An Investigation Into the Accuracy of Herbivore Diet Analysis

1986 ◽  
Vol 13 (4) ◽  
pp. 559 ◽  
Author(s):  
RD Barker

A commonly used technique of herbivore diet analysis consists of grinding ingested material to homogenise the size of particles, extracting a sub-set of these by sieving, and then reconstructing the diet by counting the particles referable to various plant species. A set of experiments revealed that this technique is inaccurate because of variation between species in the number of particles produced per unit dry weight, in the proportion of these retained by the sieve, and in the proportion that could be identified. Thus the technique is badly flawed even without the added complication of differential digestibility, which in itself is shown to be considerable. Certain correction factors derived to cope with these effects are shown to be only partly successful.

1988 ◽  
Vol 15 (3) ◽  
pp. 249 ◽  
Author(s):  
GL Norbury

In an experiment with four captive eastern grey kangaroos, Macropus giganteus, microscopic analysis of both stomach contents and faeces did not reflect the ingested dry weight proportion of most plant species in a fed diet. However, close agreement was obtained by correcting for unidentifiable microscopic fragments of plants. This suggests that differential digestion may not be as important an artefact of microscopic diet analysis as previously reported. Provided corrections are made, faecal analysis may be as reliable as stomach content analysis for describing relative proportions of plant species in the diet of macropodids. In contrast, differences in proportions of plant species between stomach and faecal samples from free-ranging western grey kangaroos, Macropus fuliginosus, suggest that faecal analysis may not be suitable for quantitative studies of diet selection (comparisons of plant species proportions in the diet with species proportions in the field) in areas with heterogeneous vegetation. In these situations, samples of stomach contents are considered more appropriate.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 335
Author(s):  
Daniel Lizzi ◽  
Alessandro Mattiello ◽  
Alessio Adamiano ◽  
Guido Fellet ◽  
Emanuele Gava ◽  
...  

Most current studies on the relationships between plans and engineered nanomaterials (ENMs) are focused on food crops, while the effects on spontaneous plants have been neglected so far. However, from an ecological perspective, the ENMs impacts on the wild plants could have dire consequences on food webs and ecosystem services. Therefore, they should not be considered less critical. A pot trial was carried out in greenhouse conditions to evaluate the growth of Holcus lanatus L. (monocot) and Diplotaxis tenuifolia L. DC. (dicot) exposed to cerium oxide nanoparticles (nCeO2). Plants were grown for their entire cycle in a substrate amended with 200 mg kg−1nCeO2 having the size of 25 nm and 50 nm, respectively. nCeO2 were taken up by plant roots and then translocated towards leaf tissues of both species. However, the mean size of nCeO2 found in the roots of the species was different. In D. tenuifolia, there was evidence of more significant particle aggregation compared to H. lanatus. Further, biomass variables (dry weight of plant fractions and leaf area) showed that plant species responded differently to the treatments. In the experimental conditions, there were recorded stimulating effects on plant growth. However, nutritional imbalances for macro and micronutrients were observed, as well.


2014 ◽  
Vol 13 (6) ◽  
pp. 821-827
Author(s):  
Frackson Mumba ◽  
Vivien Mweene Chabalengula ◽  
Asiana Banda

This study compared male and female pre-service science teachers’ understanding of the effect of phase changes and physical transformation of matter on the size of particles, spaces between particles, speed of particles, and number of particles. Data were collected using a questionnaire that has 36 items. Both gender groups had sound understanding of the effect of phase change on speed, spaces, and number of particles in a substance, and the effect of compression on speed, number, size and spaces between particles in solids and liquids. However, most female pre-service teachers had low understanding of the effect of phase change on the size of the particles in solids, liquids and gases as most of them incorrectly believed that heating increases the size of the particles and cooling decreases the size of particles. The results have implications for science teaching and learning and teacher education. Key words: gender, matter, particle, pre-service teachers, understanding.


2016 ◽  
Vol 8 (1) ◽  
pp. 140-143
Author(s):  
J. V. Thaker ◽  
R. P. Kuvad ◽  
V. S. Thaker

Leaf area is an important parameter in physiology and agronomy studies. Linear models for leaf area measurement are developed for plant species as a nondestructive method. The plant Adhatoda vasica L. (a medicinal plant) was selected and the leaves of this plant were used for development of linear model for leaf area using Leaf Area Meter (LAM) software. Planimetric parameters (length, length2, width and width2) and gravimetric (dry weight and water content) parameters are considered for the development of linear model for this plant species. Single factor ANOVA and linear correlations were worked out using these parameters and leaf area. The plant was showed significant relationship with the parameters studied. The best correlation as represented by regression coefficient (R2) was used and improved R2 is worked out. It is observed that with increase in leaf area, water content is also increased and showed best correlation with the leaf area. Thus water content can be taken as a parameter for developing linear model for leaf area is concluded.


Pastura ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 33
Author(s):  
Roni N.G.K. ◽  
S.A. Lindawati

The productivity of forage depends on the availability of nutrients in the soil where it is grown, so fertilization to replace harvested produce is absolutely necessary. This study aims to study the response of gamal and indigofera forage on application of inorganic and organic fertilizers. Research using a completely randomized design factorial pattern of two factors, the first factor is the type of plant (G = Gamal; I = Indigofera) and the second factor is the type of fertilizer (T = without Fertilizer; A = Inorganic fertilizer NPK; K = commercial organic fertilizer; O = conventional organic fertilizer; B = bioorganic fertilizer), repeated 4 times so that it consists of 40 experimental units. The variables observed were plant height, number of leaves, stem diameter, leaf dry weight, stem dry weight, total dry weight of leaves, ratio of dry weight of leaves/stems and leaf area per pot. The results showed that there was no interaction between plant species and types of fertilizer in influencing the response of gamal and indigofera plants. Plant species have a significant effect on stem diameter, while fertilizer types have a significant effect on plant height, leaf dry weight, total dry weight of leaves and leaf area per pot. Based on the results of the study it can be concluded that the response of gamal plants is similar to indigofera, all types of fertilizers can improve the response of plants and organic fertilizers produce the same crop response with inorganic fertilizers. Keywords: gamal, indigofera, inorganic fertilizer, organic fertilizer


BIBECHANA ◽  
2018 ◽  
Vol 16 ◽  
pp. 41-46 ◽  
Author(s):  
Jyoti Rauniyaar ◽  
Girja Mani Aryal ◽  
Bhanu Bhakta Neupane

Air borne particulate matter (PM) depending on size, shape, concentration, and chemical composition can cause multitude of health issues. In this study, we report the morphological study of dust samples obtained from twenty different locations of Kathmandu valley by imaging the sample directly by a bright field optical microscope. We find that the average size of particles in all the samples examined below 10 micrometer. Individual examination of particles revealed that significant number of particles asymmetric. The observation of asymmetric particles having aspect ratio as high as 20 may suggest that asbestiform particles exist in all the dust samples examined.   BIBECHANA 16 (2019) 41-46


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Nikola Unković ◽  
Milica Ljaljević Grbić ◽  
Miloš Stupar ◽  
Jelena Vukojević ◽  
Vesna Janković ◽  
...  

A comprehensive comparative analysis of antifungal potential of benzalkonium chloride and newly synthesized fullerenol/benzalkonium chloride nanocomposite was conducted to assess the possible impact of carbon-based nanocarrier on antimicrobial properties of the commonly used biocide. Physical characterization of synthesized nanocomposite showed zeta potential of +37.4 mV and inhomogeneous particles size distribution, with nanocomposite particles’ dimensions within 30–143 nm and maximum number of particles at 44 nm. The effect of pure and fullerenol nanocarrier-bound biocide was evaluated in eightAspergillusspecies. In mycelial growth assay, nanocomposite was more potent, as fungicidal effect of 1.04/0.6 μg mL−1was obtained in all but one of the isolates (A. niger), while proportional concentration of pure biocide (0.6 μg mL−1) completely inhibited mycelial growth of only threeAspergillusspecies. However, conidia appear to be less susceptible to nanocomposite treatment, as lower fungistatic (MIC) and fungicidal (MFC) concentrations were obtained with biocide alone (MIC in range from 0.03 to 0.15 μg mL−1and MFC from 0.075 to 0.45 μg mL−1). To a different degree, both substances stimulated aflatoxin B1 production and inhibited ochratoxin A synthesis. Very low mycelium biomass yield, in range from 1.0 to 3.0 mg dry weight, was documented in both biocide and nanocomposite enriched medium.


1992 ◽  
Vol 70 (8) ◽  
pp. 1684-1688 ◽  
Author(s):  
Gaku Kudo

Leaf life-spans and specific leaf weights of four plant species, Phyllodoce aleutica, Rhododendron aureum, Sieversia pentapetala, and Potentilla matsumurae were compared along a gradient of decreasing snow-free duration in alpine snow beds. Life-span was obtained by observation from emergence to senescence for deciduous plants and was estimated from leaf age distributions for evergreen plants. Along the gradient, the evergreen shrubs Ph. aleutica and R. aureum had extended leaf life-spans, whereas the deciduous shrubs S. pentapetala and the deciduous herb Po. matsumurae had reduced leaf life-spans. Specific leaf weights, obtained by dry weight per unit leaf area, increased in Ph. aleutica but decreased in S. pentapetala and Po. matsumurae along the gradient. These phenomena are considered adaptive adjustments for maintaining a positive carbon balance under the conditions of limited photosynthetic season. Key words: alpine snow bed, carbon balance, deciduous plants, evergreen plants, leaf life-span, specific leaf weight.


2001 ◽  
Vol 19 (2) ◽  
pp. 65-68
Author(s):  
Sandra B. Wilson ◽  
Nihal C. Rajapakse

Abstract Plant response to photoselective plastic films with varying spectral distribution properties was tested using three sub-tropical perennials: golden shrimp plant (Pachystachys lutea), Persian shield (Strobilanthes dyerianus), and cat whiskers (Orthosiphon stamineus). Films were designated YXE-10 [far-red (FR) light-absorbing film] and SXE-4 [red (R) light absorbing film]. Light transmitted through YXE-10 films reduced plant height (stem length) of golden shrimp plant and cat whiskers by 10 and 20%, respectively. Light transmitted through SXE-4 films increased plant height by 9% for golden shrimp plant but did not significantly increase stem length of Persian shield and cat whiskers species. Chlorophyll, leaf area, and mean days to flower generally were not affected by photoselective films, with the exception that cat whisker plants grown under YXE-10 films had reduced leaf area when compared to plants grown under SXE-4 or control films. As compared to the control film, light transmitted through YXE-10 films reduced leaf dry weight by 22–31% and stem dry weight by 19–28%, depending on the plant species. Root dry weight was not affected by spectral films.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 458B-458 ◽  
Author(s):  
Jianjun Chen ◽  
Russell D. Caldwell ◽  
Cynthia A. Robinson ◽  
Bob Steinkamp

Silicon (Si) is the second most-abundant element in soils, and its concentration in soil solution ranges from 0.1 to 0.6 mm, which is the same concentration range as some of the major nutrient elements such as calcium, magnesium, phosphorus, and sulfur. Increasing evidence has recently suggested that Si plays important roles in improving plant growth. However, little information is available on Si effects on container-grown ornamental plants, particularly since most are grown in soilless media where Si sources are greatly limited. The objectives of this research were to evaluate Si absorption and translocation in diverse container-grown ornamental plants and to determine whether Si absorption could improve plant growth. Liners from 39 plant species were potted in peat and pine bark-based soilless media and grown in a shaded greenhouse. Plants were fertigated with a Peter's 24–8–16 water-soluble fertilizer containing 0, 50, and 100 mg·L–1 of Si. Once marketable sizes were reached, plants were harvested and fresh and dry weights determined; Si and other nutrient elements in roots and shoots were measured. Results indicated that 32 of the 39 evaluated species were able to absorb Si, with large quantities further transported to shoots. Of the 32 Si-responsive species, 17 showed significant dry weight increases, whereas the other 15 only exhibited Si absorption and translocation with no apparent growth responses. The seven non-responsive plant species showed no significant increases in neither Si absorption and translocation, nor dry weight.


Sign in / Sign up

Export Citation Format

Share Document