve is detrimental to the native mammal fauna, and more targeted management is required to reduce fire size.

Nesting Biology and Taxonomy of Arpactophilus-Mimi, a New Species of Social Sphecid (Hymenoptera, Sphecidae) From Northern Australia

1988 ◽  
Vol 36 (5) ◽  
pp. 585 ◽  
Author(s):  
RW Matthews ◽  
ID Naumann
Keyword(s):  
National Park ◽  
Ovarian Development ◽  
Brood Care ◽  
Northern Australia ◽  
Nesting Biology ◽  
Selective Pressures ◽  
Nest Sites ◽  
Adult Females ◽  
Single Nest ◽  
A New Species

Arpactophilus mimi, Naumann, sp. nov., is described from Kakadu National Park, N.T. and its biology is outlined. A. mimi nests in abandoned cells of mud-dauber wasps in sandstone overhangs. Its nests are lined heavily with silk and contain 1-15 cells and 1-10 adult wasps (1-7 females, 0-3 males). On average nests contain 5.2 cells and 2.75 adult females. Prey (immature Psyllidae and Tingidae) are supplied progressively. Nests are parasitised by a species of megalyrid wasp, but incidence of parasitism is low. Nest defense is both physical (entrance guard always present) and chemical (citrus odour from heads of both sexes). Females from a single nest could be ranked on the basis of relative ovarian development, suggesting that more than one female oviposits. Females apparently cooperate in brood care and offspring in a nest develop asynchronously. The biology of A. mimi is compared to that of Microstigmus comes Krombein, the most socially advanced sphecid known, and selective pressures that may have acted to promote female cooperation in the two genera are discussed. For A. mimi the lack of available nest sites could be an important factor restricting the ability of offspring to disperse and establish nests.

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