scholarly journals Niche Complementarity and Resistance to Grazing Promote the Invasion Success of Sargassum horneri in North America

Diversity ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 54 ◽  
Author(s):  
Lindsay M. Marks ◽  
Daniel C. Reed ◽  
Sally J. Holbrook
Keyword(s):  
Native Species ◽  
Life Histories ◽  
Ecological Factors ◽  
Invasion Success ◽  
Sargassum Horneri ◽  
Algal Community ◽  
Depth Range ◽  
Niche Complementarity ◽  
Native Algae ◽  
Experimental Plots

Invasive species are a growing threat to conservation in marine ecosystems, yet we lack a predictive understanding of ecological factors that influence the invasiveness of exotic marine species. We used surveys and manipulative experiments to investigate how an exotic seaweed, Sargassum horneri, interacts with native macroalgae and herbivores off the coast of California. We asked whether the invasion (i.e., the process by which an exotic species exhibits rapid population growth and spread in the novel environment) of S. horneri is influenced by three mechanisms known to affect the invasion of exotic plants on land: competition, niche complementarity and herbivory. We found that the removal of S. horneri over 3.5 years from experimental plots had little effect on the biomass or taxonomic richness of the native algal community. Differences between removal treatments were apparent only in spring at the end of the experiment when S. horneri biomass was substantially higher than in previous sampling periods. Surveys across a depth range of 0–30 m revealed inverse patterns in the biomass of S. horneri and native subcanopy-forming macroalgae, with S. horneri peaking at intermediate depths (5–20 m) while the aggregated biomass of native species was greatest at shallow (<5 m) and deeper (>20 m) depths. The biomass of S. horneri and native algae also displayed different seasonal trends, and removal of S. horneri from experimental plots indicated the seasonality of native algae was largely unaffected by fluctuations in S. horneri. Results from grazing assays and surveys showed that native herbivores favor native kelp over Sargassum as a food source, suggesting that reduced palatability may help promote the invasion of S. horneri. The complementary life histories of S. horneri and native algae suggest that competition between them is generally weak, and that niche complementarity and resistance to grazing are more important in promoting the invasion success of S. horneri.

scholarly journals Comparison of a native and a non-native insular reptile species

2015 ◽  
Vol 31 (6) ◽  
pp. 563-566 ◽  
Author(s):  
Daniel J. Nicholson ◽  
Christopher Hassall ◽  
Julius A. Frazier
Keyword(s):  
Life History ◽  
Native Species ◽  
Life Histories ◽  
Life History Traits ◽  
Invasion Success ◽  
Population Abundance ◽  
Reptile Species ◽  
Study Sites ◽  
Gravid Females ◽  
Hemidactylus Frenatus

Abstract:This study compared the life histories of Hemidactylus frenatus, a significant invasive gecko, and Phyllodactylus palmeus, a Honduran endemic, over 10 wk, June–August 2013 at 12 study sites on the Honduran island of Cayo Menor of the Cayo Cochinos archipelago where H. frenatus arrived in 2008. Three different life-history traits related to invasion success were measured: body size, fecundity and population size. During the study 140 natives and 37 non-natives were captured, weighed, measured and marked uniquely. The number of gravid females and number of eggs were also recorded. Phyllodactylus palmeus was the significantly larger of the two species (60% larger mass, 25% longer SVL) and had higher population abundance at all 12 study sites with some sites yielding no H. frenatus individuals. However, H. frenatus had a larger proportion of gravid females. Observations that the native species is more common despite being sympatric with a known aggressive invader suggest two possibilities: the island is at the start of an invasion, or that the two species co-exist in a more stable fashion.

scholarly journals Fish Assemblage in the Euphrates River at Al-Samawa City, Southern Iraq

2019 ◽  
Vol 32 ◽  
pp. 33-46
Author(s):  
Ammar M.S. Al-Helli ◽  
Amjad K. Resen ◽  
Atheer H. Ali
Keyword(s):  
Native Species ◽  
Ecological Factors ◽  
Abundant Species ◽  
Total Hardness ◽  
Dominance Index ◽  
Oreochromis Aureus ◽  
Euphrates River ◽  
The North ◽  
Blue Tilapia ◽  
Southern Iraq

The study was conducted in the Euphrates river in Al-Samawa city at two stations during the period from October 2016 till September 2017. The first station (north station) was Al-Majd township (45°12'49.2"E, 31°22'14.9"N), and the second station (south station) was Al-Zaier region (45°20'21.4"E, 31°18'54.4"N). Some ecological factors were monthly recorded at the stations of the current study, including water temperature, salinity, dissolved oxygen, pH, transparency, the speed of water flow, BOD5 and total hardness. All factors except total hardness have not significant differences between two stations, The hardness in the north station showed higher (844-1475) mg.l-1 than south station (655-1250) mg.l-1. Fishes were collected by gill nets, cast net, hook and line, hand net and electro-fishing. A total of 4260 fish specimens were collected which belong to 24 species and 10 families, 17 species of them were native species whereas seven of them were alien species. The most abundant species was blue tilapia Oreochromis aureus constituted 26.84% of the total caught of a north station, The value of the dominance index (D3) in north station was 62.57%, while the most abundant species in south station was Prussian carp Carassius auratus constituted 27.14% of the total caught, The value of the dominance index (D3) in the south station was 56.42%.

Indirect effects and facilitation among native and non-native species promote invasion success along an environmental stress gradient

2013 ◽  
Vol 101 (4) ◽  
pp. 905-915 ◽  
Author(s):  
Phoebe L. Zarnetske ◽  
Tarik C. Gouhier ◽  
Sally D. Hacker ◽  
Eric W. Seabloom ◽  
Vrushali A. Bokil
Keyword(s):  
Environmental Stress ◽  
Indirect Effects ◽  
Native Species ◽  
Stress Gradient ◽  
Invasion Success

scholarly journals Native turncoats and indirect facilitation of species invasions

2018 ◽  
Vol 285 (1871) ◽  
pp. 20171936 ◽  
Author(s):  
Tobin D. Northfield ◽  
Susan G. W. Laurance ◽  
Margaret M. Mayfield ◽  
Dean R. Paini ◽  
William E. Snyder ◽  
...  
Keyword(s):  
Invasive Species ◽  
Native Species ◽  
Potential Role ◽  
Indirect Interactions ◽  
Invasion Success ◽  
Competitive Interactions ◽  
Species Invasion ◽  
Species Invasions ◽  
Indirect Facilitation

At local scales, native species can resist invasion by feeding on and competing with would-be invasive species. However, this relationship tends to break down or reverse at larger scales. Here, we consider the role of native species as indirect facilitators of invasion and their potential role in this diversity-driven ‘invasion paradox’. We coin the term ‘native turncoats’ to describe native facilitators of non-native species and identify eight ways they may indirectly facilitate species invasion. Some are commonly documented, while others, such as indirect interactions within competitive communities, are largely undocumented in an invasion context. Therefore, we use models to evaluate the likelihood that these competitive interactions influence invasions. We find that native turncoat effects increase with the number of resources and native species. Furthermore, our findings suggest the existence, abundance and effectiveness of native turncoats in a community could greatly influence invasion success at large scales.

scholarly journals Differences in seed properties and germination between native and introduced populations of Triadica sebifera

2019 ◽  
Vol 13 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Jialiang Zhang ◽  
Evan Siemann ◽  
Baoliang Tian ◽  
Wei Huang ◽  
Jianqing Ding
Keyword(s):  
United States ◽  
Seed Germination ◽  
Soluble Protein ◽  
Native Species ◽  
Seed Mass ◽  
The United States ◽  
Invasion Success ◽  
Native Range ◽  
Triadica Sebifera ◽  
Introduced Range

Abstract Aims Seeds of many invasive plants germinate more quickly than those of native species, likely facilitating invasion success. Assessing the germination traits and seed properties simultaneously for introduced and native populations of an invasive plant is essential to understanding biological invasions. Here, we used Triadica sebifera as a study organism to examine intraspecific differences in seed germination together with seed characteristics. Methods We measured physical (volume, mass, coat hardness and coat thickness of seeds) and chemical (crude fat, soluble protein, sugar, gibberellins [GA] and abscisic acid [ABA] of kernels) properties of T. sebifera seeds collected in 2017 from 12 introduced (United States) populations and 12 native (China) populations and tested their germination rates and timing in a greenhouse experiment in China. Furthermore, we conducted an extra experiment in the United States using seeds collected in 2016 and 2017 to compare the effects of study sites (China vs. United States) and seed collection time (2016 vs. 2017) on seed germination. Important Findings Seeds from the introduced range germinated faster than those from the native range. Physical and chemical measurements showed that seeds from the introduced range were larger, had higher GA concentrations and GA:ABA ratio, but lower crude fat concentrations compared to those from the native range. There were no significant differences in seed mass, coat hardness and coat thickness or kernel ABA, soluble protein or sugar concentrations between seeds from introduced vs. native ranges. Germination rates were correlated between United States and China greenhouses but germination rates for populations varied between collection years. Our results suggest that larger seeds and higher GA likely contribute to faster germination, potentially facilitating T. sebifera invasion in the introduced range.

Reproductive parameters of topmouth gudgeon (Pseudorasbora parva) from a heated Lake Licheńskie (Poland)

2014 ◽  
Vol 9 (2) ◽  
pp. 212-219 ◽  
Author(s):  
Eva Záhorská ◽  
Vladimír Kováč ◽  
Kristína Švolíková ◽  
Andrzej Kapusta
Keyword(s):  
Phenotypic Plasticity ◽  
Temperature Regime ◽  
Life Histories ◽  
Invasion Success ◽  
Extreme Conditions ◽  
Reproductive Parameters ◽  
Invasive Potential ◽  
Topmouth Gudgeon ◽  
Heated Water ◽  
Successful Invader

AbstractTemperature regime is known to have considerable influence on the life-histories of fish. Topmouth gudgeon is a very successful invader with high biological flexibility and phenotypic plasticity. The flexibility of topmouth gudgeon in a normal thermal regime has been well described, however there has been no information published about how it would cope with extreme conditions, e.g. permanently heated water. Several studies have demonstrated that phenotypic plasticity provides an important advantage to invasive species. To explain their invasion success, the theory of alternative ontogenies and invasive potential has been proposed. The aim of the present study was to examine if the reproductive parameters of a population living in permanently heated water differ from those living in habitats with a normal temperature regime, as well as to test a hypothesis derived from the theory of alternative ontogenies and invasive potential. Over a period of 8 years (2004–2011), a high variation in the reproductive parameters of topmouth gudgeon from Lake Licheńskie was found. With a small exception, all the observed results met the expectations predicted by the hypothesis tested. This indicates that topmouth gudgeon retains high phenotypic plasticity in life-history traits even in a habitat with extreme conditions, which is important for the species’ invasion success.

Community Structure Affects Annual Grass Weed Invasion During Restoration of a Shrub–Steppe Ecosystem

2014 ◽  
Vol 7 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Phil S. Allen ◽  
Susan E. Meyer
Keyword(s):  
Community Structure ◽  
Native Species ◽  
Propagule Pressure ◽  
Alternative Hypothesis ◽  
Perennial Grasses ◽  
Invasion Success ◽  
Sagebrush Steppe ◽  
Annual Grass ◽  
Shrub Steppe ◽  
Steppe Communities

AbstractEcological restoration of shrub–steppe communities in the western United States is often hampered by invasion of exotic annual grasses during the process. An important question is how to create restored communities that can better resist reinvasion by these weeds. One hypothesis is that communities comprised of species that are functionally similar to the invader will best resist invasion, while an alternative hypothesis is that structurally more complex and diverse communities will result in more effective competitive exclusion. In this field experiment, we examined the effects of restored community structure on the invasion success of three annual grass weeds (downy brome, jointed goatgrass, and cereal rye). We created replicated community plots that varied in species composition, structural complexity and density, then seeded in annual grass weeds and measured their biomass and seed production the following year, and their cover after 1 and 3 yr. Annual grass weeds were not strongly suppressed by any of the restored communities, indicating that it was difficult for native species to completely capture available resources and exclude annual grass weeds in the first years after planting. Perennial grass monocultures, particularly of the early seral grass bottlebrush squirreltail, were the most highly invaded communities, while structurally complex and diverse mixtures of shrubs (big sagebrush, rubber rabbitbrush), perennial grasses (bluebunch wheatgrass and bottlebrush squirreltail) and forbs (Lewis flax, Utah sweetvetch, hairy golden aster, gooseberryleaf globemallow) were more resistant to invasion. These results suggest that restoration of sagebrush steppe communities resistant to annual grass invasion benefits from higher species diversity; significant reduction of weed propagule pressure prior to restoration may be required.

scholarly journals Movement Ecology of Potamodromous Top Predator in a Large Lake: Synchrony and Coexistence of Distinct Migratory Patterns 

2020 ◽  
Author(s):  
Silviya V. Ivanova ◽  
Timothy B Johnson ◽  
Aaron T Fisk
Keyword(s):  
Native Species ◽  
Life Histories ◽  
Community Dynamics ◽  
Lake Trout ◽  
Lake Ontario ◽  
Predator Population ◽  
Large Lake ◽  
Top Predator ◽  
Large Lakes ◽  
Migratory Patterns

Abstract Migrations are a key component of the life-histories of many highly mobile animals. The study of potamodromous migrations occurring within large lakes have lagged and are poorly understood for most species. This is an issue for restoration efforts and adaptive management, as understanding the movement of species, and underlying patterns and mechanisms are essential for identifying key habitat and quantifying the species role in the ecosystem. Using acoustic telemetry, this study quantified the spatio-temporal movements and migratory patterns of lake trout (Salvelinus namaycush), an iteroparous, potamodromous predator in Lake Ontario, the 13th largest lake by volume in the world that is highly managed and supports a diverse fish community of native and non-native species. Over 2.5 years (December 2016 to April 2019), the movements of 41 lake trout were quantified across a large array of 196 acoustic receivers in Lake Ontario. Individual analysis revealed annual convergence in the fall at a location other than the spawning grounds, followed by synchronized migrations to spawning sites. Consistent with divergent migrations, out-migration was asynchronous, stretching over a longer period of time than pre-spawning movements and across multiple routes. At least two groups of individuals with distinct migratory behaviors, i.e. contingents, were identified in the population. These results illustrate the presence of contingents and provide key information on migratory patterns, convergence points and routes in a potamodromous top predator population in a large lake. Thus, we provide evidence that contingents with different behavior used different habitats across seasons. As such, this study informs management on the potential success and implications of employing different rehabilitation strategies, such as diversifying a species’ population through selective strain stocking in large deep lakes to aid reestablishment across habitats. This knowledge would improve modelling of community dynamics, understanding of nutrient cycling, and overall ecosystem function of large lakes.

scholarly journals Comparison of Behavior and Space Use of the European Bullhead Cottus gobio and the Round Goby Neogobius melanostomus in a Simulated Natural Habitat

Biology ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 821
Author(s):  
Sara Roje ◽  
Bořek Drozd ◽  
Luise Richter ◽  
Jan Kubec ◽  
Zdeněk Polívka ◽  
...  
Keyword(s):  
Native Species ◽  
Natural Habitat ◽  
Activity Patterns ◽  
Habitat Preferences ◽  
Round Goby ◽  
Space Use ◽  
Neogobius Melanostomus ◽  
Invasion Success ◽  
Low Velocity ◽  
Cottus Gobio

The round goby is an invasive fish in Europe and North America that threatens native species by predation and competition. Its habitat preferences are similar to those of the European bullhead, which it displaces from shelters and out-competes for available resources. We assessed the microhabitat preferences, shelter use, and activity of the round goby and European bullhead in single-species experiments in habitat simulator systems to investigate their behavior in a novel environment. Fish were video-recorded for 28 h in the presence of shelter and feed with water velocity ranging from 0.00 to 0.96 m s−1. The two species showed similar behavior under given conditions. A primary difference was in stress-induced behavior in the initial phases of observation. The round goby spent more time in movement when outside the shelter and a longer time in the escape zone in the exploration period during light. Our results confirmed a significant preference of round goby for low velocity areas and a preference for higher velocities in the European bullhead. Both species were able to cope with velocities > 0.7 m s−1. Therefore, the reported invasion success of round goby is probably not driven by space use or activity patterns, but rather by higher adaptability.

scholarly journals Re-examining the relationship between invasive lionfish and native grouper in the Caribbean

2014 ◽  
Author(s):  
Abel Valdivia ◽  
John F Bruno ◽  
Courtney Cox ◽  
Serena Hackerott ◽  
Stephanie Green
Keyword(s):  
Native Species ◽  
Biotic Resistance ◽  
Spatial Scales ◽  
Structural Complexity ◽  
Invasion Success ◽  
Site Characteristics ◽  
Invasive Lionfish ◽  
Caribbean Coral Reefs ◽  
Biogeographic Regions ◽  
The Relationship

Biotic resistance is the idea that native species negatively affect the invasion success of introduced species, but whether this can occur at large spatial scales is poorly understood. Here we re-evaluated the hypothesis that native large-bodied grouper and other predators are controlling the abundance of exotic lionfish (Pterois volitans/miles) on Caribbean coral reefs. We assessed the relationship between the biomass of lionfish and native predators at 71 reefs in three biogeographic regions while taking into consideration several cofactors that may affect fish abundance, including among others, proxies for fishing pressure and habitat structural complexity. Our results indicate that the abundance of lionfish, large-bodied grouper and other predators were not negatively related. Lionfish abundance was instead controlled by several physical site characteristics, and possibly by culling. Taken together, our results suggest that managers cannot rely on current native grouper populations to control the lionfish invasion.

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