scholarly journals Mangrove and Saltmarsh Distribution Mapping and Land Cover Change Assessment for South-Eastern Australia from 1991 to 2015

2021 ◽  
Vol 13 (8) ◽  
pp. 1450
Author(s):  
Alejandro Navarro ◽  
Mary Young ◽  
Peter I. Macreadie ◽  
Emily Nicholson ◽  
Daniel Ierodiaconou
Keyword(s):  
Coastal Wetlands ◽  
Coastal Wetland ◽  
Temporal Distribution ◽  
Random Forest Classification ◽  
South Eastern ◽  
Shuttle Radar Topographic Mission ◽  
Eastern Australia ◽  
Wide Range ◽  
Conservation Projects ◽  
South Eastern Australia

Coastal wetland ecosystems, such as saltmarsh and mangroves, provide a wide range of important ecological and socio-economic services. A good understanding of the spatial and temporal distribution of these ecosystems is critical to maximising the benefits from restoration and conservation projects. We mapped mangrove and saltmarsh ecosystem transitions from 1991 to 2015 in south-eastern Australia, using remotely sensed Landsat data and a Random Forest classification. Our classification results were improved by the addition of two physical variables (Shuttle Radar Topographic Mission (SRTM), and Distance to Water). We also provide evidence that the addition of post-classification, spatial and temporal, filters improve overall accuracy of coastal wetlands detection by up to 16%. Mangrove and saltmarsh maps produced in this study had an overall User Accuracy of 0.82–0.95 and 0.81–0.87 and an overall Producer Accuracy of 0.71–0.88 and 0.24–0.87 for mangrove and saltmarsh, respectively. We found that mangrove ecosystems in south-eastern Australia have lost an area of 1148 ha (7.6%), whilst saltmarsh experienced an overall increase in coverage of 4157 ha (20.3%) over this 24-year period. The maps developed in this study allow local managers to quantify persistence, gains, and losses of coastal wetlands in south-eastern Australia.

Variation in Chondrilla juncea L. in south-eastern Australia

1973 ◽  
Vol 21 (1) ◽  
pp. 113 ◽  
Author(s):  
VJ Hill ◽  
RH Groves
Keyword(s):  
Stem Elongation ◽  
Leaf Shape ◽  
Weed Species ◽  
South Eastern ◽  
Leaf Emergence ◽  
South Wales ◽  
Eastern Australia ◽  
Wide Range ◽  
South Eastern Australia ◽  
Chondrilla Juncea

Three variants or forms of Chondrilla juncea L. (skeleton weed) are distinguished in south-eastern Australia. The forms (designated A, B, and C) differ in inflorescence morphology and fruit characters, but mainly in the shape of rosette leaves, for which quantitative expressions of the differences have been developed. There were no significant differences within each form in rosette leaf shape when grown in a wide range of environments. First and second progenies of the three forms, presumably apomictic, retained the identity of their parents, as did leaves of rosettes arising vegetatively from the root system after removal of the parental rosette. The geographical limits of distribution of the forms are given, based on results from field observations and from plants grown in a glasshouse either from seed or clonal material. Plants of form A are widespread and occur in south-eastern Australia over a wide range of latitude, climate, and soil type. With one exception, the distribution of plants of forms B and C in 1969 was restricted to central New South Wales, where the forms are distributed sympatrically with plants of form A. Form B plants are confined at present to an area bounded approximately by Young, Orange, Peak Hill, and Marsden, though these boundaries are extending. Leaf emergence rates, times to stem elongation, and times to flowering are presented for the three forms. Differences between forms in these characters under some conditions are shown to exist, as well as differences between forms in their ability to regenerate vegetatively. Form C plants, at present more restricted geographically, seem to have a greater potential for regeneration from rootstocks than form A plants, already widespread throughout south-eastern Australia. The variation described in this paper is discussed in relation to control of other weed species, especially apomicts.

Agricultural weeds and coastal saltmarsh in south-eastern Australia: an insurmountable problem?

2016 ◽  
Vol 64 (4) ◽  
pp. 308 ◽  
Author(s):  
Thomas Hurst ◽  
Paul I. Boon
Keyword(s):  
Plant Species ◽  
Coastal Wetlands ◽  
Land Reclamation ◽  
Vascular Plant ◽  
Control Measures ◽  
Native Plant ◽  
Pasture Grass ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

It is often assumed that saline coastal wetlands experience environmental conditions so severe that they are largely immune to invasion by exotic plant species. The belief is implicit in many older reviews of threats to mangroves and coastal saltmarshes, where a limited range of vascular plant taxa, often focussing on *Spartina, (throughout the paper an asterisk denotes an introduced (exotic) species as per Carr 2012) have been invoked as the major species of concern. Even though the weed flora of southern Australia is derived largely from agriculture and horticulture, neither of which includes many species tolerant of waterlogged, variably saline environments, a recent assessment of Victorian saline coastal wetlands indicated that exotic plants were the third-most pervasive threat, after land ‘reclamation’ and grazing. Tall wheat grass, *Lophopyrum ponticum (Podp.) A.Love., is one of the most severe and widely distributed weeds of saline coastal wetlands in south-eastern Australia. It is promoted by the agricultural extension arm of the Victorian government as a salt-tolerant pasture grass; however, its broad ecological amplitude and robust life form make it a most serious invader of upper saltmarsh in Victoria. We assessed the effectiveness of different control measures, including slashing and herbicides, for the management of *L. ponticum infestations (and their side effects on saltmarsh communities) in the Western Port region of Victoria. A nominally monocot-specific herbicide widely used to control *Spartina, Fluazifop-P, was ineffective in controlling *L. ponticum. The broad-spectrum systemic herbicide glyphosate was more effective in controlling *L. ponticum, but had undesirable impacts on native plant species. Controlling weeds in coastal wetlands using available herbicides for use near coastal waterways would seem to remain problematic.

Are mangroves in Victoria (south-eastern Australia) already responding to climate change?

2017 ◽  
Vol 68 (12) ◽  
pp. 2366 ◽  
Author(s):  
Paul I. Boon
Keyword(s):  
Climate Change ◽  
Sediment Supply ◽  
Small Scale ◽  
Storm Activity ◽  
Plant Vigour ◽  
South Eastern ◽  
Run Off ◽  
Eastern Australia ◽  
Wide Range ◽  
South Eastern Australia

The distribution and productivity of mangroves is directly affected by a wide range of climatic drivers, including temperature, frost, rainfall, evaporation and storm activity, which, in turn, influence a suite of secondary drivers, including changes in freshwater run-off and sediment supply, groundwater dynamics and inter-species competitiveness. The highest-latitude expression of mangroves globally is at Millers Landing, Victoria (38°45′S), and because the vigour and productivity of mangroves across much of Victoria is thought to be limited by low winter temperatures and the incidence and severity of frosts, it is likely that mangroves will be among the first plant communities to be affected by climate change in coastal south-eastern Australia. An increase in plant vigour is likely, but there are almost no historical data with which to compare current rates of primary production. An extension of mangroves to higher latitudes on the mainland is impossible because of the geomorphology of the land that lies further to the south. Small-scale changes in distribution, including the progressive encroachment of mangroves into coastal saltmarsh, are likely to be among the clearest indications of the response of mangroves to a warming climate. Increased effort into tracking changes in mangrove vigour, productivity and distribution is clearly warranted.

Isozyme Variability in Field Populations of Phytophthora cinnamomi in Australia

1988 ◽  
Vol 36 (3) ◽  
pp. 355 ◽  
Author(s):  
KM Old ◽  
MJ Dudzinski ◽  
JC Bell
Keyword(s):  
Sexual Reproduction ◽  
Phytophthora Cinnamomi ◽  
Soil Samples ◽  
Mating Types ◽  
South Eastern ◽  
Enzyme Loci ◽  
Eastern Australia ◽  
Wide Range ◽  
Isozyme Variability ◽  
South Eastern Australia

Isozyme characteristics of 280 isolates from populations of Phytophthora cinnamomi in native veg- etation in six locations in south-eastern Australia were examined at 19 enzyme loci. No new enzyme genotypic arrays were identified as compared with earlier samplings. This work indicates that the low variability for P. cinnamomi in Australia obtained in earlier work, from separate isolates in a wide range of locations, is paralleled in detailed population samples in south-eastern Australia. At one location, A1 and A2 mating types coexisted in soil samples. The lack of recombinants in these population samples suggests an absence of sexual reproduction in the field.

Occurrence of Angiostrongylus species (Nematoda) in populations of Rattus rattus and Rattus fuscipes in coastal forests of south-eastern Australia

2007 ◽  
Vol 55 (3) ◽  
pp. 177 ◽  
Author(s):  
Vicki L. Stokes ◽  
David M. Spratt ◽  
Peter B. Banks ◽  
Roger P. Pech ◽  
Richard L. Williams
Keyword(s):  
Rattus Rattus ◽  
Coastal Forests ◽  
Intermediate Hosts ◽  
South Eastern ◽  
The North ◽  
Eastern Australia ◽  
Wide Range ◽  
Rattus Fuscipes ◽  
Study Sites ◽  
South Eastern Australia

The distributions of the introduced nematode parasite, Angiostrongylus cantonensis, and the native Angiostrongylus mackerrasae in Australia are poorly understood. We sampled rodents and/or their faeces, and intermediate gastropod hosts for the presence of Angiostrongylus species in coastal forests surrounding Jervis Bay in south-eastern Australia. We found A. cantonensis in populations of introduced Rattus rattus in forests to the north of Jervis Bay, and A. mackerrasae in native Rattus fuscipes in forests to the south of Jervis Bay. The apparent geographical separation of these lungworm species may be a consequence of host specificity and negative associations between R. rattus and R. fuscipes that results from interspecific competition. A. cantonensis was regularly found in R. rattus or their faeces across 9 of 12 study sites north of Jervis Bay, and three species of snail common to the area were suitable intermediate hosts. This has potential negative implications for native wildlife and human visitors to these forests, because A. cantonensis infection causes zoonotic disease (neuro-angiostrongyliasis) in humans and a wide range of bird and mammal hosts. Management of pest rodents in the study area is warranted.

Effects of environmental conditions on the production of hypocotyl hairs in seedlings of Melaleuca ericifolia (swamp paperbark)

2008 ◽  
Vol 56 (7) ◽  
pp. 564 ◽  
Author(s):  
Randall W. Robinson ◽  
Paul I. Boon ◽  
Nina Sawtell ◽  
Elizabeth A. James ◽  
Robert Cross
Keyword(s):  
Environmental Conditions ◽  
Water Availability ◽  
Coastal Wetlands ◽  
Root Hairs ◽  
Harsh Environments ◽  
Low Salinity ◽  
South Eastern ◽  
Eastern Australia ◽  
Small Wetland ◽  
South Eastern Australia

The production of hypocotyl hairs in the early stages of seedling development can strongly influence the success with which plants recruit sexually in harsh environments. Although wetlands are one type of environment in which seedlings might be expected to develop hypocotyl hairs, there have been few studies of these structures in the woody aquatic plants. We investigated the production of hypocotyl hairs in Melaleuca ericifolia Sm., a small wetland tree widely distributed across swampy coastal areas of south-eastern Australia, in relation to water availability, salinity, temperature and light regime. Hypocotyl hairs were ~20 mm long × 30 μm wide; in contrast, root hairs were generally less than 5 mm long and 15 μm wide. Hypocotyl hairs were produced only under a narrow range of environmental conditions—low salinity, low water availability, moderate temperature, and darkness—and seedlings that failed to produce hypocotyl hairs did not survive. Since the conditions under which hypocotyl hairs were produced were at least as, and possibly even more, restricted than those required for successful germination of seeds, it is likely that the successful sexual recruitment of M. ericifolia would be rare and episodic under conditions existing in most coastal wetlands in south-eastern Australia.

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