Germination of Piptochaetium Napostaense (Speg.) Hackel and Stipa Tenuis Phil. And Seedling Survival Under Field Conditions.

1992 ◽  
Vol 14 (1) ◽  
pp. 49 ◽  
Author(s):  
RA Distel ◽  
DV Pelae ◽  
OA Fernandez
Keyword(s):  
High Temperatures ◽  
Seedling Establishment ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Canopy Cover ◽  
Grass Species ◽  
Plant Canopy ◽  
Seedling Emergence And Survival ◽  
Neighbouring Plant ◽  
High Level

The objectives of this work were to investigate the germination of Piptochaetium napostaense and Stipa tenuis under laboratory conditions and to evaluate the effects of different plant canopy cover on seedling emergence and survival of the two species in the field. Fresh seeds of both species present a high level of dormancy associated with the lemma and palea, preventing seedling emergence immediately after the seeds fall in NovemberPecember. Seventy per cent of the seedlings of both species emerged in autumn. The germination behavior of these grass species may be an ecological adaptation serving to avoid seedling loss through exposure to the high temperatures and drought occurring during summer in the Calden District. Seedling survival was greater in the grazed, low plant canopy cover site, indicating that a certain degree of disturbance to reduce neighbouring plant interference favours seedling establishment in both species.

Seed-bank and seedling dynamics in Hyparrhenia hirta are influenced by herbicide application and mowing management

2012 ◽  
Vol 34 (2) ◽  
pp. 199 ◽  
Author(s):  
V. K. Chejara ◽  
P. Kristiansen ◽  
B. M. Sindel ◽  
R. D. B. Whalley ◽  
C. Nadolny
Keyword(s):  
Seed Bank ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Climatic Conditions ◽  
Control Treatment ◽  
Native Flora ◽  
Seedling Dynamics ◽  
Herbicide Treatments ◽  
Seedling Emergence And Survival

Hyparrhenia hirta (L.) Stapf (Coolatai grass) is a summer-active, C4 perennial tussock grass, native to southern Africa and the Mediterranean region, which has invaded areas of native flora in Australia in recent decades. Understanding its seed and seedling dynamics and how various management treatments (e.g. mowing, herbicide and no management) affect these may assist in identifying the conditions and management strategies required to limit its invasion. The population dynamics of H. hirta have not been comprehensively studied previously. A 2-year field experiment (December 2005–December 2007) was conducted to determine the seed-bank size, pattern of seedling emergence and survival of H. hirta seedlings at three sites in northern New South Wales, Australia, under three treatments: unmanaged (control), mowing and herbicide treatments. The density of H. hirta seeds in the soil at each experimental site under different treatments was measured in December 2005 at the start of the experiment, in December 2006 before the application of the second round of treatments and again at the end of the experiment in December 2007. Hyparrhenia hirta seedlings were assessed at monthly intervals in permanent quadrats (0.5 × 0.5 m) to determine seedling emergence and survival. Seedling emergence occurred on many occasions during the 2-year period of the experiment in each treatment and at all sites but the main seedling flushes were observed from mid summer to early autumn. In 2007, at all sites, seedling emergence declined by more than 90% on the mowing and herbicide treatments compared with the control treatment. Seedling survival was greater in the mowing and herbicide treatments than in the control treatment. The seedling cohorts emerging in winter had a lower survival. This study showed that H. hirta infestations have a large viable seed-bank (~3000 m–2), dependent on the level of infestation and climatic conditions, but that the seed-bank declines rapidly when seed addition is prevented. Some form of direct control of established H. hirta plants in combination with providing appropriate grazing management to encourage competition between grasses will assist in the control of H. hirta.

Seedling emergence and survival of Warea carteri (Brassicaceae), an endangered annual herb of the Florida Scrub

2007 ◽  
Vol 85 (7) ◽  
pp. 621-628 ◽  
Author(s):  
Carl W. Weekley ◽  
Eric S. Menges ◽  
Pedro F. Quintana-Ascencio
Keyword(s):  
Seedling Survival ◽  
Seedling Emergence ◽  
Annual Plants ◽  
Seedling Density ◽  
Florida Scrub ◽  
Seedling Emergence And Survival ◽  
History Of ◽  
Annual Herb ◽  
Winter Annual ◽  
Persistent Seed Bank

Seedling emergence and survival to flowering are critical processes in the life history of annual plants. We evaluated the importance of year and habitat on seedling emergence and the effects of year, habitat, timing of seedling emergence, and seedling density on survival of Warea carteri Small, an annual mustard endemic to Florida scrub. We tagged 1329 seedlings in 78 permanent 0.25 m2 quadrats in two habitats (scrub and disturbed) between 1999 and 2002 and followed seedlings monthly. Most (>80%) seedling emergence occurred between September and December. Emergence peaked 2 months earlier and was more variable in disturbed sites than in scrub. Seedling survival among years ranged from 3.5% to 12.0%. Seedling density varied from 1 to 75 per 0.25 m2 quadrat, with an overall median of 6.0. Survival was not density dependent. Median age at flowering ranged from 11.7 to 15.2 months, with late season recruits most likely to survive to flowering. Warea carteri recruits like a winter annual but flowers like a summer annual. Its delayed germination and a 12–15 month life span contribute to population cycling. Complete reproductive failure in unfavorable years, high seed production in favorable years, low rates of seed germination, and a persistent seed bank are consistent with predictions for an annual species in a variable habitat.

scholarly journals Seed encrusting with salicylic acid: A novel approach to improve establishment of grass species in ecological restoration

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0242035
Author(s):  
Simone Pedrini ◽  
Jason C. Stevens ◽  
Kingsley W. Dixon
Keyword(s):  
Salicylic Acid ◽  
Seed Germination ◽  
Ecological Restoration ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Field Conditions ◽  
Grass Species ◽  
Seed Coating ◽  
Seedling Density ◽  
Survival And Growth

To achieve global ambitions in large scale ecological restoration, there is a need for approaches that improve the efficiency of seed-based interventions, particularly in overcoming the bottleneck in the transition from germination to seedling establishment. In this study, we tested a novel seed-based application of the plant stress modulator compound salicylic acid as a means to reduce seedling losses in the seed-to-seedling phase. Seed coating technology (encrusting) was developed as a precursor for optimising field sowing for three grass species commonly used in restoration programs, Austrostipa scabra, Microlaena stipoides, and Rytidosperma geniculatum. Salicylic acid (SA, 0.1mM) was delivered to seeds via imbibition and seed encrusting. The effects of SA on seed germination were examined under controlled water-limited conditions (drought resilience) in laboratory setting and on seed germination, seedling emergence, seedling growth and plant survival in field conditions. Salicylic acid did not impact germination under water stress in controlled laboratory conditions and did not affect seedling emergence in the field. However, seedling survival and growth were improved in plants grown from SA treated seeds (imbibed and encrusted) under field conditions. When SA delivery methods of imbibing and coating were compared, there was no significant difference in survival and growth, showing that seed coating has potential to deliver SA. Effect of intraspecific competition as a result of seedling density was also considered. Seedling survival over the dry summer season was more than double at low seedling density (40 plants/m2) compared to high seedling density (380 plants/m2). Overall, adjustment of seeding rate according to expected emergence combined with the use of salicylic acid via coating could improve seed use efficiency in seed-based restoration.

Seedbed and canopy cover effects on balsam fir seedling establishment in Isle Royale National Park

1996 ◽  
Vol 26 (5) ◽  
pp. 782-793 ◽  
Author(s):  
Brian E. McLaren ◽  
Robert A. Janke
Keyword(s):  
Seedling Establishment ◽  
National Park ◽  
Seedling Survival ◽  
Canopy Cover ◽  
Balsam Fir ◽  
Isle Royale ◽  
Isle Royale National Park ◽  
Rotten Wood ◽  
The Difference ◽  
Overwinter Mortality

While balsam fir (Abiesbalsamea (L.) Mill.) dominated forests are vanishing from the southwest end of Isle Royale National Park, Michigan, renewal of fir stands is occurring on the northeast end. We speculate that the difference is related both to severe browsing by moose (Alcesalces L.), and to the frequency of disturbances like fire and windthrow. A survey of 24 stands and in situ experimentation on Isle Royale show that balsam fir seedling survival is optimal under 40–79% canopy cover. Late-season and overwinter mortality in 1-year-old seedlings is highest under >80% canopy cover, while germination is lowest under <40% cover. We also rank germination substrates by "preference ratios," and by comparing the overwinter survival of young fir seedlings on five natural media. We find best performance on hypnaceous moss, variable survival success on rotten wood, and highest mortality on broadleaf litter. However, ample seedling densities occur on the southwest end of the island, and the failure of fir to reach the overstory in this area is apparently not related to poor seedling establishment.

Germination and seedling establishment in cashew (Anacardium occidentale L.): An interaction between seed size, relative growth rate and seedling biomass

2017 ◽  
Vol 45 (2) ◽  
pp. 110
Author(s):  
Babli Mog, J.D. Adiga M.G. Nayak and G.S. Mohana
Keyword(s):  
Leaf Area ◽  
Seed Size ◽  
Seedling Establishment ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Seed Mass ◽  
Germination Percentage ◽  
Mass Ratio ◽  
Unit Leaf ◽  
Seedling Biomass

<p>Seeds of cashew were used to determine the effect of seed mass (5.2 to 7.8 g) on germination, seedling emergence and growth<br />under nursery conditions. Germination percentage and germination time showed significant correlation with seed mass. Large<br />sized seeds had higher germination percentage (81.6%) and produced more vigorous seedlings. Per cent seedling emergence was<br />related to seed mass with large sized seeds exhibited faster emergence. Seed mass significantly affected seedling survival and<br />survival rate was high in seedlings arising from large sized seeds (62.9%). Seedling vigor expressed in terms of shoot and root<br />length, leaf number, leaf area and total dry matter was significantly affected by seed mass. Seedlings that emerged from large sized<br />seeds showed better growth and produced heavier seedlings as compared to medium sized seeds. RGR showed significant variation<br />(0.152 to 0.240 g g-1day-1) among two seed size classes positively correlated with seed mass, leaf area (LA), unit leaf rate per unit<br />leaf area (ULRM), root to shoot ratio (R/S) and root mass ratio (RMR) and negatively with stem mass ratio (SMR). The study<br />concluded that the seed mass and RGR have influence on seedling growth and success of seedling establishment in cashew.</p>

scholarly journals Giant buttercup (Ranunculus acris L) seedling emergence and survival in Golden Bay dairy pastures

2009 ◽  
Vol 62 ◽  
pp. 222-227 ◽  
Author(s):  
C.S. Lusk ◽  
S.L. Lamoureaux ◽  
G.W. Bourd?t
Keyword(s):  
New Zealand ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Dairy Farms ◽  
Permanent Plots ◽  
Pasture Management ◽  
Seedling Emergence And Survival ◽  
Ranunculus Acris ◽  
Milk Solids ◽  
Autumn And Winter

Giant buttercup (Ranunculus acris L) is an unpalatable weed in New Zealand dairy pastures and is estimated to cost the dairy industry over 150 million annually in lost milk solids revenue In this study the survival of giant buttercup seedlings was determined by following their fates in permanent plots on eight randomly selected dairy farms in the Takaka Valley from November 2004 to August 2008 Seedling emergence occurred yearround but tended to be higher in winter and spring than in summer and autumn Seedling survival was very low with less than 5 of seedlings surviving beyond 12 months Seedlings that germinated in autumn had significantly higher survival at 6 and 12 months (22 and 12 respectively) than seedlings germinating in spring summer and winter (37 and 23 respectively) Good pasture management that prevents overgrazing and pugging in autumn and winter should reduce the autumn flush of seedlings and minimise their survival

Effects of inoculum density, temperature, seeding depth, seeding date and fungicidal seed treatment on the impact of Rhizoctonia solani on lentil

2008 ◽  
Vol 88 (4) ◽  
pp. 799-809 ◽  
Author(s):  
K. F. Chang ◽  
S. F. Hwang ◽  
B. D. Gossen ◽  
G. D. Turnbull ◽  
H. Wang ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Seedling Establishment ◽  
Root Rot ◽  
Seed Treatment ◽  
Field Experiments ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Inoculum Density ◽  
Seeding Date ◽  
The Impact

Rhizoctonia solani causes seedling blight and root rot in lentil, which reduces plant populations and the vigour and yield of surviving plants. Factors in the seedling environment, such as inoculum density, temperature, seeding depth, seeding date, and fungicidal seed treatment were studied to determine the degree to which they affect the impact of R. solani on lentil seedlings. Survival of lentil plants was evaluated after planting into soil artificially inoculated with various concentrations of a highly aggressive isolate of R. solani (AG-4). Emergence, seedling survival and shoot dry matter production decreased with increasing inoculum density, but these declines varied with temperature. Low soil temperatures delayed the emergence of lentil seedlings in non-inoculated soil, but in inoculated soils, emergence was inhibited with increasing temperatures. Depth of seeding did not affect seedling establishment, but root rot severity increased with depth of seeding in a growth cabinet trial. Root nodulation was reduced as root rot severity increased. In field experiments carried out over 3 station years, seeding date had a substantial effect on seedling emergence and yield of inoculated treatments, but the trends were not consistent between sites. In field assessments of fungicide efficacy, treatment of seed with thiabendazole plus carbathiin (Crown) and carbathiin plus thiram (Vitaflo 280) improved seedling establishment relative to the inoculated control. Key words: Lens culinaris, damping-off, root rot, seeding date, fungicide seed treatment depth of seeding, thiabendazole, carbathiin, thiram

Effects of overstory tree density, site preparation and ground vegetation on natural Scots pine seedling emergence and survival in northern boreal pine forests

2021 ◽  
Author(s):  
Mikko Johannes Kyrö ◽  
Ville Hallikainen ◽  
Sauli Valkonen ◽  
Mikko Hyppönen ◽  
Pasi Puttonen ◽  
...  
Keyword(s):  
Seedling Survival ◽  
Seedling Emergence ◽  
Mineral Soil ◽  
Site Preparation ◽  
Ground Vegetation ◽  
Seedling Mortality ◽  
Bottom Part ◽  
High Coverage ◽  
Efficient Treatment ◽  
Seedling Emergence And Survival

Natural regeneration is commonly used forest regeneration method in Northern Finland. It is not known however, what would be the optimal overstory density and ground vegetation composition for seedling emergence and survival, and if site preparation is needed to accompany overstory density manipulation. We studied the effects of overstory density (unthinned control and thinning to 50, 150 and 250 trees ha-1) and ground vegetation removal (mechanical site preparation with disc trenching) on the number of naturally germinated pine seedlings and survival of individual seedlings during 8-11 years. Bare mineral soil was a superior seedbed compared to intact vegetation cover, even though also mortality rate was high on mineral soil. Greater cover of lingonberry, crowberry and slash had a negative effect on seedling number. Seedling mortality was initially high (60% died during the first two years) but decreased throughout the first five years. The mineral soil in the elevated part of disc trencher track showed twice the survival rate in the bottom part of the track. High coverage of small haired mosses was associated with poorer seedling survival. An overstory density of 50-150 trees ha-1 with site preparation seems to be an efficient treatment to promote regeneration under these circumstances.

scholarly journals Environmental factors influencing the establishment, height and fecundity of the annual grass Sorghum intrans in an Australian tropical savanna

2010 ◽  
Vol 26 (3) ◽  
pp. 313-322 ◽  
Author(s):  
Kenneth A. Scott ◽  
Samantha A. Setterfield ◽  
Michael M. Douglas ◽  
Alan N. Andersen
Keyword(s):  
Environmental Factors ◽  
Seed Production ◽  
Fire Regime ◽  
Seedling Emergence ◽  
Canopy Cover ◽  
Bare Soil ◽  
Grass Species ◽  
Annual Grass ◽  
Factors Influencing ◽  
And Performance

Abstract:Environmental factors influencing grass establishment and performance in tropical savannas are poorly understood, particularly in relation to disturbance. We describe a seed sowing experiment that examined the effects of fire regime, canopy cover and litter cover on the emergence, establishment, height and fecundity (seed production) of the regionally dominant annual grass Sorghum intrans in northern Australia. Establishment was significantly lower under the woody canopy compared with canopy gaps, and where seeds were sown on a layer of litter compared with bare soil. However, variation in fire regime had no significant effect on establishment or seed production. Additionally, a shade-house experiment was conducted to test the effects of litter on seedling emergence of S. intrans and six other grass species representative of the local flora (Pseudopogonatherum contortum, Sorghum plumosum, Chrysopogon latifolius, Eriachne triseta, Heteropogon triticeus and Alloteropsis semialata). All species showed reduced emergence when sown either above or below litter, compared with bare soil. Our results demonstrate the importance of the overstorey as a determinant of S. intrans abundance and savanna grass composition more generally, through its effect on establishment. The aversion of savanna grasses to litter (and S. intrans to canopy shading) supports the notion of savanna species being highly adapted to disturbance.

Impact of sowing, canopy cover and litter on seedling dynamics of two Polylepis species at upper tree lines in central Ecuador

2007 ◽  
Vol 23 (3) ◽  
pp. 309-318 ◽  
Author(s):  
Arne Cierjacks ◽  
Juan Enrique Iglesias ◽  
Karsten Wesche ◽  
Isabell Hensen
Keyword(s):  
Linear Models ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Canopy Cover ◽  
Climatic Conditions ◽  
First Year ◽  
Tree Line ◽  
Seedling Dynamics ◽  
Log Linear

Failure of reproduction is hypothesized as being a main reason for the formation of upper tree lines but there is, as yet, little supportive evidence of such. This study investigates the effects of experimental sowing, canopy cover and litter depth on seedling emergence and survival of Polylepis incana and Polylepis pauta at the upper distribution limit of the species in the Páramo de Papallacta, central Ecuador. We established 18 study plots located in the interior, at the edge and at the exterior of closed forests at the upper tree line and analysed seedling dynamics for 1 y following experimental sowing with four different litter treatments. For both species, seedling numbers were significantly higher in the forest interior than outside, and higher in the treatments with the litter layer removed. In P. pauta, sowing significantly increased seedling number, which was more pronounced within and at the edge of the forest than outside. In contrast, there was no impact of sowing on seedling emergence in P. incana. First-year seedling survival and mean growth rate per month were low in both species. Log-linear models did not reveal significant interactions between survival and canopy cover or litter removal. Our data show that seedling recruitment is limited at the upper tree line – presumably due to extreme climatic conditions – which indicates the importance of constraints in sexual regeneration for tree-line formation in central Ecuador.

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