Using the n-alkanes of plant cuticular wax to estimate the species composition of herbage mixtures

1992 ◽  
Vol 43 (8) ◽  
pp. 1711 ◽  
Author(s):  
H Dove
Keyword(s):  
Species Composition ◽  
Species Differences ◽  
Trifolium Subterraneum ◽  
Simultaneous Equations ◽  
Cuticular Wax ◽  
Grass Species ◽  
Holcus Lanatus ◽  
Saturated Hydrocarbons ◽  
Pure Species ◽  
Clover Content

This study examined whether or not between-species differences in the concentrations of saturated hydrocarbons (n-alkanes) in the cuticular wax of pasture species could be exploited to estimate the species composition of herbage mixtures. Six sets of mixtures were prepared, containing either two, three or four species. The levels of cuticular wax alkanes were estimated in samples of the pure species and the mixtures, and used in simultaneous equations to compute species composition. The levels of Lolium perenne and Trifolium subterraneum in mixtures of these two species were accurately estimated from alkane analyses, as were the levels of these two species and Holcus lanatus when all three were mixed. In mixtures of T. subterraneum, L. rigidum and Phalaris aquatica, the first two species were well estimated, but phalaris was under-estimated, perhaps because of its relatively low alkane levels. In mixtures of these three species and Medicago sativa, the amounts of the grass species were estimated accurately, but the two legume species were not well distinguished from each other. However, total legume content was estimated very accurately. The species composition of mixtures of T. subterraneum and the above three grasses was also accurately estimated. It is concluded that the use of cuticular wax alkanes should allow a greater differentiation of herbage mixtures into their component species than was possible in previous studies using other markers. Results are also presented to indicate that ratios of alkane concentrations, especially the ratio of C29:C33 alkanes, can also be used to quantify, or at least rank, the clover content of herbage mixtures.

scholarly journals The breeding of 'Grasslands Muster' browntop and other low-fertility grasses for moist hill country

1990 ◽  
pp. 143-146
Author(s):  
W. Rumball ◽  
R.B. Claydon
Keyword(s):  
Grazing Pressure ◽  
Low Fertility ◽  
Grass Species ◽  
Festuca Rubra ◽  
Holcus Lanatus ◽  
Hill Country ◽  
Red Fescue ◽  
Lower Fertility ◽  
Mowing Regime ◽  
Clover Content

Breeding projects have been carried out in each of five grass species already common in New Zealand moist hill country. Although the source of breeding material varied widely among the five species, the breeding goals in each were for improved amount and seasonal spread of productivity, persistence, disease resistance, palatability, uniform heading, and tolerance of white clover. The projects began around 1973 and were all completed by 1980. From 198 I-85, the selections were evaluated in small plots on sunny and shady slopes of hill country near Palmerston North. In all species except Yorkshire fog, the selections outyielded their respective commercial controls in the first l-2 years. In the two browntop species (Agrostis capillaris and A. castellana) this superiority continued through the trial, despite selective grazing pressure. In Yorkshire fog (Holcus lanatus) and red fescue (Festuca rubra) the selections were more palatable but not as persistent as their controls after 5 years. In crested dogstail (Cynosurus cristatus) neither selection nor control persisted, and the mowing regime applied did not allow natural reseeding. In a further trial on lowland, all five selections except dryland browntop were confirmed as considerably more palatable than the controls, and most had more clover content. The best strategy would probably be to market these selections as a hill country/lower fertility seed package (with suitable clovers), so as to exclude less palatable components. Keywords hill country, breeding, browntop, Yorkshire fog, crested dogstail, red fescue, low fertility grasses

scholarly journals Host plant recognition by the root feeding clover weevil, Sitona lepidus (Coleoptera: Curculionidae)

2004 ◽  
Vol 94 (5) ◽  
pp. 433-439 ◽  
Author(s):  
S.N. Johnson ◽  
P.J. Gregory ◽  
P.J. Murray ◽  
X Zhang ◽  
I.M. Young
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Plant Roots ◽  
Grass Species ◽  
Movement Rates ◽  
Sitona Lepidus ◽  
Macro Scale ◽  
Significant Difference ◽  
Invasive Techniques ◽  
Root Feeding

AbstractThis study investigated the ability of neonatal larvae of the root-feeding weevil, Sitona lepidus Gyllenhal, to locate white clover Trifolium repens L. (Fabaceae) roots growing in soil and to distinguish them from the roots of other species of clover and a co-occurring grass species. Choice experiments used a combination of invasive techniques and the novel technique of high resolution X-ray microtomography to non-invasively track larval movement in the soil towards plant roots. Burrowing distances towards roots of different plant species were also examined. Newly hatched S. lepidus recognized T. repens roots and moved preferentially towards them when given a choice of roots of subterranean clover, Trifolium subterraneum L. (Fabaceae), strawberry clover Trifolium fragiferum L. (Fabaceae), or perennial ryegrass Lolium perenneL. (Poaceae). Larvae recognized T. repens roots, whether released in groups of five or singly, when released 25 mm (meso-scale recognition) or 60 mm (macro-scale recognition) away from plant roots. There was no statistically significant difference in movement rates of larvae.

Influence of neighbors on node production, stolon growth, and branching of Trifolium repens transplants in a pasture

1993 ◽  
Vol 71 (9) ◽  
pp. 1266-1269 ◽  
Author(s):  
Roy Turkington ◽  
Elena Klein
Keyword(s):  
Trifolium Repens ◽  
Maximum Rate ◽  
Light Quality ◽  
Dactylis Glomerata ◽  
Phleum Pratense ◽  
Grass Species ◽  
Holcus Lanatus ◽  
Subsequent Growth ◽  
Local Environments ◽  
Trifolium Repens L

Ten individual plants of Trifolium repens L. were transplanted into a 49-year-old cattle pasture in British Columbia. They were protected from grazing and their subsequent growth was monitored at 2- to 3-week intervals throughout the summer from May to October. The rate of stolon elongation was greatest (2.01 cm ∙ week−1) in late July and a maximum rate of node production (1.48 new nodes per stolon ∙ week−1) occurred in early August. As stolons extended through the pasture they encountered a number of different grass species: Dactylis glomerata, Holcus lanatus, Lolium perenne, Phleum pratense, and Poa spp. The stolons grew through a total of 2 m of H. lanatus neighborhood and produced only 3 branches, whereas they produced 11 branches in only 57.2 cm of P. pratense neighborhood. Neighboring grasses impose different local environments on the nodes and stolons of T. repens and consequently influence the dynamics of node production, the rate of stolon elongation, and the amount of stolon branching. Key words: stolon branching, neighbors, light quality, Trifolium repens.

The germinable soil seedbank of Eucalyptus victrix grassy woodlands at Roy Hill station, Pilbara district, Western Australia

2004 ◽  
Vol 26 (1) ◽  
pp. 17 ◽  
Author(s):  
R. A. Graham ◽  
S. K. Florentine ◽  
J. E. D. Fox ◽  
T. M. Luong
Keyword(s):  
Species Composition ◽  
Western Australia ◽  
Perennial Grass ◽  
Summer Rainfall ◽  
Distribution Patterns ◽  
Grass Species ◽  
Surface Areas ◽  
Hill Station ◽  
Soil Seedbank ◽  
Germinable Seed

The paper reports soil seedbank species composition, of Eucalyptus victrix grassy woodlands, of the upper Fortescue River in the Pilbara District, Western Australia. In this study, our objectives were to investigate germinable soil seedbanks and species composition in response to three simulated seasons, using emergence. Variation in seed density from three depths was tested. Four field sites were sampled. Thirty samples were collected in late spring, after seed rain and before summer rainfall. From each sample spot, three soil depths (surface, 1–5, and 6–10 cm) were segregated from beneath surface areas of 100 cm2. Samples were later incubated in a glasshouse to simulate three different seasonal conditions (autumn, winter and spring). Germinating seedlings were recorded on emergence and grown until identified. Forty-one species germinated, comprising 11 grasses (7 annuals and 4 perennials), 25 annual herbs and 5 perennial herbs. Distribution patterns of germinable seed in both the important annual grass Eragrostis japonica and the perennial Eragrostis setifolia (a preferred cattle fodder species), suggest that seedbank accumulation differs among species and between sites. In part, this may be associated with the absence of grazing. Species with most total germinable seed were E. japonica (Poaceae; 603/m2), and the annual herbs Calotis multicaulis (Asteraceae; 346/m2), and Mimulus gracilis (Scrophulariaceae; 168/m2). Perennial grass seed was sparse. Spring simulation gave most germination (1059), followed by autumn (892) and winter (376) sets. Greatest species diversity was produced from the spring simulation (33 species), followed by autumn (26), and winter (22). Of the total germination, 92% came from 17 species that were represented in all three simulations. Of the 1227 grass seedlings counted, most were recruited from the surface soil (735), followed by the 5 (310) and 10 (182) cm depths. Marginally more grass seedlings germinated from the spring simulation (558) than the autumn set (523). Only 11.9% of grass germinants came from the winter simulation. All grass species recruited from the soil seedbanks had a C4 photosynthetic pathway. Except for Cenchrus ciliaris all grass species are native to Australia. Of the four sites sampled, one fenced to exclude cattle five years earlier had significantly more germination than the three unfenced sites. Seedbank sampling produced several new records for plants in the areas sampled.

scholarly journals Structure of spider-harvestman assemblages (Arachnida, Araneae, Opiliones) of model biotopes of Visimskiy natural reserve

2021 ◽  
pp. 191-205
Author(s):  
Sergei L. Esyunin ◽  
◽  
Nadezhda L. Ukhova ◽  
Anna M. Domolazova ◽  
◽  
...  
Keyword(s):  
Species Composition ◽  
Seasonal Dynamics ◽  
Dominant Species ◽  
Species Differences ◽  
Occurrence Rate ◽  
Pitfall Traps ◽  
Spruce Forests ◽  
Natural Reserve

The assemblages of herpetobion spiders from four habitats: two seven-year-old burns, spruce-birch and fir-spruce forests, were examined in the Visimskiy Reserve (Sverdlovsk Region) during May-September 2017 using pitfall-traps. The structure of the spiders population of burns significantly differs from that of forests in species composition, total occurrence rate (ind./100 trap-days), seasonal dynamics and composi-tion of the dominant species. Differences in the structure of the population are most pronounced in the summer. In summer spider assemblages of burns, the most abundant are Agyneta allosubtilis, Alopecosa pulverulenta, P. fulvipes, P. lugubris, P. riparia and Piratula hygrophila, in forests - Allomengea scopigera and Haplodrassus soerenseni.

Productivity of restored grassland-steppe ecosystems

2019 ◽  
Author(s):  
Е. Пещанская ◽  
В. Кожевников
Keyword(s):  
Species Composition ◽  
Rare Species ◽  
Dominant Species ◽  
Civil Engineering ◽  
Botanical Garden ◽  
Grass Species ◽  
Anthropogenic Effect ◽  
Steppe Ecosystems ◽  
Stavropol Region ◽  
The One

Необходимость восстановления луговой степи центрального Ставрополья возникла ещё в середине прошлого столетия. Причиной тому послужило усиление воздействия антропогенных факторов на окружающую среду: распашка целины, промышленное и гражданское строительство, чрезмерный выпас скота, а также воздействие различного вида эрозий. В целях сохранения уникального природного комплекса степей с большим набором ценных и редких видов, а также в качестве опыта по восстановлению кормовых угодий в Ставропольском ботаническом саду в 1963 году были начаты исследования по интродукции дёрна. В период с 1963 по 1984 год на площади около 2 га были воссозданы фрагменты луговой степи. Изучение состояния искусственных ценозов, получение сравнительных данных в отношении видового состава, хозяйственно-ботанических групп, урожайности ценозов важнейшие компоненты исследования. В качестве эталонов обследовались территории естественных целинных степей (эталоны) (г. Бучинка, г. Стрижамент, урочище Новомарьевская поляна) с доминантами, сходными с доминантами изучаемых участков, восстановленных дёрном ( Бучинка , Стрижамент , Новомарьевская поляна ). Количество видов на эталонных участках составляет 6592, на восстановленных участках 83103. Видовой состав максимально представлен разнотравьем: от 44 до 72 видов. Во всех выборках проб преобладают злаки (31,9446,17) и разнотравье (29,4041,64), значительный удельный вес приходится на сухие остатки (старику) 7,6128,64. Масса бобовых колеблется в пределах от 0,85 до 11,01, осок от 0,1 до 13,83. Урожайность травостоя восстановленных ценозов сохраняется высокой 3,243,97 т/га. Показатели урожайности травостоя восстановленных формаций превышают показатели эталонов с разницей от 0,61 до 1,65 т/га. Restoration of grasslands became important in the Central Stavropol region in the middle of the last century. The reason was an increased anthropogenic effect: plowing, industrial and civil engineering, cattle grazing and erosion. Experiments on turf introduction got started at the Stavropol Botanical Garden in 1963 to preserve and restore the unique natural steppe area with a large number of valuable and rare species. Fragments of steppe were grown on 2 ha area from 1963 to 1984. The investigation focused on ecosystem conditions, species composition, botanical groups and yield. Natural steppes performed as controls (Buchinka, Strizhament, Novomaryevskaya Polyana) having similar dominant species as the trial areas. Control areas contained 6592 species, the restored ones 83103. There were 4472 different grass species grown. Proportions of gramineous averaged to 31.9446.17, grass mixtures 29.4041.64, grassland litter 7.6128.64. Contents of legumes varied within 0.8511.01, sedge 0.113.83. Grass productivity of the restored area was high 3.243.97 t ha-1. It exceeded the one of the natural areas by 0.611.65 t ha-1.

Correlations between environmental factors, the biomass of exotic annual grasses and the frequency of native perennial grasses

2006 ◽  
Vol 54 (7) ◽  
pp. 655 ◽  
Author(s):  
Tanja I. Lenz ◽  
José M. Facelli
Keyword(s):  
Species Composition ◽  
Soil Fertility ◽  
Perennial Grass ◽  
Perennial Grasses ◽  
Annual Rainfall ◽  
Grass Species ◽  
Soil Factors ◽  
Annual Grasses ◽  
Exotic Annual Grasses ◽  
Native Perennial Grass

The species composition of temperate grasslands in the mid-north of South Australia has been radically altered from a system dominated by native perennial grasses to a system dominated by Mediterranean annual grasses. This study investigated the importance of chemical and physical soil characteristics, topographical features and climatic variables on the abundance of native and exotic grass species in nine ungrazed grasslands. Overall, climatic and other abiotic factors were highly variable. In addition, past management practices and original species composition are generally unknown, leading to further unexplained variation in the data. On a large spatial scale (among sites), the abundance of exotic annual grasses was positively correlated with mean annual rainfall, and on any scale, with finer soil textures and higher soil organic carbon levels. The most abundant annual grass, Avena barbata (Pott ex Link), was generally associated with soil factors denoting higher soil fertility. The abundance of native perennial grass species was not correlated with any environmental variables at any scale. The various native perennial grass species did not show clear associations with soil factors, although they tended to be associated with factors denoting lower soil fertility. However, at small spatial scales (within some sites) and among sites, the abundances of exotic annual and native perennial grasses were strongly negatively correlated. The results suggest that at the present time, rainfall and soil properties are important variables determining the abundance of annual grasses. The driving variables for the abundance of perennial grasses are less clear. They may be controlled by other factors or extreme rainfall events, which were not surveyed. In addition, they are likely to be controlled by competitive interactions with the annual grasses.

Effects of time and rate of paraquat application on yield and botanical composition of annual pastures containing subterranean clover in a Mediterranean climate

1973 ◽  
Vol 13 (64) ◽  
pp. 556
Author(s):  
DW Barrett ◽  
GW Arnold ◽  
NA Campbell
Keyword(s):  
Dry Matter ◽  
Mediterranean Climate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Botanical Composition ◽  
Minimum Loss ◽  
Major Species ◽  
Nitrogen Phosphorus ◽  
Clover Content ◽  
Made In

Pastures containing subterranean clover (Trifolium subterraneum) and either Vulpia spp. or Bromus rigidus as the other major species were sprayed at 0, 0.07, 0.14 and 0.21 kg a.i. ha-1 of paraquat ion between June and early October in Western Australia. Spraying removed the grasses and produced pastures containing up to 95 per cent clover. Mid-winter applications were more effective in increasing clover content than those made in spring. These changes in botanical composition were evident in the year following spraying, but were less marked. Yields of dry matter were reduced by paraquat, especially 'in the period immediately following spraying. These losses tended to decline as the growing season progressed, but at the close they were still evident on the Bromus rigidus pasture sprayed in July. Yields at the end of the subsequent season were similar on all treatments. Paraquat applied in mid-August at 0.14 kg a.i. ha-1 to both pastures produced the greatest change in botanical composition with the minimum loss of yield. The concentrations of nitrogen, phosphorus, calcium and magnesium were higher in mature herbage on paraquat treatments. Total yields of nutrients were similar between treatments because of reduced dry matter yield.

A comparison of the effects of feed supplements cobalt and selenium, and perennial and annual pastures on the production of medium Peppin Merino weaner sheep in south-western Australia

1989 ◽  
Vol 29 (3) ◽  
pp. 361
Author(s):  
HL Davies ◽  
PP Mann ◽  
B Goddard
Keyword(s):  
Western Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Grass Species ◽  
Feed Supplement ◽  
Protein Meal ◽  
Wool Production ◽  
Phalaris Aquatica ◽  
High Protein Meal ◽  
Cereal Group

Two experiments on weaner production are reported. In experiment 1, the liveweight and wool production were measured in medium Peppin Merino sheep that grazed at 10.5 weanerstha 8 plots of a mixed Phalaris aquatica-subterranean clover pasture or 8 plots of annual pasture (Trifolium subterraneum cv. Woogenellup and volunteer annual grass species). This was repeated over 2 years using autumn-born sheep; 4 groups on each pasture type were offered no supplement, 2 groups a cereal supplement (340 goats), and 2 groups of supplement isoenergetic with the cereal group but having a high protein meal replace some of the cereal (250 g oats and 60 g protein). The feed supplement was offered over the summer (January-April). The sheep on 2 of the unsupplemented plots and 1 of the 2 plots receiving either a cereal or cereal + protein supplement were offered access to a composite mineral block formulated to meet the mineral requirements of sheep with the exception of cobalt and selenium. There were 16 sheep on each plot within each group of 16 weaners, 4 were given an intraruminal cobalt 'bullet', 4 were given 5 mg of selenium orally, 4 given cobalt plus selenium and 4 were untreated controls. Experiment 2 was in year 3 with spring-born weaners on the same plots. The mineral block treatment was discarded on the plots receiving supplement and the effect of supplementary feeding at the beginning of March was compared with feeding in early January; barley was also compared with oats and protein. The stocking rate was raised to 13.5 sheep/ha. There were no statistically significant differences in sheep liveweight due to pasture type in either of the years of experiment 1 or experiment 2. Supplementation with cereals or protein-fortified cereals resulted in a significantly ( P < 0.05) increased liveweight at the end of March (5.6 kg in year 1,2.4 kg in year 2 of experiment 1, and 2.5 kg in experiment 2), and wool production (0.49 kg clean wool in year 1 and 0.3 1 kg in year 2 in experiment 1, and 0.49 in experiment 2). There was a significant liveweight response on the perennial plots to selenium + cobalt in year 1 of experiment 1. All cobalt-treated sheep were heavier ( P < 0.001) in year 2. Neither selenium nor cobalt significantly affected liveweight in experiment 2. The proportion of Phalaris aquatica on the perennial pasture diminished from 18% to less than 9% by the end of year 2 in experiment 1. These results suggest that, if perennial pastures cannot be maintained, then their establishment in the south-west of Western Australia would not result in greater animal production than on annual pasture. Decisions on using supplements would be dependent upon feed and wool prices.

A survey of native grasses in the Goulburn District and factors influencing their abundance.

1991 ◽  
Vol 13 (2) ◽  
pp. 118 ◽  
Author(s):  
DJ Munnich ◽  
PC Simpson ◽  
HI Nicol
Keyword(s):  
Species Differences ◽  
New South ◽  
Acid Tolerance ◽  
Trifolium Subterraneum ◽  
Common Species ◽  
Native Grasses ◽  
South Wales ◽  
Cent Increase ◽  
Annual Grasses ◽  
Microlaena Stipoides

A survey of natural and improved paddocks on 34 farms was conducted over winter within a 60 km radius of Goulburn on the Southern Tablelands of New South Wales. Seventeen of the properties which were found to have significant (greater than 10 per cent) proportions of potentially useful native grasses were resurveyed in the subsequent summer to identify specific Danthonia spp. The survey revealed that useful native yearlong green species such as Microlaena stipoides and Danthonia spp. were relatively abundant in natural paddocks surveyed over winter (16 per cent and 10 per cent respectively), Danthonia being represented by four common species. These natural paddocks, most of which contained Trifolium subterraneum and had some superphosphate input, carried 80 per cent as many stock as their improved counterparts in terms of average DSE/ha. Factors such as cultivation and the presence of naturalized or sown species influenced the abundance of these species, but species differences were apparent. Cultivation reduced the abundance of Danthonia spp. but did not affect the abundance of M. stipoides, which was thus more prevalent than Danthonia spp. in improved pastures. Microlaena stipoides was also more prevalent in uncleared than cleared paddocks. The frequency of Danthonia spp. was negatively associated with high percentage frequencies of annual grasses (principally Vulpia spp.), declining by approximately 2.5 per cent for each 10 per cent increase in annual grasses over winter. The proportion of M. stipoides observed in paddocks appeared to be more influenced by sown pasture species, with lowest percentages recorded where species such as Phalaris aquatica had been sown and highest percentages where no exotic species had been introduced. The abundance of M. stipoides was affected by pH, with percentage frequency increasing as pH declined (down to pH 4 (Cacl~)), indicating the possible acid tolerance of this species. Species' percentages recorded changed with season. For example, Danthonia percentages recorded were considerably greater over summer when flowering heads were obvious than those recorded in winter. This aspect highlights the importance of recording different species during specific seasons to increase the accuracy of frequency estimates.

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