Effects of heat and smoke on germination of soil-stored seed in a south-eastern Australian sand heathland

2002 ◽  
Vol 50 (2) ◽  
pp. 197 ◽  
Author(s):  
Timothy J. Wills ◽  
Jennifer Read
Keyword(s):  
Seed Germination ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Type Systems ◽  
Treated Soil ◽  
South Eastern ◽  
Heat Treated ◽  
Eastern Australia ◽  
And Control

Various fire-related agents, including heat, smoke, ash and charred wood, have been shown to break dormancy and promote germination of soil-stored seed in a broad range of species in mediterranean-type systems. However, relatively little work has been conducted in south-eastern Australian heathlands. This study examined the effects of heat and smoked water on germination of the soil seed bank in a mature sand heathland within the Gippsland Lakes Coastal Park, in south-eastern Australia. Heat was clearly the most successful treatment for promoting seed germination, followed by smoked water, then controls, with 55% of species present in the germinable soil seed bank requiring a heat or smoke stimulus to promote seed germination. Mean species richness of the germinable soil seed bank was found to be significantly higher in heat-treated soil than in smoke and control treatments. Seedling density of heat-treated soil was almost 10 times that of controls, while smoke-treated soil was almost five times that of controls. Seedling emergence was fastest in heat-treated soil, followed by smoke and control soils. Of the species found in the soil seed bank, 25% were absent from the extant vegetation, suggesting the existence of post-fire colonisers in the soil seed bank. The results have implications for the design of soil seed bank experiments and the use of fire as a tool in vegetation management.

Seed Germination Ecology of South Eastern Australian Rigid Ryegrass (Lolium rigidum) Populations

Weed Science ◽  
2021 ◽  
pp. 1-30
Author(s):  
Michael Thompson ◽  
Gulshan Mahajan ◽  
Bhagirath S. Chauhan
Keyword(s):  
Salt Stress ◽  
Seed Germination ◽  
Herbicide Resistance ◽  
Seedling Emergence ◽  
Effective Control ◽  
Burial Depth ◽  
Lolium Rigidum ◽  
South Eastern ◽  
Eastern Australia ◽  
Rigid Ryegrass

Abstract Herbicide resistance is an increasing issue in many weed species, including rigid ryegrass (Lolium rigidum Gaudin); a major weed of winter cropping systems in southern Australia. Recently, this weed has also been found in summer crops in the south eastern region of Australia. Effective control of this herbicide resistant weed across south eastern Australia requires alternative management strategies. These strategies can be informed from analyses on the interaction of germinable seeds with their regional environment and by identifying the differences between populations of varying herbicide resistance levels. In this study, we explore how various environmental factors differentially affect the seed germination and seedling emergence of three L. rigidum populations, including one glyphosate-resistant population (GR), one glyphosate-susceptible population (GS) and one population of unknown resistance status (CC04). Germination was greater than 90% for all populations at each temperature regime except 15/5 C. Populations germinated at a lower rate under 15/5 C, ranging from 74 to 87%. Salt stress had a similar effect on the germination of all populations, with 0% germination occurring at 250 mM salt stress. Population GS had greater tolerance to osmotic stress with 65% germination at −0.4 MPa compared to 47% and 43% germination for CC04 and GR, respectively; however, germination was inhibited at −0.8 and −1.6 MPa for all populations. All populations had lower germination when placed in complete darkness as opposed to alternating light/dark. Germination in darkness was lower for CC04 (69%) than GR (83%) and GS (83%). Seedling emergence declined with increasing burial depth but retained 37% emergence at 8 cm when averaged over the populations. These results indicate that L. rigidum Gaud. can survive under a range of environmental variables and the extent of survival differs based on population, however, there was no difference based on herbicide resistance status.

Hemp Dogbane Growth and Control

Weed Science ◽  
1972 ◽  
Vol 20 (2) ◽  
pp. 156-159 ◽  
Author(s):  
Laren R. Robison ◽  
Larry S. Jeffery
Keyword(s):  
Seed Germination ◽  
Soil Type ◽  
Vegetative Growth ◽  
Soil Cover ◽  
Seedling Emergence ◽  
Control Seed ◽  
Cover Soil ◽  
And Control ◽  
Emergence Response ◽  
Made In

Hemp dogbane (Apocynum cannabinum L.) was investigated relative to seed germination, depth of seedling emergence, response to clipping, influence of soil type and fertility on vegetative growth, and herbicidal control. Seed germination in this study was influenced by light and scarification. Seedling emergence was influenced by the amount of soil cover. Soil type and fertility affected vegetative growth. In a greenhouse clipping study, hemp dogbane became perennial 41 days after emergence and by 65 days was producing more than one shoot per plant following clipping. Hemp dogbane was more completely controlled following September application of herbicide than from application made in June.

The effects of recreation disturbance on subalpine seed banks in the Rocky Mountains of Montana

2000 ◽  
Vol 78 (5) ◽  
pp. 577-582 ◽  
Author(s):  
Catherine Zabinski ◽  
Todd Wojtowicz ◽  
David Cole
Keyword(s):  
Organic Matter ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Density ◽  
Soil Cores ◽  
Bare Ground ◽  
Recreation Impacts ◽  
Natural Revegetation ◽  
Site Types

We investigated the soil seed bank in a subalpine ecosystem with patchy disturbance from camping. Soil cores were collected from three site types, heavily impacted, lightly impacted, and undisturbed, that differed in area of bare ground and depth of surface organic matter. We hypothesized that the density and composition of the seed bank would vary with depth of surface organic matter and distance from established vegetation. Seedling emergence was determined in the greenhouse. Seed density was significantly lower on disturbed sites, averaging 441 seeds/m2 on heavily impacted sites, 1495 seeds/m2 on lightly impacted sites, and 4188 seeds/m2 on undisturbed sites. Seed density declined exponentially with distance from established vegetation and increased with depth of surface organic matter. The number of species present did not vary across site types, but 10 species that occurred on lightly impacted and undisturbed sites were not present on heavily impacted sites. We concluded that disturbance that causes removal of surface organic matter can affect natural revegetation by lowering the density of propagules and affecting the species represented in the seed bank.Key words: seed bank, subalpine, patchy disturbance, recreation impacts.

scholarly journals ESTUDOS DE UM BANCO DE SEMENTES NO SOLO DE UM FRAGMENTO FLORESTAL COM Araucaria angustifolia NO ESTADO DO PARANÁ

FLORESTA ◽  
2011 ◽  
Vol 41 (2) ◽  
Author(s):  
Marcelo Lima de Souza ◽  
Antônio Carlos Nogueira ◽  
Renato Luiz Grisi Macedo ◽  
Carlos Roberto Sanquetta ◽  
Nelson Venturin
Keyword(s):  
Vertical Distribution ◽  
Seed Bank ◽  
Tree Species ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Forest Tree ◽  
Araucaria Angustifolia ◽  
Forest Fragment ◽  
Regeneration Strategy ◽  
Soil Layers

O objetivo do presente trabalho foi estudar o banco de sementes no solo de um fragmento florestal com Araucaria angustifolia (Bert.) O. Ktze. no estado do Paraná. Para isso, investigou-se a distribuição vertical das sementes, a influência do sombreamento sobre a emergência das plântulas, sua identificação e quantificação. A distribuição vertical de sementes em quatro camadas foi analisada através da identificação e quantificação das plântulas emergentes em casa de vegetação, levando em consideração o nível de sombreamento. Os dados referentes ao banco de sementes foram obtidos no período de 210 dias, por meio de identificação botânica e contagens semanais das plântulas germinadas das quatro profundidades de solo em quatro parcelas experimentais. As amostras foram colocadas para germinar sob 0 e 50% de sombreamento em casa de vegetação. Os resultados obtidos no estudo de banco de sementes permitiram as seguintes conclusões: o banco de sementes parece ser pobre em espécies arbóreas e abundante em espécies herbáceas; o banco de sementes das espécies arbóreas foi maior na segunda camada; ocorreu maior germinação sob 0% de sombreamento. Provavelmente, a estratégia de regeneração da maioria das espécies presentes nessa área de estudo parece não ser pelo banco de sementes no solo.Palavras-chave: Banco de sementes no solo; Araucaria angustifolia; fragmento florestal. AbstractSoil seed bank analysis in a forest fragment with Araucaria angustifolia, State of Parana. A research on soil seed bank had been developed in an Araucaria angustifolia (Bert.) O. Ktze. forest fragment in the State of Paraná. It had surveyed vertical distribution of seeds within the soil and shadow influence on seedling emergence, besides the improvement of their identification and quantity measuring. Vertical distribution of seeds in four soil layers had been analyzed by identification and quantification of germinated seedlings in greenhouse, with full light or 50% shaded conditions. Data related to seedlings of trees, weeds, grasses and lianas were calculated separately in weekly intervals during a 210-day period. Results suggested that the soil seed bank in this forest was poor in relation to tree species, in diversity as far as density. On the other hand, seeds of grasses and weeds decreased along vertical soil profile, and forest tree species tended to abundance in the 5-10 cm layer. Germination was higher with full light than in 50% shaded conditions. Probably, regeneration strategy for most species in this focused area doesn’t seem to be soil seed bank.Keywords: Soil seed bank; Araucaria angustifolia; forest fragment.

scholarly journals Seed Rain, Soil Seed Bank, and Seedling Emergence Indicate Limited Potential for Self-Recovery in a Highly Disturbed, Tropical, Mixed Deciduous Forest

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1391
Author(s):  
Anussara Chalermsri ◽  
La-aw Ampornpan ◽  
Witoon Purahong
Keyword(s):  
Mortality Rate ◽  
Seed Bank ◽  
Tree Species ◽  
Deciduous Forest ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Rain ◽  
Reproductive Phenology ◽  
Mixed Deciduous Forest ◽  
Standing Vegetation

Human activity negatively affects the sustainability of forest ecosystems globally. Disturbed forests may or may not recover by themselves in a certain period of time. However, it is still unclear as to what parameters can be used to reasonably predict the potential for self-recovery of human-disturbed forests. Here, we combined seed rain, soil seed bank, and seed emergence experiments to evaluate the potential for self-recovery of a highly disturbed, tropical, mixed deciduous forest in northeastern Thailand. Our results show a limited potential for self-recovery of this forest due to low seedling input and storage and an extremely high mortality rate during the drought period. There were 15 tree species of seedlings present during the regeneration period in comparison with a total number of 56 tree species in current standing vegetation. During the dry season, only four tree seedling species survived, and the highest mortality rate reached 83.87%. We also found that the correspondence between the combined number of species and composition of plant communities obtained from seed rain, soil seed bank, and seedling emergence experiments and the standing vegetation was poor. We clearly show the temporal dynamics of the seed rain and seedling communities, which are driven by different plant reproductive phenology and dispersal mechanisms, and drought coupled with mortality. We conclude that this highly disturbed forest needs a management plan and could not recover by itself in a short period of time. We recommend the use of external seed and seedling supplies and the maintenance of soil water content (i.e., shading) during periods of drought in order to help increase seedling abundances and species richness, and to reduce the mortality rate.

scholarly journals Seed bank modelling of volunteer oil seed rape: from seeds fate in the soil to seedling emergence

2013 ◽  
Vol 31 (2) ◽  
pp. 267-279 ◽  
Author(s):  
E. Soltani ◽  
A. Soltani ◽  
S. Galeshi ◽  
F. Ghaderi-Far ◽  
E. Zeinali
Keyword(s):  
Oilseed Rape ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Viability ◽  
Burial Depth ◽  
Soil Seed Banks ◽  
Seed Bank Dynamics ◽  
Autumn And Winter ◽  
Lower Slope

Studies were conducted to estimate parameters and relationships associated with sub-processes in soil seed banks of oilseed rape in Gorgan, Iran. After one month of burial, seed viability decreased to 39%, with a slope of 2.03% per day, and subsequently decreased with a lower slope of 0.01 until 365 days following burial in the soil. Germinability remained at its highest value in autumn and winter and decreased from spring to the last month of summer. Non-dormant seeds of volunteer oilseed rape did not germinate at temperatures lower than 3.8 ºC and a water potential of -1.4 MPa ºd. The hydrothermal values were 36.2 and 42.9 MPa ºd for sub- and supra-optimal temperatures, respectively. Quantification of seed emergence as influenced by burial depth was performed satisfactorily (R² = 0.98 and RMSE = 5.03). The parameters and relationships estimated here can be used for modelling soil seed bank dynamics or establishing a new model for the environment.

scholarly journals Epidemiology and control of tuberculosis in Victoria, a low-burden state in south-eastern Australia, 2005–2010

2013 ◽  
Vol 17 (6) ◽  
pp. 752-758 ◽  
Author(s):  
C. J. Lavender ◽  
M. Globan ◽  
H. Kelly ◽  
L. K. Brown ◽  
A. Sievers ◽  
...  
Keyword(s):  
South Eastern ◽  
Eastern Australia ◽  
And Control ◽  
South Eastern Australia
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