Population Studies on Acacia melanoxylon R. Br. I. Variation in Seed and Vegetative Characteristics

1978 ◽  
Vol 26 (3) ◽  
pp. 365 ◽  
Author(s):  
TP Farrell ◽  
DH Ashton
Keyword(s):  
Environmental Parameters ◽  
Morphological Characters ◽  
Annual Rainfall ◽  
Clinal Variation ◽  
Acacia Melanoxylon ◽  
Open Forest ◽  
Popu Lations ◽  
Eastern Australia ◽  
Closed Forest ◽  
Shape And Size

Considerable variation in phyllode shape and size was found between populations of Acacia melanoxylon sampled over the wide geographical range (27° of latitude) of this species in tropical and temperate eastern Australia. Communities sampled range from closed-forest to open-forest and grassy woodland. Some evidence of relationships between morphological characters of the phyllodes and environ- mental conditions of the collecting site was found, although such relationships are complex and not easily understood. The most important factors determining phyllode shape and size were the distance of the collecting site from the coast, and the seasonal distribution of the annual rainfall. Phyllodes tended to be smaller and more symmetric in the drier inland areas. Differences were found between seed characteristics of selected populations, although there was no evidence of correlation of these with selected environmental parameters. Seedlings of 17 popu- lations of A. melanoxylon grown under uniform glasshouse conditions showed some differences in leaf morphology. The age at which conversion to phyllodes begins is correlated with the mean annual rainfall at the site of origin of the seeds. The occurrence of this species in such a wide variety of habitats in eastern Australia is probably due to its clinal variation.

Clinal Variation in Electrophoretic and Morphological Characters between Two Nominal Species of the Genus Pseudomugil (Pisces : Atheriniformes : Pseudomugilidae)

1979 ◽  
Vol 30 (3) ◽  
pp. 375 ◽  
Author(s):  
AJ Hadfield ◽  
V Ivantsoff ◽  
PG Johnson
Keyword(s):  
Principal Components ◽  
Major Part ◽  
Single Species ◽  
Morphological Characters ◽  
Morphological Data ◽  
Nominal Species ◽  
Clinal Variation ◽  
Brackish Waters ◽  
Coastal Species ◽  
Eastern Australia

Electrophoretic and morphological comparisons were made between 14 populations representing the major part of the known range of the nominal fish species, Pseudomugil signifer Kner and Pseudomugil signatus (Gunther), described from the fresh and brackish waters of eastern Australia. Analysis by principal components was used to assess the morphological data. .Clinal variation revealed in 10 morphological characters and at two enzyme loci was found to bridge most of the previously described differences between species. The type material of P. signatus afinis from the Low Isles, Queensland, was re-examined and did not appear to differ morphologically from the coastal species. It is therefore suggested that the populations studied represent a single species Pseudomugil signifer Kner.

Persistence and productivity of phalaris (Phalaris aquatica) germplasm in dry marginal rainfall environments of south-eastern Australia

2017 ◽  
Vol 68 (8) ◽  
pp. 781
Author(s):  
R. A. Culvenor ◽  
M. R. Norton ◽  
J. De Faveri
Keyword(s):  
Environmental Benefits ◽  
Annual Rainfall ◽  
Summer Drought ◽  
Environment Interaction ◽  
Phalaris Aquatica ◽  
Mixed Farming ◽  
Eastern Australia ◽  
Summer Dormancy ◽  
Average Annual Rainfall ◽  
Establishment Phase

Perennial grasses have production and environmental benefits in areas of southern Australia typified by the mixed farming zone of southern New South Wales (NSW). The perennial grass phalaris (Phalaris aquatica L.) is widely used in southern Australia; however, it would find more use in the mixed farming zone if its persistence in marginal rainfall areas (450–500 mm average annual rainfall) were improved. We evaluated a range of germplasm (n = 29) including wild accessions, lines bred from these, and existing cultivars for persistence and production at three sites in a summer-dry area of southern NSW with 430–460-mm average annual rainfall. Two sites were used over 4 years and the third site over 5 years. Summer dormancy, maturity time and seedling growth were also assessed. Analysis of genotype × environment interaction employing factor analytic models and accounting for spatial and temporal correlations indicated that changes in persistence occurred mainly over time rather than between sites. Ranking changes occurred in the dry establishment phase of the experiment and during a severe final summer drought, with few changes occurring in the intervening high-rainfall years. Lines that survived the establishment phase best had vigorous seedlings and earlier maturity, whereas those surviving the final summer best were earlier maturing and higher in summer dormancy with high winter-growth activity. Some later maturing lines within the higher summer dormancy group were less persistent. Some accessions from North Africa were the most persistent; also, populations bred from these and other more persistent accessions generally persisted and produced better than cultivars used presently. However, present cultivars were capable of high yield in the higher rainfall years. We suggest that persistence of higher summer dormancy cultivars over very dry years could be improved by selecting for earlier maturity time.

scholarly journals Antlers Characterization for Identification of Deer Species (Family Cervidae) in Indonesia

2019 ◽  
Vol 4 (3) ◽  
pp. 97
Author(s):  
Donan Satria Yudha ◽  
M Zulfiqar Meizar Pratama ◽  
Rury Eprilurahman
Keyword(s):  
Principal Component Analysis ◽  
Principal Component ◽  
Morphological Characters ◽  
Main Beam ◽  
Size Measurement ◽  
Economic Values ◽  
Deer Species ◽  
Unique Character ◽  
Long Time ◽  
Shape And Size

There are five species of deer (family Cervidae) living in Indonesia today. Male deer possesses antlers, a unique character of male deer. Antlers have economic values for quite a long time. Antler’s growth is influenced by several factors, therefore each species of deer have its own unique antlers’ shape and size. Antler’s identification usually relies on size measurement and overall shape of complete antlers which still attach to the skull. It is difficult to identify shed, broken or individual antler. The purpose of the research is to understand antlers’ morphological characters on each species to become diagnostic characters. Specimens analysed were collections of LIPI and were analysed with Principal Component Analysis (PCA) using PAST3 software. The results showed each species of deer having their own unique antlers’ character, and so it can be used to determine the species of Indonesian deer. The important structures for identification are relief, pedicle, brow, bez, and main beam.

Accumulation of soil carbon under zero tillage cropping and perennial vegetation on the Liverpool Plains, eastern Australia

Soil Research ◽  
2009 ◽  
Vol 47 (3) ◽  
pp. 273 ◽  
Author(s):  
R. R. Young ◽  
B. Wilson ◽  
S. Harden ◽  
A. Bernardi
Keyword(s):  
Field Experiment ◽  
Soil Carbon ◽  
Cropping Systems ◽  
Annual Rainfall ◽  
Continuous Cropping ◽  
Zero Tillage ◽  
Accumulation Rates ◽  
Eastern Australia ◽  
Perennial Vegetation ◽  
Semi Arid

Australian agriculture contributes an estimated 16% of all national greenhouse gas emissions, and considerable attention is now focused on management approaches that reduce net emissions. One area of potential is the modification of cropping practices to increase soil carbon storage. Here, we report short–medium term changes in soil carbon under zero tillage cropping systems and perennial vegetation, both in a replicated field experiment and on nearby farmers’ paddocks, on carbon-depleted Black Vertosols in the upper Liverpool Plains catchment. Soil organic carbon stocks (CS) remained unchanged under both zero tillage long fallow wheat–sorghum rotations and zero tillage continuous winter cereal in a replicated field experiment from 1994 to 2000. There was some evidence of accumulation of CS under intensive (>1 crop/year) zero tillage response cropping. There was significant accumulation of CS (~0.35 Mg/ha.year) under 3 types of perennial pasture, despite removal of aerial biomass with each harvest. Significant accumulation was detected in the 0–0.1, 0.1–0.2, and 0.2–0.4 m depth increments under lucerne and the top 2 increments under mixed pastures of lucerne and phalaris and of C3 and C4 perennial grasses. Average annual rainfall for the period of observations was 772 mm, greater than the 40-year average of 680 mm. A comparison of major attributes of cropping systems and perennial pastures showed no association between aerial biomass production and accumulation rates of CS but a positive correlation between the residence times of established plants and accumulation rates of CS. CS also remained unchanged (1998/2000–07) under zero tillage cropping on nearby farms, irrespective of paddock history before 1998/2000 (zero tillage cropping, traditional cropping, or ~10 years of sown perennial pasture). These results are consistent with previous work in Queensland and central western New South Wales suggesting that the climate (warm, semi-arid temperate, semi-arid subtropical) of much of the inland cropping country in eastern Australia is not conducive to accumulation of soil carbon under continuous cropping, although they do suggest that CS may accumulate under several years of healthy perennial pastures in rotation with zero tillage cropping.

The Brigalow Catchment Study: III. Productivity changes on brigalow land cleared for long-term cropping and for grazing

Soil Research ◽  
2007 ◽  
Vol 45 (7) ◽  
pp. 512 ◽  
Author(s):  
B. J. Radford ◽  
C. M. Thornton ◽  
B. A. Cowie ◽  
M. L. Stephens
Keyword(s):  
Crop Production ◽  
Clay Soil ◽  
Soil Nutrient ◽  
Grain Protein Content ◽  
Annual Rainfall ◽  
Soil N ◽  
Stocking Rate ◽  
Beef Production ◽  
Eastern Australia ◽  
Productivity Decline

Productivity of grain crops and grazed pastures inevitably declines without soil nutrient replacement and may eventually make these enterprises unprofitable. We monitored these declines in north-eastern Australia during 23 years after clearing 2 of 3 adjacent brigalow catchments, in order to define the productivity levels of developed brigalow land over time. One catchment (11.7 ha) was used for grain production and another (12.7 ha) for beef production from a sown buffel grass pasture. There was no upward or downward trend in annual rainfall amounts throughout the study period. In the cropped catchment, grain yield from 14 winter crops without added nutrients declined significantly in 20 years from 2.9 to 1.1 t/ha.year on the upper-slope clay soil (92 kg/ha.year) and from 2.4 to 0.6 t/ha.year on the Sodosol (88 kg/ha.year). Crop production per year declined by 20% between 2 successive 10-year periods. Wheat grain protein content also declined with time, falling below the critical value for adequate soil N supply (11.5%) 12 years after clearing on the Sodosol and 16 years after clearing on the clay soil. Such declines in grain quantity and quality without applied fertiliser reduce profitability. The initial pasture dry matter on offer of 8 t/ha had halved 3 years after clearing, and a decline in cattle liveweight gain of 4 kg/ha.year was observed over an 8-year period with constant stocking of 0.59 head/ha. Due to fluctuating stocking rate levels of 0.3–0.7 head/ha over the trial period, liveweight productivity trends are attributed to the multiple effects of stocking rate changes and fertility decline. The amount of nitrogen exported from the cleared catchments was 36.1 kg/ha.year in grain but only 1.6 kg/ha.year in cattle (as liveweight gain). Total soil N at 0–0.3 m declined by 84 kg/ha.year under cropping but there was no significant decline under grazing. The soil nutrients removed during grain and beef production need to be replaced in order to avert productivity decline post-clearing.

Soil organic matter in rainfed cropping systems of the Australian cereal belt

Soil Research ◽  
2001 ◽  
Vol 39 (3) ◽  
pp. 435 ◽  
Author(s):  
R. C. Dalal ◽  
K. Y. Chan
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Management Practices ◽  
Performance Indicator ◽  
Annual Rainfall ◽  
Soil Productivity ◽  
Organic C ◽  
Soil C ◽  
Eastern Australia

The Australian cereal belt stretches as an arc from north-eastern Australia to south-western Australia (24˚S–40˚S and 125˚E–147˚E), with mean annual temperatures from 14˚C (temperate) to 26˚C (subtropical), and with annual rainfall ranging from 250 mm to 1500 mm. The predominant soil types of the cereal belt include Chromosols, Kandosols, Sodosols, and Vertosols, with significant areas of Ferrosols, Kurosols, Podosols, and Dermosols, covering approximately 20 Mha of arable cropping and 21 Mha of ley pastures. Cultivation and cropping has led to a substantial loss of soil organic matter (SOM) from the Australian cereal belt; the long-term SOM loss often exceeds 60% from the top 0–0.1 m depth after 50 years of cereal cropping. Loss of labile components of SOM such as sand-size or particulate SOM, microbial biomass, and mineralisable nitrogen has been even higher, thus resulting in greater loss in soil productivity than that assessed from the loss of total SOM alone. Since SOM is heterogeneous in nature, the significance and functions of its various components are ambiguous. It is essential that the relationship between levels of total SOM or its identif iable components and the most affected soil properties be established and then quantif ied before the concentrations or amounts of SOM and/or its components can be used as a performance indicator. There is also a need for experimentally verifiable soil organic C pools in modelling the dynamics and management of SOM. Furthermore, the interaction of environmental pollutants added to soil, soil microbial biodiversity, and SOM is poorly understood and therefore requires further study. Biophysically appropriate and cost-effective management practices for cereal cropping lands are required for restoring and maintaining organic matter for sustainable agriculture and restoration of degraded lands. The additional benefit of SOM restoration will be an increase in the long-term greenhouse C sink, which has the potentialto reduce greenhouse emissions by about 50 Mt CO2 equivalents/year over a 20-year period, although current improved agricultural practices can only sequester an estimated 23% of the potential soil C sink.

Systematic revision and phylogeny of the Australian myrmecomorphic seed bug genus Daerlac Signoret (Insecta:Heteroptera:Rhyparochromidae:Udeocorini)

2012 ◽  
Vol 26 (1) ◽  
pp. 41 ◽  
Author(s):  
Gerasimos Cassis ◽  
Celia Symonds
Keyword(s):  
Leaf Litter ◽  
Cladistic Analysis ◽  
Morphological Characters ◽  
Key To Species ◽  
Systematic Revision ◽  
Seed Predators ◽  
Taxonomic Key ◽  
Open Forest ◽  
High Degree ◽  
Degree Of Overlap

The Australian endemic ant-mimetic seed bug genus Daerlac is revised. This paper provides a redescription of the genus Daerlac and four species: D. apicalis, D. cephalotes, D. nigricans and D. picturatus. Daerlac tricolor is synonomised with D. cephalotes. A taxonomic key to species is provided. Known distributions of D. apicalis, D. nigricans and D. picturatus are each extended beyond previously known ranges. Daerlac species are found predominantly in temperate open forest and woodlands in association with ants and eucalypts. All species are broadly distributed and there is a high degree of overlap in distributions. They are seed predators found on the ground, in leaf litter, under bark or on trunks of eucalypts, and putatively forage on post-dispersed seeds. Cladistic analysis of morphological characters finds that the four species of Daerlac form two well-supported sister-groups (D. apicalis + D. picturatus, and D. cephalotes + D. nigricans). A discussion of the distribution, biology and myrmecomorphy of the genus is provided, and the tribal placement of Daerlac and its relationship to Laryngodus are discussed.

Developmental Pattern and Structural Organisation of Leaf Chloroplasts in Lepidozamia peroffskyana

1990 ◽  
Vol 38 (1) ◽  
pp. 53 ◽  
Author(s):  
PM Bonatti ◽  
RB Fornasiero
Keyword(s):  
Leaf Development ◽  
Natural Habitat ◽  
High Ratio ◽  
Light Conditions ◽  
Structural Pattern ◽  
Chl A ◽  
Eastern Australia ◽  
Closed Forest ◽  
Weak Light ◽  
Characteristic Features

The ontogenesis of chloroplasts during leaf development in Lepidozamia peroffskyana Regel is described; this cycad lives in the ground layer of the evergreen subtropical closed forest of south-eastern Australia. Characteristic features in young plastids are long bands of multilayered thylakoids, resembling photosynthetic structures of some green algae and ferns. 'Optional' structures, namely prothylakoid bodies and crystalline inclusions, are present in the pre-grana stages, in relation to the slow rate of leaf development. Mature chloroplasts are characterised by a great number of randomly oriented high grana stacks, a lack of starch, a high ratio of appressed to exposed thylakoids, and a low ratio of Chl a to Chl b; these shade features appear coherent with the natural habitat of Lepidozamia. However, since similar structures have been reported in mature chloroplasts of other cycads living in exposed sites, the existence of a genetically superimposed structural pattern is hypothesised, reflecting a primitive adaptation to weak light conditions of this group of ancient seed plants.

Crop stubbles are as important for sheep production as annual pastures in the Victorian Mallee

2006 ◽  
Vol 46 (8) ◽  
pp. 993 ◽  
Author(s):  
S. M. Robertson
Keyword(s):  
Plant Density ◽  
Cropping Systems ◽  
Management Strategies ◽  
Simulation Modelling ◽  
Annual Rainfall ◽  
Pasture Management ◽  
Pasture Production ◽  
Eastern Australia ◽  
Sheep Production ◽  
The Impact

The impact of different management strategies on production and profit can be evaluated with knowledge of how sheep production responds to changes in the available feed base and sheep or pasture management. This study aimed to quantify on-farm pasture and sheep production in mixed sheep and cropping systems in the Victorian Mallee of south-eastern Australia (325 ± 50 mm annual rainfall) as a prelude to computer simulation modelling. During 2001 (average rainfall) and 2002 (extreme drought) pasture production, the feed base and sheep production were monitored in 15 paddocks on 5 properties located across the region. Crop stubbles were the major source of feed for 6 months of the year, enabling ewes to maintain liveweight. There was more variation in pasture parameters between paddocks at the 1 location than between locations. The botanical composition, plant density, soil fertility and management were key variables associated with between-paddock variation in pasture production. Variation in pasture production between years was larger than within-year differences. In contrast, stocking rates were not much lower in the drought year of 2002 than in 2001. This study suggests there is potential for management to improve pasture production, and demonstrates the importance of feed sources other than annual pasture for sheep production in environments where the annual pasture growing season is short.

Sign in / Sign up

Export Citation Format

Share Document