scholarly journals Intraspecific variation promotes species coexistence and trait clustering through higher order interactions

2018 ◽  
Author(s):  
Gaurav Baruah ◽  
Robert John
Keyword(s):  
Intraspecific Variation ◽  
Individual Variation ◽  
Species Coexistence ◽  
Species Traits ◽  
Higher Order ◽  
Competitive Interactions ◽  
Volterra Model ◽  
Trait Divergence ◽  
Pairwise Interactions ◽  
Coexisting Species

AbstractEcological and evolutionary effects of individual variation on species coexistence remains unclear. Competition models for coexistence have emphasized species-level differences in pairwise interactions, and invoked no role for intraspecific variation. These models show that stronger competitive interactions result in smaller numbers of coexisting species. However, the presence of higher-order interactions (HOIs) among species appears to have a stabilizing influence on communities. How species coexistence is affected in a community where both pairwise and higher-order interactions are pervasive is not known. Furthermore, the effect of individual variation on species coexistence in complex communities with pairwise and HOIs remains untested. Using a Lotka-Volterra model, we explore the effects of intraspecific variation on the patterns of species coexistence in a competitive community dictated by pairwise and HOIs. We found that HOIs greatly stabilize species coexistence across different levels of strength in competition. Notably, high intraspecific variation promoted species coexistence, particularly when competitive interactions were strong. However, species coexistence promoted by higher levels of variation was less robust to environmental perturbation. Additionally, species’ traits tend to cluster together when individual variation in the community increased. We argue that individual variation can promote species coexistence by reducing trait divergence and attenuating the inhibitory effects of dominant species through HOIs

scholarly journals Beyond direct neighbourhood effects: higher-order interactions improve modelling and predicting tree survival and growth

2020 ◽  
Author(s):  
Yuanzhi Li ◽  
Margaret M Mayfield ◽  
Bin Wang ◽  
Junli Xiao ◽  
Kamil Kral ◽  
...  
Keyword(s):  
Species Diversity ◽  
Temperate Forest ◽  
Species Coexistence ◽  
Biotic Interactions ◽  
Higher Order ◽  
Individual Level ◽  
Pairwise Interactions ◽  
Tree Survival ◽  
Survival And Growth ◽  
Tree Performance

Abstract It is known that biotic interactions are the key to species coexistence and maintenance of species diversity. Traditional studies focus overwhelmingly on pairwise interactions between organisms, ignoring complex higher-order interactions (HOIs). In this study, we present a novel method of calculating individual-level HOIs for trees, and use this method to test the importance of size- and distance-dependent individual-level HOIs to tree performance in a 25-ha temperate forest dynamic plot. We found that full HOIs-inclusive models improved our ability to model and predict the survival and growth of trees, providing empirical evidence that HOIs strongly influence tree performance in this temperate forest. Specifically, assessed HOIs mitigate the competitive direct effects of neighbours on survival and growth of focal trees. Our study lays a foundation for future investigations of the prevalence and relative importance of HOIs in global forests and their impact on species diversity.

scholarly journals Higher order interactions and coexistence theory

2019 ◽  
Author(s):  
Pragya Singh ◽  
Gaurav Baruah
Keyword(s):  
Intraspecific Competition ◽  
Species Coexistence ◽  
General Rule ◽  
Higher Order ◽  
Volterra Model ◽  
Ecological Communities ◽  
Coexistence Theory ◽  
Wide Range ◽  
Analytical Result ◽  
Underlying Mechanisms

AbstractHigher order interactions (HOIs) have been suggested to stabilize diverse ecological communities. However, their role in maintaining species coexistence from the perspective of modern coexistence theory is unknown. Here, using a three-species Lotka-Volterra model, we derive a general rule for species coexistence modulated by HOIs. We show that negative HOIs that intensify pairwise competition, can promote coexistence across a wide range of fitness differences, provided that HOIs strengthen intraspecific competition more than interspecific competition. In contrast, positive HOIs that alleviate pairwise competition can also stabilize coexistence across a wide range of fitness differences, irrespective of differences in strength of inter- and intraspecific competition. Furthermore, we extend our three-species analytical result to multispecies competitive community and show, using simulations, that feasible multispecies coexistence is possible provided that strength of negative intraspecific HOIs is higher than interspecific HOIs. In addition, multispecies communities, however, become unstable with positive HOIs as such higher-order interactions could lead to disproportionately infeasible growth rates. This work provides crucial insights on the underlying mechanisms that could maintain species diversity and links HOIs with modern coexistence theory.

scholarly journals Higher order interactions and species coexistence

2020 ◽  
Author(s):  
Pragya Singh ◽  
Gaurav Baruah
Keyword(s):  
Intraspecific Competition ◽  
Species Interactions ◽  
Species Coexistence ◽  
General Rule ◽  
Higher Order ◽  
Volterra Model ◽  
Ecological Communities ◽  
Wide Range ◽  
Analytical Result ◽  
Underlying Mechanisms

AbstractHigher order interactions (HOIs) have been suggested to stabilize diverse ecological communities. However, their role in maintaining species coexistence from the perspective of modern coexistence theory is not known. Here, using generalized Lotka-Volterra model, we derive a general rule for species coexistence modulated by HOIs. We show that where pairwise species interactions fail to promote species coexistence in regions of extreme fitness differences, negative HOIs that intensify pairwise competition, however, can promote coexistence provided that HOIs strengthen intraspecific competition more than interspecific competition. In contrast, positive HOIs that alleviate pairwise competition can stabilize coexistence across a wide range of fitness differences, irrespective of differences in strength of inter- and intraspecific competition. In addition, we extend our three-species analytical result to multispecies communities and show, using simulations, that multispecies coexistence is possible provided that strength of negative intraspecific HOIs is higher than interspecific HOIs. Our work sheds light on the underlying mechanisms through which HOIs can maintain species diversity.

scholarly journals The effect of non-linear competitive interactions on quantifying niche and fitness differences

2021 ◽  
Author(s):  
Jurg Spaak ◽  
Remi Millet ◽  
Po-Ju Ke ◽  
Andrew D. Letten ◽  
Frederik De Laender
Keyword(s):  
Nonlinear Dynamics ◽  
Community Dynamics ◽  
Species Coexistence ◽  
Higher Order ◽  
Competitive Interactions ◽  
Alternative Methods ◽  
Standard Methods ◽  
Coexistence Theory ◽  
Non Linear

AbstractThe niche and fitness differences of modern coexistence theory separate mechanisms into stabilizing and equalizing components. Although this decomposition can help us predict and understand species coexistence, the extent to which mechanistic inference is sensitive to the method used to partition niche and fitness differences remains unclear. We apply two alternative methods to assess niche and fitness differences to four well known community models. We show that because standard methods based on linear approximations do not capture the full community dynamics, they can sometimes lead to incorrect predictions of coexistence and misleading interpretations of stabilizing and equalizing mechanisms. Conversely, a more recently developed method to decompose niche and fitness differences, that accounts for the full nonlinear dynamics of competition, consistently identifies the correct contribution of stabilizing and equalizing components. This approach further reveals that when the true complexity of the system is taken into account, essentially all mechanisms comprise both stabilizing and equalizing components. Amidst growing interest in the role of non-additive and higher-order interactions in regulating species coexistence, we propose that the effective decomposition of niche and fitness differences will become increasingly reliant on methods that account for the inherent non-linearity of community dynamics.

scholarly journals Higher-order temporal network effects through triplet evolution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qing Yao ◽  
Bingsheng Chen ◽  
Tim S. Evans ◽  
Kim Christensen
Keyword(s):  
Real World ◽  
Link Prediction ◽  
Higher Order ◽  
Prediction Algorithm ◽  
Interaction Patterns ◽  
Temporal Networks ◽  
World Systems ◽  
Order Interaction ◽  
Space And Time ◽  
Pairwise Interactions

AbstractWe study the evolution of networks through ‘triplets’—three-node graphlets. We develop a method to compute a transition matrix to describe the evolution of triplets in temporal networks. To identify the importance of higher-order interactions in the evolution of networks, we compare both artificial and real-world data to a model based on pairwise interactions only. The significant differences between the computed matrix and the calculated matrix from the fitted parameters demonstrate that non-pairwise interactions exist for various real-world systems in space and time, such as our data sets. Furthermore, this also reveals that different patterns of higher-order interaction are involved in different real-world situations. To test our approach, we then use these transition matrices as the basis of a link prediction algorithm. We investigate our algorithm’s performance on four temporal networks, comparing our approach against ten other link prediction methods. Our results show that higher-order interactions in both space and time play a crucial role in the evolution of networks as we find our method, along with two other methods based on non-local interactions, give the best overall performance. The results also confirm the concept that the higher-order interaction patterns, i.e., triplet dynamics, can help us understand and predict the evolution of different real-world systems.

scholarly journals The evolution of size‐dependent competitive interactions promotes species coexistence

2021 ◽  
Author(s):  
Jaime M. Anaya‐Rojas ◽  
Ronald D. Bassar ◽  
Tomos Potter ◽  
Allison Blanchette ◽  
Shay Callahan ◽  
...  
Keyword(s):  
Species Coexistence ◽  
Competitive Interactions ◽  
Size Dependent

scholarly journals Metabolic Symbiosis Facilitates Species Coexistence and Generates Light-Dependent Priority Effects

2021 ◽  
Vol 8 ◽  
Author(s):  
Veronica Hsu ◽  
Holly V. Moeller
Keyword(s):  
Carbon Source ◽  
Community Composition ◽  
Green Algae ◽  
Species Interactions ◽  
Species Coexistence ◽  
Priority Effects ◽  
Competitive Interactions ◽  
Paramecium Bursaria ◽  
Mutual Benefit ◽  
Cascading Effects

Metabolic symbiosis is a form of symbiosis in which organisms exchange metabolites, typically for mutual benefit. For example, acquired phototrophs like Paramecium bursaria obtain photosynthate from endosymbiotic green algae called Chlorella. In addition to facilitating the persistence of P. bursaria by providing a carbon source that supplements P. bursaria’s heterotrophic digestion of bacteria, symbiotic Chlorella may impact competitive interactions between P. bursaria and other bacterivores, with cascading effects on community composition and overall diversity. Here, we tested the effects of metabolic symbiosis on coexistence by assessing the impacts of acquired phototrophy on priority effects, or the effect of species arrival order on species interactions, between P. bursaria and its competitor Colpidium. Our results suggest light-dependent priority effects. The acquired phototroph benefited from metabolic symbiosis during sequential arrival of each organism in competition, and led to increased growth of late-arriving Colpidium. These findings demonstrate that understanding the consequences of priority effects for species coexistence requires consideration of metabolic symbiosis.

scholarly journals Intrinsic and extrinsic drivers of intraspecific variation in seed dispersal are diverse and pervasive

AoB Plants ◽  
2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Eugene W Schupp ◽  
Rafal Zwolak ◽  
Landon R Jones ◽  
Rebecca S Snell ◽  
Noelle G Beckman ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Intraspecific Variation ◽  
Individual Variation ◽  
Habitat Structure ◽  
Ecological Context ◽  
Seed Colour ◽  
Crop Size ◽  
Starting Point ◽  
Evolutionary Consequences ◽  
Selection Of

Abstract There is growing realization that intraspecific variation in seed dispersal can have important ecological and evolutionary consequences. However, we do not have a good understanding of the drivers or causes of intraspecific variation in dispersal, how strong an effect these drivers have, and how widespread they are across dispersal modes. As a first step to developing a better understanding, we present a broad, but not exhaustive, review of what is known about the drivers of intraspecific variation in seed dispersal, and what remains uncertain. We start by decomposing ‘drivers of intraspecific variation in seed dispersal’ into intrinsic drivers (i.e. variation in traits of individual plants) and extrinsic drivers (i.e. variation in ecological context). For intrinsic traits, we further decompose intraspecific variation into variation among individuals and variation of trait values within individuals. We then review our understanding of the major intrinsic and extrinsic drivers of intraspecific variation in seed dispersal, with an emphasis on variation among individuals. Crop size is the best-supported and best-understood intrinsic driver of variation across dispersal modes; overall, more seeds are dispersed as more seeds are produced, even in cases where per seed dispersal rates decline. Fruit/seed size is the second most widely studied intrinsic driver, and is also relevant to a broad range of seed dispersal modes. Remaining intrinsic drivers are poorly understood, and range from effects that are probably widespread, such as plant height, to drivers that are most likely sporadic, such as fruit or seed colour polymorphism. Primary extrinsic drivers of variation in seed dispersal include local environmental conditions and habitat structure. Finally, we present a selection of outstanding questions as a starting point to advance our understanding of individual variation in seed dispersal.

scholarly journals Consequences of intraspecific variation in seed dispersal for plant demography, communities, evolution and global change

AoB Plants ◽  
2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Rebecca S Snell ◽  
Noelle G Beckman ◽  
Evan Fricke ◽  
Bette A Loiselle ◽  
Carolina S Carvalho ◽  
...  
Keyword(s):  
Global Change ◽  
Seed Dispersal ◽  
Intraspecific Variation ◽  
Individual Variation ◽  
Temporal Dynamics ◽  
Biodiversity Loss ◽  
Mean Value ◽  
Plant Fitness ◽  
Spatial And Temporal Dynamics ◽  
The Mean

AbstractAs the single opportunity for plants to move, seed dispersal has an important impact on plant fitness, species distributions and patterns of biodiversity. However, models that predict dynamics such as risk of extinction, range shifts and biodiversity loss tend to rely on the mean value of parameters and rarely incorporate realistic dispersal mechanisms. By focusing on the mean population value, variation among individuals or variability caused by complex spatial and temporal dynamics is ignored. This calls for increased efforts to understand individual variation in dispersal and integrate it more explicitly into population and community models involving dispersal. However, the sources, magnitude and outcomes of intraspecific variation in dispersal are poorly characterized, limiting our understanding of the role of dispersal in mediating the dynamics of communities and their response to global change. In this manuscript, we synthesize recent research that examines the sources of individual variation in dispersal and emphasize its implications for plant fitness, populations and communities. We argue that this intraspecific variation in seed dispersal does not simply add noise to systems, but, in fact, alters dispersal processes and patterns with consequences for demography, communities, evolution and response to anthropogenic changes. We conclude with recommendations for moving this field of research forward.

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