scholarly journals Interacting Flooding and Competition Negatively Affect Growth of Riparian Species Dominating a Reservoir Shoreline

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1471
Author(s):  
Yu-Han Chen ◽  
Xin-Sheng Sun ◽  
Yuan Cui ◽  
Na Zhuo ◽  
Guan-Wen Wei ◽  
...  
Keyword(s):  
Interspecific Competition ◽  
Chlorophyll Content ◽  
Intraspecific Competition ◽  
Total Biomass ◽  
Plant Interactions ◽  
Polygonum Hydropiper ◽  
Riparian Species ◽  
Xanthium Sibiricum ◽  
Topographic Positions ◽  
Photosynthetic Capacities

Plant–plant interactions change in response to environmental conditions, and riparian species are commonly influenced by flooding. This study tested whether flooding affects the intraspecific and interspecific competition of two riparian species and whether such effects depend on the topographic positions where plants have established. Seeds of the riparian species Polygonum hydropiper were collected from both low and high positions within the shoreline of the Three Gorges Reservoir. Groups of P. hydropiper seedlings from each position were either grown alone (i.e., without competition), with another group of P. hydropiper seedlings (i.e., intraspecific competition), or with a group of seedlings of the companion species Xanthium sibiricum (i.e., interspecific competition). Each group comprised six replicates. In total, 288 plants of P. hydropiper and 84 plants of X. sibiricum were selected for the experiment. Seedlings were subjected to control and flooding treatments for 60 days. Irrespective of competition type (i.e., intra- or interspecific), both flooding and competition negatively affected the growth and/or photosynthetic capacities of P. hydropiper. Flooding only interacted with competition to explain total biomass. Flooding reduced total biomass in a larger proportion in the absence of competition, and, to a lesser extent, with intraspecific competition, compared to interspecific competition. However, such interaction effects were independent of the positions where the seeds that originated from the plants were collected from. Interspecific competition significantly decreased the chlorophyll content and photosynthetic efficiency of plants, while intraspecific competition did not. In general, plants from lower positions had higher total chlorophyll content than plants from higher positions. These results suggest that flooding may regulate the population dynamics of P. hydropiper by altering its competitive interactions.

scholarly journals Seeding year alfalfa population development as influenced by weed competition and density of establishment

1980 ◽  
Vol 52 (4) ◽  
pp. 403-422
Author(s):  
Seppo Pulli
Keyword(s):  
Interspecific Competition ◽  
Intraspecific Competition ◽  
Competitive Ability ◽  
Plant Competition ◽  
Maximum Yield ◽  
Michigan State University ◽  
Total Biomass ◽  
State University ◽  
Seeding Rate ◽  
Yield Level

The research in intraspecific competition within an alfalfa stand and interspecific competition between alfalfa and weeds was begun on the Michigan State University farm in East Lansing in 1972. Alfalfa seeding densities of 50, 400 and 800 seeds/m2 were used to determine intraspecific competition. Interspecific competition between alfalfa and weeds occurred mainly in noncontrolled alfalfa stands at various levels of seeding densities. Plant competition was evaluated with importance values and with relative crowding coefficients. Both measurements were found to be suitable for this kind of study. Importance values primarily indicated the quantity relationships of different species. Relative crowding coefficients mainly characterized the competitive ability of a species in a mixed stand. The importance of alfalfa exceeded the importance of weeds in noncontrolled and herbicide controlled stands at the seeding rates of 14 and 7 kg/ha respectively. Relative crowding coefficients show the competitive ability of alfalfa with regard to weeds. In the case of intraspecific competition there was no change in the crowding coefficient of alfalfa in respect of weeds when the seeding rate of alfalfa was increased beyond 9 kg/ha. The crowding coefficient of weeds presented equal values under all treatments thereby indicating the variability and plasticity of weeds. The maximum yield level was obtained in all treatments with the alfalfa seeding rate of 9 kg/ha. The total biomass production per unit area was equal in the noncontrolled system at all seeding densities and in the herbicide controlled system at seeding rates of 9 kg/ha or more.

Competition and the response of three plant species to a salinity gradient

1991 ◽  
Vol 69 (11) ◽  
pp. 2497-2502 ◽  
Author(s):  
N. C. Kenkel ◽  
A. L. McIlraith ◽  
C. A. Burchill ◽  
G. Jones
Keyword(s):  
Salt Tolerance ◽  
Interspecific Competition ◽  
Poa Pratensis ◽  
Salinity Gradient ◽  
Belowground Biomass ◽  
Peak Performance ◽  
Total Biomass ◽  
Salinity Response ◽  
Hordeum Jubatum ◽  
Puccinellia Nuttalliana

Three grasses (Poa pratensis, Hordeum jubatum, and Puccinellia nuttalliana) were grown in monoculture and three-species mixture at each of eight salinity levels in a controlled environment chamber. In monoculture, all species grew best when no salts were added to the nutrient medium. When salts were added the species showed differing degrees of salt tolerance. Percent decreases in total biomass with increasing salinity and shifts in aboveground to belowground biomass ratios suggested increased salt tolerance in the order P. pratensis < H. jubatum < P. nuttalliana. In mixture, all species showed a significant change in salinity response when compared with their responses in monoculture. Interspecific competition resulted in P. pratensis being suppressed at all but the lowest salinities. Hordeum jubatum showed the least suppression at intermediate salinities, while P. nuttalliana was least suppressed at the highest salinities. These results indicate that interspecific competition results in a shift in the peak performance of more salt-tolerant species toward the high end of the salinity gradient. The species distributions in our experimental mixtures reflected those observed in the field, suggesting that competition plays an important role in structuring inland saline plant communities. Key words: halophyte, glycophyte, community, Hordeum jubatum, Puccinellia nuttalliana, Poa pratensis.

Competition betweenElymus elymoidesandTaeniatherum caput-medusae

Weed Science ◽  
1999 ◽  
Vol 47 (6) ◽  
pp. 720-728 ◽  
Author(s):  
David W. Clausnitzer ◽  
Michael M. Borman ◽  
Douglas E. Johnson
Keyword(s):  
Soil Moisture ◽  
Interspecific Competition ◽  
Seed Production ◽  
Intraspecific Competition ◽  
Field Experiments ◽  
Block Design ◽  
Low Oxygen ◽  
Competitive Effects ◽  
Growing Seasons ◽  
Randomized Block Design

Two field experiments were conducted from 1993–1994 through 1995–1996 growing seasons in Harney County, OR, to determine the relative competitive abilities ofElymus elymoides(squirreltail) a native perennial range grass, andTaeniatherum caput-medusae(medusahead), an exotic annual grass weed. The 1993–1994 growing season was very dry, 1994–1995 was dry, and 1995–1996 was wetter than average. One experiment tested seedlings vs. seedlings in each of three seasons. The second experiment tested seedlings plus second- and third-year establishedE. elymoidesplants vs. 77caput-medusaeover 2 yr. Biomass, seed production, and soil moisture utilization 15, 30, 45, and 60 cm deep by the two species were measured. A randomized block design with factorial arrangement was used, with 25 2.25-m2plots per block. Initial seeding densities of each species were 0, 10, 74, 550, and 4,074 seeds m−2in all combinations of density. In the seedling vs. seedling experiment, intraspecific competition by 77caput-medusaeon itself was always significant (P ≤ 0.10) for both biomass and seed production. Interspecific competition byE. elymoidesseedlings onT. caput-medusaebiomass and seed production was not significant (P ≥ 0.10) in 2 of 3 yr and was always less than intraspecific competition by 77caput-medusae. Only 0.4% ofE. elymoidesseed germinated, and no seed was produced in the very dry first year, but 84% of remaining seed was viable for the next year, which had better moisture conditions for germination and establishment. Interspecific competition affected (P ≤ 0.10)E. elymoidesseedling biomass and seed production throughout the study. Intraspecific competition affected (P ≤ 0.10) seedlingE. elymoidesseed production in the dry year but not in the wetter than average year. In the matureE. elymoidesexperiment, intraspecific competition byT. caput-medusaeon weight and seed production per plant was greater than interspecific competition fromE. elymoides. Seedling/matureE. elymoidesreducedT. caput-medusaeweight per plant in the dry year but the effect was not biologically significant. Larger, matureEelymoidesplants produced 600 to 3,000 seeds per plant during the wet year; neither intra- nor interspecific competition was a factor.Taeniatherum caput-medusaewas better able to access deeper soil moisture and was more aggressive at extracting soil moisture than wereE. elymoidesseedlings in the wet year. Cold soils and low oxygen due to wet soils may have restrictedE. elymoidesseedling root activity. MatureE. elymoidesplants did not appear restricted by cold soils or low oxygen. Established second- and third-yearE. elymoidesplants were able to compete for soil moisture down to 45 cm. The generally greater interspecific competitive effects ofT. caput-medusaeonE. elymoidesthan vice versa suggested that it will be difficult to establish anE. elymoidesstand in an existingT. caput-medusaecommunity without first suppressingT. caput-medusae. IndividualE. elymoidesplants did establish and were productive with and withoutT. caput-medusaecompetition.

Plant Water Stress of Soybean (Glycine max) and Common Cocklebur (Xanthium pensylvanicum): A Comparison Under field Conditions

Weed Science ◽  
1979 ◽  
Vol 27 (3) ◽  
pp. 285-289 ◽  
Author(s):  
H. D. Scott ◽  
R. D. Geddes
Keyword(s):  
Glycine Max ◽  
Water Stress ◽  
Interspecific Competition ◽  
Intraspecific Competition ◽  
Vegetative Growth ◽  
Species Differences ◽  
Plant Water ◽  
Plant Water Stress ◽  
Diffusive Resistance ◽  
Early Afternoon

The study was conducted to determine the seasonal and diurnal water stress of soybeans [Glycine max (L.) Merr. ‘Lee 74′] grown under intraspecific competition (competition between plants of the same species) and interspecific competition (competition between plants of different species) with common cocklebur (Xanthium pensylvanicum Wallr.). Midday xylem potentials decreased as the season progressed and were lower in common cocklebur during vegetative growth of soybean and in soybean during reproductive growth. For a given species differences in xylem potential due to mode of competition were small. In the diurnal studies xylem potential for each species decreased to a minimum in the early afternoon but recovered to the original pre-dawn values at night. As the season progressed leaf xylem potential (a) decreased at a greater rate, (b) decreased sooner in the day, and (c) recovered at a slower rate. It was shown that differences in xylem potential between soybean and common cocklebur on a given day were small. Greater diffusive resistance values generally were found with soybean than with common cocklebur and with each species grown under interspecific competition.

Competition between endoparasitic nematodes and effect on biomass of Ammophila arenaria (marram grass) as affected by timing of inoculation and plant age

Nematology ◽  
2005 ◽  
Vol 7 (2) ◽  
pp. 169-178 ◽  
Author(s):  
Wim van der Putten ◽  
Henk Duyts ◽  
E. Pernilla Brinkman
Keyword(s):  
Interspecific Competition ◽  
Intraspecific Competition ◽  
Plant Biomass ◽  
Nematode Species ◽  
Pratylenchus Penetrans ◽  
Agricultural Systems ◽  
Ammophila Arenaria ◽  
Marram Grass ◽  
Natural Dune ◽  
Dune Grass

AbstractWe studied the effects of intra- and interspecific competition on the abundance of endoparasitic nematodes and assessed the consequences for biomass production of the natural dune grass Ammophila arenaria. Pratylenchus penetrans was limited by intraspecific competition and it suppressed the abundance of Heterodera arenaria, whilst the interaction between H. arenaria and Meloidogyne maritima was neutral. Pratylenchus penetrans and H. arenaria reduced plant biomass, whereas M. maritima did not. Plant biomass was not differently affected by adding one or two nematode species. When added to older plants, numbers of H. arenaria and M. maritima were higher but numbers of P. penetrans were lower, resulting in less reduction of plant biomass. We discuss our results on this natural system with respect to patterns of interspecific nematode competition observed in agricultural systems.

Total chlorophyll, growth and productivity of soybean [Glycine Max (L) Merril] under different levels and sources of phosphorus and plant growth regulators in south Rajasthan, India

2016 ◽  
Author(s):  
Shankar Lal Khaswan ◽  
R. K. Dubey ◽  
R. C. Tiwari ◽  
S. K. Dubey ◽  
Raj Kumari Chaudhary
Keyword(s):  
Plant Growth ◽  
Chlorophyll Content ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Total Biomass ◽  
Total Chlorophyll ◽  
Water Spray ◽  
Benzyl Adenine ◽  
Total Chlorophyll Content ◽  
Different Levels

An experiment was conducted at the Instructional Farm of Rajasthan College of Agriculture, Udaipur during Kharif 2009 and 2010 on medium clay loam soils to assess the influence of different levels and sources of phosphorus fertilization as well as plant growth regulators on productivity of soybean. Twenty seven treatments i.e. three levels (20, 30 and 40 kg P2O5 ha-1) and three sources (Single super phosphate or SSP; phosphorus rich organic manure or PROM and di-ammonium phosphate or DAP) of phosphorus in main plots and three PGRs (water spray, benzyl adenine 50 ppm and NAA 100 ppm) in sub plots of a split plot design having three replications. Results revealed that application of 40 kg P2O5 ha-1 recorded significantly higher pooled yield (q ha-1) of grain (25.95), stover (37.34) and total biomass (63.29); crop growth rate or CGR (g m-2day-1) between 30-60 days after sowing ( DAS)(18.83) and 61-90 DAS (11.96); total chlorophyll content at 45 DAS (2.26%) and 60 DAS (2.80%); Leaf area index(LAI) at 45 DAS (1.56) and 60 DAS (3.44) and green leaves plant-1 at 45 DAS (11.98) and 60 DAS (21.43). Among different phosphorus sources, SSP outperformed DAP and PROM on pooled yield (q ha-1) of grain (25.12), stover (36.23) and total biomass (61.35); CGR (g m-2day-1) between 30-60 DAS (11.22) and 61-90 DAS (10.94); total chlorophyll content at 45 DAS (2.26%) and 60 DAS (2.76%); LAI at 45 DAS (1.51) and 60 DAS (3.42) and green leaves plant-1 at 45 DAS (11.77) and 60 DAS (21.35). Foliar application of NAA recorded significantly higher pooled yield (q ha-1) of grain (24.23), stover (35.73) and total biomass (60.01) than benzyl adenine and water spray. However, variations recorded under NAA and benzyl adenine in CGR, total chlorophyll content, LAI and green leave plant-1at different stages of soybean crop were statistically at par.

Influence of Phosphorus Fertility on Intra- and Interspecific Interference between Lettuce (Lactuca sativa) and Spiny Amaranth (Amaranthus spinosus)

Weed Science ◽  
1994 ◽  
Vol 42 (4) ◽  
pp. 574-578 ◽  
Author(s):  
James W. Shrefler ◽  
Donn G. Shilling ◽  
Joan A. Dusky ◽  
Barry J. Brecke
Keyword(s):  
Interspecific Competition ◽  
Lactuca Sativa ◽  
Intraspecific Competition ◽  
Relative Yield ◽  
Shoot Biomass ◽  
Low Density ◽  
Yield Analysis ◽  
Amaranthus Spinosus ◽  
Affected Relative

Greenhouse studies were conducted to determine the effect of phosphorus (P) fertility on intra- and interspecific competition between lettuce and spiny amaranth for 4 wk after emergence. Total lettuce shoot biomass per pot and weight per plant increased 39 and 44% in response to increased P fertility, respectively. P fertility had no impact on growth of spiny amaranth. Total shoot biomass of spiny amaranth increased with increasing density from four to eight plants, however, lettuce did not. Total shoot biomass of both species increased as density increased from 4 to 16 plants. Spiny amaranth, but not lettuce, weight per plant decreased in response to intraspecific competition. Reciprocal yield analysis showed that spiny amaranth produced 2.4 times more biomass than lettuce when competing intraspecifically and four times more biomass under interspecific competition. Lettuce weight per plant was not affected. Relative yield analysis indicated that spiny amaranth was more competitive than lettuce regardless of P fertility. However, increased P fertility increased competitiveness of lettuce. Relative crowding coefficients indicated that spiny amaranth at the low density with low P fertility was 33 times more competitive than lettuce. Addition of P caused lettuce and spiny amaranth to be equally competitive at the lowest density; however, at the highest density, spiny amaranth was 4 tunes more competitive than lettuce regardless of additional P.

scholarly journals RELATIVE COMPETITIVENESS BETWEEN MAIZE HYBRIDS AND WILD POINSETTIA

2021 ◽  
Vol 34 (2) ◽  
pp. 298-309
Author(s):  
LEANDRO GALON ◽  
RICARDO LUIS GABIATTI ◽  
FELIPE JOSÉ MENIN BASSO ◽  
ANDRÉ LUIZ RADÜNZ ◽  
FRANCISCO WILSON REICHERT JÚNIOR ◽  
...  
Keyword(s):  
Interspecific Competition ◽  
Leaf Area ◽  
Intraspecific Competition ◽  
Competitive Ability ◽  
Dry Mass ◽  
Plant Population ◽  
Grain Production ◽  
Replacement Series ◽  
Maize Hybrids ◽  
Chlorophyll Index

ABSTRACT Maize is one of the main cereals cultivated worldwide and wild poinsettia is among the weeds that cause damage in grain production. The objective of this study was to evaluate the relative competitive ability of maize hybrids in the presence of a wild poinsettia biotype through experiments in replacement series. In preliminary experiments, it was determined the plant population in which the dry mass becomes constant. For the maize hybrids ‘Agroeste’, ‘Morgan’, ‘Nidera’, and ‘Velox’, as well as the wild poinsettia, the population was 20 individuals vase-1. Subsequently, experiments were carried out in replacement series in different combinations of species that varied the relative proportions (100:0, 75:25, 50:50, 25:75, and 0:100%). The analysis of the species' competitiveness was carried out using diagrams applied to the replacement experiments and by the relative competitiveness indexes. The height (PH), chlorophyll index (CI), leaf area (LA), and the shoot dry mass (DM) of the plants were evaluated 50 days after emergence. There was competition between the maize hybrids and the wild poinsettia; both were negatively affected, regardless of the proportion of plants, causing reductions in the species' PH, CI, LA, and DM. The competition between maize and wild poinsettia occurs for the same resources in the environment, and interspecific competition caused greater damage to maize and wild poinsettia than intraspecific competition. In general, it was observed that only the hybrids ‘Nidera’ and ‘Velox’ were more competitive than the wild poinsettia.

Root physiological responses can explain the effects of short-term plant-plant interactions on growth of two subalpine coniferous species

2021 ◽  
Author(s):  
Xuefeng Hu ◽  
Wanting Li ◽  
Qinghua Liu ◽  
Chunying Yin
Keyword(s):  
Physiological Responses ◽  
Root Traits ◽  
Interspecific Interaction ◽  
Total Biomass ◽  
Plant Interactions ◽  
Short Term ◽  
Intraspecific Interaction ◽  
Coniferous Species ◽  
Lower Root ◽  
Plant Plant

Root functional traits play an important role in nutrient acquisition of plants, affecting the outcome of plant-plant interactions. However, few studies have comprehensively investigated the plastic responses of plant root traits to plant-plant interactions. A pot experiment was conducted to quantify the effects of intraspecific and interspecific interactions on seedlings growth and multiple root traits of two coniferous species, Picea asperata and Abies faxoniana. The results showed that plant-plant interactions changed root physiology of two species but did not affect their root system, morphological, architectural and biotic traits. Intraspecific interaction resulted in lower root N content and stronger resource competition than under interspecific interaction. Under intraspecific interaction, P. asperata had lower root vigor and nitrate reductase activity, which impeded the acquisition and utilization of the limited resources, and thus resulted in marginally decreased total biomass; while total biomass for A. faxoniana was not significantly affected. Under interspecific interaction, the high total biomass of A. faxoniana could be explained by rhizosphere interactive effects and reduced metabolic (carbon and nitrogen) costs due to lower root exudative outputs. Our results demonstrate that root physiological responses can explain the effects of short-term plant-plant interactions on plant growth.

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