scholarly journals Botanical Composition and Diet Quality of the Vicuñas (Vicugna vicugna Mol.) in Highland Range of Parinacota, Chile

Animals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1205
Author(s):  
Giorgio Castellaro ◽  
Carla Orellana ◽  
Juan Escanilla ◽  
Camilo Bastías ◽  
Patrich Cerpa ◽  
...  
Keyword(s):  
Nitrogen Concentration ◽  
Mean Value ◽  
Foraging Strategies ◽  
Grass Species ◽  
Botanical Composition ◽  
Diet Diversity ◽  
Grassland Species ◽  
Vicugna Vicugna ◽  
Quality Diet ◽  
High Degree

Understanding the botanical composition of herbivores’ diets and their nutritional quality is an important question in the development of sustainable strategies for the management of natural resources. In Chilean highland vicuña-grazed grasslands, there is little information in this regard and, therefore, this study aimed to determine the year-round profile of the diet’s botanical composition and quality. In highland grasslands, on an area of 21.9 ha, continuously grazed for 3.06 VU/ha/year (18°03′ S, 69°13′ W; 4425 m.o.s.l), twelve feces piles were sampled monthly and were analyzed through microhistology, and the nitrogen concentration [NF, OM basis] was determined. The botanical composition, diversity (J) and selectivity index (Ei) of the main species were estimated. Diets were composed of dry–grassland grasses (37.7%), wet–grassland grasses (36.6%), graminoids (14.3%) and forbs (10.2%). The diet diversity ranged from 0.79 (dry–winter) to 0.87 (wet–summer). The main dominant grassland species obtained negative Ei values. The annual mean value of [NF] was estimated as 1.82%, with a higher value in summer months (2.21%), which coincides with the physiological states of higher nutritional demand. The vicuñas behave like generalist ungulates, having a high degree of selectivity towards grass species, which mostly fulfill a nutritional role in subsistence and a functional role in survival, applying foraging strategies that allow them to obtain a better quality diet during the season of greatest nutritional demand.

scholarly journals Interrelation between frequency dominance and dry-weight percentages of species in grassland vegetation.

1969 ◽  
Vol 17 (2) ◽  
pp. 161-167
Author(s):  
J.G.P. Dirven ◽  
B.J. Hoogers ◽  
D.M. De Vries
Keyword(s):  
Dry Weight ◽  
Plant Size ◽  
Size Ratio ◽  
Grass Species ◽  
Botanical Composition ◽  
Quadrat Size ◽  
Grassland Species ◽  
Tropical Grasslands ◽  
Weight Analysis ◽  
Grassland Research

In botanical grassland research in the Netherlands, dry weight analysis and the combined 25 cm2 frequency and order method have mainly been applied. Since the botanical composition of many fields had been analysed by both methods, it was possible to study the interrelation between the percentages of frequency, dominance and dry weight. The results showed that the relation between dominance and percentage dry weight depended on the plant-size/ quadrat-size ratio. As this quotient becomes greater, the relation progressively approaches the 45 degrees line. In the analysis of tropical grasslands it is possible to obtain sufficiently reliable information about the quantitative ratios of the various grass species fairly rapidly by determining the dominance percentage. The relation between frequency percentage (F%) and dominance percentage (D%) is also determined by plant-size ratio and can be expressed by the general equation: D% = -m Iog10 (100-F%) + 2 m. The coefficient m is a reliable standard of the dominance tendency of the grassland species.-A.G.G.H. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Formation of botanical composition of clover cereal and alfalfa cereal crops agrophytocenoses depending on sowing method

2020 ◽  
pp. 160-168
Author(s):  
I. Senyk
Keyword(s):  
Festuca Arundinacea ◽  
Global Climate ◽  
Phleum Pratense ◽  
Grass Species ◽  
Cereal Crops ◽  
Forest Steppe ◽  
Botanical Composition ◽  
Cross Sectional ◽  
Row Crops ◽  
Adverse Weather

Botanical composition of grasses is one of the most important indicators the biological value and quality of the obtained hay and pasture forage, the longevity of hayfi elds and pastures depend on. The issue of changing the botanical composition of agrophytocenoses is especially important in the context of global climate change, which in recent decades is also manifested in the territory of Ukraine, as it is possible to establish the most adapted species of legumes and cereals to adverse weather conditions and to identify eff ective technological methods of managing these processes for maximum conservation economically valuable species in the herbage. The purpose of the research is to establish the infl uence of diff erent ways of sowing of clover and alfalfa cereal crops agrophytocenoses on the formation of their botanical composition. Field studies have established diff erent eff ects of conventional in-line, cross-section and cross-sectional methods of sowing on the formation of botanical composition of grass mixtures of clover meadow (Trifolium pratense) varieties Sparta and Pavlyna with timothy meadow (Phleum pratense) and fenugreek multifl oral (Lolium multifl orum) and of agrophytocenoses of alfalfa of Sinyukha and Seraphima sowing varieties with reed fire (Festuca arundinacea Schreb) and middle wheatgrass (Elytrigia intermedia). For the average of four years of life of clover and alfalfa cereal crops agrophytocenoses, the highest proportion of legume component was observed with split-cross sowing – 51.6 % for Sparta, 53.1 % for Pavlyna, 60.3 % for Seraphima and 61.6 % for the Sinyukha variety. In the fourth year of life (the third year of use) of sowed leguminous-cereals agrophytocenoses, the preservation of the legume component was 14.6–15.5 % in clover-cereals grass mixtures with the Sparta variety and 16.0–16.8 % with the Pavlyna variety. In alfalfa grasslands, these indicators were 54.0–55.1 % with Seraphim and 55.0–56.2 % with Sinyukha. Among the studied varieties of clover meadow and alfalfa sowing proved better in the conditions of the Forest Steppe of western Pavlyna and Sinyukha. Cross-sectional and divided cross-sectional sowing of legumes and cereals mixtures proved to be better compared to conventional row crops in terms of conservation of economically valuable grass species. Key words: agrophytocenosis, botanical composition, clover meadow, alfalfa sowing, sowing methods.

scholarly journals Bark Characteristics of Scots Pine Logs

2020 ◽  
Vol 3 (1) ◽  
pp. 66
Author(s):  
Ferréol Berendt ◽  
Erik Pegel ◽  
Lubomir Blasko ◽  
Tobias Cremer
Keyword(s):  
Scots Pine ◽  
Tree Species ◽  
Waste Product ◽  
Mean Value ◽  
Bark Thickness ◽  
Water Displacement ◽  
Federal States ◽  
Bark Damage ◽  
Great Relevance ◽  
High Degree

The wood of Scots pine (Pinus sylvestris L.) shows good properties as building and construction timber but also as furniture or pulp and paper, and thus, is one of the most commercially important European tree species. Scots pine are mostly harvested and processed with a high degree of mechanization. In Northeast Germany (federal states of Brandenburg and Berlin), 36% of harvested Scots pine have a diameter at breast height (DBH) between 7 and 19.9 cm. As a typical industrial wood assortment, a large proportion of the resulting small-sized logs are used in the wood industry to produce boards. Although bark is considered a by-product or waste product of the industry, no actual study has quantified the bark thickness, bark volume, bark mass and bark damage of such Scots pine logs. Therefore, the bark characteristics from 50 logs from 10 different piles were analyzed. Bark volume was quantified using the water displacement method, bark mass by weighing, bark thickness with a precision caliper and bark damage by tape measurements. The diameters of the analyzed 150 log discs were normally distributed and the mean value was 12.9 cm. The results showed average bark damages from 12.0%, which were mostly caused during the felling and processing of logs with the harvester. No significant correlation was found between double bark thickness (mean: 3.0 mm) and the diameter; whereas fresh bark volume (mean: 5.6%) and dry bark mass (mean: 3.3%) were significantly affected by the diameter. As shown for spruce by other authors, bark characteristics may change over time and therefore, should be measured regularly. Moreover, it was shown that bark parameters are site dependent. Thus, quantifying bark characteristics for economically important tree species at both the local and national scale is of great relevance. More detailed analyzes are described by Berendt et al. (2021) [1].

scholarly journals Nutrient Analysis of Grass Species Consumed by Greater One-Horned Rhinoceros (Rhinoceros Unicornis) in Chitwan National Park, Nepal

2014 ◽  
Vol 2 (4) ◽  
pp. 402-408 ◽  
Author(s):  
S. Thakur ◽  
C.R. Upreti ◽  
K. Jha
Keyword(s):  
National Park ◽  
Mean Value ◽  
Grass Species ◽  
Systematic Sampling ◽  
Slight Variation ◽  
Sample Collection ◽  
Nutrient Analysis ◽  
Mean Values ◽  
Rhinoceros Unicornis ◽  
Chitwan National Park

The Greater One-horned Rhinoceros (Rhinoceros unicornis) is found almost exclusively in Nepal and North-Eastern India. There have beenonly a few studies made on the food and the nutrient compositions of fodder species preferred by The Greater One- horned Rhinoceros. Thepresent study identifies the nutrient content of the fodder species consumed by One-horned rhinoceros which would be helpful to develop proper strategies for rhinoceros food management. For this altogether 8 grass species which were most preferred by rhinoceros were collected from Chitwan National Park. Systematic sampling was applied for sample collection and collected samples were taken to the Animal Nutrition Laboratory, Khumaltar for nutrient analysis. Among all the collected species the highest OM% was seen in Faank (93.98 ± 0.88) while Ash% and CP% was found to be highest in Eragrastic Tenella (13.67 ± 2.92) and Phragmatic karka (11.94 ± 2.26) respectively. Lowest NDF% was again seen in Eragrastic tenella (76.76 ± 2.93) and lowest ADF% and ADL% were found in Mala dubo with mean values (43.50 ± 6.86) and (6.41 ± 2.16) respectively showing high digestibility of these grasses. There were only slight variation in the EE% of the grass species withhighest mean value of (3.702 ± 1.73) of Imperata cylindrical to lowest mean value of (1.722 ± 0.11) of Eragrastic tenella. Highest energy was found in Faank (4181.90 ±1.10) and Calcium content was seen highest in Cynodon dactylon (1.30 ± 0.83).DOI: http://dx.doi.org/10.3126/ijasbt.v2i4.11119 Int J Appl Sci Biotechnol, Vol. 2(4): 402-408 

Persistence of perennial ryegrass, tall fescue and cocksfoot following annual sowings: influence of grass species, ryegrass cultivar and pasture age on yield, composition and density

2021 ◽  
Vol 17 ◽  
Author(s):  
Tom Maxwell ◽  
Grant Edwards ◽  
Katherine Tozer ◽  
Gerald Cosgrove
Keyword(s):  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Grass Species ◽  
Botanical Composition ◽  
Release Date ◽  
Confounding Effect ◽  
Pasture Grass ◽  
Age Cohort ◽  
Tiller Density ◽  
Pasture Age

Persistence is an important component of perennial pasture-grass productivity. Defining traits that affect persistence is essential for improving pasture longevity through plant breeding and for identifying persistence traits that should be included in cultivar ranking indices. Compared with conventional longitudinal studies, where a single sowing is monitored over time, repeated annual sowings allow the effects on persistence of sowing year and the ensuing interactions between environment and age of pasture to be identified. An experiment was commenced in 2015 under sheep grazing in Canterbury and in 2016 under cattle grazing in Waikato, where eight cultivars of perennial ryegrass representing different ploidy, flowering date, and cultivar age (release date), and one cultivar each of tall fescue and cocksfoot were sown in four randomised complete blocks in autumn each year. This paper reports interim data on spring and autumn pasture yield, composition, and density of 3-year-old, 2-year-old and 1-year-old pastures exposed to the same environmental conditions within the same, single year. There were significant effects on yield, botanical composition, basal cover and tiller density due to cultivar, pasture age, and their interaction. When the confounding effect of year-to-year variation was removed by comparing each age cohort in the same year, the underlying differences among grass species and cultivars, and ages of pasture, is starting to reveal the nature of this influence on pasture persistence.

Respiration in the African Lungfish Protopterus Aethiopicus

1968 ◽  
Vol 49 (2) ◽  
pp. 437-452 ◽  
Author(s):  
CLAUDE LENFANT ◽  
KJELL JOHANSEN
Keyword(s):  
Gas Exchange ◽  
Haemoglobin Concentration ◽  
Temperature Shift ◽  
Mean Value ◽  
Gas Analysis ◽  
Air Exposure ◽  
Air Breathing ◽  
African Lungfish ◽  
High Degree ◽  
Protopterus Aethiopicus

1. Respiratory properties of blood and pattern of aerial and aquatic breathing and gas exchange have been studied in the African lungfish, Protopterus aethiopicus. 2. The mean value for haematocrit was 25%. Haemoglobin concentration was 6.2 g% and O2 capacity 6.8 vol. %. 3. The affinity of haemoglobin for O2 was high. P50 was 10 mm. Hg at PCOCO2, 6 mm. Hg and 25 °C. The Bohr effect was smaller than for the Australian lungfish, Neoceratodus, but exceeded that for the South American lungfish, Lepidosiren. The O2 affinity showed a larger temperature shift in Protopterus than Neoceratodus. 4. The CO2 combining power and the over-all buffering capacity of the blood exceeded values for the other lungfishes. 5. Both aerial and aquatic breathing showed a labile frequency. Air exposure elicited a marked increase in the rate of air breathing. 6. When resting in aerated water, air breathing accounted for about 90% of the O2 absorption. Aquatic gas exchange with gills and skin was 2.5 times more effective than pulmonary gas exchange in removing CO2. The low gas-exchange ratio for the lung diminished further in the interval between breaths. 7. Protopterus showed respiratory independence and a maintained O2 uptake until the ambient O2 and CO2 tensions were 85 and 35 mm. Hg respectively. A further reduction in O2 tension caused an abrupt fall in the oxygen uptake. 8. Gas analysis of blood samples drawn from unanaesthetized, free-swimming fishes attested to the important role of the lung in gas exchange and the high degree of functional separation in the circulation of oxygenated and deoxygenated blood.

scholarly journals Effects of leaf length and development stage on the triple oxygen isotope signature of grass leaf water and phytoliths: insights for a proxy of continental atmospheric humidity

2019 ◽  
Vol 16 (23) ◽  
pp. 4613-4625 ◽  
Author(s):  
Anne Alexandre ◽  
Elizabeth Webb ◽  
Amaelle Landais ◽  
Clément Piel ◽  
Sébastien Devidal ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Climate Model ◽  
Isotope Composition ◽  
Leaf Growth ◽  
Development Stage ◽  
Mean Value ◽  
Leaf Length ◽  
Leaf Water ◽  
Grass Species ◽  
Leaf Biomass

Abstract. Continental relative humidity (RH) is a key climate parameter, but there is a lack of quantitative RH proxies suitable for climate model–data comparisons. Recently, a combination of climate chamber and natural transect calibrations have laid the groundwork for examining the robustness of the triple oxygen isotope composition (δ′18O and 17O-excess) of phytoliths, that can preserve in sediments, as a new proxy for past changes in RH. However, it was recommended that besides RH, additional factors that may impact δ′18O and 17O-excess of plant water and phytoliths be examined. Here, the effects of grass leaf length, leaf development stage and day–night alternations are addressed from growth chamber experiments. The triple oxygen isotope compositions of leaf water and phytoliths of the grass species F. arundinacea are analysed. Evolution of the leaf water δ′18O and 17O-excess along the leaf length can be modelled using a string-of-lakes approach to which an unevaporated–evaporated mixing equation must be added. We show that for phytoliths to record this evolution, a kinetic fractionation between leaf water and silica, increasing from the base to the apex, must be assumed. Despite the isotope heterogeneity of leaf water along the leaf length, the bulk leaf phytolith δ′18O and 17O-excess values can be estimated from the Craig and Gordon model and a mean leaf water–phytolith fractionation exponent (λPhyto-LW) of 0.521. In addition to not being leaf length dependent, δ′18O and 17O-excess of grass phytoliths are expected to be impacted only very slightly by the stem vs. leaf biomass ratio. Our experiment additionally shows that because a lot of silica polymerises in grasses when the leaf reaches senescence (58 % of leaf phytoliths in mass), RH prevailing during the start of senescence should be considered in addition to RH prevailing during leaf growth when interpreting the 17O-excess of grass bulk phytoliths. Although under the study conditions 17O-excessPhyto do not vary significantly from constant day to day–night conditions, additional monitoring at low RH conditions should be done before drawing any generalisable conclusions. Overall, this study strengthens the reliability of the 17O-excess of phytoliths to be used as a proxy of RH. If future studies show that the mean value of 0.521 used for the grass leaf water–phytolith fractionation exponent λPhyto-LW is not climate dependent, then grassland leaf water 17O-excess obtained from grassland phytolith 17O-excess would inform on isotope signals of several soil–plant-atmosphere processes.

The value of faecal nitrogen and faecal crude fibre in estimating intake of four subtropical grass species

1957 ◽  
Vol 8 (4) ◽  
pp. 359 ◽  
Author(s):  
R Milford
Keyword(s):  
Dry Matter ◽  
Regression Line ◽  
Mean Value ◽  
The Other ◽  
Dry Matter Intake ◽  
Grass Species ◽  
Panicum Maximum ◽  
Crude Fibre ◽  
Common Mean ◽  
Faecal Nitrogen

For each four subtropical grasses there is a significant correlation between daily dry matter intake and total nitrogen in faeces per day. The data have been tested for homogeneity under two hypotheses. In the first a test of the difference in slope between the four regression lines showed that they were not statistically different. It was shown that for a common mean value for total faecal nitrogen, the calculated mean daily dry matter intakes of Paspalum commersonii Lam., Urochloa pullulans Stapf, and Chloris gayana Kunth were similar and the relationship for these three could be expressed by one regression line. However, the calculated mean daily dry matter intake for Panicum maximum var. trichoglume (K. Schum.) Eyles was significantly different from those for the other three grasses and P. maximum var. trichoglume cannot be included in a general regression. In the second hypothesis it was shown that all regression lines could pass through the origin. However, as in the first hypothesis, P. commersonii, U. pullulans, and C. gayana could be represented by a common regression line whllst the regression line for P. maximum differed significantly in slope from those of the other three grasses. The results indicate that species can be grouped for this relationship, and that it could be used to measure intake of the free grazing animal on monospecific swards or on mixed swards of species with similar relationships. Lancaster's technique for determining digestibility is discussed in the light of these relationships. Neither percentage faecal nitrogen nor faecal crude fibre was found to be satisfactorily correlated with dry matter digestibility.

The response to moisture and defoliation stresses, and traits for resilience of perennial grasses on the Northern Tablelands of New South Wales, Australia

2003 ◽  
Vol 54 (9) ◽  
pp. 903 ◽  
Author(s):  
S. P. Boschma ◽  
M. J. Hill ◽  
J. M. Scott ◽  
G. G. Rapp
Keyword(s):  
Festuca Arundinacea ◽  
Plant Biomass ◽  
Nitrogen Concentration ◽  
Perennial Grass ◽  
Basal Area ◽  
Perennial Grasses ◽  
Rooting Depth ◽  
Grass Species ◽  
Severe Drought ◽  
Moderate Drought

A field experiment was conducted to study the effects of defoliation and moisture stresses on perennial pasture grasses and to identify traits associated with their resilience. The experiment, conducted near Armidale on the Northern Tablelands of NSW, studied 4 introduced perennial grass species (Phalaris aquatica, Festuca arundinacea, Dactylis glomerata, and Lolium perenne) and 2 native grass species (Microlaena stipoides and Austrodanthonia richardsonii) subjected to 3 moisture regimes (non-stress moisture, moderate drought, and severe drought) and 2 defoliation intensities (severe and moderate). Basal area, herbage mass, phenological growth stage, nitrogen concentration, root mass, and rooting depth were compared over 2 independent 6-month periods: spring–summer (1 September 1994–28 February 1995) and summer–autumn (1 December 1994–31 May 1995). Multiple regression was used to determine which traits were important for determining plant resilience.The differences between species and their respective responses were evident in the traits measured. In general, basal area tended to increase over summer and show little change during autumn. Severe defoliation stimulated plant growth, resulting in higher harvested herbage mass than from those moderately defoliated. Reproductive development was suppressed by severe drought and reduced by moderate drought. Severe defoliation suppressed flowering of Dactylis and Lolium at both drought intensities, compared with moderate defoliation. Phalaris, Festuca, and Austrodanthonia were the deepest rooting species during spring–summer, and Dactylis the shallowest. All species had similar rooting depths during summer–autumn, with those under severe and moderate drought having the deepest and shallowest rooting, respectively.Carbohydrate reserves and basal area were important traits for determining plant resilience during spring–summer. During summer–autumn, maintaining basal area and plant biomass through moderate grazing was important for resilience.

The use of sheep fitted with oesophageal fistulas to measure diet quality

1964 ◽  
Vol 4 (12) ◽  
pp. 71 ◽  
Author(s):  
GW Arnold ◽  
WR McManus ◽  
IG Bush ◽  
J Ball
Keyword(s):  
Daily Intake ◽  
Sampling Period ◽  
Complete Recovery ◽  
Mean Value ◽  
Soluble Carbohydrates ◽  
Soluble Carbohydrate ◽  
Botanical Composition ◽  
Herbage Intake ◽  
Sources Of Variation ◽  
Sampling Procedures

Ewes and wethers with oesophageal fistulas were compared with normal sheep in several experiments over three years. The grazing behaviour, herbage intake, liveweight changes, and ability to bear and rear lambs were altered little by fistulation, provided fistulas were less than 5 cm in length and closure of the fistulas was good. This was so even at a relatively high stocking rate of G ewes to the acre. These findings infer that studies with fistulated sheep provide information validly applicable to normal sheep. Fistulas that allowed good closure control (<5 cm in length) did not always allow complete recovery of ingested material. However, with incomplete recovery representative diet samples were obtained. Sampling procedures for obtaining adequately representative diet samples for individual sheep, and for obtaining estimates of diet composition for flocks of sheep on different pastures were established. The routine that must be followed to avoid obtaining untrue diet samples is to sample sheep when they are accustomed to a pasture, without prior fasting, and at the time(s) of the day when sheep are normally grazing. An hour's sampling period will collect about l/l0th of the total daily intake and longer periods may cause rumen dysfunction. Pooling data from once-a-day samples for two successive days for an individual sheep seemed to give accurate values for the whole diet over those two days for sheep set stocked on pasture. Variation between-sheep, between-days, and within-days in the nitrogen and soluble carbohydrate content and botanical composition of extrusa samples was studied. The contribution of these sources of variation to total variation differed for different diet constituents. For nitrogen, between-sheep variation was greater than between-day variation but for soluble carbohydrates the position was reversed. Within-day variation was much the same as between-day variation in a constituent. The standard deviations of nitrogen and soluble carbohydrate contents and botanical composition were large and a true mean value for any of these parameters for a flock of sheep, could only be obtained by pooling data for several sheep on several successive days.

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