Ramet spacing of Elymus lanceolatus (thickspike wheatgrass) in response to neighbour density

2001 ◽  
Vol 79 (9) ◽  
pp. 1122-1126 ◽  
Author(s):  
L David Humphrey ◽  
David A Pyke
Keyword(s):  
Clonal Growth ◽  
Soil Resource ◽  
High Resource ◽  
Elymus Lanceolatus ◽  
Second Year ◽  
Resource Levels ◽  
Resource Patches ◽  
Physical Resistance ◽  
Clonal Foraging ◽  
Field Plots

Many plants exploit patchy resources through clonal foraging. Plants established in field plots were used to determine if Elymus lanceolatus ssp. lanceolatus (Scribner et J.G. Smith) Gould (thickspike wheatgrass) showed a clonal foraging response to neighbour densities, as it had previously shown to patchy soil nutrients. Neighbours consisted of the rhizomatous E. lanceolatus ssp. lanceolatus and the bunchgrass Elymus lanceolatus ssp. wawawaiensis (Scribner et Gould) J.R. Carlson et D.R. Dewey (proposed name), which are both native to the semiarid western U.S.A., and their ratios as well as total densities varied. Rather than an increase in spacing of exploratory ramets at high densities, as expected with clonal foraging, there was a decrease in spacing in both years of the experiment. Fewer target plants produced exploratory ramets at higher densities only in the second year. These reductions in exploratory clonal growth at higher neighbour densities, which were opposite to E. lanceolatus ssp. lanceolatus' response to low-resource patches, occurred perhaps because soil resource levels were too low overall to support rhizome production, and this condition was more pronounced in the second year. Physical resistance from neighbour roots perhaps also reduced rhizome production. However, rhizome growth may not be beneficial in such cases, and plants may be adapted to produce exploratory rhizomes only when some high-resource patches are encountered by the clone.Key words: clonal growth, competition, Elymus lanceolatus, plasticity, resource levels, rhizomes.

Studies on the Reproductive Biology of Leafy Spurge (Euphoriba esula)

Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 106-109 ◽  
Author(s):  
L. A. Morrow
Keyword(s):  
Soil Moisture ◽  
Dry Matter ◽  
Perennial Grass ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
First Year ◽  
Growth Room ◽  
Available Soil Moisture ◽  
Second Year ◽  
Field Plots

Studies on the development of leafy spurge (Euphorbia esula L.) were conducted in the field and growth room. Sixteen months after planting in field plots, leafy spurge plants arising from underground bud-producing root segments, transplanted seedlings, or seeds averaged 96, 83, and 136 shoots per plant, respectively, when grown free of interference from other vegetation. A number of plants arising from each source flowered the first year, and all plants flowered and produced seed the second year after planting. When grown in a perennial grass sod consisting of crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult.] and smooth brome (Bromus inermis Leyss.), no plant flowered or produced additional shoots. Soil moisture was less where a dense sod was present. In the growth room, total dry matter of tops and roots was greatest at a soil temperature of 18.3 C or higher, and plant height was greatest at 33.3 C. An early emerging crop might suppress leafy spurge by utilizing the available soil moisture early in the growing season.

Resource transport between ramets alters soil resource pattern: a simulation study on clonal growth

2004 ◽  
Vol 18 (5-6) ◽  
pp. 469-492 ◽  
Author(s):  
Gabriella Magyar ◽  
Miklós Kertész ◽  
Beáta Oborny
Keyword(s):  
Simulation Study ◽  
Clonal Growth ◽  
Soil Resource

scholarly journals Extrafloral nectary phenotypic plasticity is damage- and resource-dependent in Vicia faba

2006 ◽  
Vol 2 (4) ◽  
pp. 583-585 ◽  
Author(s):  
Edward B Mondor ◽  
Michelle N Tremblay ◽  
Russell H Messing
Keyword(s):  
Phenotypic Plasticity ◽  
Vicia Faba ◽  
General Pattern ◽  
Leaf Tissue ◽  
Leaf Damage ◽  
High Resource ◽  
Resource Limited ◽  
Npk Fertilizer ◽  
Resource Levels ◽  
Secretion Rates

Phenotypic plasticity enables many damaged plants to increase nectar secretion rates from extrafloral nectaries (EFNs), or in the case of broad bean, Vicia faba L., to produce additional EFNs, to attract natural enemies of herbivores. While plants benefit greatly from these defensive mutualisms, the costs of producing EFNs are largely unknown. We hypothesized that if EFN production is costly, then damaged plants with high resource levels would be able to produce more EFNs than plants that are resource-limited. Here, we show that this indirect inducible defence does follow this general pattern. Vicia faba enriched with 6 or 12 g of 14 : 14 : 14 NPK fertilizer increased EFN numbers after leaf damage by 46 and 60%, respectively, compared with nutrient-poor plants. Thus, EFN production is both damage- and resource-dependent. Analogous to direct defences, production of EFNs may limit the overall loss of leaf tissue when risk of herbivory increases.

scholarly journals Effects of fragmentation of clones compound over vegetative generations in the floating plant Pistia stratiotes

2020 ◽  
Vol 127 (1) ◽  
pp. 123-133
Author(s):  
Michael Opoku Adomako ◽  
Peter Alpert ◽  
Dao-Lin Du ◽  
Fei-Hai Yu
Keyword(s):  
Clonal Growth ◽  
Clonal Plants ◽  
Physiological Integration ◽  
Pistia Stratiotes ◽  
Morphological Properties ◽  
Nutrient Level ◽  
Negative Effects ◽  
Nutrient Levels ◽  
Growth Properties ◽  
Resource Levels

Abstract Background and Aims Clonal plants dominate many plant communities, especially in aquatic systems, and clonality appears to promote invasiveness and to affect how diversity changes in response to disturbance and resource availability. Understanding how the special physiological and morphological properties of clonal growth lead to these ecological effects depends upon studying the long-term consequences of clonal growth properties across vegetative generations, but this has rarely been done. This study aimed to show how a key clonal property, physiological integration between connected ramets within clones, affects the response of clones to disturbance and resources in an aquatic, invasive, dominant species across multiple generations. Methods Single, parental ramets of the floating stoloniferous plant Pistia stratiotes were grown for 3 weeks, during which they produced two or three generations of offspring; connections between new ramets were cut or left intact. Individual offspring were then used as parents in a second 3-week iteration that crossed fragmentation with previous fragmentation in the first iteration. A third iteration yielded eight treatment combinations, zero to three rounds of fragmentation at different times in the past. The experiment was run once at a high and once at a low level of nutrients. Results In each iteration, fragmentation increased biomass of the parental ramet, decreased biomass of the offspring and increased number of offspring. These effects persisted and compounded from one iteration to another, though more recent fragmentation had stronger effects, and were stronger at the low than at the high nutrient level. Fragmentation did not affect net accumulation of mass by groups after one iteration but increased it after two iterations at low nutrients, and after three iterations at both nutrient levels. Conclusions Both the positive and negative effects of fragmentation on clonal performance can compound and persist over time and can be stronger when resource levels are lower. Even when fragmentation has no short-term net effect on clonal performance, it can have a longer-term effect. In some cases, fragmentation may increase total accumulation of mass by a clone. The results provide the first demonstration of how physiological integration in clonal plants can affect fitness across generations and suggest that increased disturbance may promote invasion of introduced clonal species via effects on integration, perhaps especially at lower nutrient levels.

Benzene Hexachloride (BHC) as a Rapid Control Agent for White Grubs (Phyllophaga spp.)

1949 ◽  
Vol 81 (8) ◽  
pp. 200-201
Author(s):  
G. H. Hammond
Keyword(s):  
Control Agent ◽  
White Grub ◽  
White Grubs ◽  
Feeding Level ◽  
Control Value ◽  
Rapid Control ◽  
Benzene Hexachloride ◽  
Second Year ◽  
Suitable Area ◽  
Field Plots

The effectiveness of benzene hexachloride (BHC) when applied to pasture sod as a control for June beetles was demonstrated (1) during 1947 at Marmora. Tests were continued during 1948 to determine the control value of the same contact insecticide against second-year, second- and third-instar larvae at the summer-feeding level in sod land.A block of field plots was laid out in a pasture which was so severely infested by second-year grubs that it was expected to show most extensive destruction of sod before the end of the summer. It was considered as a most suitable area to determine the efficiency of BHC, in terms of sod protection and white grub mortality.

Endophytic fungus fine-tunes the persistence strategy of its alpine host grass in response to soil resource levels

Oikos ◽  
2012 ◽  
Vol 122 (3) ◽  
pp. 367-376 ◽  
Author(s):  
Anaïs Gibert ◽  
Danièle Magda ◽  
Laurent Hazard
Keyword(s):  
Endophytic Fungus ◽  
Soil Resource ◽  
Resource Levels
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