scholarly journals Homogenization of species composition and species association networks are decoupled

2018 ◽  
Author(s):  
Daijiang Li ◽  
Timothée Poisot ◽  
Donald Waller ◽  
Benjamin Baiser
Keyword(s):  
Species Composition ◽  
Pine Barrens ◽  
Ecological Communities ◽  
Species Relationships ◽  
Species Association ◽  
Closed Canopy ◽  
Community Types ◽  
Fragmented Forests ◽  
Occurrence Patterns

AbstractEcological communities are comprised of both species and the biotic relationships among them. Biotic homogenization in species composition (i.e. increased site-to-site similarity) is recognized a common consequence of global change, but less is known about how species relationships change over space and time. Does homogenization of species composition lead to homogenization of species relationships or are the dynamics of species relationships decoupled from changes in species composition? To answer this question, we used long-term resurvey data to analyze changes in plant species association patterns between the 1950s and 2000s at 266 sites distributed among three community types in Wisconsin, USA. We used species associations (quantified via local co-occurrence patterns) as a proxy for species relationships. Species pairs that co-occur more/less than expected by chance have positive/negative associations. Shifts in species associations consistently exceeded the shifts observed in species composition. Less disturbed forests of northern Wisconsin have converged somewhat in species composition but not much in species associations. In contrast, forests in central Wisconsin succeeding from pine barrens to closed-canopy forests have strongly homogenized in both species composition and species associations. More fragmented forests in southern Wisconsin also tended to converge in species composition and in the species negative associations, but their positive associations diverged over the last half century. We conclude that long-term shifts in species relationships may be decoupled from those of species composition despite being affected by similar environmental variables.

Erratic occurrence of anostracans in a temporary pond: colonization and extinction or adaptation to variations in annual weather?

1983 ◽  
Vol 61 (7) ◽  
pp. 1492-1498 ◽  
Author(s):  
David B. Donald
Keyword(s):  
Species Composition ◽  
The Other ◽  
Temporary Pond ◽  
Review Of Literature ◽  
Weather Patterns ◽  
Species Specific ◽  
Occurrence Patterns ◽  
Branchinecta Paludosa ◽  
Critical Times

Five species of Anostraca (Branchinecta paludosa (O.F.M.), Branchinecta lindahli Packard, Eubranchipus bundyi Forbes, Eubranchipus intricatus Hartland-Rowe, and Eubranchipus ornatus Holmes) inhabited a temporary pond near Calgary, Alberta. During a 14-year study of this pond, occurrence and species composition of anostracans changed almost every year. In most years only one to three species were common or abundant, and the other species were either absent or rare. Four of the five species were dominant in at least 1 year. A review of literature on anostracans and analyses of annual weather patterns at Calgary were carried out in order to determine the cause of these erratic occurrence patterns and changes in species composition. For Eubranchipus bundyi, Branchinecta lindahli, and possibly Eubranchipus intricatus, the cause was probably due to long-term viability of eggs in association with species specific requirements of the embryo for certain quantities of precipitation at critical times of the year. It is suggested that when these precipitation requirements were ideal, hatching was substantial. For two other species, Branchinecta paludosa and Eubranchipus ornatus, erratic occurrence patterns could be explained by either the above or by a colonization–extinction hypothesis.

Long-term dynamics and destruction of marsh vegetation in the Kolokolkova Bay of the Barents Sea

2012 ◽  
pp. 66-77 ◽  
Author(s):  
I. A. Lavrinenko ◽  
O. V. Lavrinenko ◽  
D. V. Dobrynin
Keyword(s):  
Species Composition ◽  
Plant Communities ◽  
Barents Sea ◽  
Mean Value ◽  
Marsh Vegetation ◽  
Composition And Structure ◽  
The Mean ◽  
Species Composition And Structure

The satellite images show that the area of marshes in the Kolokolkova bay was notstable during the period from 1973 up to 2011. Until 2010 it varied from 357 to 636 ha. After a severe storm happened on July 24–25, 2010 the total area of marshes was reduced up to 43–50 ha. The mean value of NDVI for studied marshes, reflecting the green biomass, varied from 0.13 to 0.32 before the storm in 2010, after the storm the NDVI decreased to 0.10, in 2011 — 0.03. A comparative analysis of species composition and structure of plant communities described in 2002 and 2011, allowed to evaluate the vegetation changes of marshes of the different topographic levels. They are fol­lowing: a total destruction of plant communities of the ass. Puccinellietum phryganodis and ass. Caricetum subspathaceae on low and middle marches; increasing role of halophytic species in plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. typicum on middle marches; some changes in species composition and structure of plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. festucetosum rubrae on high marches and ass. Parnassio palustris–Salicetum reptantis in transition zone between marches and tundra without changes of their syntaxonomy; a death of moss cover in plant communities of the ass. Caricetum mackenziei var. Warnstorfia exannulata on brackish coastal bogs. The possible reasons of dramatic vegetation dynamics are discussed. The dating of the storm makes it possible to observe the directions and rates of the succession of marches vegetation.

scholarly journals Historical discarding in Mediterranean fisheries: a fishers' perception

2015 ◽  
Vol 72 (9) ◽  
pp. 2600-2608 ◽  
Author(s):  
Dimitrios Damalas ◽  
Christos D. Maravelias ◽  
Giacomo C. Osio ◽  
Francesc Maynou ◽  
Mario Sbrana ◽  
...  
Keyword(s):  
Species Composition ◽  
Market Demand ◽  
Sampling Protocol ◽  
The Past ◽  
Regulatory Constraints ◽  
Fishing Strategies ◽  
Commercially Important ◽  
Trawl Fisheries ◽  
Important Fish

Abstract Discarding of commercially important fish species in the bottom trawl fisheries in the northern Mediterranean Sea was investigated by soliciting the long-term recollections of fishers engaged or formerly engaged in such fisheries. The main aim of our investigation was to describe the prevalence of discarding and its evolution over the past 70 years using information gathered through individual questionnaire-based interviews with fishers from ports in Spain, Italy, and Greece, following a standardized sampling protocol. Although it proved impossible to derive absolute estimates of the volume of discarded catches over the period investigated, we conclude that over the past 70 years, discarding as a practice has gradually increased in the northern Mediterranean trawl fisheries and has been accompanied by a shift in the species composition of the discarded catch. While discarding can occur for a number of reasons, our investigations indicate that discarding in the past was mostly driven by market demand, but recent legal and regulatory constraints have led to changes in fishing strategies and became a significant reason for discards.

Predicted long-term effects of group selection on species composition and stand structure in northern hardwood forests

2017 ◽  
Vol 400 ◽  
pp. 677-691 ◽  
Author(s):  
Corey R. Halpin ◽  
Craig G. Lorimer ◽  
Jacob J. Hanson ◽  
Brian J. Palik
Keyword(s):  
Species Composition ◽  
Group Selection ◽  
Stand Structure ◽  
Hardwood Forests ◽  
Long Term Effects ◽  
Northern Hardwood Forests ◽  
Northern Hardwood

Development of Forest Shelterbelts Considering Statistical Forecasts Modelling of Local Weather

2021 ◽  
Vol 18 (1) ◽  
pp. 7-14
Author(s):  
Irina Volkova ◽  
Kseniia Pitulko ◽  
Anzhelika Sergeeva ◽  
Saida Pshidatok
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Structural Changes ◽  
Moscow Oblast ◽  
Phytopathogenic Bacteria ◽  
Heat Damage ◽  
Class 1 ◽  
Local Weather ◽  
Species Class

This work aims to study the effect of high temperatures and phytopathogenic bacteria on different types of trees in the forest shelterbelts. Therefore, in 2018, 17 tree species were studied from 50 sample sites in the Moscow oblast (Russia). Leaf scorching, diseases caused by phytopathogenic bacteria, and heat damage to the crowns were examined in 5224 tree species. Based on the degree of crown damage, the studied tree species were divided into four classes. It was found that the heat damage to tree crowns was identical between the three sampling aspects (correlation coefficient 0.99). The plant species composition must be considered when developing forest shelterbelts. A long-term forecast on structural changes of planted areas is possible, considering the species composition and climatic characteristics of the region. Class 5 includes only chestnut; class 4 includes three species; class 3 is represented by seven species. Class 2, includes six species, and is the most suitable in developing forest plantations. No tree species in class 1 were found (trees with no damage). There is a connection between pathologies and heat injuries in trees from classes 4 to 5 (correlation 0.89).

scholarly journals Species composition and within archipelago co-occurrence patterns in the Canary Islands

Ecography ◽  
1993 ◽  
Vol 16 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Jose Maria Fernandez-Palacios ◽  
Christian Andersson
Keyword(s):  
Species Composition ◽  
Canary Islands ◽  
Occurrence Patterns

Cooperation between Species

2017 ◽  
Author(s):  
Raymond Pierotti ◽  
Brandy R. Fogg
Keyword(s):  
Cooperative Behavior ◽  
Natural World ◽  
Western Science ◽  
Ecological Communities ◽  
Cooperative Hunting ◽  
Wide Range

This chapter reviews the study of cooperative behavior between species, with emphasis on examples of cooperative hunting found in a wide range of species. Seen in this context, the idea of cooperative hunting between humans and wolves that evolved into present relationships with dogs does not seem unusual or surprising. The chapter then critiques the proposal that competition between species is more important than cooperation in structuring ecological communities, discussing how this notion leads to a suite of ideas philosophically separating humans from the rest of the natural world. In many ways Western science is unintentionally complicit in such thinking. The chapter concludes by discussing complex cooperation, including long-term relationships between members of different species.

scholarly journals The importance of motivation, weapons, and foul odors in driving encounter competition in carnivores

2020 ◽  
Author(s):  
ML Allen ◽  
CC Wilmers ◽  
LM Elbroch ◽  
JM Golla ◽  
Heiko Wittmer
Keyword(s):  
Interference Competition ◽  
Current Theory ◽  
Lynx Rufus ◽  
Natural Environments ◽  
Ecological Communities ◽  
Competitive Advantages ◽  
Ecological Society ◽  
Strategic Behaviors ◽  
Species Specific ◽  
Occurrence Patterns

© 2016 by the Ecological Society of America. Encounter competition is interference competition in which animals directly contend for resources. Ecological theory predicts the trait that determines the resource holding potential (RHP), and hence the winner of encounter competition, is most often body size or mass. The difficulties of observing encounter competition in complex organisms in natural environments, however, has limited opportunities to test this theory across diverse species. We studied the outcome of encounter competition contests among mesocarnivores at deer carcasses in California to determine the most important variables for winning these contests. We found some support for current theory in that body mass is important in determining the winner of encounter competition, but we found that other factors including hunger and species-specific traits were also important. In particular, our top models were "strength and hunger" and "size and hunger," with models emphasizing the complexity of variables influencing outcomes of encounter competition. In addition, our wins above predicted (WAP) statistic suggests that an important aspect that determines the winner of encounter competition is species-specific advantages that increase their RHP, as bobcats (Lynx rufus) and spotted skunks (Spilogale gracilis) won more often than predicted based on mass. In complex organisms, such as mesocarnivores, species-specific adaptations, including strategic behaviors, aggressiveness, and weapons, contribute to competitive advantages and may allow certain species to take control or defend resources better than others. Our results help explain how interspecific competition shapes the occurrence patterns of species in ecological communities.

scholarly journals Successional dynamics of a 35 year old freshwater mitigation wetland in southeastern New Hampshire

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251748
Author(s):  
J. Grant McKown ◽  
Gregg E. Moore ◽  
Andrew R. Payne ◽  
Natalie A. White ◽  
Jennifer L. Gibson
Keyword(s):  
Species Composition ◽  
New Hampshire ◽  
Wetland Restoration ◽  
Wetland Mitigation ◽  
Freshwater Wetland ◽  
Compensatory Mitigation ◽  
Avian Community ◽  
Long Term Monitoring ◽  
Term Monitoring

The long-term ecological success of compensatory freshwater wetland projects has come into question based on follow-up monitoring studies over the past few decades. Given that wetland restoration may require many years to decades to converge to desired outcomes, long-term monitoring of successional patterns may increase our ability to fully evaluate success of wetland mitigation projects or guide adaptive management when needed. In Portsmouth, New Hampshire a 4 ha wetland was constructed in an abandoned gravel quarry as off-site compensatory mitigation for impacts to a scrub-shrub swamp associated with property expansion. Building upon prior evaluations from 1992 and 2002, we conducted a floral survey in 2020 to compare results with prior surveys to document vegetation successional trends over time. In addition, we monitored the avian community throughout the growing season as a measure of habitat quality. The plant community mirrored documented successional trends of freshwater wetland restoration projects as native hydrophytes dominated species composition. Plant species composition stabilized as the rate of turnover, the measurement of succession, declined by nearly half after 17 years. Researchers should consider long-term monitoring of specific sites to better understand successional patterns of created wetlands as we documented long time frames required for the development of scrub-shrub swamps, red maple swamps, and sedge meadows. High species richness was attributed to beaver activity, topographic heterogeneity from Carex stricta tussocks, and the seed bank from the application of peat from the original wetland. Habitat heterogeneity of open water, herbaceous cover, and woody vegetation supports a diverse avian community including 11 wetland dependent species. Although the mitigation project has not created the full area of lost scrub-shrub swamp after 35 years, it has developed a structurally complex habitat and diverse avian community that effectively provides the functions and values of the impacted system.

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