scholarly journals Within-Species Trait Variation Can Lead to Size Limitations in Seed Dispersal of Small-Fruited Plants

2021 ◽  
Vol 9 ◽  
Author(s):  
Finn Rehling ◽  
Bogdan Jaroszewicz ◽  
Leonie Victoria Braasch ◽  
Jörg Albrecht ◽  
Pedro Jordano ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Plant Species ◽  
Fruit Size ◽  
Anthropogenic Pressure ◽  
Trait Variation ◽  
Individual Level ◽  
Size Limitation ◽  
Species Trait ◽  
Gape Size ◽  
The Individual

The inability of small-gaped animals to consume very large fruits may limit seed dispersal of the respective plants. This has often been shown for large-fruited plant species that remain poorly dispersed when large-gaped animal species are lost due to anthropogenic pressure. Little is known about whether gape-size limitations similarly influence seed dispersal of small-fruited plant species that can show a large variation in fruit size within species. In this study, fruit sizes of 15 plant species were compared with the gape sizes of their 41 animal dispersers in the temperate, old-growth Białowieża Forest, Poland. The effect of gape-size limitations on fruit consumption was assessed at the plant species level, and for a subset of nine plant species, also at the individual level, and subindividual level (i.e., fruits of the same plant individual). In addition, for the species subset, fruit-seed trait relationships were investigated to determine whether a restricted access of small-gaped animals to large fruits results in the dispersal of fewer or smaller seeds per fruit. Fruit sizes widely varied among plant species (74.2%), considerably at the subindividual level (17.1%), and to the smallest extent among plant individuals (8.7%). Key disperser species should be able to consume fruits of all plant species and all individuals (except those of the largest-fruited plant species), even if they are able to consume only 28-55% of available fruits. Fruit and seed traits were positively correlated in eight out of nine plant species, indicating that gape size limitations will result in 49% fewer (in one) or 16–21% smaller seeds (in three plant species) dispersed per fruit by small-gaped than by large-gaped main dispersers, respectively. Our results show that a large subindividual variation in fruit size is characteristic for small-fruited plant species, and increases their connectedness with frugivores at the level of plants species and individuals. Simultaneously, however, the large variation in fruit size leads to gape-size limitations that may induce selective pressures on fruit size if large-gaped dispersers become extinct. This study emphasizes the mechanisms by which gape-size limitation at the species, individual and subindividual level shape plant-frugivore interactions and the co-evolution of small-fruited plants.

scholarly journals Internal seed dispersal by parrots: an overview of a neglected mutualism

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1688 ◽  
Author(s):  
Guillermo Blanco ◽  
Carolina Bravo ◽  
Erica C. Pacifico ◽  
Daniel Chamorro ◽  
Karina L. Speziale ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Plant Species ◽  
Fruit Size ◽  
Food Plants ◽  
Size Difference ◽  
Population Declines ◽  
Columnar Cacti ◽  
Parrot Species ◽  
The Mean ◽  
Germination Experiments

Despite the fact that parrots (Psitacifformes) are generalist apex frugivores, they have largely been considered plant antagonists and thus neglected as seed dispersers of their food plants. Internal dispersal was investigated by searching for seeds in faeces opportunistically collected at communal roosts, foraging sites and nests of eleven parrot species in different habitats and biomes in the Neotropics. Multiple intact seeds of seven plant species of five families were found in a variable proportion of faeces from four parrot species. The mean number of seeds of each plant species per dropping ranged between one and about sixty, with a maximum of almost five hundred seeds from the cactiPilosocereus pachycladusin a single dropping of Lear’s Macaw (Anodorhynchus leari). All seeds retrieved were small (<3 mm) and corresponded to herbs and relatively large, multiple-seeded fleshy berries and infrutescences from shrubs, trees and columnar cacti, often also dispersed by stomatochory. An overview of the potential constraints driving seed dispersal suggest that, despite the obvious size difference between seeds dispersed by endozoochory and stomatochory, there is no clear difference in fruit size depending on the dispersal mode. Regardless of the enhanced or limited germination capability after gut transit, a relatively large proportion of cacti seeds frequently found in the faeces of two parrot species were viable according to the tetrazolium test and germination experiments. The conservative results of our exploratory sampling and a literature review clearly indicate that the importance of parrots as endozoochorous dispersers has been largely under-appreciated due to the lack of research systematically searching for seeds in their faeces. We encourage the evaluation of seed dispersal and other mutualistic interactions mediated by parrots before their generalized population declines contribute to the collapse of key ecosystem processes.

scholarly journals Adaptive foraging behaviour of individual pollinators and the coexistence of co-flowering plants

2014 ◽  
Vol 281 (1776) ◽  
pp. 20132437 ◽  
Author(s):  
Zhiyuan Song ◽  
Marcus W. Feldman
Keyword(s):  
Population Dynamics ◽  
Plant Species ◽  
Plant Communities ◽  
Foraging Behaviour ◽  
Adaptive Behaviour ◽  
Native Plant ◽  
Flower Constancy ◽  
Individual Level ◽  
The Individual ◽  
Adaptive Foraging

Although pollinators can play a central role in determining the structure and stability of plant communities, little is known about how their adaptive foraging behaviours at the individual level, e.g. flower constancy, structure these interactions. Here, we construct a mathematical model that integrates individual adaptive foraging behaviour and population dynamics of a community consisting of two plant species and a pollinator species. We find that adaptive foraging at the individual level, as a complementary mechanism to adaptive foraging at the species level, can further enhance the coexistence of plant species through niche partitioning between conspecific pollinators. The stabilizing effect is stronger than that of unbiased generalists when there is also strong competition between plant species over other resources, but less so than that of multiple specialist species. This suggests that adaptive foraging in mutualistic interactions can have a very different impact on the plant community structure from that in predator–prey interactions. In addition, the adaptive behaviour of individual pollinators may cause a sharp regime shift for invading plant species. These results indicate the importance of integrating individual adaptive behaviour and population dynamics for the conservation of native plant communities.

scholarly journals Community level individual-based plant-pollinator networks unveil pollen flow dynamics and plant reproductive success

2021 ◽  
Author(s):  
Alfonso Allen-Perkins ◽  
María Hurtado ◽  
David García-Callejas ◽  
Oscar Godoy ◽  
Ignasi Bartomeus
Keyword(s):  
Reproductive Success ◽  
Plant Species ◽  
Individual Plant ◽  
Ecological Communities ◽  
Ecological Processes ◽  
Individual Level ◽  
Heterospecific Pollen ◽  
Plant Reproductive Success ◽  
The Individual ◽  
Plant Pollinator

Ecological networks are a widely used tool to understand the dynamics of ecological communities in which plants interact with their pollinator counterparts. However, while most mutualistic networks have been defined at the species level, ecological processes, such as pollination, take place at the individual level. This recognition has led to the development of individual-based networks, yet current approaches only account for individuals of a single plant species due to conceptual and mathematical limitations. Here, we introduce a multilayer framework designed to depict the conspecific and heterospecific pollen flows mediated by floral visitors among plant individuals belonging to different species. Pollen transfer is modeled as a transport-like system, where an ensemble of conspecific plant-pollinator “circuits” are coupled through pollinators. With this physical conceptualization of ecological processes, we investigate how the reproductive success of plant individuals is affected by the overall dynamics of the whole multilayer network (macrostructure), as well as by their local position within the network (mesostructure). To illustrate this multiscale analysis, we apply it to a dataset of nine well-resolved individual plant-pollinator interaction networks from annual plant grasslands. Our results show that the resulting individual-based networks are highly modular, with insect visitors effectively connecting individuals of the same and different plant species. We also obtain empirical evidence that network structure is critical for modulating individual plant reproduction. In particular, the mesoscale level is the best descriptor of plant reproductive success, as it integrates the net effect of local heterospecific and conspecific interactions on seed production of a given individual. We provide a simple, but robust set of metrics to scale down network ecology to functioning properties at the individual level, where most ecological processes take place, hence moving forward the description and interpretation of multitrophic communities across scales.

Differential Effects of Competence and Morality on Self-Esteem at the Individual and the Collective Level

2020 ◽  
Vol 51 (3) ◽  
pp. 183-198
Author(s):  
Wiktor Soral ◽  
Mirosław Kofta
Keyword(s):  
Self Esteem ◽  
Differential Effects ◽  
Individual Level ◽  
The Subject ◽  
The Individual

Abstract. The importance of various trait dimensions explaining positive global self-esteem has been the subject of numerous studies. While some have provided support for the importance of agency, others have highlighted the importance of communion. This discrepancy can be explained, if one takes into account that people define and value their self both in individual and in collective terms. Two studies ( N = 367 and N = 263) examined the extent to which competence (an aspect of agency), morality, and sociability (the aspects of communion) promote high self-esteem at the individual and the collective level. In both studies, competence was the strongest predictor of self-esteem at the individual level, whereas morality was the strongest predictor of self-esteem at the collective level.

Metonymy in Dance: Ballet Bunheads Take a Cognitive Turn

2019 ◽  
Vol 37 (1) ◽  
pp. 18-34
Author(s):  
Edward C. Warburton
Keyword(s):  
Identity Formation ◽  
Cognitive Science ◽  
Artistic Development ◽  
Individual Level ◽  
Figures Of Speech ◽  
Self Image ◽  
Level I ◽  
Dance Educators ◽  
The Individual ◽  
Metaphor And Metonymy

This essay considers metonymy in dance from the perspective of cognitive science. My goal is to unpack the roles of metaphor and metonymy in dance thought and action: how do they arise, how are they understood, how are they to be explained, and in what ways do they determine a person's doing of dance? The premise of this essay is that language matters at the cultural level and can be determinative at the individual level. I contend that some figures of speech, especially metonymic labels like ‘bunhead’, can not only discourage but dehumanize young dancers, treating them not as subjects who dance but as objects to be danced. The use of metonymy to sort young dancers may undermine the development of healthy self-image, impede strong identity formation, and retard creative-artistic development. The paper concludes with a discussion of the influence of metonymy in dance and implications for dance educators.

Exploring the effect of weight loss on food reward at the individual level

2019 ◽  
Author(s):  
Pauline Oustric ◽  
Kristine Beaulieu ◽  
Nuno Casanova ◽  
Francois Husson ◽  
Catherine Gibbons ◽  
...  
Keyword(s):  
Weight Loss ◽  
Food Reward ◽  
Individual Level ◽  
The Individual

Personality change and environmental concerns

2020 ◽  
Author(s):  
Christopher James Hopwood ◽  
Ted Schwaba ◽  
Wiebke Bleidorn
Keyword(s):  
Personality Traits ◽  
Personality Change ◽  
Environmental Concerns ◽  
Big Five Personality ◽  
German Population ◽  
Individual Level ◽  
Sustainable Behavior ◽  
Nationally Representative ◽  
The Individual ◽  
Over Time

Personal concerns about climate change and the environment are a powerful motivator of sustainable behavior. People’s level of concern varies as a function of a variety of social and individual factors. Using data from 58,748 participants from a nationally representative German sample, we tested preregistered hypotheses about factors that impact concerns about the environment over time. We found that environmental concerns increased modestly from 2009-2017 in the German population. However, individuals in middle adulthood tended to be more concerned and showed more consistent increases in concern over time than younger or older people. Consistent with previous research, Big Five personality traits were correlated with environmental concerns. We present novel evidence that increases in concern were related to increases in the personality traits neuroticism and openness to experience. Indeed, changes in openness explained roughly 50% of the variance in changes in environmental concerns. These findings highlight the importance of understanding the individual level factors associated with changes in environmental concerns over time, towards the promotion of more sustainable behavior at the individual level.

Reply to Connor and Evers (2020): Critique of the Bias of Crowds Model Simply Restates the Model

2020 ◽  
Author(s):  
Keith Payne ◽  
Heidi A. Vuletich ◽  
Kristjen B. Lundberg
Keyword(s):  
Implicit Bias ◽  
Group Level ◽  
Systemic Racism ◽  
Individual Level ◽  
The Core ◽  
Psychological Science ◽  
Implicit Biases ◽  
The Individual

The Bias of Crowds model (Payne, Vuletich, &amp; Lundberg, 2017) argues that implicit bias varies across individuals and across contexts. It is unreliable and weakly associated with behavior at the individual level. But when aggregated to measure context-level effects, the scores become stable and predictive of group-level outcomes. We concluded that the statistical benefits of aggregation are so powerful that researchers should reconceptualize implicit bias as a feature of contexts, and ask new questions about how implicit biases relate to systemic racism. Connor and Evers (2020) critiqued the model, but their critique simply restates the core claims of the model. They agreed that implicit bias varies across individuals and across contexts; that it is unreliable and weakly associated with behavior at the individual level; and that aggregating scores to measure context-level effects makes them more stable and predictive of group-level outcomes. Connor and Evers concluded that implicit bias should be considered to really be noisily measured individual construct because the effects of aggregation are merely statistical. We respond to their specific arguments and then discuss what it means to really be a feature of persons versus situations, and multilevel measurement and theory in psychological science more broadly.

Leadership Enactment for Information System Acceptance: an Explanation from a Sensemaking Perspective

2019 ◽  
pp. 78-106
Author(s):  
Aruna Dayanatha ◽  
J A S K Jayakody
Keyword(s):  
Information System ◽  
User Involvement ◽  
High Rate ◽  
Is Success ◽  
Managerial Leadership ◽  
Individual Level ◽  
System Acceptance ◽  
The Individual ◽  
Leadership Intervention ◽  
Is Failure

Information system (IS) projects have been seen to be failing at an alarmingly high rate. The prevailing explanations of IS failure have had only a limited success. Thus, the time may be right to look at the reasons for IS failure through an alternative perspective. This paper proposes that IS success should be explained in terms of managerial leadership intervention, from the sensemaking perspective. Managers are responsible for workplace outcomes; thus, it may be appropriate to explain their role in IS success as well. The sensemaking perspective can explain IS success through holistic user involvement, a concept which critiques of existing explanations have stated to be a requirement for explaining IS failure. This paper proposes a framework combining the theory of enactment and leadership enactment to theorize managerial leadership intervention for “IS success.” The proposed explanation postulates that the managerial leader’s envisioning of the future transaction set influences the liberation of the follower and cast enactment, while liberating followers and cast enactment constitute manager sensegiving. The managerial leader’s sense-giving influences follower sensemaking. Follower sensemaking, under the influence of managerial sensegiving, will lead to followers’ IS acceptance, and that constitutes IS success at the individual level. Further, collective level IS acceptance constitutes IS adaption/success, and this will influence the leader’s sensegiving, for the next round of sensemaking.

Sign in / Sign up

Export Citation Format

Share Document