A preliminary survey of seed input into fallow fields in Saskatchewan

1983 ◽  
Vol 61 (4) ◽  
pp. 1216-1221 ◽  
Author(s):  
O. W. Archibold ◽  
L. Hume
Keyword(s):  
Tree Species ◽  
Seedling Emergence ◽  
Grass Species ◽  
Soil Cores ◽  
Weed Communities ◽  
Buried Seed ◽  
Seed Reserves ◽  
Viable Seeds ◽  
Summer Fallow ◽  
Different Parts

Seed traps were installed in 10 summer fallow sites across Saskatchewan to monitor annual additions to buried seed populations. Soil cores (7.5 cm deep) were also collected at these sites and tested for viable seeds through seedling emergence under greenhouse conditions. Seedlings of 33 forb species, 5 grass species, and 3 tree species emerged from the traps, whereas seedlings of 28 forb species, 4 grass species, and 1 tree species emerged from the cores. Although the nature of seed input for agricultural sites in different parts of Saskatchewan was highly variable, the annual seed rain onto fallow represented an important supplement to the buried seed reserves and would be an influence on subsequent weed communities in cultivated fields.

Effects of partial removal of seed reserves on some aspects of seedling ecology of seven dune species

1991 ◽  
Vol 69 (7) ◽  
pp. 1457-1462 ◽  
Author(s):  
Jianhua Zhang ◽  
M. A. Maun
Keyword(s):  
Seed Germination ◽  
Panicum Virgatum ◽  
Dry Matter ◽  
Early Stage ◽  
Seedling Emergence ◽  
Grass Species ◽  
Partial Removal ◽  
Seedling Size ◽  
Seed Reserves ◽  
Food Reserves

Greenhouse studies were conducted to determine the effects of partial removal of endosperm or cotyledons from seeds of seven dune species on seed germination, seedling emergence, seedling size, and dry matter allocation. Different proportions (0, 30, and 60%) were surgically removed from seeds of Agropyron psammophilum, Calamovilfa longifolia, Elymus canadensis, Leymus arenarius, Panicum virgatum, Lupinus perennis, and Strophostyles helvola. Partial removal of seed reserves caused a significant reduction in seedling variables 1 or 2 weeks after planting in sand. For example, seedling height, leaf area, dry weight of leaves, stem, and roots were significantly lower than control. The data suggest that the principal determinant of seedling size at an early stage was the amount of energy reserves in the endosperm or cotyledons of seeds. In addition to reduction in food reserves, partial removal of seed reserves caused some physiological damage to seedlings. In grass species, seedlings from surgically treated seeds devoted more dry matter to the roots and less to the leaves and stem than control seedlings. In dicot species, however, plants from treated seeds devoted more dry matter to the leaves and less to the roots. Key words: seed injury, seed germination, seedling size, energy allocation, dune plants.

scholarly journals Diversity of Angiospermic Plants in estuarine and Adjoining Riparian Areas of Sabarmati and Mahi Rivers, Gujarat, India

2020 ◽  
pp. 116-124
Author(s):  
Raj B. Patel ◽  
Ketan Tatu ◽  
R. D. Kamboj
Keyword(s):  
Tree Species ◽  
Flowering Plants ◽  
Grass Species ◽  
Riparian Zones ◽  
Ecological Groups ◽  
View Point ◽  
Riparian Areas ◽  
Shrub Species ◽  
Religious Importance ◽  
Herb Species

The present study was conducted with an aim of documenting the diversity of flowering plants in selected localities in the estuarine and adjoining riparian zones of Sabarmati and Mahi rivers of Gujarat, India. The Sabarmati and Mahi rivers are west-flowing perennial rivers having considerable ecological and religious importance. A total of 40 species of flowering plants belonging to 26 different families were recorded in the study area which were dominated by herbaceous plants. Among the 40 species recorded 2 species were trees, 8 species were shrubs, 28 species were herbs and 2 species were grasses. Moreover, as far as ecological groups are concerned, 6 species were halophytes, 13 species were hydrophytes, 17 species were mesophytes and 4 species were xerophytes. In the study area of Sabarmati river, 28 species were recorded that included 2 tree species, 6 shrub species, 18 herb species and 2 grass species. From the view point of ecological groups 5 species were halophytes, 3 species were hydrophytes, 16 species were mesophytes and 4 species were xerophytes. In the study area of Mahi river, 24 species were recorded that included 2 tree species, 6 shrub species, 14 herb species and 2 grass species. From the view point of ecological groups 5 species were halophytes, 12 species were hydrophytes, 5 species were mesophytes and 2 species were xerophytes.

Stimulation of Common Cocklebur (Xanthium pensylvanicum) and Redroot Pigweed (Amaranthus retroflexus) Seed Germination by Injections of Ethylene into Soil

Weed Science ◽  
1980 ◽  
Vol 28 (5) ◽  
pp. 510-514 ◽  
Author(s):  
G. H. Egley
Keyword(s):  
Seed Germination ◽  
Laboratory Tests ◽  
Seedling Emergence ◽  
Amaranthus Retroflexus ◽  
Redroot Pigweed ◽  
Plastic Bags ◽  
Viable Seeds ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Stimulation Of

The effects of ethylene upon germination of common cocklebur (Xanthium pensylvanicumWallr.) and redroot pigweed (Amaranthus retroflexusL.) seeds were studied. In laboratory tests with seeds in sealed flasks in the dark, 10 μl/L ethylene increased germination of redroot pigweed seeds from 7% to 52% at 30 C, and increased germination of large and small common cocklebur seeds from 30% and 0% to 100% and 90% respectively, at 25 C. At least 12 h of exposure to ethylene was necessary for appreciable stimulation of germination. In growth chamber studies with known numbers of seeds in pots of soil, ethylene at 11 kg/ha was injected into the soil, and the pots were enclosed in plastic bags for 24 h. One such injection at 2 weeks after planting, and successive injections at 2, 3, and 4 weeks, significantly increased redroot pigweed seedling emergence, and significantly decreased the numbers of dormant, viable seeds remaining in the soil. When pots were not enclosed, injections did not significantly effect redroot pigweed seeds, but significantly increased common cocklebur seedling emergence and decreased the number of viable common cocklebur seeds remaining in the soil.

Suitability of Wild Host Plants and Firewood as Hosts of Prostephanus truncatus (Coleoptera: Bostrichidae) in Mozambique

2019 ◽  
Vol 112 (4) ◽  
pp. 1705-1712 ◽  
Author(s):  
Bernardo L Muatinte ◽  
Johnnie Van den Berg
Keyword(s):  
Plant Species ◽  
Tree Species ◽  
Host Plants ◽  
Crop Residues ◽  
Grass Species ◽  
Small Scale ◽  
Prostephanus Truncatus ◽  
Maize Crop ◽  
Wild Host ◽  
Brachystegia Spiciformis

Abstract Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) populations are maintained in wild host plants such as trees that act as pest reservoirs from where beetle infestation of maize granaries take place. In this study, we assessed the suitability of plant species sold and transported as firewood as well as other plant species in Mozambique as hosts for P. truncatus. Prostephanus truncatus was only recorded from three tree species, which are sold as firewood, i.e., Brachystegia spiciformis, Strychnos spinosa, and Colophospermum mopane. The pest survived and bred in 13 tree and 7 grass species. Dry wood of several tree species and the grasses Acroceras macrum and Hyparrhenia hirta were suitable hosts for pest development. Sale and transport of certain firewood species may be an important driver of the spread of this pest. The importance of dry maize stalks and several grass species in sustaining pest populations is described for the first time. Several grass species are used as thatch or fencing material and, together with maize crop residues close to small-scale granaries, may provide significant sources of beetle infestation.

scholarly journals Do polyembryonic seeds of Carapa surinamensis (Meliaceae) have advantages for seedling development?

2019 ◽  
Vol 49 (2) ◽  
pp. 97-104 ◽  
Author(s):  
Débora Najara de SOUZA FERREIRA ◽  
José Luís Campana CAMARGO ◽  
Isolde Dorothea Kossmann FERRAZ
Keyword(s):  
Tree Species ◽  
Shoot Development ◽  
Seedling Development ◽  
External Factors ◽  
Initial Development ◽  
Advantages And Disadvantages ◽  
Single Seed ◽  
Seed Reserves

ABSTRACT Polyembryony is the differentiation and development of multiple embryos in a single seed. This characteristic can provide advantages, as more than one embryo is produced with the same amount of resources, and the probability of establishment of at least one seedling increases. However, sibling seedlings may also increase competition, affecting development and survival. In the present study, the possible advantages and disadvantages of polyembryony were analyzed in the initial establishment of seedlings of Carapa surinamensis (Meliaceae), a tree species that produces monoembryonic or polyembryonic seeds. In this regard, the development of single seedlings was compared with a pair of seedlings emerging from polyembryonic seeds. We compared the development of seedlings attached to or detached from each other and to the seed resources. We observed two levels of competition: (a) for the seed reserves during germination and initial development, as multiple embryos of C. surinamensis share the same reserves, and (b) for external factors, mostly space for root and shoot development, and also for light. Reducing the competition for external factors by separating the siblings was not enough to reduce the effects of competition for seed reserves in the first six months of development. Nevertheless, viable seedlings were produced in all treatments. Thus, depending on sprout management in the nursery, the number of seedlings per seed can be significantly increased by detaching the seedlings, or more vigorous seedlings can be obtained when only one seedling is maintained.

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.

Viable seed populations by soil depth and potential site recolonization after disturbance

1977 ◽  
Vol 55 (18) ◽  
pp. 2408-2412 ◽  
Author(s):  
Janice M. Moore ◽  
Ross W. Wein
Keyword(s):  
Soil Depth ◽  
Seedling Emergence ◽  
Mineral Soil ◽  
Organic Soil ◽  
Viable Seed ◽  
Soil Layers ◽  
Forest Experiment Station ◽  
Viable Seeds ◽  
Study Sites ◽  
Germination Experiment

Seedling emergence from organic and mineral soil layers was measured for nine study sites at the Acadia Forest Experiment Station near Fredericton, New Brunswick. The number of viable seeds showed a decrease from deciduous-dominated forest, to conifer-dominated forest, to organic soil study sites. Viable seed number varied from 3400/m2 for a deciduous-dominated forest study site to zero for a bog study site. Most seeds germinated from the upper organic soil layers of all study sites and were predominantly Rubus strigosus Michx. After the germination experiment, ungerminated seeds, which showed no viability by the tetrazolium test, were separated from the soil. These seeds were almost entirely Betula spp. and seed numbers were as high as 4200–9400/m2 for a deciduous-dominated forest. The applicability of the results to differing types of postdisturbance revegetation is discussed.

Increased weed emergence and seed bank depletion by soil disturbance in a no-tillage system

Weed Science ◽  
1997 ◽  
Vol 45 (2) ◽  
pp. 234-241 ◽  
Author(s):  
Dawit Mulugeta ◽  
David E. Stoltenberg
Keyword(s):  
Seed Bank ◽  
Seedling Emergence ◽  
Soil Disturbance ◽  
No Tillage ◽  
Common Lambsquarters ◽  
Redroot Pigweed ◽  
Giant Foxtail ◽  
Tillage System ◽  
Level Of Aggregation ◽  
Viable Seeds

The influence of secondary soil disturbance on the emergence pattern and seed bank depletion of an annual weed community in a long-term, no-tillage corn cropping system was determined in 1992 and 1993. As a component of this research, the seed bank was characterized prior to implementation of soil disturbance treatments. The seed bank was initially composed of common lambsquarters, redroot pigweed, and giant foxtail, with approximately 55, 36, and 8% of the total viable seeds, respectively. The remaining 1% was comprised of five other species in 1992 and eight in 1993. The spatial distribution of viable seeds of each species, except common lambsquarters and redroot pigweed, was described by a negative binomial distribution. Three dispersion indices indicated that seeds of individual and total weed species were aggregated and that the level of aggregation of viable seeds of a species was associated with seed density; at lower seed densities, the level of aggregation was greater. Soil disturbance increased common lambsquarters emergence 6-fold in 1992 relative to nondisturbed soil, but did not influence emergence in 1993. Rainfall was about 50% less in 1993. In contrast, soil disturbance increased giant foxtail and redroot pigweed emergence approximately 6- and 3-fold in 1992 and 1993, respectively. Seedling emergence associated with soil disturbance, relative to nondisturbed soil, increased seed bank depletion of common lambsquarters 16-fold in 1992, and giant foxtail and redroot pigweed and average of 6- and 3-fold in 1992 and 1993, respectively. These results indicated that soil disturbance increased seedling emergence and seed bank depletion of the predominant species in the weed community of a long-term, no-tillage system, but that this response was dependent on rainfall for common lambsquarters.

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.

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