Invasion by Pittosporum undulatum of the Forests of Central Victoria. I. Invasion Patterns and Plant Morphology

1981 ◽  
Vol 29 (6) ◽  
pp. 705 ◽  
Author(s):  
RM Gleadow ◽  
DH Ashton
Keyword(s):  
Urban Areas ◽  
Plant Morphology ◽  
Weed Species ◽  
Important Species ◽  
Ilex Aquifolium ◽  
Central Victoria ◽  
South Central ◽  
Eastern Australia ◽  
Forest Remnants ◽  
Eucalypt Forests

Pittosporum undulatum is invading eucalypt open forests in south-central Victoria, 200 km west of its native habitat in eastern Australia. This is due to horticultural plantings of P. unduiatum and to the suppression of wildfires: it has thin bark and is killed by fires which most eucalypts can survive. Near Melbourne, P. undulatum preferentially establishes around the butts of eucalypts and other established trees although in denser forests this clumping is not so obvious. Seedlings of other weed species such as Ilex aquifolium and Cotoneaster pannosa similarly aggregate around established shrubs and trees. Classification of quadrats by monothetic division showed P. undulatum to be the most important species in the community. The weedy nature of P. undulatum is clear from its rapid dispersal, early seed production and fast growth. The dense canopy dramatically reduces the light intensity and completely suppresses the original sclerophyllous understorey: only Gahnia radula remains. Soil beneath the canopy is fertile and the litter is high in nutrients but bioassays indicate that inhibitors may be present. The root system is variable, depending on soil texture and compaction. The invasion of forest remnants by P. undulatum and other weeds is threatening the survival of the eucalypt forests in urban areas.

The Litoria ewingi Complex (Anura:Hylidae) in South-Eastern Australia VIII.* Hybridization between L. ewingi and L. verreauxi alpina in the Mount Baw Baw Area, South Central Victoria

1985 ◽  
Vol 33 (2) ◽  
pp. 143 ◽  
Author(s):  
GF Watson ◽  
MJ Littlejohn ◽  
DF Gartside ◽  
JJ Loftus-Hills
Keyword(s):  
Northern Slope ◽  
Blood Proteins ◽  
Genetic Compatibility ◽  
Hybrid Swarm ◽  
Geographic Ranges ◽  
Central Victoria ◽  
South Central ◽  
Eastern Australia ◽  
High Level

Contacts between the geographic ranges of the widely distributed species, Litoria ewingi, and the montane-adapted taxon, L. verreauxi alpina, occur at about 1200 m on the Great Dividing Range in south central Victoria. Data for adult morphology, genetic compatibility, blood proteins (haemoglobins and transferrins), and structure of male advertisement calls, were obtained from seven populations at altitudes between 640 m and 1450 m in the region of the Mount Baw Baw Plateau. The results indicate that hybrids are present at intermediate altitudes (1140-1270 m), but that the nature of the interaction differs between overlap of parental taxa together with recombination products on the south-westem slope (the Baw Baw transect), and a hybrid swarm on the northern slope of the Mount Baw Baw plateau. Results of in vitro crosses (female L, ewingi by male L. v. alpina) indicate that there is a high level of genetic compatibility between the taxa. Estimates of the width of the hybrid zone on the Baw Baw transect vary from less than 4 km for morphology and calls, to between 10 and 24 km for blood proteins.

Acoustic analysis of an intergrade zone between two call races of the Limnodynastes tasmaniensis complex (Anura : Leptodactylidae) in south-eastern Australia

1975 ◽  
Vol 23 (1) ◽  
pp. 113 ◽  
Author(s):  
MJ Littlejohn ◽  
JD Roberts
Keyword(s):  
Acoustic Analysis ◽  
Secondary Contact ◽  
Ecological Gradient ◽  
North Central ◽  
Call Structure ◽  
Central Victoria ◽  
South Eastern ◽  
Eastern Australia ◽  
Mating Calls ◽  
South Eastern Australia

Mating calls of the northern and southern call races of the L. tasmaniensis complex are described. Analysis of call structure along a transect across the main contact between these allopatric forms in north central Victoria indicates that there is a zone of intergradation between 90 and 135 km wide, about 215 km long and with a north-westerly orientation. The interaction is interpreted as a secondary contact in which there is hybrid or recombinant superiority along a subtle ecological gradient.

Water Ownership and Governance

2021 ◽  
Author(s):  
Sally Babidge
Keyword(s):  
Urban Areas ◽  
Water Distribution ◽  
Multiple Scales ◽  
Water Governance ◽  
Resource Scarcity ◽  
Regulatory Control ◽  
Early 21St Century ◽  
Eastern Australia ◽  
Governance Challenges ◽  
Key Sites

Water governance refers to the material and regulatory control of water and waters. It involves questions such as who makes decisions about water and how; at what scale such decisions are made in relation to different waters; and who and which water or ecosystem benefits. Classical work in anthropology considered how irrigation practices may have given rise to the development of state forms, and in response to early-21st-century privatization regimes, anthropologists have considered how different groups have challenged the apparent global dominance of commodity values and water as property. Infrastructures for water distribution in urban areas (such as systems of canals, pipes, and faucets), and considerations of the sociocultural effects of hydrological unit delineation and definition (e.g., groundwater or river “basins”) have become key sites for the ethnographic investigation of water governance, emerging forms of personhood, and societal inequalities. The diversity in anthropologies of water unsettles generalized models in global regimes of water governance. The anthropology of water governance and ownership considers the context and contingencies of water and power. It reveals the global dominance of markets, rights, and technical approaches to water management, such as the case of “private water” in Chile, in which water markets have failed to provide equity and environmental health, but also how certain groups avoided complete privatization of water under this extreme example. Ethnographic studies of the cultural organization of resource scarcity over topographically complex and remote terrain, such as that of irrigators in the Andean cordillera, express the diversity of human innovation at the intersection of politics and ecology. In arid South Eastern Australia, basin plans that treat water as a unit of calculation and economic trade place social and ecological relations in peril. Infrastructures of development provide a narrative of unsettled state and development ideologies, and the problem of groundwater management reveals governance challenges in the face of unstable, unknown, and invisible material. Anthropological studies of water contribute to knowledge of earth’s diverse humanity, knowledge practices, and ecologies. Researchers propose that water governance might engage with human differences articulated at multiple scales, as well as in understanding water’s material agency and waters as dynamic, especially in an ever-changing climate.

scholarly journals Control Spectra for Quito

2016 ◽  
Author(s):  
Roberto Aguiar ◽  
Alicia Rivas-Medina ◽  
Pablo Caiza ◽  
Diego Quizanga
Keyword(s):  
Urban Areas ◽  
Slip Rate ◽  
Response Spectra ◽  
Elastic Response ◽  
Minimum Size ◽  
Physical Parameters ◽  
North Central ◽  
South Central ◽  
Elastic Response Spectra ◽  
Maximum Minimum

Abstract. The Metropolitan District of Quito is divided into five areas: south, south-central, central, north-central and north. It is located on or very close to segments of reverse blind faults: Puengasí, Ilumbisí-La Bota, Carcelen-El Inca, Bellavista-Catequilla and Tangahuilla as indicated in Alvarado et al. (2014), making it one of the most seismically dangerous cities in the world. For each of the urban areas of Quito, elastic response spectra are presented in this paper, which are found using some of the new models of the PEER's NGA-West2 Program, models developed by: Abrahamson et al. (2013), Campbell and Borzognia (2013), and Chiou and Youngs (2013). These spectra are calculated considering the maximum amount that could be generated by the rupture of each fault segments, and taking into account the soil type that exists in each zone according to the Norma Ecuatoriana de la Construcción 2015 (NEC-15). Subsequently, the recurrence period of earthquakes of high magnitude in each fault segment is determined from the physical parameters of the fault segments (size of the fault plane and slip rate), and considering that the fault can break in earthquakes of magnitude less than the expected maximum (minimum size 5.0 Mw). For this, the pattern of recurrence of type GR earthquakes (Gutenberg and Richter, 1944) with double truncation magnitude (Mmin and Mmax) proposed by Cosentino et al. (1977) is used.

Uraba lugens (eucalypt leaf skeletonizer).

2021 ◽  
Author(s):  
Lisa Berndt
Keyword(s):  
New Zealand ◽  
Western Australia ◽  
Timber Production ◽  
Native Range ◽  
Natural Forests ◽  
Eastern Australia ◽  
Important Pest ◽  
Eucalypt Forests

Abstract U. lugens was first considered a serious pest of natural eucalypt forests in Western Australia in 1983 when the first severe outbreak occurred there (Strelein, 1988). Prior to that it was widely known as a pest of eucalypt forests in eastern Australia (Campbell, 1962; Harris, 1974). As these natural forests are or were managed for timber production, it is considered an economically important pest in its native range. Damage to amenity trees is also a common problem, although few trees are killed by this defoliation (Anonymous, 1979).U. lugens was recorded as invasive in New Zealand by Crabtree (1997). In its exotic range it has become a significant pest of amenity trees, particularly Lophestemon confertus (Australian brush box), which is commonly planted in some parts of Auckland City (Kriticos et al., 2007).

Performance and weed-suppressive potential of selected pasture legumes against annual weeds in south-eastern Australia

2019 ◽  
Vol 70 (2) ◽  
pp. 147 ◽  
Author(s):  
Sajid Latif ◽  
Saliya Gurusinghe ◽  
Paul A. Weston ◽  
William B. Brown ◽  
Jane C. Quinn ◽  
...  
Keyword(s):  
Subterranean Clover ◽  
Weed Suppression ◽  
Weed Species ◽  
Mixed Stands ◽  
South Eastern ◽  
Pasture Legumes ◽  
Eastern Australia ◽  
Weed Suppressive Ability ◽  
Weed Infestation ◽  
South Eastern Australia

Mixed farming systems have traditionally incorporated subterranean clover (Trifolium subterraneum L.) and lucerne (Medicago sativa L.) as key components of the pasture phase across south-eastern Australia. However, poor adaptation of subterranean clover to acidic soils, insufficient and inconsistent rainfall, high input costs, soil acidification and the emergence of herbicide-resistant weeds have reduced efficacy of some traditional clover species in recent years. To overcome these challenges, numerous novel pasture species have been selectively improved and released for establishment in Australia. Despite their suitability to Australian climate and soils, limited knowledge exists regarding their weed-suppressive ability in relation to establishment and regeneration. Field trials were therefore conducted over 3 years in New South Wales to evaluate the suppressive potential of selected pasture legume species and cultivars as monocultures and in mixed stands against dominant annual pasture weeds. Pasture and weed biomass varied significantly between pasture species when sown as monocultures, but mixtures of several species did not differ with regard to establishment and subsequent weed infestation. Arrowleaf clover (T. vesiculosum Savi.) and biserrula (Biserrula pelecinus L.) cv. Casbah showed improved stand establishment, with higher biomass and reduced weed infestation compared with other pasture species. Generally, weed suppression was positively correlated with pasture biomass; however, yellow serradella (Ornithopus compressus L.) cv. Santorini exhibited greater weed suppression than other pasture legumes while producing lower biomass, thereby suggesting a mechanism other than competition for resources affecting weed-suppressive ability. Over the period 2015–17, arrowleaf clover and biserrula cv. Casbah were generally the most consistent annual pasture legumes with respect to yearly regeneration and suppression of annual pasture weed species.

Detection of grassy weeds in bermudagrass with deep convolutional neural networks

Weed Science ◽  
2020 ◽  
Vol 68 (5) ◽  
pp. 545-552
Author(s):  
Jialin Yu ◽  
Arnold W. Schumann ◽  
Shaun M. Sharpe ◽  
Xuehan Li ◽  
Nathan S. Boyd
Keyword(s):  
Neural Networks ◽  
Convolutional Neural Networks ◽  
Cynodon Dactylon ◽  
Plant Morphology ◽  
Weed Species ◽  
Deep Convolutional Neural Networks ◽  
Control Cost ◽  
Weed Density ◽  
Murdannia Nudiflora ◽  
Vision Detection

AbstractSpot spraying POST herbicides is an effective approach to reduce herbicide input and weed control cost. Machine vision detection of grass or grass-like weeds in turfgrass systems is a challenging task due to the similarity in plant morphology. In this work, we explored the feasibility of using image classification with deep convolutional neural networks (DCNN), including AlexNet, GoogLeNet, and VGGNet, for detection of crabgrass species (Digitaria spp.), doveweed [Murdannia nudiflora (L.) Brenan], dallisgrass (Paspalum dilatatum Poir.), and tropical signalgrass [Urochloa distachya (L.) T.Q. Nguyen] in bermudagrass [Cynodon dactylon (L.) Pers.]. VGGNet generally outperformed AlexNet and GoogLeNet in detecting selected grassy weeds. For detection of P. dilatatum, VGGNet achieved high F1 scores (≥0.97) and recall values (≥0.99). A single VGGNet model exhibited high F1 scores (≥0.93) and recall values (1.00) that reliably detected Digitaria spp., M. nudiflora, P. dilatatum, and U. distachya. Low weed density reduced the recall values of AlexNet at detecting all weed species and GoogLeNet at detecting Digitaria spp. In comparison, VGGNet achieved excellent performances (overall accuracy = 1.00) at detecting all weed species in both high and low weed-density scenarios. These results demonstrate the feasibility of using DCNN for detection of grass or grass-like weeds in turfgrass systems.

scholarly journals Supporting Urban Weed Biosecurity Programs with Remote Sensing

2020 ◽  
Vol 12 (12) ◽  
pp. 2007
Author(s):  
Kathryn Sheffield ◽  
Tony Dugdale
Keyword(s):  
Remote Sensing ◽  
Urban Areas ◽  
Data Availability ◽  
Surveillance Program ◽  
Urban Landscapes ◽  
Weed Species ◽  
Species Introduction ◽  
Weed Detection ◽  
Invasive Weed ◽  
Detection Rates

Weeds can impact many ecosystems, including natural, urban and agricultural environments. This paper discusses core weed biosecurity program concepts and considerations for urban and peri-urban areas from a remote sensing perspective and reviews the contribution of remote sensing to weed detection and management in these environments. Urban and peri-urban landscapes are typically heterogenous ecosystems with a variety of vectors for invasive weed species introduction and dispersal. This diversity requires agile systems to support landscape-scale detection and monitoring, while accommodating more site-specific management and eradication goals. The integration of remote sensing technologies within biosecurity programs presents an opportunity to improve weed detection rates, the timeliness of surveillance, distribution and monitoring data availability, and the cost-effectiveness of surveillance and eradication efforts. A framework (the Weed Aerial Surveillance Program) is presented to support a structured approach to integrating multiple remote sensing technologies into urban and peri-urban weed biosecurity and invasive species management efforts. It is designed to support the translation of remote sensing science into operational management outcomes and promote more effective use of remote sensing technologies within biosecurity programs.

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.

Australian rainfall patterns and the southern oscillation. 2. A regional perspective in relation to Luni-solar (Mn) and Solar-cycle (Sc) signals

2008 ◽  
Vol 30 (3) ◽  
pp. 349 ◽  
Author(s):  
R. G. Vines
Keyword(s):  
Southern Oscillation ◽  
New South ◽  
New South Wales ◽  
Sunspot Cycle ◽  
South Wales ◽  
Ecological Aspects ◽  
Eastern Australia ◽  
Cyclic Variations ◽  
Rainfall Patterns ◽  
Eucalypt Forests

This investigation is an extension of earlier work on rainfall patterns in eastern Australia. Using district averages rather than rainfall data for individual cities or towns, further evidence is provided for cyclic variations in precipitation with periods of 18–19, 10–11 and 6–7 years. Results from various regional areas in western Queensland and western New South Wales differ from those found further south in Victoria, and connections are suggested between El Niño/southern oscillation events and the incidence of drought in these two separate areas. Such findings are consistent with ecological aspects of the quasi-periodic occurrence of bushfire seasons as observed in both Victorian eucalypt forests after prolonged drought, or after intermittent widespread rains in the semi-arid Mallee rangelands of western New South Wales. The ~19-year cycles may be at least partly a reflection of solar and lunar tidal components and the ~11-year cycles (connected with the Sunspot cycle) could be the result of absorption of short wavelength solar emissions in the stratosphere and resultant photochemical events magnified to produce sea surface temperature changes. The ~19-year cycles are apparently associated with either increased or decreased rainfall, and such connections appear to reverse in parts of Australia about every 100 years. These reversals have been associated with major droughts at the end of the 19th and 20th centuries.

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