Phenology of Growth and Resource Deployment in Alexgeorgea nitens (Nees) Johnson and Briggs (Restionaceae), a Clonal Species From South-Western Western Australia

1990 ◽  
Vol 38 (6) ◽  
pp. 543 ◽  
Author(s):  
KA Meney ◽  
JS Pate ◽  
KW Dixon

Seasonal patterns are described for growth and partitioning of dry matter and selected nutrients between different age classes and types of plant organs of ramets of non-reproductive, presumed female clones of Alexgeorgea nitens in native sandplain habitat at Eneabba, south-western Western Australia. New rhizome extension and associated production of new culms and nodal roots are initiated following onset of rain in autumn. Rate of growth of these parts remains slow through winter, peaks in spring and early summer and then becomes much reduced in the hot, dry summer. The bulk (87%) of the season's dry matter increment of new ramet parts is estimated to be derived from current photosynthesis, the remaining 13% by mobilisation of dry matter from older parts of the ramet, especially from 1- and 2-yearold culms. Growth of new organs is severely reduced by removal or shading of culms at the beginning of the season. Older culms and rhizomes carry substantial starch reserves, but mobilisation of this reserve accounts for 2% at most of the dry matter gain of new organs of intact ramets, 19% of that of shaded and 65% of detopped ramets. A substantial fraction of the starch pool of a rhizome segment normally remains until its senescence, possibly as a long-term energy reserve, utilisable after destruction of above-ground parts by fire or grazing. Concentrations of N, P, K, Ca and Mg in organ dry matter of A. nitens are generally very low in comparison with species other than those Cyperaceae or Restionaceae from similar habitats. There is no evidence of preferential storage in below-ground parts, and efficiencies of emptying of nutrient reserves from senescing ramet parts are not high. Mobilisation from older source organs of ramets of intact, unstressed clones is estimated to provide 14% of the new organ's seasonal gain of P, 16% of Mg, 21% of Ca, 22% of N and 58% of K. Annual factorial increases of a ramet in the studied nutrient elements range from 1.3 (for K) to 2.4 (for P), indicating flexibility in exploiting sources of different nutrients as their respective availabilities change from season to season.

1982 ◽  
Vol 30 (2) ◽  
pp. 231 ◽  
Author(s):  
J Kuo ◽  
PJ Hocking ◽  
JS Pate

Seed reserves of eight species of Proteaceae from south-western Australia were examined by chemical analysis, microscopy and scanning X-ray microanalysis. Cotyledons were the principal reserve organs of all species. Seeds had 30-500 times the level of P, 8-100 times the level of N, Cu and Zn and, on most species, higher levels of Mg, K, Mn and S than leaves or woody parts of fruits. Levels of Ca, Fe, Na and Cl in leaves and fruit parts were the same as or higher than those in seeds. The K:Ca ratios of seeds were very low (1:2). Seeds had only 1-16% of total fruit dry matter but contained 83-98% of a fruit's P, 43-78% of its N and much of its Zn, Mn and Cu. Seeds had no more than 3% of a fruit's Na or Cl. Oil (14-31%) and protein (15-64%) were major organic reserves of seeds; starch was absent. Protein bodies occurred at high density throughout the parenchyma of cotyledons of all species, and in epidermal and provascular tissues of some species. Globoids occurred in some protein bodies; crystalloids were absent. Globoid-containing protein bodies were confined to central mesophyll layers of cotyledons of Hakea spp. and Grevillea annulifera, to subepidermal parenchyma of Banksia spp. and Xylomelum angustifolium, but occurred in most cotyledonary tissues of Grevillea leucopteris; X-ray microanalysis of cotyledon tissues suggested that the globoids were rich in P, Ca, S and Mg, and in some species also in Fe, Zn and K. The species of Proteaceae investigated were considered to be very effective in channelling essential nutrients to their seeds.


1988 ◽  
Vol 28 (6) ◽  
pp. 765 ◽  
Author(s):  
MDA Bolland ◽  
MJ Baker

Seed of 2 cultivars of wheat (Triticum aestivum) and 1 burr medic (Medicago polymorpha) with increasing phosphorus (P) concentrations (wheat 1.4-3.7 g P/kg dry matter, medic 3.3-7.9 g P/kg dry matter) were collected from field experiments with variable levels of applied superphosphate (wheat 0- 577 kg P/ha, medic 0-364 kg P/ha) in south-western Australia. These seeds were used in further experiments to examine the effect of seed P concentration on the subsequent dry matter (DM) production of seedlings and plants in 3 glasshouse pot experiments and 1 field experiment. Seed of the same size (wheat, 35 mg/seed; medic, 3.6 mg/seed) but with increasing P concentration produced substantially higher DM yields in the absence or presence of freshly applied superphosphate P up to 28-35 days after sowing in the pot experiments and 67 days after sowing in the field experiment.


1972 ◽  
Vol 52 (6) ◽  
pp. 941-948 ◽  
Author(s):  
L. B. MacLEOD ◽  
H. T. KUNELIUS ◽  
F. W. CALDER

The effects of early summer and fall cutting managements on two alfalfa (Medicago sativa L.) cultivars were studied over a 3-year period. Removal of the first crop of Saranac and Narrangansett alfalfas at prebud stage, followed by two cuts at the early bloom stage before early September, and a late fall harvest on October 25, produced seasonal dry matter (DM) yields of 7.5–8.6 metric T/ha in the 1st year. Stand deterioration, however, was severe and by the 3rd year, practically all alfalfa had disappeared. Average percent crude protein (CP) in cut 1 was 17.7–21.9 and percent in vitro dry matter digestibility (IVD) 67.4–73.8. Removal of the first cut at bud stage with two subsequent harvests at the early bloom stage also allowed a total of three harvests before early September and resulted in seasonal DM yields of 8.6–8.8 in the 1st year. Although the survival of alfalfa was increased over the managements where cut 1 was at prebud stage, a considerable decrease of alfalfa was still observed in the 3rd year. Under this management, average CP in cut 1 was 15.8–16.3 and IVD 64.1–68.4. Harvesting the first crop at early to midbloom stage and the second crop at early bloom in early to mid-August, followed by third harvest in late October, resulted in good survival with seasonal DM yields of 6.1–10.6. Lower CP and IVD were recorded in cut 1 than in the more intensive managements. Under all managements, average CP in cuts 2 and 3 was 14.9–17.3 and 13.3–19.4, respectively. IVD was 54.5–60.7 in cut 2 and 56.0–64.4 in cut 3.


2019 ◽  
Vol 65 (4) ◽  
pp. 155-163
Author(s):  
Miriam Kizeková ◽  
Radoslava Kanianska ◽  
Ľubica Jančová ◽  
Jozef Čunderlík ◽  
Zuzana Dugátová ◽  
...  

Abstract This paper aimed to monitory the dry matter biomass production and carbon stocks of above-and below-ground biomass in five types of grasslands in Slovakia: i) lowland oversowed pasture ii) lowland hay meadows, iii) mesophilous pasture, iv) mountain hay meadows, v) abandoned grassland. Averaged over two cropping seasons the total above-and below-ground biomass differed significantly across the monitored grasslands. It ranged respectively from 2.18 to 7.86 t/ha and from 9.64 to 22.67 t/ha dry matter depending on the pedoclimatic condition and the botanical composition of each grassland type. Consequently, this resulted also in the carbon stocks in above-and below-ground biomass. Generally, the mean carbon stocks were 1.56 t/ha for above-ground biomass (24%) and 4.83 t/ha for below-ground biomass (76%). The botanical composition for all the grassland types was also described. The highest number of plant species (55) was observed in lowland hay meadow located in Slovak Karst, the lowest one (23) for the oversowed grassland located in Eastern Slovak Upland. This monitoring paper showed that semi-natural grassland habitats and improved grasslands as well are an important carbon sink, and they can play a key role in global climate change mitigation.


Author(s):  
C.J. Hoogendoorn ◽  
C.W. Holmes ◽  
A.C.P. Chu

Two levels of grazing intensity were unposed on pasture during a spring-time pre-treatment period in two years at Massey University's Dary Cattle Research Unit. The two grazing intensws were lax (L), 2000-2500 kg DMlha residual herbage mass (RHM) and intense (I) 1000-1500 kg DM/ha RHM imposed for 2 grazing rotations. During this period, net herbage accumulation (NHA) on the L swards was approximately twice that on I wards. However, by early summer, NHA was greater on the I than L swards. Subsequently, during the experimental feeding period in early summer, herbage on the I swards contained lower percentages of reproductive tillers, grass stem, and senescent matter, and was of higher digestibllity than herbage on the L wards. Durmg the feedlng period, cows grazing the I wards had greater yields of milk and milk fat than cows on the L wards when offered both generous and restricted daily herbage dry matter allowances. The effect of ward type on dry matter intake (DMI) was dependent on dry matter allowance. However, when a common allowance of leaf was offered, DMI, milk and milk fat yield were not significantly affected by sward type on offer. The results emphasise the importance of maintaining green, leafy swards into late spring and summer in order to maximise milk yield per cow at this time. This was achieved by maintaining a RHM of no more than 1500 kg DMlha throughout spring by imposing sufficiently high stocking rates. Keywords: residual herbage mass, ward characteristics, dry matter allowance, leaf allowance, dry matter intake, milk yield.


Diversity ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 482
Author(s):  
Huon L. Clark ◽  
Bruno A. Buzatto ◽  
Stuart A. Halse

Knowledge of subterranean fauna has mostly been derived from caves and streambeds, which are relatively easily accessed. In contrast, subterranean fauna inhabiting regional groundwater aquifers or the vadose zone (between surface soil layers and the watertable) is difficult to sample. Here we provide species lists for a globally significant subterranean fauna hotspot in the Robe Valley of the Pilbara region, Western Australia. This fauna was collected from up to 50 m below ground level using mining exploration drill holes and monitoring wells. Altogether, 123 subterranean species were collected over a distance of 17 km, comprising 65 troglofauna and 58 stygofauna species. Of these, 61 species were troglobionts and 48 stygobionts. The troglofauna occurs in small voids and fissures in mesas comprised mostly of an iron ore formation, while the stygofauna occurs in the alluvium of a river floodplain. The richness of the Robe Valley is not a localized aberration, but rather reflects the richness of the arid Pilbara region. While legislation in Western Australia has recognized the importance of subterranean fauna, mining is occurring in the Robe Valley hotspot with conditions of environmental approval that are designed to ensure species persistence.


2018 ◽  
Vol 58 (12) ◽  
pp. 2269 ◽  
Author(s):  
D. Real ◽  
C. M. Oldham ◽  
A. van Burgel ◽  
E. Dobbe ◽  
J. Hardy

Tedera (Bituminaria bituminosa C.H Stirt. vars. albomarginata and crassiuscula) is a traditional forage species for goats in the Canary Islands, Spain. It has agronomic characteristics ideally suited to Mediterranean-like climates that allows it to provide high quality green forage for grazing animals during summer and autumn. It can be used to extend the growing season into late spring and early summer and/or to reduce or eliminate the need for expensive hand feeding of grain and hay to sheep to fill the ‘feed gap’ during the dry season in southern Australian farming systems. Three sheep grazing experiments were carried out with the objective to evaluate sheep production during summer and autumn with tedera as the sole diet. A 3-ha site at Dandaragan, Western Australia was grazed during the summer and autumn of 2014–2015 and 2016 and a 2.4-ha site was grazed at Kojonup, Western Australia during the same period in 2016. At each site, two grazing treatments were evaluated, continuous grazing and rotational grazing with six plots (14 days of grazing and 70 days of recovery). The first hypothesis tested was that tedera plants would not survive continuous grazing during summer and autumn. The second hypothesis tested was that without hand feeding, 10 dry sheep equivalents/ha would be able to at least maintain weight and condition score during summer and autumn. The third hypothesis tested was that rotational grazing would improve the production of the sheep (liveweight and condition score) compared with continuous grazing. The first hypothesis was rejected, the population of tedera plants did not significantly decline due to being continuously grazed during summer and autumn. The second hypothesis was confirmed, at the three experimental sites, 10 dry sheep equivalents/ha were able to at least maintain weight and condition score without any hand feeding. The third hypothesis was partially rejected; continuous grazing had a better performance of the sheep than rotational grazing. However, the rotational grazing plots had more tedera on offer in the remaining grazing plots in the rotation with the potential for a longer grazing time. These three experiments clearly demonstrate that tedera can be used to reduce or eliminate expensive hand feeding during summer and autumn using the simplest and least expensive grazing management; continuous grazing.


1962 ◽  
Vol 2 (4) ◽  
pp. 40 ◽  
Author(s):  
AB Beck

Levels of copper, molybdenum, and inorganic sulphate are reported for samples of Western Australian pastures from areas where copper deficiency diseases in ruminants have occurred and from unaffected areas. The copper contents of the pastures were determined previously. It was found that the copper deficiency diseases commonly occurred where pastures contained less than 3 p.p.m. Cu in the dty matter during the growing period, while such diseases were absent where the pastures contained more than 6 p.p.m. Cu. Values between 3 and 6 p.p.m Cu were classified as marginal. The molybdenum and inorganic sulphate contents of the original pasture samples have now been determined. The molybdenum contents of the three classes of pasture were found to lie within the same range (0.1 to 4 p.p.m. Mo in the dry matter, with the majority less than 1 p.p.m.). These values are similar to those recorded by overseas workers for normal pastures. Inorganic sulphate contents of the three classes of pasture also lay within the same range (0.1 to 0.9 per cent SO4, with the majorio between 0.2 and 0.4 per cent). The results for the pastures examined suggest that in Western Australia the low copper level is the constant and the most significant factor associated with enzootic ataxia in sheep and falling disease in cattle.


1968 ◽  
Vol 8 (31) ◽  
pp. 177 ◽  
Author(s):  
RJ Jones ◽  
Davies J Griffiths ◽  
RB Waite ◽  
IF Fergus

Five irrigated pasture mixtures (four containing tropical and temperate species and one containing only temperate species (winter mixture) ) were compared under grazing at three nitrogen levels -nil, 100, and 300 lb N an acre a year as urea-over a four-year period 1960-1963. Pastures were grazed for approximately one week every six weeks with a twelve-week rest period in the winter of 1962 and 1963. Under this management mean annual yields of dry matter increased from 15,700 lb to 25,000 lb an acre over the four-year period. Pasture growth rates varied from over 90 lb DM an acre a day in early summer to 10-40 lb DM an acre a day in winter due to variations in radiation and temperature. Urea increased pasture dry matter yields and also the yields of nitrogen measured in 1961 and 1962. Mean response was 19 lb and 14.5 lb DM/lb N applied at the N100 and N300 rates respectively. Yield of nitrogen was increased by a mean of 79 lb an acre a year by application of urea, but there was no significant difference between rates. Dry matter responses to urea were small in winter and spring and large in summer and autumn. The N300 rate reduced the yield of white clover in the first two years of the pasture, but there was no reduction in the yield of white clover at the N100 rate compared with the N0 treatment. There were no significant differences in yield between the pasture mixtures in the establishment year. In subsequent years mixtures containing summer and winter species outyielded (P<0.001) the winter mixture, particularly in summer and autumn. The pattern of production was similar for all mixtures and there was no significant difference between mixtures in yield of nitrogen. Chloris gayana Kunth CV. Samford and Setaria sphacelata (Schum) Stapf and C. E. Hubbard CV. Nandi. were the most successful summer grasses and Bromus unioloides (Willd.) H.B.K. cv. Priebes, the best winter grass. Three Paspalum species failed to compete with the Setaria and three winter grasses were low yielding after the first year. Trifolium repens L. CV. Ladino was the only successful legume of three winter and three summer legumes sown. It enabled yields of 400 lb N an acre a year to be achieved, increased total soil nitrogen, and made an estimated contribution of 760-810 lb N an acre over the four-year period. It is considered to be the key species for irrigated pastures in south-eastern Queensland.


1977 ◽  
Vol 17 (85) ◽  
pp. 301 ◽  
Author(s):  
DF Beech

Experiments with irrigated lemongrass (Cymbopogon citratus) have shown that high oil yields can be obtained in the Ord Irrigation area, Western Australia. The highest oil yield of 419 1 ha-1 over a 360 day period was obtained when the plants were cut at 60 day intervals and at a height of 20 cm. Longer intervals and higher cutting heights gave lower oil yields, although in some cases, fresh and dry matter yields were increased. Studies on the effect of water stress showed that time between irrigations in the dry season should not be more than ten days if oil yields are to be maintained. Wilting of cut lemongrass in the dry season was shown to result in a loss of oil, with losses increasing with the duration of wilting up to 11 hours. Under irrigated conditions, lemongrass removed large quantities of nutrients, particularly potassium. Over the 360 day period, maximum amounts of N, P and K removed were 186, 26 and 384 kg ha-1 respectively.


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