Comparison of the vegetation and seedbanks of soybean fields, adjacent boundaries, and hedgerows in Ontario

2006 ◽  
Vol 86 (2) ◽  
pp. 557-567 ◽  
Author(s):  
Céline Boutin
Keyword(s):  
Species Richness ◽  
Seedling Emergence ◽  
Minor Component ◽  
Vegetation Composition ◽  
Weed Species ◽  
Total Species Richness ◽  
Significant Difference ◽  
Seedling Emergence Method ◽  
Weedy Species ◽  
A Minor

Patterns of plant assemblages in habitats located within agroecosystems are poorly understood. A study of the seedbank and standing vegetation in 10 soybean [Glycine max (L.) Merr.] fields, their adjacent boundaries, and adjoining woody hedgerows was undertaken in Ontario. The objective was to examine the composition of plants of conservation value and weedy species in these habitats. The seedbank of each habitat was determined from soil cores in quadrats located at regular intervals along transects, using the seedling emergence method in the greenhouse. The vegetation was surveyed in plots adjacent to the seedbank sampling areas. There was no significant difference in total species richness of vegetation or the seedbank among habitat types. However, there was a marked difference in species composition. In the seedbank, no difference in weed species richness among habitats was observed. In vegetation, however, fields harboured significantly more weedy species than adjacent boundaries and hedgerows. The dissimilarity between the seedbank and the vegetation was confirmed in detrended correspondence analyses, which showed that hedgerow vegetation, and to a lesser extent boundary vegetation, differed from field vegetation and all the habitats of the seedbank. The analysis of soil properties indicated that organic matter and nutrient levels were often higher in hedgerows than in fields. It can be concluded that hedgerows are valuable habitats for plant diversity and that weed species represent a minor component of their overall vegetation composition. Key words: Agroecosystems, field boundaries, hedgerows, soil seedbank, vegetation composition

scholarly journals Soil seedbanks in natural and restored boxironbark forests at Stawell Gold Mine, Victoria

2004 ◽  
Vol 10 (1) ◽  
pp. 9 ◽  
Author(s):  
E. Comino ◽  
B. P. Miller ◽  
N. J. Enright
Keyword(s):  
Species Richness ◽  
Exotic Species ◽  
Management Practice ◽  
Seedling Emergence ◽  
Woody Species ◽  
Natural Vegetation ◽  
Weed Species ◽  
Total Species Richness ◽  
Forest Remnants ◽  
Chemical Attributes

Natural communities have the capacity to regenerate themselves, and this functional ecosystem attribute must be regarded as a key indicator of success for revegetation programmes. The accumulation of species (and individuals) as dormant propagules in a soil seedbank, representing potential future states for the vegetation, is one possible index of revegetation success. Here, we investigate the soil seedbanks for five natural vegetation (Box-Ironbark forest) remnants, a topsoil stockpile and three revegetated mine-site areas associated with gold mining at Stawell (Victoria, Australia). The revegetation efforts largely date from 1987 and, in terms of their composition and structure, are relatively similar to natural vegetation remnants. Soil samples were treated with heat or smoke (plus control) and were monitored for seedling emergence, species composition and density in the glasshouse for 150 days. Seedling densities in treated seedbank samples were high (2 200 to 17 500 seedlings m-2) while species richness was low, ranging from 10 to 20 species per sample. Exotic species made up 22?61 % of emergents and 33?50% of species observed. Correlation of seedbank composition and density with chemical attributes of soils, and with above ground (extant) vegetation at sites showed few significant relationships. Total species richness and the proportion of exotic species varied significantly between natural bushland remnants and revegetation areas. Richness was highest, and the proportion of exotic species was lowest in natural bushland samples. Total emergent numbers and the density of exotic emergents did not vary significantly between remnant bushland and revegetation areas. Declining vigour of some woody species in revegetation sites that are well represented in the seedbank, including Acacia pycnantha and A. genistifolia, indicates that the reintroduction of fire might be an appropriate management practice to facilitate long-term recovery of a functional community on these revegetated surfaces, but the potential for the establishment of weed species from the seed-bank following fire may pose a challenge to management.

scholarly journals INFLUENCE OF SUGARCANE STRAW AND SOWING DEPTH ON THE EMERGENCE OF WEED SPECIES

2015 ◽  
Vol 33 (3) ◽  
pp. 405-412 ◽  
Author(s):  
P. V. SILVA ◽  
P. A. MONQUERO ◽  
F. B. SILVA ◽  
N. C. BEVILAQUA ◽  
M. R. MALARDO
Keyword(s):  
Ricinus Communis ◽  
Seedling Emergence ◽  
Dry Mass ◽  
Weed Species ◽  
Sowing Depth ◽  
Sugarcane Straw ◽  
Randomized Design ◽  
Significant Difference ◽  
Completely Randomized Design ◽  
Luffa Aegyptiaca

ABSTRACT This study aimed to understand the influence of sowing depth and the amount of sugarcane straw on the emergence of weed species Luffa aegyptiaca Miller (Cucurbitaceae); Mucuna aterrima Piper & Tracy (Fabaceae - Leguminosae) and Ricinus communis (Euphorbiaceae). A completely randomized design with a 5 x 4 x 3 factorial layout with four replications was used, at five sowing depths (0, 2, 4, 8 and 10 cm), four different amounts of sugarcane straw (0, 5, 10 and 15 t ha-1) and three different evaluation periods (7, 14 and 21 days after sowing). After sowing, different amounts of sugarcane straw (0, 5, 10 and 15 t ha-1) were deposited on soil. Seedling emergence was analyzed at 7, 14 and 21 days after sowing, counting the number of seedlings that had emerged. At the end of the trial, weed height (cm), leaf area (cm2) and shoot dry mass (g) were measured. In relation to emergence ability, studied species presented different responses according to sowing depth and to the amount of sugarcane straw deposited on the soil. For the L.aegyptiacaand M.aterrima, no significant difference was observed in the interaction between depth and sugarcane straw, showing the adaptation of these species to no-burn sugarcane system. For R.communis, seeds placed at 0 cm of sugar cane straw depth were observed to favor the emergence of seedlings.

Banded herbicide, rotary hoeing and cultivation effects on weed populations in ridge-tilled soybean

2006 ◽  
Vol 21 (3) ◽  
pp. 151-158 ◽  
Author(s):  
Thomas W. Jurik
Keyword(s):  
Seedling Emergence ◽  
Amaranthus Retroflexus ◽  
Weed Species ◽  
Soybean Yield ◽  
Setaria Faberi ◽  
Giant Foxtail ◽  
Significant Difference ◽  
Tillage System ◽  
Polygonum Pensylvanicum ◽  
Ridge Tillage

Can banded herbicide be eliminated in ridge-tilled soybean (Glycine max)? The effects of banded herbicide, rotary hoeing and cultivation on weed populations and soybean yield in a ridge-tillage system were tested on three farms in Iowa, USA in 1989 and 1990. In 1989, plots either had no herbicide or had herbicide banded in the row at planting in mid-May; all plots received two rotary hoeings and two cultivations. In 1990, treatments were banded herbicide with no rotary hoeing, banded herbicide with one rotary hoeing, and no herbicide with one or two rotary hoeings; all plots received two or three cultivations. In both years, over all weed species [primarily giant foxtail (Setaria faberi), Pennsylvania smartweed (Polygonum pensylvanicum) and redroot pigweed (Amaranthus retroflexus)], seedling emergence was highest in late May and early June, with few seedlings emerging after mid-June. Weed populations were highest in May and June, after which rotary hoeing and cultivation reduced weed numbers in all plots. There were no consistent differences among treatments in weed numbers in early August for the 2 years. In both years, there was no significant difference in soybean yield among treatments. Within-farm mean yields ranged from 2.26 to 3.01 Mg ha−1among farms in 1989 and from 2.07 to 2.93 Mg ha−1among farms in 1990. Ridge-tillage without herbicide was generally equivalent to ridge-tillage with banded herbicide, with respect to total number of weeds and number of broad-leaved weeds remaining in August after tillage, and to soybean yield.

scholarly journals Phytochemical Analysis of Tephrosia vogelii across East Africa Reveals Three Chemotypes that Influence Its Use as a Pesticidal Plant

Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 597 ◽  
Author(s):  
Angela G. Mkindi ◽  
Yolice Tembo ◽  
Ernest R. Mbega ◽  
Beth Medvecky ◽  
Amy Kendal-Smith ◽  
...  
Keyword(s):  
East Africa ◽  
Minor Component ◽  
Hybrid Plant ◽  
Phytochemical Analysis ◽  
Wet Season ◽  
Botanical Pesticide ◽  
Methanolic Extracts ◽  
Significant Difference ◽  
Tephrosia Vogelii ◽  
A Minor

Tephrosia vogelii is a plant species chemically characterized by the presence of entomotoxic rotenoids and used widely across Africa as a botanical pesticide. Phytochemical analysis was conducted to establish the presence and abundance of the bioactive principles in this species across three countries in East Africa: Tanzania, Kenya, and Malawi. Analysis of methanolic extracts of foliar parts of T. vogelii revealed the occurrence of two distinct chemotypes that were separated by the presence of rotenoids in one, and flavanones and flavones that are not bioactive against insects on the other. Specifically, chemotype 1 contained deguelin as the major rotenoid along with tephrosin, and rotenone as a minor component, while these compounds were absent from chemotype 2, which contained previously reported flavanones and flavones including obovatin-3-O-methylether. Chemotype 3 contained a combination of the chemical profiles of both chemotype 1 and 2 suggesting a chemical hybrid. Plant samples identified as chemotype 1 showed chemical consistency across seasons and altitudes, except in the wet season where a significant difference was observed for samples in Tanzania. Since farmers are unable to determine the chemical content of material available care must be taken in promoting this species for pest management without first establishing efficacy. While phytochemical analysis serves as an important tool for quality control of pesticidal plants, where analytical facilities are not available simple bioassays could be developed to enable extension staff and farmers to determine the efficacy of their plants and ensure only effective materials are adopted.

scholarly journals Germination Ecology of Ivy-Leaved Morning-Glory: an Invasive Weed in Soybean Fields, Iran

2020 ◽  
Vol 38 ◽  
Author(s):  
A. SIAHMARGUEE ◽  
M. GORGANI ◽  
F. GHADERI-FAR ◽  
R. ASGARPOUR
Keyword(s):  
Seed Germination ◽  
Seedling Emergence ◽  
Chloride Concentration ◽  
Morning Glory ◽  
Limiting Factor ◽  
Burial Depth ◽  
Weed Species ◽  
Invasive Weed ◽  
Significant Difference ◽  
Alkaline Conditions

ABSTRACT: Ivy-leaved morning-glory (Ipomoea hederacea Jacq.) is an exotic species that is becoming an increasing problem in soybean fields of Golestan province, Iran. Because little information is available on the biology of this weed species in Iran, experiments were conducted to investigate the effects of different factors on seed germination and emergence of Ivy-leaved morning-glory. Maximum germination occurred at constant temperature of 20 oC (82%) and alternating temperature of 15/25 oC (94%). Germination was reduced with increasing salinity and drought stresses. Sodium chloride concentration and osmotic potential that inhibited 50% maximum germination were -1.64 and -1.03 MPa, respectively. Acidity was a limiting factor for the germination, due to inhibiting effect of alkaline conditions on germination. However, the results showed that high temperature pretreatment >100 oC decreased seed germination. Germination decreased from 82 to 3% as temperature increased from 100 to 130 oC. There was no significant difference between seedling emergence in burial depths of 1 to 10 cm, but emergence reduced with increasing burial depth from 10 to 14 cm, and no seedling was emerged from a depth of 15 cm. The results of the flooding experiment also revealed that the seeds of this species are sensitive to this stress, so that emergence was 9% after 3 d flooding.

scholarly journals The species diversity of cereal and root communities in the municipalities located in the strug river valley in Podkarpackie Voivodeship

2013 ◽  
Vol 66 (3) ◽  
pp. 89-94
Author(s):  
Maria Ziaja
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Diversity Index ◽  
River Valley ◽  
Cereal Crops ◽  
Special Importance ◽  
Weed Species ◽  
Total Species Richness ◽  
Wiener Diversity Index ◽  
Segetal Flora

The research on segetal flora and agricultural ecosystems has gained special importance in recent years, since they are an important element in biodiversity conservation. An evaluation of the status of the segetal flora was made on the basis of a study conducted in the period 1998–2002 in crop fields of four municipalities located in the Strug River valley in Podkarpackie Voivodeship. This research was carried out in root and cereal crops. Total species richness and the average number of species per relevé were determined in this study. In determining species diversity of the communities, the Shannon-Wiener diversity index (H’) was used. In cereal crops, the community <em>Vicietum tetraspermae typicum </em>was characterized by the greatest species richness (109 species), while <em>Vicietum tetraspermae consolidetosum </em>showed the lowest richness (57 species). In root crops, the association <em>Oxalido-Chenopodietum polyspermi </em>exhibited the greatest richness (78 species), whereas <em>Galinsogo-Setarietum typicum </em>the lowest richness (53 species). In the cereal communities, a total 149 of weed species were recorded, while in the root communities their total number was 97. The values of the Shannon-Wiener diversity index (H’) ranged from 3.10 to 2.42. The phytocoenoses <em>Oxalido-Chenopodietum polyspermi, Vicietum tetraspermae typicum,</em> and<em> Vicietum tetraspermae</em>, the<em> </em>variant with<em> Vicia grandiflora, </em>were characterized by the highest values of the Shannon-Wiener diversity index (H’), whereas the association <em>Galinsogo-Setarietum typicum</em> and the impoverished communities from the alliance <em>Aperion spicae-venti </em>showed the lowest values.

scholarly journals Kelimpahan Vegetasi dan Simpanan Biji Gulma pada Pertanaman Jagung Berbeda Sejarah Pola Tanam di Lahan Kering

2020 ◽  
Vol 48 (1) ◽  
pp. 22-29
Author(s):  
Andreas Kefi ◽  
Dwi Guntoro ◽  
Edi Santosa
Keyword(s):  
Seed Bank ◽  
Weed Management ◽  
Seedling Emergence ◽  
Cropping Pattern ◽  
Vegetation Analysis ◽  
Weed Species ◽  
Dry Land ◽  
Cropping Patterns ◽  
Seedling Emergence Method ◽  
History Of

Weed management is an important aspect in the dry land; however, weed resides in dry land like East Nusa Tenggara is rarely reported. The study aimed to evaluate weed species and its seed bank on maize fields from the different history of cropping patterns in order to develop effective weed control. The research was conducted in April-June 2019 at farmer fields at Kupang District, East Nusa Tenggara, Indonesia. Weeds were evaluated from four maize fields experienced a different history of cropping pattern (L1, L2, L3, and L4), and its seed bank from the depth of 0-10, 11-20, 21-30, and 31-40 cm were evaluated using seedling emergence method. The evaluation revealed 13 species at which 4 species exclusively were found in vegetation analysis, 2 species in the seed bank and 7 species in both vegetation and seed bank analysis. Dominant weed at podzolic L2 and L3 that experienced fallow for two months was Chloris barbata, while without fallow of podzolic L1 and grumusol L4 were Digitaria adscendens and Mazus japonicus, respectively. Cropping history and soil depths affected weed density, but depths of 0-20 cm had the highest density irrespective preceding the cropping pattern. Research implies both vegetation and seed bank analysis should be addressed and integrated in weed management. Keywords: dry land, fallow, weed management, East Nusa Tenggara, vegetation analysis

Vegetation diversity influences endozoochoric seed dispersal by moose (Alces alces L.)

2013 ◽  
Vol 8 (12) ◽  
pp. 1250-1264 ◽  
Author(s):  
Bogdan Jaroszewicz ◽  
Ewa Pirożnikow ◽  
Marcin Churski
Keyword(s):  
Species Richness ◽  
Seed Dispersal ◽  
Plant Species ◽  
Seedling Emergence ◽  
Pine Forest ◽  
Vegetation Diversity ◽  
Seed Content ◽  
Seedling Emergence Method ◽  
The Mean ◽  
Species Richness And Abundance

AbstractResearch on moose-mediated seed dispersal is limited. However, its potential role in transferring seeds in patchy landscapes may be of great importance. In this work we examined how seasons and vegetation diversity influence the species richness and abundance of seeds dispersed endozoochorically by moose. Samples of moose faeces were collected year-round, fortnightly, from contrasting vegetation types, dominated by diverse, species-rich wetland or poor, dry pine forest. The viable seed content of dung was studied by the seedling emergence method. The mean number of emerged seedlings per 0.8 L sample and the mean number of plant species per 0.8 L sample were several times higher in the diverse wetland vegetation than in the poor pine forest vegetation. Maximum species richness and seed abundance was observed during the fructification period, and the minimum during spring. The species richness of samples did not differ between winter and the growing season, although the composition of plant species was different. The results of this study suggest that moose are efficient seed vectors, especially of grasses typical for grasslands and wetlands. The species richness and abundance of dispersed seeds coincides with the diversity of the vegetation of the animal’s habitat.

Assemblage Patterns of Hymenoptera at Different Elevations of Gunung Datuk, Rembau

2017 ◽  
Vol 14 (2) ◽  
pp. 1 ◽  
Author(s):  
Noor Nasuha Abd Aziz ◽  
Siti Khairiyah Mohd Hatta ◽  
Idris Abd Ghani ◽  
Saiyid Jalaluddin Saiyid Shaifuddin
Keyword(s):  
Species Richness ◽  
Diversity Index ◽  
High Elevation ◽  
Significant Difference ◽  
Index Site ◽  
Evenness Index ◽  
Abundance And Diversity ◽  
Richness Index ◽  
Paired T Test ◽  
Malaise Traps

A study on abundance and diversity of Hymenoptera was conducted in Gunung Datuk, Rembau. Samplings were conducted from November 2014 to February 2015 using six Malaise traps. Three traps were placed at Site 1 at 700m height for high elevation and the remaining traps were placed at Site 2 at 200m height for low elevation. A total number of 221 Hymenopteran were collected which consist of nine families namely Ichneumonidae, Formicidae, Braconidae, Bethylidae, Evaniidae, Tiphiidae, Vespidae, Pompilidae and Apidae. In this study, 93 individuals were obtained from Site 1, comprising nine families and 43 morphospecies while 127 individuals were obtained from Site 2 with nine families and 45 morphospecies. Formicidae was the most dominant family collected from both sites with a total of 104 individuals while the least family recorded was Apidae with only one individual. Shannon’s Weiner Diversity Index (H’) showed Site 1 had the higher diversity value with H’ = 3.17 compared to Site 2 with value H’ = 3.12. For Evenness Index, Site 1 had higher value compared to Site 2 with E’ = 0.84 and E’ = 0.82 respectively. Moreover, for Margalef Richness Index, Site 1 recorded R’ = 9.24 while site two recorded R’ = 9.08 which concluded that Site 1 had higher species richness compared to Site 2. Paired t-test showed that both sites had no significant difference with p>0.05. Overall study showed that the diversity and abundance of Hymenoptera in Gunung Datuk were low since the value of H’ is less than 3.50.

Protonation effects on dynamic flux properties of aqueous metal complexes

2009 ◽  
Vol 74 (10) ◽  
pp. 1543-1557 ◽  
Author(s):  
Herman P. Van Leeuwen ◽  
Raewyn M. Town
Keyword(s):  
Complex Formation ◽  
Metal Ion ◽  
Good Description ◽  
Minor Component ◽  
Outer Sphere ◽  
Metal Species ◽  
Central Metal ◽  
Inner Sphere ◽  
A Minor ◽  
Protonated Ligand

The degree of (de)protonation of aqueous metal species has significant consequences for the kinetics of complex formation/dissociation. All protonated forms of both the ligand and the hydrated central metal ion contribute to the rate of complex formation to an extent weighted by the pertaining outer-sphere stabilities. Likewise, the lifetime of the uncomplexed metal is determined by all the various protonated ligand species. Therefore, the interfacial reaction layer thickness, μ, and the ensuing kinetic flux, Jkin, are more involved than in the conventional case. All inner-sphere complexes contribute to the overall rate of dissociation, as weighted by their respective rate constants for dissociation, kd. The presence of inner-sphere deprotonated H2O, or of outer-sphere protonated ligand, generally has a great impact on kd of the inner-sphere complex. Consequently, the overall flux can be dominated by a species that is a minor component of the bulk speciation. The concepts are shown to provide a good description of experimental stripping chronopotentiometric data for several protonated metal–ligand systems.

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