scholarly journals Comparison of seedling growth among three co-occurring varieties of Araucaria angustifolia (Bertol.) Kuntze under greenhouse conditions

2010 ◽  
Vol 24 (2) ◽  
pp. 567-570 ◽  
Author(s):  
André Luiz Coutinho ◽  
Lúcia Rebello Dillenburg
Keyword(s):  
Seedling Recruitment ◽  
Lateral Roots ◽  
The Other ◽  
Initial Growth ◽  
Seed Color ◽  
Araucaria Angustifolia ◽  
Southern Brazil ◽  
Main Root ◽  
Positive Effects ◽  
Mass Allocation

Araucaria angustifolia (Bertol.) Kuntze is a tall, long-lived tree species, which grows as an emergent tree in the araucaria forests of southern Brazil. Four varieties have been described for this species, and three of them were selected for this study: "angustifolia" (the type variety), "caiova" and "indehiscens". These are co-occurring varieties that differ in external seed color and timing of seed maturation. The purpose of this study was to compare the initial growth of plants originated from seeds of these three varieties, in order to test the hypothesis that these varieties also differ in the initial growth of their seedlings. Seeds were collected from a single forest location, and 60 plants per variety were grown in pots for a period of 244 days. The "angustifolia" variety accumulated significantly more mass (both in shoot and root) than the other two, but the three varieties did not differ in mass allocation between shoot and root and between lateral roots and the main root. The greater growth of the type variety may help explain its greater natural abundance, since attaining a larger size will have positive effects on seedling recruitment and survival.

scholarly journals INITIAL DEVELOPMENT OF FIVE TREE SPECIES NATIVE TO THE ATLANTIC FOREST IN RECOMPOSITION PLANTATIONS IN SOUTHERN BRAZIL

FLORESTA ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 070
Author(s):  
Charles Rodrigo Belmonte Maffra ◽  
Felipe Turchetto ◽  
Edison Bisognin Cantarelli
Keyword(s):  
Atlantic Forest ◽  
Tree Species ◽  
Native Species ◽  
Forest Restoration ◽  
The Other ◽  
Initial Growth ◽  
Araucaria Angustifolia ◽  
Economic Returns ◽  
Initial Development ◽  
Schizolobium Parahyba

The regularization of rural properties in the molds of the New Forest Code depends on the silvicultural study of the native species of the Brazilian biomes. The objective of this study was to evaluate the initial growth of five native tree species of the Atlantic Forest, with a view to their use in forest restoration projects. The following species were produced in the nursery, planted in the field, and evaluated for performance: Araucaria angustifolia, Mimosa scabrella, Trichilia claussenii, Schizolobium parahyba, and Cordia trichotoma. These species were distributed in two different areas, based on the randomized block experimental design. In experiment 1, the species A. angustifolia, M. scabrella, and C. trichotoma were distributed in three randomized blocks, each composed of 11 plants of each species. In experiment 2, the species A. angustifolia, M. scabrella, T. claussenii, and S. parahyba were distributed in three randomized blocks, each one composed of five plants of each species. In general, S. parahyba and M. scabrella showed faster development than the other species and, in this regard, are promising candidates for forest areas constitution or reconstitution in which there is interest in obtaining economic returns in less time. Araucaria angustifolia and T. claussenii showed relatively low development, whereas C. trichotoma showed intermediate development in relation to the other species studied. Despite their differences in performance, all species proved to be suitable for use in reforestation, mainly in the region where the study was developed.

Astrobiology and its influence on the renewal of the way we see the world from the teloempathic, educational and astrotheological perspective

2020 ◽  
Vol 19 (4) ◽  
pp. 330-334
Author(s):  
Octavio A. Chon Torres
Keyword(s):  
Natural Sciences ◽  
The Other ◽  
Positive Effects ◽  
The World ◽  
The Way

AbstractThere is a record of the positive effects of astrobiological research for the natural sciences and eventually for their technological use on Earth. However, on the philosophical effects, this is not as visible as the other sciences, which is why it can be assumed that it is a waste of time speculating on astrobioethics or also on the philosophy of astrobiology. This is the reason why this work seeks to identify and sustain the philosophical utility of astrobioethics. To achieve this, this article focuses on three essential aspects: teloempathy, education and astrotheology. Russell's argument about the value of philosophy will be used as a fundamental basis for the usefulness of astrobioethics.

scholarly journals The influence of two wildfires and biological control agents on the population dynamics of Melaleuca quinquenervia in a seasonally inundated wetland

2021 ◽  
Vol 14 (1) ◽  
pp. 3-8
Author(s):  
Philip W. Tipping ◽  
Melissa R. Martin ◽  
Jeremiah R. Foley ◽  
Ryan M. Pierce ◽  
Lyn A. Gettys
Keyword(s):  
Biological Control ◽  
Population Dynamics ◽  
Seedling Recruitment ◽  
Additional Treatment ◽  
Seed Rain ◽  
The Other ◽  
Melaleuca Quinquenervia ◽  
Biological Control Agents ◽  
Seedling Mortality ◽  
Sapling Growth

AbstractThe potential of Melaleuca quinquenervia (Cav.) S.T. Blake to reinvade cleared areas was evaluated over a 13-yr period that included two wildfires and the introduction of biological control agents. The first wildfire occurred in 1998 and was followed by a mean of 591.5 recruited seedlings m−2. Recruits from that fire were cleared 7 yr later in July 2005 for a second experiment to evaluate seedling recruitment into cleared areas. Seed rain, seedling recruitment and mortality, and sapling growth rates were measured in four plots located around individual large reproductive trees. A second natural wildfire in 2007 burned through those plots, leading to increases in seed rain followed by a pulse in recruitment of 21.04 seedlings m−2, 96.5% fewer than after the 1998 fire. Recruits in half of the plots around each tree were then treated with regular applications of an insecticide to restrict herbivory by biological control agents, while herbivory was not restricted in the other half. There was no difference in seedling mortality between treatments 1,083 d post-fire (2007) with 96.6% seedling mortality in the unrestricted herbivory treatment and 89.4% mortality in the restricted herbivory treatment. Recruits subjected to the restricted herbivory treatment grew taller than those in the unrestricted herbivory treatment, 101.3 cm versus 37.4 cm. Many of the recruits were attacked by the biological control agents, which slowed their growth. Although solitary M. quinquenervia trees retain some capacity to reinvade areas under specific circumstances, there was a downward trend in their overall invasiveness at this site, with progressively smaller recruitment cohorts due to biological control agents. Land managers should prioritize removing large reproductive trees over treating recently recruited populations, which can be left for many years for the biological control agents to suppress before any additional treatment would be needed.

scholarly journals Competition-free gaps are essential for the germination and recruitment of alpine species along an elevation gradient in the European Alps

Alpine Botany ◽  
2021 ◽  
Author(s):  
Vera Margreiter ◽  
Janette Walde ◽  
Brigitta Erschbamer
Keyword(s):  
Vegetation Cover ◽  
Seedling Recruitment ◽  
Environmental Control ◽  
Elevation Gradient ◽  
European Alps ◽  
Plant Interactions ◽  
Experimental Conditions ◽  
Positive Effects ◽  
Seed Sowing ◽  
Plant Plant

AbstractSeed germination and seedling recruitment are key processes in the life cycle of plants. They enable populations to grow, migrate, or persist. Both processes are under environmental control and influenced by site conditions and plant–plant interactions. Here, we present the results of a seed-sowing experiment performed along an elevation gradient (2000–2900 m a.s.l.) in the European eastern Alps. We monitored the germination of seeds and seedling recruitment for 2 years. Three effects were investigated: effects of sites and home sites (seed origin), effects of gaps, and plant–plant interactions. Seeds of eight species originating from two home sites were transplanted to four sites (home site and ± in elevation). Seed sowing was performed in experimentally created gaps. These gap types (‘gap + roots’, ‘neighbor + roots’, and ‘no-comp’) provided different plant–plant interactions and competition intensities. We observed decreasing germination with increasing elevation, independent of the species home sites. Competition-released gaps favored recruitment, pointing out the important role of belowground competition and soil components in recruitment. In gaps with one neighboring species, neutral plant–plant interactions occurred (with one exception). However, considering the relative vegetation cover of each experimental site, high vegetation cover resulted in positive effects on recruitment at higher sites and neutral effects at lower sites. All tested species showed intraspecific variability when responding to the experimental conditions. We discuss our findings considering novel site and climatic conditions.

scholarly journals Weaning Holstein Calves at 17 Weeks of Age Enables Smooth Transition from Liquid to Solid Feed

Animals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1132
Author(s):  
Sarah Schwarzkopf ◽  
Asako Kinoshita ◽  
Jeannette Kluess ◽  
Susanne Kersten ◽  
Ulrich Meyer ◽  
...  
Keyword(s):  
Metabolic Stress ◽  
Live Weight ◽  
The Other ◽  
Smooth Transition ◽  
Blood Metabolites ◽  
Positive Effects ◽  
Weaning Age ◽  
Holstein Calves ◽  
Positive Effect ◽  
Over Time

Development of calves depends on prenatal and postnatal conditions. Primiparous cows were still maturing during pregnancy, which can lead to negative intrauterine conditions and affect the calf’s metabolism. It is hypothesized that weaning calves at higher maturity has positive effects due to reduced metabolic stress. We aimed to evaluate effects of mothers’ parity and calves’ weaning age on growth performance and blood metabolites. Fifty-nine female Holstein calves (38.8 ± 5.3 kg birth weight, about 8 days old) were used in a 2 × 2 factorial experiment with factors weaning age (7 vs. 17 weeks) and parity of mother (primiparous vs. multiparous cows). Calves were randomly assigned one of these four groups. Live weight, live weight gain and morphometry increased over time and were greater in calves weaned later. Metabolic indicators except total protein were interactively affected by time and weaning age. Leptin remained low in early-weaned calves born to primiparous cows, while it increased in the other groups. The results suggest that weaning more mature calves has a positive effect on body growth, and calves born to primiparous cows particularly benefit from this weaning regimen. It also enables a smooth transition from liquid to solid feed, which might reduce the associated stress of weaning.

scholarly journals Effect of Different Antimicrobial Applications on Color Stability of Ground Pork

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
H. D. Garnica ◽  
M. F. Miller ◽  
D. A. Vargas ◽  
A. R. English ◽  
K. E. Hanlon ◽  
...  
Keyword(s):  
Peracetic Acid ◽  
Storage Period ◽  
Color Stability ◽  
The Other ◽  
Color Analysis ◽  
B Values ◽  
Positive Effects ◽  
Ph Values ◽  
Ground Pork ◽  
Hue Angle

ObjectivesThe purpose of the study was to evaluate color changes during dark storage of ground pork following application with one of three different antimicrobial interventions to pork trim.Materials and MethodsTreatments included a control (no antimicrobial), lactic acid (LA; 3%), PAA+Titon [sulfuric acid and sodium sulfate (pH 1.3) combined with peracetic acid (350 ppm)], PAA+Acetic [peracetic acid (400 ppm) with 2% acetic acid]. Four 22.7-kg batches of pork trim were treated with one intervention, ground [coarse (3/16’’) followed by a fine (1/8”) grind] and packaged in 454-g rollstock vacuum packaging (n = 40/treatment). After random assignment to an aging time (0, 7, 14, 21, or 28 d), product was held under dark storage at 2–4°C. On each storage day, samples (n = 8/treatment) were opened and L*, a*, and b* values were taken using a HunterLab Miniscan XE spectrophotometer at 0 min, 10 min, and 20 min for bloom color analysis, with hue angle [arctangent (b*/a*)] and chroma [ (a* + b*)1/2 ] calculated from a* and b* values. For pH, 5 g of sample and 90 mL of distillated water were homogenized and analyzed with a bench top pH probe. Finally, fat, moisture, and protein percentage were determined using a FOSS FoodScan. Statistical analysis was conducted using the GLM procedure of SAS with a means separation using the Tukey adjustment and significance set at P < 0.05.ResultsProximate analysis of the ground pork in this study showed 20.04 ± 1.13% for fat, 61.15 ± 1.11% for moisture, and 16.83 ± 0.39% for protein content. For initial pork color, at 0 min, LA had greater L* values compared to PAA+Titon at 0d, 7d and 14d (P < 0.05), but no treatment differences were detected in L* values at 21d and 28d (P > 0.05). After 10 min of bloom time, PAA+Titon maintained the highest chroma value throughout all aging days (P < 0.05) demonstrating the most color intensity. At 21d PAA+Titon increased blooming properties through 20min (P < 0.05), based on a*, while control samples had no bloom development (P > 0.05). At 21d and 28d aging LA hue angle was highest (P < 0.05) indicating more potential metmyoglobin discoloration. PAA+Titon presented the highest pH values compared to all the other treatments for each day during the storage period except for Day 14, while LA presented lower values compared to all the other treatments for each day (P < 0.05).ConclusionAs an organic acid application on pork trim prior to grinding, PAA+Titon demonstrates positive effects on color of ground pork based on color and pH values, after post-grinding storage.

scholarly journals Influence of Root Morphology on Ecological Slope Protection

2020 ◽  
Vol 198 ◽  
pp. 04036
Author(s):  
JI Xiaolei ◽  
XU Lanlan ◽  
YANG Guoping
Keyword(s):  
Root Morphology ◽  
Lateral Root ◽  
Lateral Roots ◽  
Soil Mass ◽  
Soil Reinforcement ◽  
Main Root ◽  
Protection Effect ◽  
Included Angle ◽  
Theoretical Support ◽  
Object Based

Ecological slope protection is of great importance for preventing the water and soil loss on bare slopes, improving the ecological environment, and realizing the sustainable ecosystem development. The root-soil composite slope consisting of homogenous soil mass and oleander root system was taken as the study object. Based on the mechanics principle of soil reinforcement by roots in ecological slope protection, the influences of the lateral root quantity of plants and included angle between main root and lateral root on the slope protection were investigated via the finite element (FE) software ABAQUS. The simulation results show that the larger the quantity of lateral roots, the more obvious the displacement reduction of the soil mass on the slope surface will be. The slope protection effect varies with the root morphology, the included angle between main root and lateral root is an important factor influencing the slope protection effect of plants, and the slope protection effect at included angle of 30° is apparently superior to that at 90°. The research results can provide a theoretical support for the plant selection in the ecological slope protection.

Biometric relationships of the Argentinean prawn Artemesia longinaris (Decapoda: Penaeidae) in the south-western Atlantic

2010 ◽  
Vol 90 (7) ◽  
pp. 1385-1393 ◽  
Author(s):  
L.F.C. Dumont ◽  
F. D'Incao
Keyword(s):  
Population Structure ◽  
Marked Reduction ◽  
The Other ◽  
Distribution Area ◽  
Southern Brazil ◽  
Simple Linear Regression ◽  
The South ◽  
Western Atlantic ◽  
Relative Growth ◽  
Autumn And Winter

Biometric relationships of size and weight were estimated for the Argentinean prawn (Artemesia longinaris), a new commercial penaeid prawn exploited in the south-western Atlantic. Morphometric and meristic traits were used to elucidate population structure of this species along its distribution area. The morphological relationships were estimated by a simple linear regression, considering total length (TL) as the dependent variable. The males collected in southern Brazil, an area under influence of the Subtropical Convergence, presented a slightly lower TL increment than females. A marked reduction in slopes of males between populations from southern Brazil was observed in autumn and winter. Additionally, relative growth in length of males from Argentina is similar to that observed during autumn and winter in southern Brazil. The other morphometric and meristic variables used also indicated higher similarities between southern Brazil and Argentina, which may be explained by relative growth associated to water temperatures or migration during winter, taking advantage of the oceanographic systems connecting both sites. Moreover, the population from Rio de Janeiro seems morphologically apart from the others, forming a separate unit stock.

The effects of burning, fertilizing and clipping on populations of Aristida armata, Thyridolepis mitchelliana and Monachather paradoxa in a mulga woodland pasture.

1986 ◽  
Vol 8 (1) ◽  
pp. 4 ◽  
Author(s):  
RF Brown
Keyword(s):  
Seedling Recruitment ◽  
Perennial Grasses ◽  
The Other ◽  
Dry Period ◽  
Seedling Regeneration ◽  
Nitrogenous Fertilizer ◽  
Drought Tolerant ◽  
Acacia Aneura ◽  
A Minor ◽  
Permanent Quadrats

The effects of burning, clipping, applying nitrogenous fertilizer, and protection from grazing on populations of three perennial grasses were monitored over four years in permanent quadrats in a mulga (Acacia aneura) woodland pasture near Charleville. Queensland. The grasses were the weedy invader Aristida armata (wiregrass), and two desirable species, Thyridolepis mitchelliana (mulga grass) and Monachather paradoxa (mulga oats). They comprised 70%, 16%, and 12%. respectively, of the pasture at the start of the experiment. Rainfall had a greater effect on plant numbers. especially of A. armata, than any treatment other than repeated clipping. The greatest mortality amongst A. armata plants occurred during a protracted dry period between March 1982 and April 1983 but the losses were more than compensated by mass germination during April 1983. The other two species responded similarly but less markedly. Repeated clipping caused attrition of all three species but failed to improve pasture composition. Pasture recovery after burning was slow and accompanied by a minor deterioration in pasture composition as measured by the proportion of A. armata plants. Burning caused greater mortality in A. armata plants than in the other two species but this was offset by greater A. armata seedling regeneration. Both initial survival and subsequent seedling recruitment were reduced by slashing a week prior to burning. When left ungrazed. T mitchelliana and M. paradoxa were more drought tolerant than A. armata and their relative numbers in the ungrazed plots increased over the four years of the experiment. Thus, protection from grazing offers the best prospect of improving pasture condition as none of the other treatments reduced A. armata numbers without adversely affecting those of T. mitchelliana and M. paradoxa.

scholarly journals Using Goals to Motivate College Students: Theory and Evidence From Field Experiments

2020 ◽  
Vol 102 (4) ◽  
pp. 648-663 ◽  
Author(s):  
Damon Clark ◽  
David Gill ◽  
Victoria Prowse ◽  
Mark Rush
Keyword(s):  
College Students ◽  
Loss Aversion ◽  
Field Experiments ◽  
Theoretical Framework ◽  
The Other ◽  
Task Completion ◽  
Course Performance ◽  
Positive Effects ◽  
Present Bias

Will college students who set goals work harder and perform better? We report two field experiments that involved four thousand college students. One experiment asked treated students to set goals for performance in the course; the other asked treated students to set goals for a particular task (completing online practice exams). Task-based goals had robust positive effects on the level of task completion and marginally significant positive effects on course performance. Performance-based goals had positive but small and statistically insignificant effects on course performance. A theoretical framework that builds on present bias and loss aversion helps to interpret our results.

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