Establishment of Salsola tragus on aeolian sands: A Southern Colorado Plateau case study

2019 ◽  
Vol 12 (02) ◽  
pp. 124-132
Author(s):  
Kathryn A. Thomas ◽  
Margaret Hiza Redsteer
Keyword(s):  
Sand Dune ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Sandy Soils ◽  
Soil Surface ◽  
Summer Rainfall ◽  
Natural Areas ◽  
Growing Seasons ◽  
Surface Microtopography ◽  
Aeolian Sands

AbstractRussian-thistle (Salsola tragus L.), is a nonnative, C4 photosynthesizing, annual plant that infests disturbed and natural areas in the arid U.S. Southwest. Land managers of natural areas may need to decide whether a S. tragus infestation is potentially harmful and whether it should be actively managed. One factor informing that decision is an understanding of the conditions under which this weed emerges and establishes and how those processes affect where and when infestations occur. We studied S. tragus establishment on aeolian (windblown) sandy soils at Petrified Forest National Park, AZ. Our sites were a previously disturbed sand sheet and a semistabilized sand dune. Measurements in plots on these sites over two growing seasons revealed a similar number of S. tragus seedlings emerging on both sites early in the 2015 growing season. As the season progressed, S. tragus cover (seedling survival and growth) was lower on the sand dune, except for a plot placed entirely on a coppice mound. In 2016, S. tragus seedling emergence and development of cover, measured on plots at both sites, was exceptionally low, as was summer rainfall. A growth chamber assay of seedling emergence from soil and litter samples collected at each site showed emergence was greatest from samples collected where S. tragus litter remained on the soil surface, and otherwise was infrequent. Our study suggests that S. tragus emergence and early establishment are sensitive to low precipitation and that soil-surface microtopography and grass and shrub cover may be determinants of the spatial pattern of infestation on sandy soils. As aeolian sands occur throughout drylands of the U.S. Southwest, deeper understanding of the conditions under which S. tragus seedlings emerge and establish can inform management of this invasive annual in those habitats.

Direct seeding of PinusSylvestris using microsite preparation and invigorated seed lots of different quality: 2-year results

1994 ◽  
Vol 24 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Hans Winsa ◽  
Urban Bergsten
Keyword(s):  
Seed Quality ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Mineral Soil ◽  
Direct Seeding ◽  
Growing Seasons ◽  
Humus Layer ◽  
Negative Effect ◽  
Mean Germination Time ◽  
Better Than

Direct seeding of Pinussylvestris L. is a regeneration method, with potential for development considering scarification, microsite preparation, seed invigoration, and seed quality. Three seed lots of different quality concerning seed weight, germination percent, and mean germination time were used on two sites in northern Sweden. Microsite preparation, 2 cm deep pyramidal indentations, of the mineral soil improved seedling emergence on the two sites by 48 and 62%, respectively, compared with seeding without preparation other than removal of the humus layer. Microsite preparation in combination with invigorated seed, i.e., seed incubated at 30% moisture content for 7 days at 15 °C, resulted in seedling emergence of about 85% for the highest and about 50% for the lowest seed quality at both sites. Noninvigorated seed, seeded without microsite preparation, reached about 55% for the highest and 22% at one and 43% at the other for the lowest seed quality. Without microsite preparation there was no, or a negative, effect of seed invigoration on seedling emergence. Seedling survival after the first winter improved significantly with better seed quality. Survival averaged 92 and 72% at the two sites, with frost heaving causing most mortality. Seedlings from invigorated and redried seed survived better than seedlings from untreated seed. Seedlings from the best seed quality had higher values in seedling height, about 35%, shoot length, about 60%, and needle length, about 30%, after two growing seasons than seedlings from lower seed qualities. Invigoration and microsite preparation had no effect on measured growth characteristics.

Seed and seedling studies of three Trifolium subterraneum var. brachycalycinum lines, in a predominantly summer rainfall environment

1995 ◽  
Vol 35 (8) ◽  
pp. 1101
Author(s):  
GM Lodge
Keyword(s):  
Seed Production ◽  
Field Experiments ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Trifolium Subterraneum ◽  
Summer Rainfall ◽  
Sowing Time ◽  
Buried Seeds ◽  
Initial Seed ◽  
Total Seed

Field experiments were conducted in a predominantly summer rainfall environment to investigate burr burial, seed production, seed characteristics, seedling emergence and survival, and the effects of time of sowing on 3 Trifolium subterraneum var. brachycalycinum lines (cv. Clare and 2 local lines). Each line produced more surface than buried burrs; surface burrs were 59% (range 56-62%) of the total number of burrs recovered and produced 59% of the total seed number. Numbers of seeds per burr were similar for surface and buried burrs, however, buried seeds were 0.97 mg heavier (P<0.05) than surface seeds. Storage for 5 months at 25/60�C decreased hardseed content of surface seed by 50% and buried seed by 70%. Surface and buried seeds stored at 25/25�C for 3 months prior to sowing in trays had a total emergence of <10%, compared with 70% emergence for seeds stored at 25/60�C before sowing. These emergence differences reflected their levels of hardseededness. Numbers of seeds recovered from the soil were not significantly different among lines, declining from about 4200 seeds/m2 after initial seed set to 150 seeds/m2 by the following winter, a 97% decrease. Seed production in the second year increased seed reserves to about 8730 seeds/m2. With no further seed production, levels had declined by 93% in June 1990 and by 99% in May 1991. These data confirm the importance of annual seed production for persistence. Total seedling emergence in summer-autumn accounted for only 10% of the estimated seed production in each year. Seedling survival in summer-autumn 1988-89 was 92.7%, more than double the survival in 1989-90. The effect of sowing time on flowering was always significant, with time to first flower being highest (196 days) for the earliest sowing in March (P<0.05), progressively decreasing (P<0.05) to 108 days for the latest sowing in July. In March, April and May sowings, inflorescence numbers on the first day of flowering were similar at about 120/m2, but increased markedly (P<0.05) for sowing in June or July. However, for the March and July sowings, number of inflorescences at the 9 November 1990 count, were lowest (P<0.05). May or June sowings had the highest number of burrs and seeds (P<0.05), indicating that these may be the best sowing times for maximum seed production in these Trifolium subterraneum var. brachycalycinum lines.

Adaptations of plants to burial in coastal sand dunes

1998 ◽  
Vol 76 (5) ◽  
pp. 713-738 ◽  
Author(s):  
M A Maun
Keyword(s):  
Sand Dune ◽  
Sand Dunes ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Threshold Level ◽  
Coastal Sand Dune ◽  
Bare Area ◽  
Plant Vigour ◽  
Storage Organs ◽  
Coastal Sand

One of the most obvious features on the foredunes and strands of coasts and lakes is recurrent burial in sand. Burial levels vary in different coastal sand dune systems and influence the physical and biotic microenvironment of the plant and soil. Foredune plants along coasts possess numerous adaptations to withstand burial. Studies show that below a certain threshold level of burial, the growth of all foredune plant species is stimulated probably because of multiple factors, namely improved soil resources, increase in soil volume, reactive plant growth, and enhanced mycorrhizal activity. However, as the level of burial increases, the positive response starts to decline until it becomes a negative value. For example, burial may reduce seed germination, seedling emergence, survival, and growth of seedlings and adult plants. At the community level, burial acts as a filter and selectively eliminates susceptible species, reduces the relative abundance of less tolerant species, and increases the abundance of tolerant and sand-dependent species. However, if sand deposition continues unabated, even the sand-dependent species are eliminated and a bare area is created. The emergence of a plant from a burial deposit primarily depends on the energy reserves in its storage organs and the speed, depth, and frequency of burial. Upon burial the plants shift resources from the belowground to the aboveground parts. Different plants show varied morphological responses to sand accretion. For example, the culms of grasses emerge by an increase in the number of nodes per culm and the elongation of internodes. Similarly, the emergent trunks and woody branches of tolerant trees and shrubs produce new buds and suckers at a higher level on the stem. In response to burial, the coastal sand dune species produce shootborne roots close to the new soil surface probably because of decreased oxygen levels.Key words: sand accretion, adaptations to burial, zonation of vegetation, burial of seeds, plant vigour, impact on communities, modes of emergence.

Growth, Development, and Seed Biology of Feather Fingergrass (Chloris virgata) in Southern Australia

Weed Science ◽  
2017 ◽  
Vol 65 (3) ◽  
pp. 413-425 ◽  
Author(s):  
The D. Ngo ◽  
Peter Boutsalis ◽  
Christopher Preston ◽  
Gurjeet Gill
Keyword(s):  
Seedling Emergence ◽  
Soil Surface ◽  
Summer Rainfall ◽  
Management Program ◽  
Field Conditions ◽  
Shoot Biomass ◽  
Base Temperature ◽  
Weed Species ◽  
Seed Biology ◽  
Growth Development

Feather fingergrass is a major weed in agricultural systems in northern Australia and has now spread to southern Australia. To better understand the biology of this emerging weed species, its growth, development, and seed biology were examined. Under field conditions in South Australia, seedlings that emerged after summer rainfall events required 1,200 growing degree days from emergence to mature seed production and produced 700 g m−2shoot biomass. Plants produced up to 1,000 seeds panicle−1and more than 40,000 seeds plant−1, with seed weight ranging from 0.36 to 0.46 mg. Harvested seeds were dormant for a period of about 2 mo and required 5 mo of after-ripening to reach 50% germination. Freshly harvested seed could be released from dormancy by pretreatment with 564 mM sodium hypochlorite for 30 min. Light significantly increased germination. Seed could germinate over a wide temperature range (10 to 40 C), with maximum germination at 15 to 25 C. At 20 to 25 C, 50% germination was reached within 2.7 to 3.3 d, and the predicted base temperature to germinate was 2.1 to 3.0 C. The osmotic potential and NaCl concentration required to inhibit germination by 50% were −0.16 to −0.20 MPa and 90 to 124 mM, respectively. Seedling emergence was highest (76%) for seeds present on soil surface and was significantly reduced by burial at 1 (57%), 2 (49%), and 5 cm (9%). Under field conditions, seeds buried in the soil persisted longer than those left on the soil surface, and low spring–summer rainfall increased seed persistence. This study provides important information on growth, development, and seed biology of feather fingergrass that will contribute to the development of a more effective management program for this weed species in Australia.

Redistribution of water following precipitation on previously dry sandy soils

Soil Research ◽  
1975 ◽  
Vol 13 (1) ◽  
pp. 13 ◽  
Author(s):  
BA Carbon
Keyword(s):  
Soil Water ◽  
Seedling Emergence ◽  
Soil Water Potential ◽  
Sandy Soils ◽  
Soil Surface ◽  
Field Capacity ◽  
Wetting Front ◽  
Applied Water ◽  
Dry Soil ◽  
The Relationship

Theoretical and experimental evidence is provided to show that the redistribution of a given amount of water some days after infiltration into a previously dry soil can be predicted, provided that the relationship between soil water potential and soil water content is known. The capillary potential at the wetting front during infiltration into the dry soil is also required. In sandy soils an increase in amount of applied water leads to a decrease in the soil moisture content at the soil surface. This change in 'field capacity' as a function of applied water is shown to strongly influence seedling emergence.

scholarly journals PHYSICAL PROTECTOR IN DIRECT SOWING OF BARU INFLUENCING IN THE INITIAL GROWTH OF THE SEEDLINGS

2018 ◽  
Vol 5 (4) ◽  
pp. 20-25
Author(s):  
Rogério Costa da Silva ◽  
Ana Paula Leite de Lima ◽  
Sebastião Ferreira de Lima ◽  
Guilherme Marchesini Trevizani ◽  
João Batista Leite Junior
Keyword(s):  
Seedling Survival ◽  
Block Design ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Stem Diameter ◽  
Initial Growth ◽  
Randomized Complete Block Design ◽  
Number Of Leaves ◽  
Direct Sowing

The objective of this study was to evaluate the influence of using physical protectors on the emergence and initial growth of Baru seedlings in a direct sowing system. The experiment was installed in a randomized complete block design, testing the use of physical protectors (no protection, P0; plastic cup (500 mL) without the bottom, P1; laminated wood, P2), with 12 repetitions. Weekly soil temperature monitoring was carried out in the morning and in the afternoon in the period between 14 and 56 days after sowing (DAS). Daily emergence follow-up was also performed, and the stem diameter, total height and number of leaves were measured at 81 DAS. The use of physical protectors in the direct seeding of Baru interfered in the soil surface temperature on the sowing point, on the seedling emergence speed index, seedling survival, stem diameter and seedling height. Implementing protectors slowed the seedling emergence speed, however it provided higher percentages of emergence, survival and greater growth in diameter and height.

Amelioration of subsurface acidity in sandy soils in low rainfall regions .1. Responses of wheat and lupins to surface-applied gypsum and lime

Soil Research ◽  
1994 ◽  
Vol 32 (4) ◽  
pp. 835 ◽  
Author(s):  
CDA Mclay ◽  
GSP Ritchie ◽  
WM Porter
Keyword(s):  
Sandy Soils ◽  
Soil Surface ◽  
Field Trials ◽  
Application Rate ◽  
Growing Seasons ◽  
Application Rates ◽  
Lime Application ◽  
Water Holding ◽  
Different Sources ◽  
Gypsum Application

Amelioration of subsoil acidity using gypsum (CaSO4.2H2O) or lime (CaCO3) was studied on sandy textured soils with low water holding capacity in a low rainfall environment. Field trials were established in 1989 at two sites on yellow sandplain soils to investigate whether different rates, sources and combinations of gypsum and lime application could be used to increase wheat and lupin yields. Gypsum increased wheat yields by up to 45% in the first two growing seasons whereas lime increased wheat yields by up to only 15% in the second season. The highest yields were generally recorded when gypsum and lime were applied together. The response of wheat to the various treatments varied both regionally and temporally and it is suggested that the inherent soil solution composition affected the magnitude and rapidity of wheat responses to gypsum. The rate of gypsum application affected the longevity of the wheat responses, with a low application rate (1 t ha-1) increasing yields for only one season. No differences in wheat yields were recorded between different sources of gypsum or application rates higher than 3 t ha-1. In contrast to wheat, lupin yields were substantially lower on gypsum-treated plots. The yield decline did not appear to be related to any simple nutritional factor and the gypsum effect was generally minimized when lime was added with the gypsum. The results indicated that lower rates of gypsum than used in previous subsoil amelioration studies were suitable for increasing wheat yields on sandy soils in low rainfall environments, and that gypsum should not be used if lupins are to be grown within at least 2 years of its application to the soil surface.

Influence of selected environmental factors on seed germination and seedling survival of the arid zone invasive species tobacco bush (Nicotiana glauca R. Graham)

2016 ◽  
Vol 38 (4) ◽  
pp. 417 ◽  
Author(s):  
Singarayer K. Florentine ◽  
Sandra Weller ◽  
Patrick F. Graz ◽  
Martin Westbrooke ◽  
Arunthathy Florentine ◽  
...  
Keyword(s):  
Invasive Species ◽  
Heat Shock ◽  
Seed Germination ◽  
Arid Zone ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Stress Factors ◽  
Burial Depth ◽  
Nicotiana Glauca

Tobacco bush (Nicotiana glauca R. Graham) is an aggressive invading species, which is active after disturbances such as high rainfall events and flooding. Past studies have focussed on population dynamics and allelopathic effects associated with the species, but little is known about its seed ecology. To address this dearth of information, this study aimed to investigate: (i) the effect of various stress factors (temperature, light, osmotic potential, salt stress, heat-shock, a combination of heat-shock and smoke, pH buffer, and burial depth of seed) on seed germination and seedling emergence, and (ii) factors affecting the fate of seedlings. The results show that N. glauca was able to germinate over a broad range of temperatures with highest seed germination occurring at 30/20°C with 12 h of light and 12 h of dark conditions. Seed germination was greatest (89%) when seeds were placed on the soil surface and emergence decreased considerably as planting depth increased from 0.5 to 1.5 cm. Water stress greatly reduced seed germination (58% germination at osmotic potentials below –0.2 MPa) and germination was completely inhibited at water potentials of –0.4 to –0.6 MPa. Although increasing salinity reduced the seed germination of this invasive species, N. glauca seed was able to germinate in both alkaline (81% at pH 10) and acidic (80% at pH 4) conditions. The trial on the effect of seed age and field seed burial on seed germination showed a slight decline in seed germination after 120 days of burial compared with non-buried seeds. Further, the combined effect of heat-shock and smoke effectively inhibited the germination of N. glauca seeds; however, our study shows that seedlings of N. glauca can withstand heat-shock of up to 130°C. Studies such as this will assist in the development of control strategies to prevent the spread of this invasive species into arid landscapes.

scholarly journals Effects of High Soil Surface Temperature on Seedling Survival in Pearl Millet

1993 ◽  
Vol 29 (2) ◽  
pp. 215-225 ◽  
Author(s):  
J. M. Peacock ◽  
P. Soman ◽  
R. Jayachandran ◽  
A. U. Rani ◽  
C. J. Howarth ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Pearl Millet ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Soil Moisture Deficit ◽  
High Soil ◽  
Moisture Deficit ◽  
Seedling Emergence And Survival ◽  
Soil Surface Temperature

SummaryA field technique to screen pearl millet genotypes for their emergence and survival at high soil surface temperatures is described. Genetic variation in seedling emergence and survival is shown and it is argued that this variation is largely due to tolerance of high temperatures rather than tolerance of soil moisture deficit, although some interaction occurred. An index for ‘thermotolerance’ is defined and genotypes are ranked accordingly for this trait, which is shown to be highly heritable. The technique is repeatable and allows a large number of genotypes to be screened at the same time.

scholarly journals Effect of tillage, slope, and rainfall on soil surface microtopography quantified by geostatistical and fractal indices during sheet erosion

2020 ◽  
Vol 12 (1) ◽  
pp. 232-241
Author(s):  
Na Ta ◽  
Chutian Zhang ◽  
Hongru Ding ◽  
Qingfeng Zhang
Keyword(s):  
Surface Roughness ◽  
Fractal Dimension ◽  
Soil Surface ◽  
Rainfall Events ◽  
Tillage Practices ◽  
Surface Microtopography ◽  
Artificial Rainfall ◽  
Soil Surface Roughness ◽  
The Difference ◽  
Sheet Erosion

AbstractTillage and slope will influence soil surface roughness that changes during rainfall events. This study tests this effect under controlled conditions quantified by geostatistical and fractal indices. When four commonly adopted tillage practices, namely, artificial backhoe (AB), artificial digging (AD), contour tillage (CT), and linear slope (CK), were prepared on soil surfaces at 2 × 1 × 0.5 m soil pans at 5°, 10°, or 20° slope gradients, artificial rainfall with an intensity of 60 or 90 mm h−1 was applied to it. Measurements of the difference in elevation points of the surface profiles were taken before rainfall and after rainfall events for sheet erosion. Tillage practices had a relationship with fractal indices that the surface treated with CT exhibited the biggest fractal dimension D value, followed by the surfaces AD, AB, and CK. Surfaces under a stronger rainfall tended to have a greater D value. Tillage treatments affected anisotropy differently and the surface CT had the strongest effect on anisotropy, followed by the surfaces AD, AB, and CK. A steeper surface would have less effect on anisotropy. Since the surface CT had the strongest effect on spatial variability or the weakest spatial autocorrelation, it had the smallest effect on runoff and sediment yield. Therefore, tillage CT could make a better tillage practice of conserving water and soil. Simultaneously, changes in semivariogram and fractal parameters for surface roughness were examined and evaluated. Fractal parameter – crossover length l – is more sensitive than fractal dimension D to rainfall action to describe vertical differences in soil surface roughness evolution.

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