scholarly journals Sexual reproduction vs. clonal propagation in the recovery of a seagrass meadow after an extreme weather event

2019 ◽  
Vol 83 (4) ◽  
pp. 357 ◽  
Author(s):  
Diogo Paulo ◽  
Onno Diekmann ◽  
Ana Alexandra Ramos ◽  
Filipe Alberto ◽  
Ester Alvares Serrão
Keyword(s):  
Sexual Reproduction ◽  
Clonal Propagation ◽  
Seagrass Meadow ◽  
Genotypic Diversity ◽  
Weather Event ◽  
Winter Storms ◽  
Relative Contribution ◽  
Sexual Propagation ◽  
Seedling Germination

Marine flowering plants can reproduce sexually and clonally, and the relative contribution of these two modes can be dependent on the environmental conditions. Zostera marina, a seagrass widely distributed in the northern hemisphere, can form annual and perennial meadows with different proportions of sexual versus clonal propagation depending on the environmental disturbance regime. We study the hypothesis that the contribution of sexual propagation varies during the recovery of a seagrass meadow. In this case study, we compare the proportion of sexual versus clonal propagation of a perennial Z. marina meadow before its disappearance due to winter storms and after recovery. Before disturbance, genotypic diversity was high, indicating frequent sexual reproduction events likely to create an abundant seed bank. Seedling germination allowed the population to recover after the extreme disturbance. As months passed, seedlings became rare and finally absent, giving place to adult shoots. In an advanced stage of colonization, the shoots colonized the area by vegetative growth, which lowered the genotypic diversity. Despite this reduction over time, the genotypic diversity of the new meadow is still high, demonstrating the importance of sexual reproduction in meadow recovery and persistence.

scholarly journals High genotypic diversity of the reef-building coral Porites lobata (Scleractinia: Poritidae) in Isla del Coco National Park, Costa Rica

2017 ◽  
pp. 279-292
Author(s):  
Jennifer N. Boulay ◽  
Jorge Cortés ◽  
Jaime Nivia-Ruiz ◽  
Iliana B. Baums
Keyword(s):  
Costa Rica ◽  
Sexual Reproduction ◽  
Colony Size ◽  
National Park ◽  
Southern Oscillation ◽  
Genotypic Diversity ◽  
Physical Structure ◽  
Ecosystem Recovery ◽  
Relative Contribution ◽  
Porites Lobata

The isolated Isla del Coco experiences periodic, extreme disturbances which devastate coral reefs surrounding the island. Scleractinian corals build the physical structure of the reef therefore ecosystem recovery relies on coral species recovery. Coral recruits can be of sexual or asexual origin, and the relative success of the two recruit types influences the speed and spread of recovery processes. Here we focus on the massive coral, Porites lobata, because it is the main reef-builder around Isla del Coco to describe the relative contribution of asexual and sexual recruits to population maintenance. P. lobata samples were collected using a spatially explicit random sampling design in three plots at Isla del Coco: Punta Ulloa (n=17), Bahía Weston (n=20) and Punta María (n=20) and samples were genotyped with 11 microsatellite markers. Additional sampling was conducted at three “coastal” sites near the Costa Rican mainland (Isla del Caño Biological Reserve): Caño1 (n=8), Caño2 (n=10), Caño5 (n=11) to compare the contributions of asexual and sexual recruits at Isla del Coco sites to coastal sites. Isla del Coco sites were characterized by small colony size (>60% of colonies <0.5m2) and high sexual reproduction. Sites were either mostly or entirely sexual,consisting of only unique genotypes (NG/N= 0.90-1.00; G O/GE=0.83-1.00; D=0.99-1.00). Although there were no significant differences in genetic diversity (number of alleles per locus, number of private alleles) or colony size between Isla del Coco and the coastal sites, the coastal sites exhibited a greater range of genotypic diversity from moderately asexual (NG/N=0.5; GO/GE=0.36; D=0.8) to purely sexual (NG/N=1.0; GO/GE=1.0; D=1.0). The mode of asexual reproduction in P. lobata is likely fragmentation of adult colonies rather than asexual larval production because ramets of P. lobata occurred close together and asexually produced larvae have not been reported in gonochoric broadcast spawners like P. lobata. Frequent sexual reproduction at Isla del Coco National Park might represent a resource for rapid recovery following extreme El Niño-Southern Oscillation (ENSO) disturbance events. In contrast, larger, asexuallyproduced fragments rather than smaller, sexually-produced larvae appear to have the advantage at some coastal sites. The high frequency of sexual reproduction at Isla del Coco indicates that not only are sexual partners available but also current conditions are favorable for the delivery of larvae and the rate of predation on small larval recruits must be moderate. Citation: Boulay, J.N., J. Cortés, J. Nivia-Ruiz & I.B. Baums. 2012. High genotypic diversity of the reef-building coral Porites lobata (Scleractinia: Poritidae) in Isla del Coco National Park, Costa Rica. Rev. Biol. Trop. 60 (Suppl. 3): 279-292. Epub 2012 Dec 01.

Nitrogen and litter addition decreased sexual reproduction and increased clonal propagation in grasslands

Oecologia ◽  
2021 ◽  
Vol 195 (1) ◽  
pp. 131-144
Author(s):  
Zimeng Li ◽  
Jinfeng Wu ◽  
Qing Han ◽  
Kunyan Nie ◽  
Jiani Xie ◽  
...  
Keyword(s):  
Sexual Reproduction ◽  
Clonal Propagation ◽  
Litter Addition

scholarly journals A high-resolution modelling case study of a severe weather event over New Zealand

2008 ◽  
Vol 9 (3) ◽  
pp. 119-128 ◽  
Author(s):  
Stuart Webster ◽  
Michael Uddstrom ◽  
Hilary Oliver ◽  
Simon Vosper
Keyword(s):  
New Zealand ◽  
High Resolution ◽  
Severe Weather ◽  
Weather Event ◽  
Severe Weather Event

RESPONSE OF EMPIRICALLY MANAGED SITES TO WINTER STORMS. CASE STUDY: LA MANCHA, VERACRUZ, MEXICO

2017 ◽  
pp. 15
Author(s):  
Valeria Chávez-Cerón ◽  
Edgar Mendoza-Baldwin ◽  
Erika Ramírez-Méndez ◽  
Rodolfo Silva-Casarín
Keyword(s):  
Physical Parameters ◽  
Winter Storms ◽  
Beach Sediment ◽  
La Mancha ◽  
Circulation Patterns ◽  
Estuarine Lagoon ◽  
Opening And Closing ◽  
Topographic Surveys ◽  
Natural Cycles

The coastal lagoon of La Mancha, Veracruz, Mexico is significantly affected by winter storms, meteorological events known as Nortes. Because of the influence of the wind on beach sediment transport and therefore on the dynamics of the inlet, four topographic surveys were made, three during winter storms (November 2013, November 2014 and February 2015) and one more in the dry season (May 2014). Physicochemical parameters at the mouth were registered during November 2014. The circulation patterns of the lagoon were obtained using the numerical model H2D. The beach morphology field data shows that the beach is resilient to the effects of winter storms, as long as sediment availability is not interrupted. The circulation patterns of the lagoon indicate that winds and waves induce the opening and closing of the inlet. The governing force in the lagoon patterns is the tidal oscillations, as corroborated by the physical parameters measured. However, these natural cycles are interrupted by the actions of the local fishermen, who empirically manage the lagoon opening the inlet once or twice a year. We found that the environmental resilience of the estuarine-lagoon system is susceptible to the change in the frequency of the opening of the mouth, so the anthropogenic interference threats the dynamics of the natural system.

Use of soil organic biomarkers for tracing the origin of eroded sediment: case study in Petzenkirchen (Austria)

2020 ◽  
Author(s):  
Lionel Mabit ◽  
Modou Mbaye ◽  
Arsenio Toloza ◽  
Max Gibbs ◽  
Andrew Swales ◽  
...  
Keyword(s):  
Climatic Conditions ◽  
Organic Carbon Content ◽  
Relative Contribution ◽  
Stream Bank ◽  
Dominant Soil ◽  
Maize Cultivation ◽  
Austrian Study ◽  
Organic Biomarkers ◽  
Isotope Mixing Models

&lt;p&gt;Compound-specific stable isotopes (CSSI) technique based on the measurement of &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C signatures of organic biomarker compounds such as fatty acids (FAs) has been used since the end of the 2000s to reinforce the knowledge about sediment production and budget in various ecosystems.&lt;br&gt;The watershed of Petzenkirchen, located 100 km west from Vienna (Austria), was selected to establish the origin of the sediment produced at its outlet using &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C-FAs analysis. The climatic conditions of the area are temperate with continental influences with a mean temperature of 9.5&amp;#730; C and yearly precipitation of 823 mm. The dominant soil types are Cambisols and Planosols. Based on existing land-use records, most of the agricultural fields are dominated by a rotation of winter wheat followed by maize cultivation.&lt;br&gt;Considering the specific geomorphology, the flow of the runoff, the significant interaction of roads, the distance and connection of the potential sources to the outlet, the contributing area of the site has been set to around 50 ha and 7 sources most likely to contribute to the sediment at the outlet were investigated. Using the mixing polygons approach, the &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C of saturated long chain FAs (i.e. C24:0 and C26:0) allowed the best discrimination for establishing the contribution of sources to the sediment collected at the exit of the watershed (i.e. the mixture). The relative contribution to the soil mixture of the different source soils identified has been determined using the Stable Isotope Mixing Models in R (SIMMR) and the specific organic carbon content of each source. The simulated results derived with SIMMR highlights that more than half of the sediment reaching the outlet of the watershed originates from stream bank.&amp;#160;&lt;br&gt;This Austrian study confirms that the information gained with &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C-FAs analysis could provide unique support for allowing effective agroecosystems management.&lt;/p&gt;

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