scholarly journals Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3591 ◽  
Author(s):  
Tineke Kraaij ◽  
Richard M. Cowling ◽  
Brian W. van Wilgen ◽  
Diba R. Rikhotso ◽  
Mark Difford
Keyword(s):  
Floristic Composition ◽  
Fire Season ◽  
Summer Drought ◽  
Winter Rainfall ◽  
Recruitment Success ◽  
Floral Diversity ◽  
Four Seasons ◽  
Different Seasons ◽  
Varied Response ◽  
One Year

Season of fire has marked effects on floristic composition in fire-prone Mediterranean-climate shrublands. In these winter-rainfall systems, summer-autumn fires lead to optimal recruitment of overstorey proteoid shrubs (non-sprouting, slow-maturing, serotinous Proteaceae) which are important to the conservation of floral diversity. We explored whether fire season has similar effects on early establishment of five proteoid species in the eastern coastal part of the Cape Floral Kingdom (South Africa) where rainfall occurs year-round and where weather conducive to fire and the actual incidence of fire are largely aseasonal. We surveyed recruitment success (ratio of post-fire recruits to pre-fire parents) of proteoids after fires in different seasons. We also planted proteoid seeds into exclosures, designed to prevent predation by small mammals and birds, in cleared (intended to simulate fire) fynbos shrublands at different sites in each of four seasons and monitored their germination and survival to one year post-planting (hereafter termed ‘recruitment’). Factors (in decreasing order of importance) affecting recruitment success in the post-fire surveys were species, pre-fire parent density, post-fire age of the vegetation at the time of assessment, and fire season, whereas rainfall (for six months post-fire) and fire return interval (>7 years) had little effect. In the seed-planting experiment, germination occurred during the cooler months and mostly within two months of planting, except for summer-plantings, which took 2–3 months longer to germinate. Although recruitment success differed significantly among planting seasons, sites and species, significant interactions occurred among the experimental factors. In both the post-fire surveys and seed planting experiment, recruitment success in relation to fire- or planting season varied greatly within and among species and sites. Results of these two datasets were furthermore inconsistent, suggesting that proteoid recruitment responses are not related to the season of fire. Germination appeared less rainfall-dependent than in winter-rainfall shrublands, suggesting that summer drought-avoiding dormancy is limited and has less influence on variation in recruitment success among fire seasons. The varied response of proteoid recruitment to fire season (or its simulation) implies that burning does not have to be restricted to particular seasons in eastern coastal fynbos, affording more flexibility for fire management than in shrublands associated with winter rainfall.

Analysis of Influencing on the Ground Calibration for PIG Based on Seasons

2014 ◽  
Vol 609-610 ◽  
pp. 1207-1212
Author(s):  
Hong Liu ◽  
Xiao Peng Song ◽  
Guo Jun Zhang ◽  
Meng Ran Liu ◽  
Ze Ming Jian
Keyword(s):  
Orientation Angle ◽  
Vector Sensor ◽  
Four Seasons ◽  
Different Seasons ◽  
Dry Soil ◽  
The Difference ◽  
One Year ◽  
The Impact ◽  
Experiment Analysis ◽  
Ground Calibration

In order to achieve accurate positioning of the detector in the pipeline, explore the affection of the different seasons and soil moisture on the ground calibration, then ground marking studies by MEMS acoustic vector sensor is proposed. To select four seasons in one year to do comparative experiment, analysis the signals and drawn the angle table. Secondly, we select the most accurate period, to research the impact of the dry soil and wet soil. The results show that: The result of direction on Autumn is the most accurate season, the difference between angle of the measurement point and the true angle can be achieve to 1.051 degrees; On Winter, the relative error is the largest, the orientation angle is the most inaccurate; it is more accurate when the soil is dry than it in wet soil. Far-reaching meaning has been provided in this research.

Delayed emergence and post-fire recruitment success: effects of seasonal germination, fire season and dormancy type

2010 ◽  
Vol 58 (4) ◽  
pp. 248 ◽  
Author(s):  
Mark K. J. Ooi
Keyword(s):  
Seedling Survival ◽  
Seedling Emergence ◽  
Fire Season ◽  
Recruitment Success ◽  
Emergence Patterns ◽  
Physiological Dormancy ◽  
Delayed Emergence ◽  
Population Comparisons ◽  
Different Seasons ◽  
The Impact

Delayed seedling emergence can negatively affect plant recruitment. Recent work has shown that some species with innate seasonal requirements for germination can have seedling emergence delayed, depending on the season of fire. The impact of this delay, which is in relation to both resprouters and seedlings of species that emerge independent of season, remains unknown. I assessed delayed emergence and subsequent impacts on post-fire recruitment success of three Leucopogon species, which all display a seasonal emergence pattern related to their physiological dormancy. Intra-population comparisons showed that both small (1–6 months) and much larger (12–15 months) delays of emergence reduced seedling survival and growth, and increased the time taken for plants to reach maturity. Fire season induced delays produced very similar results, with higher mortality and slower growth after winter fires compared with post-summer fire cohorts. Seasonal emergence patterns, associated with seed dormancy and germination cues, may therefore provide a mechanism that determines the variation of recruitment success after fires in different seasons. A better understanding of the relationship between fire season and timing of emergence of physiologically dormant species would be timely considering the forecast widening of the fire season due to climate change.

Shooting and Rooting Behaviour in Relation to Season, Age and Growing Conditions of Dendrocalamus asper Backer

2020 ◽  
Vol 27 (1) ◽  
pp. 56-60
Author(s):  
Reena Joshi ◽  
Salil Tewari ◽  
Rajesh Kaushal
Keyword(s):  
Summer Monsoon ◽  
Block Design ◽  
Research Centre ◽  
Agroforestry Research ◽  
Randomized Block Design ◽  
Different Seasons ◽  
Dendrocalamus Asper ◽  
Growing Conditions ◽  
One Year ◽  
Effect Of Age

The experiment was conducted at Agroforestry Research Centre, of G. B. Pant University of Agriculture and Technology, Pantnagar to assess the effect of age (one and two year old), growing condition (intermittent misting and no misting) and different seasons (summer, monsoon, autumn and spring) on rooting and shooting of culm cuttings of Dendrocalamus asper. The experiment was laid out in factorial randomized block design with three replications. The findings indicated that in D. asper, one year old culm cuttings in the intermittent misting condition showed good results. The findings also indicated that shooting and rooting per cent of culm cuttings planted in different season showed response as Spring (March)> Summer (June)> Monsoon (August)> Autumn (October).

SEASONAL VARIATIONS IN THE CHEMICAL COMPOSITION OF GRASSES HARVESTED FROM THE NATURAL PASTURE IN OGUN STATE SOUTH-WESTERN NIGERIA

2021 ◽  
Vol 20 (1) ◽  
pp. 65-77
Author(s):  
O. A. OKUKENU ◽  
B. T. AKINYEMI ◽  
P. A. DELE ◽  
A. A. OLAJIDE ◽  
A.O. JOLAOSHO ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Rainy Season ◽  
Crude Protein ◽  
P Value ◽  
Ogun State ◽  
Natural Pasture ◽  
Four Seasons ◽  
Acid Detergent Fibre ◽  
Different Seasons ◽  
Dominant Grasses

The research was carried was carried out to evaluate the chemical composition of the dominant grasses harvested from the natural pasture in selected villages in Ogun State, South-western Nigeria at different seasons. The study was carried out using a 4 × 6 factorial arrangement comprising four seasons (early rain, late rain, early dry and late dry) at six locations (Afami, Atokun, Ibooro, Ileniku, Ipaaya, and Okerori). Results showed that the crude protein (CP) content significantly (p<0.05) varied from 5.56 % for Okerori to 7.34 % for Ibooro and the grasses harvested at Afami had the highest (72.75 %) neutral detergent fibre (NDF) values with the least (68.75 %) value recorded for Okerori, while the acid detergent fibre (ADF) values ranged from 41.00 % for Atokun to 48.25 % for Okerori. Also, CP value as affected by the season ranged from 4.23 % for late rainy to 9.44 % for the early rainy season and NDF values from 67.33% for late dry to 72.33 % for late rainy season while the early dry season had the highest value (48.00 %) for ADF with the least value (40.33 %) was recorded for the early rainy season. The phosphorus (P) value was highest at Ipaaya (2.99 g/kg) with the least value observed at Okerori (1.62 g/kg). The value for calcium ranged from 2.55 g/kg at Afami to 6.59 g/kg at Okerori. The P value of grasses as affected by seasons ranged from 1.46 g/kg for early dry to 2.66 g/kg for early rainy seasons.

scholarly journals Short-term community dynamics in seasonal and hyperseasonal cerrados

2009 ◽  
Vol 69 (2) ◽  
pp. 231-240 ◽  
Author(s):  
MV. Cianciaruso ◽  
MA. Batalha
Keyword(s):  
Rainy Season ◽  
Community Dynamics ◽  
Plant Density ◽  
Floristic Composition ◽  
Species Density ◽  
Environmental Filters ◽  
Floristic Similarity ◽  
Different Seasons ◽  
Cylindrical Volume ◽  
Vegetation Form

In South America, the largest seasonal savanna region is the Brazilian cerrado. Our aim was to study temporal changes in some community descriptors, such as floristic composition, richness, species density, plant density, and cylindrical volume, in a seasonal cerrado, comparing it to a nearby hyperseasonal cerrado. In four different seasons, we placed randomly ten 1 m² quadrats in each vegetation form and sampled all the vascular plants. Seasonal changes in floristic composition, species density, and plant density were less pronounced in the seasonal than in the hyperseasonal cerrado. Floristic similarity between the vegetation forms was lower when the hyperseasonal cerrado was waterlogged. Richness and species density were higher in the seasonal cerrado, which reached its biomass peak at mid rainy season. The hyperseasonal cerrado, in turn, reached its biomass peak at early rainy season and, despite the waterlogging, maintained it until late rainy season. In the hyperseasonal cerrado, waterlogging acts as an environmental filter restricting the number of cerrado species able to withstand it. The seasonal cerrado community was more stable than the hyperseasonal one. Our results corroborated the idea that changes in the environmental filters will affect floristic composition and community structure in savannas.

scholarly journals Ruderal succession starting at different seasons

2014 ◽  
Vol 55 (3) ◽  
pp. 403-419 ◽  
Author(s):  
Reinhard Bornkamm
Keyword(s):  
Poa Pratensis ◽  
Floristic Composition ◽  
Clayey Loam ◽  
First Year ◽  
Conyza Canadensis ◽  
Senecio Vulgaris ◽  
Different Seasons ◽  
Winter Annual ◽  
Second Year ◽  
Different Soils

Succession experiments were carried out in 1 m<sup>2</sup> sized plots on three different soils (S = sand. SCL = silty clayey loam, CL = clayey loam). Vegetation was allowed to grow for 9 years, starting at different dates between 18.06.1969 and 1.04.1971. The greatest part of the variation of floristic composition and cover was brought about by the different soils. Direct effects of the starting season were detected only in the first two years. On sand in the first year the winter annual <em>Conyza canadensis</em> was well developed on the plots that had started in spring, but was poorly developed on the summer and fall plots. In the second year it decreased in the spring plots but increased in the summer and fall plots. The same was true for the winter annual <em>Sonchus asper</em> on CL. On SCL, however., <em>Senecio vulgaris</em>, belonging to the therophyta epeteia (overwintering in summer habit), was well developed in both the spring and summer plots, and showed an increase towards the second year in the fall plots only. In the later years of the experiment plots that had been started early in the year mostly were dominated by <em>Poa pratensis</em> ssp. <em>angustifolia (or Quercus rubra)</em>, whereas plots that had been started late in the year mostly were dominated by <em>Solidagn canadensis</em> together with <em>Artemsia vulgaris</em>. The analyses of the transition events between the (sub)dominant species showed a variety of replacement patterns, but no determinated series of species following each other. It remains, therefore, unclear in what manner the differentiation between the terminal dominants may be related to the starting season.

scholarly journals The effect of four commercial broiler hybrids and the season on occurrence of broiler condemnations in the abattoirs

2020 ◽  
Vol 50 (10) ◽  
Author(s):  
Antonise Mariely Jaguezeski ◽  
Ana Martiele Engelmann ◽  
Ivna Nalério dos Reis Machado ◽  
Beatriz Pavei Bez Batti
Keyword(s):  
Financial Impact ◽  
Welfare Programs ◽  
Conviction Rate ◽  
Commercial Broiler ◽  
Different Seasons ◽  
Time Of Year ◽  
One Year ◽  
The One ◽  
Inspection Service ◽  
Abattoir Data

ABSTRACT: Condemnations in the broilers abattoirs can represent an overview farms health and effectiveness of welfare programs, as well as predisposition between hybrids. The aim of this study was to investigate the prevalence of condemnation among four commercial broiler hybrids and the oscillation of condemnations in different seasons in a poultry abattoir. Data from condemnations of the Federal Inspection Service of a slaughterhouse were analyzed during one year, in which a total of 12.81% of partial condemnations were observed and total condemnations represented 0.41% of slaughtered broiler. There was a difference in total and partial condemnation among the hybrids evaluated, with Hubbard hybrid being the one with the highest number of condemnations (0.67% - 17.71%), followed by Ross 95 (0.42% - 14.21%), Cobb (0.30% - 10.03%); and Cobb Fast (0.26% - 9.29%). The analysis between the seasons showed a higher conviction rate in winter and a lower rate in autumn for both total and partial condemnation. Hubbard had the highest rates and Cobb Fast the lowest for most causes of condemnation. We concluded that the metabolic cause led to higher losses by total condemnation, while contamination or technopathies represented the highest rates in partial losses. The broiler hybrid and the time of year may influence the causes of condemnation in the abattoir. This information should be considered by the abattoir and the farms in sanitary planning, considering the financial impact due to losses by condemnations of carcasses.

scholarly journals Conversion of Pinus nigra Plantations with Natural Regeneration in the Slovenian Karst: The Importance of Intermediate, Gradually Formed Canopy Gaps

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1136
Author(s):  
Jurij Diaci ◽  
Tomaž Adamič ◽  
Andrej Rozman ◽  
Gal Fidej ◽  
Dušan Roženbergar
Keyword(s):  
Natural Regeneration ◽  
Soil Depth ◽  
Pinus Nigra ◽  
Quercus Petraea ◽  
Summer Drought ◽  
Natural Disturbances ◽  
Site Factors ◽  
Insect Infestations ◽  
One Year ◽  
Ostrya Carpinifolia

Since the mid-19th century, Pinus nigra plantations have played a key role in the restoration of degraded European landscapes. Nowadays, these plantations are aging and prone to natural disturbances, insect infestations, and diseases. For their successful gradual conversion, knowledge of optimal gap spatiotemporal dynamics is crucial. We studied herb and natural regeneration patterns along with site factors on 477 subplots within 44 plots distributed over four stand types: closed stand (14% diffuse light), open stand (21%), gap edge (23%), and gap (57%). Despite the abundant Quercus petraea, Q. cerris, and Q. pubescens mast year, no one-year seedlings were recorded, which is likely due to the summer drought. Short seedlings (h < 20 cm) of Quercus sp., Fraxinus ornus and Ostrya carpinifolia were more successful within closed stands. Short Quercus seedlings were positively associated with soil depth and negatively associated with soil nutrients, distance to seed trees, and Sesleria autumnalis coverage. Taller Quercus seedlings required more light than both of its strongest competitors and were positively related to humid soils and less rocky sites. Ungulate overbrowsing significantly impeded natural regeneration. The results indicate a satisfactory Quercus density for conversion and the importance of advanced regeneration, which should be gradually, but persistently, released by progressively widening gaps.

scholarly journals Growth of escarole in different seasons of year, RS, Brazil

2018 ◽  
Vol 39 (2) ◽  
pp. 455
Author(s):  
Daniele Cristina Fontana ◽  
Braulio Otomar Caron ◽  
Denise Schmidt ◽  
Daniela Meira ◽  
Thais Pollon Zanatta ◽  
...  
Keyword(s):  
Block Design ◽  
Global Radiation ◽  
Technical Information ◽  
Dry Mass ◽  
Four Seasons ◽  
Randomized Complete Block Design ◽  
Different Seasons ◽  
Crop Cycle ◽  
Number Of Leaves ◽  
Santa Maria

The lack of research about escarole cultivars adapted to each region, as well as technical information on plant growth have been some of the factors related to low yields. Therefore, the aim of this work was to evaluate the growth of escarole crop in four seasons of year in Santa Maria, RS. The experiment was conducted in a randomized complete block design, 1 x 4, being a escarole (cultivar Escorola Lisa®) evaluated in four seasons of year (summer, autumn, winter and spring), in six replications. The evaluations were performed in a destructive manner every seven days, from date of transplant to harvest point. The following components were analyzed: number of leaves, number of residues, dry mass of leaves, dry mass of leaves, stem and residue. Thus, it was determined the parameters for growth analysis. With the data obtained, we performed a variance analysis, and presented significant results, and the means of each season of the year submitted to the Tukey test at 5% of error probability. The air temperature and global radiation influence crop cycle. Lower temperatures and lower incidence of radiation result in cycle extended, as observed in autumn. The escarole growth is influenced by seasons of year in Rio Grande do Sul (RS), and summer and spring finish the cycle in advance to others, presenting a larger leaf area. Summer and spring are most indicated season to escarole crop in RS, Brazil.

Simple Techniques for Monitoring Footpath Erosion in Mountain Areas of North-West England

1977 ◽  
Vol 4 (2) ◽  
pp. 145-148 ◽  
Author(s):  
Rosalind A. Coleman
Keyword(s):  
Aerial Photography ◽  
Technical Expertise ◽  
Short Term ◽  
Mountain Areas ◽  
North West ◽  
Different Types ◽  
Different Seasons ◽  
One Year ◽  
Site Types

Very precise measurements of the movement of coarse-textured, unconsolidated materials may be meaningless. Therefore the study of individual processes operating on footpaths may require a different approach. However, for identification of changes of reasonable dimensions, methods such as those described above are inexpensive, quick, and require no technical expertise. It may be argued that, for path management, erosion that is too limited to be measured by these methods is too limited to be a problem. It can certainly be argued that the problem of spatial correlation implies a large number of measurements. What is lost in lack of precision may be more than compensated for by the gain in data from the larger area and wider variation in site-types that it is possible to monitor with such simple techniques.To monitor the effects of recreation in mountain areas, it is desirable to be able to measure any change in path-state and relate this to recreation factors at different seasons and under different sit; -conditions. Three methods of measurement have been considered in this paper, corresponding to three time-scales. Aerial photography has been used to demonstrate trends over the long term, and has proved adequate to differentiate between path sections with differing resistance to erosion.Short-term measurement has been carried out relative to known fixed positions. Two methods are suggested. One is less precise, but simple and widely applicable, and can be used for measurement intervals of six months to one year. The other is more detailed and can be used for measurement intervals of a few days, but is limited in its application by practical considerations.It is suggested that simple techniques used at a large number of different types of site may be more effective than detailed measurements at a few sites.

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