scholarly journals Linking multi-level population dynamics: trait, role, and population

Author(s):  
Nao Takashina

Species interactions characterize population dynamics and ecosystem structure. While the population-level discussion is common in many ecological studies, trait variations within a population and ontogenetic diet/trophic niche shift are prevail across taxa. The ontogenetic development may lead to an individual’s role shift, such as inferior/superior competitor, prey, or predator. Here, we develop a novel mathematical framework to bridge multiple levels of population dynamics, such as trait, role, and population-level. We start with a nonlinear trait-level model, and derive role-level and population-level dynamics. By utilizing the connections, we demonstrate that the population-level model predicts the equilibrium status of the role-level model. In the role-level model, we discuss multiple role-shift scenarios: from (i) inferior/superior competitor to superior/inferior competitor, (ii) competitor to predator, and (iii) prey to predator. Our approach connects traits, roles, and population dynamics consistently, thus offering an opportunity to discuss the effect of species traits in the population-level dynamics.

2018 ◽  
Vol 2 ◽  
pp. e25343
Author(s):  
José Augusto Salim ◽  
Antonio Saraiva ◽  
Kayna Agostini ◽  
Marina Wolowski ◽  
Allan Veiga ◽  
...  

The Brazilian Plant-Pollinator Interactions Network*1 (REBIPP) aims to develop scientific and teaching activities in plant-pollinator interaction. The main goals of the network are to: generate a diagnosis of plant-pollinator interactions in Brazil; integrate knowledge in pollination of natural, agricultural, urban and restored areas; identify knowledge gaps; support public policy guidelines aimed at the conservation of biodiversity and ecosystem services for pollination and food production; and encourage collaborative studies among REBIPP participants. To achieve these goals the group has resumed and built on previous works in data standard definition done under the auspices of the IABIN-PTN (Etienne Américo et al. 2007) and FAO (Saraiva et al. 2010) projects (Saraiva et al. 2017). The ultimate goal is to standardize the ways data on plant-pollinator interactions are digitized, to facilitate data sharing and aggregation. A database will be built with standardized data from Brazilian researchers members of the network to be used by the national community, and to allow sharing data with data aggregators. To achieve those goals three task groups of specialists with similar interests and background (e.g botanists, zoologists, pollination biologists) have been created. Each group is working on the definition of the terms to describe plants, pollinators and their interactions. The glossary created explains their meaning, trying to map the suggested terms into Darwin Core (DwC) terms, and following the TDWG Standards Documentation Standard*2 in definition. Reaching a consensus on terms and their meaning among members of each group is challenging, since researchers have different views and concerns about which data are important to be included into a standard. That reflects the variety of research questions that underlie different projects and the data they collect. Thus, we ended up having a long list of terms, many of them useful only in very specialized research protocols and experiments, sometimes rarely collected or measured. Nevertheless we opted to maintain a very comprehensive set of terms, so that a large number of researchers feel that the standard meets their needs and that the databases based on it are a suitable place to store their data, thus encouraging the adoption of the data standard. An update of the work will soon be available at REBIPP website and will be open for comments and contributions. This proposal of a data standard is also being discussed within the TDWG Biological Interaction Data Interest Group*3 in order to propose an international standard for species interaction data. The importance of interaction data for guiding conservation practices and ecosystem services provision management has led to the proposal of defining Essential Biodiversity Variables (EBVs) related to biological interactions. Essential Biodiversity Variables (Pereira et al. 2013) were developed to identify key measurements that are required to monitoring biodiversity change. EBVs act as intermediate abstract layer between primary observations (raw data) and indicators (Niemeijer 2002). Five EBV classes have been defined in an initial stage: genetic composition, species populations, species traits, community composition, ecosystem function and ecosystem structure. Each EBV class defines a list of candidate EBVs for biodiversity change monitoring (Fig. 1). Consequently, digitalization of such data and making them available online are essential. Differences in sampling protocols may affect data scalability across space and time, hence imposing barriers to the full use of primary data and EBVs calculation (Henry et al. 2008). Thus, common protocols and methods should be adopted as the most straightforward approach to promote integration of collected data and to allow calculation of EBVs (Jürgens et al. 2011). Recently a Workshop was held by GLOBIS B*4 (GLOBal Infrastructures for Supporting Biodiversity research) to discuss Species Interactions EBVs (February, 26-28, Bari, Italy). Plant-pollinator interactions deserved a lot of attention and REBIPP's work was presented there. As an outcome we expect to define specific EBVs for interactions, and use plant-pollinators as an example, considering pairwise interactions as well as interaction network related variables. The terms in the plant-pollinator data standard under discussion at REBIPP will provide information not only on EBV related with interactions, but also on other four EBV classes: species populations, species traits, community composition, ecosystem function and ecosystem structure. As we said, some EBVs for specific ecosystem functions (e.g. pollination) lay beyond interactions network structures. The EBV 'Species interactions' (EBV class 'Community composition') should incorporate other aspects such as frequency (Vázquez et al. 2005), duration and empirical estimates of interaction strengths (Berlow et al. 2004). Overall, we think the proposed plant-pollinator interaction data standard which is currently being developed by REBIPP will contribute to data aggregation, filling many data gaps and can also provide indicators for long-term monitoring, being an essential source of data for EBVs.


2018 ◽  
Vol 2 ◽  
pp. e25409
Author(s):  
Quentin Groom ◽  
Robert Guralnick ◽  
W. Daniel Kissling

Can Essential Biodiversity Variables (EBVs) be developed to monitor changes in species interactions? That was the difficult question asked at the GLOBIS-B workshop in February, 2017 in which >50 experts participated. EBVs can be defined as harmonized measurements that allow us to inform policy about essential changes in biodiversity. They can be seen as biological state variables from which more refined indicators may be derived. They have been presented as a means to monitor global biodiversity change and as a concept to drive the gathering, sharing, and standardisation of data on our biota (Geijzendorffer et al. 2015, Kissling et al. 2017, Pereira et al. 2013). There are different classes of EBVs that characterize, for example, the state of species populations, species traits and ecosystem structure and function. It has also been proposed that there should be EBVs related to species interactions. However, until now there has been little progress formulating what these should be, even though species interactions are central to ecology. Species interactions cover a wide range of important processes, from mutualisms, such as pollination, to different forms of heterotrophic nutrition, such as the predator-prey relationship. Indeed, ecological interactions are critical to understand why an ecosystem is more than the sum of its parts. Nevertheless, direct observation of species interactions is often difficult and time consuming work, which makes it difficult to monitor them in the long-term. For this reason the workshop focused on those species interactions that are feasible to study and are most relevant to policy. To bring focus to our discussions we concentrated on pollination, predation and microbial interactions. Taking pollination as an example, there was recognition of the importance of ecological networks and that network metrics may be a sensitive indicator of change. Potential EBVs might be the number of pairwise interactions between species or the modularity and interaction diversity of the whole network. This requires standardised data collection and reporting (e.g. standardization of measures of interaction strength or minimum data specifications for ecological networks) and sufficient data across time to regularly calculate these metrics. Other simpler surrogates for pollination might also prove useful, such as flower visitation rates or the proportion of fruit set. Finally, there was a recognition that we do not yet have enough tools to monitor some important interactions. Many interactions, particular among microbes, can currently only be inferred from the co-occurrence of taxa. However, technology is rapidly developing and it is possible to foresee a future where even these interactions can be monitored efficiently. Species interactions are essential to understanding ecology, but they are also difficult to monitor. Yet, delegates at the workshop left with a positive outlook that it is valuable to develop standardisation and harmonization of species interaction data to make them suitable for EBV production.


Author(s):  
André M. de Roos ◽  
Lennart Persson

The previous two chapters discussed how the size scaling of foraging and metabolic rates affected the dynamics of consumer-resource systems. Using different modeling approaches, it was shown that stage-dependent competitive ability was the main predictor of population dynamics; that is, it largely set the conditions for different types of cycles to occur. This chapter adds another intraspecific interaction on top of the consumer-resource system, namely, cannibalism. It uses a discrete-continuous population-level model based on individual-level net-production energetics to investigate the effects of cannibalism. The focus will be on the effects of cannibalism on population dynamics related to four processes that have been discussed in the literature regarding cannibalism: effects on mortality, competition, energy gain, and the size dependence of interactions.


Biosystems ◽  
2017 ◽  
Vol 161 ◽  
pp. 3-14 ◽  
Author(s):  
Roman Borisyuk ◽  
Robert Merrison-Hort ◽  
Steve R. Soffe ◽  
Stella Koutsikou ◽  
Wen-Chang Li

2012 ◽  
Vol 279 (1746) ◽  
pp. 4505-4512 ◽  
Author(s):  
Hannah J. Tidbury ◽  
Alex Best ◽  
Mike Boots

Exposure to low doses of pathogens that do not result in the host becoming infectious may ‘prime’ the immune response and increase protection to subsequent challenge. There is increasing evidence that such immune priming is a widespread and important feature of invertebrate host–pathogen interactions. Immune priming clearly has implications for individual hosts but will also have population-level implications. We present a susceptible–primed–infectious model—in contrast to the classic susceptible–infectious–recovered framework—to investigate the impacts of immune priming on pathogen persistence and population stability. We describe impacts of immune priming on the epidemiology of the disease in both constant and seasonal environments. A key result is that immune priming may act to destabilize population dynamics. In particular, when the proportion of individuals becoming primed rather than infected is high, but this priming does not confer full immunity, the population may be strongly destabilized through the generation of limit cycles. We discuss the implications of our model both in the context of invertebrate immunity and more widely.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
P. Lorenzo Bozzelli ◽  
Seham Alaiyed ◽  
Eunyoung Kim ◽  
Sonia Villapol ◽  
Katherine Conant

The perineuronal net (PNN) represents a lattice-like structure that is prominently expressed along the soma and proximal dendrites of parvalbumin- (PV-) positive interneurons in varied brain regions including the cortex and hippocampus. It is thus apposed to sites at which PV neurons receive synaptic input. Emerging evidence suggests that changes in PNN integrity may affect glutamatergic input to PV interneurons, a population that is critical for the expression of synchronous neuronal population discharges that occur with gamma oscillations and sharp-wave ripples. The present review is focused on the composition of PNNs, posttranslation modulation of PNN components by sulfation and proteolysis, PNN alterations in disease, and potential effects of PNN remodeling on neuronal plasticity at the single-cell and population level.


2020 ◽  
Author(s):  
Diana E. Bowler ◽  
Mikkel A. J. Kvasnes ◽  
Hans C. Pedersen ◽  
Brett K. Sandercock ◽  
Erlend B. Nilsen

AbstractAccording to classic theory, species’ population dynamics and distributions are less influenced by species interactions under harsh climatic conditions compared to under more benign climatic conditions. In alpine and boreal ecosystems in Fennoscandia, the cyclic dynamics of rodents strongly affect many other species, including ground-nesting birds such as ptarmigan. According to the ‘alternative prey hypothesis’ (APH), the densities of ground-nesting birds and rodents are positively associated due to predator-prey dynamics and prey-switching. However, it remains unclear how the strength of these predator-mediated interactions change along a climatic harshness gradient in comparison with the effects of climatic variation. We built a hierarchical Bayesian model to estimate the sensitivity of ptarmigan populations to interannual variation in climate and rodent occurrence across Norway during 2007–2017. Ptarmigan abundance was positively linked with rodent occurrence, consistent with the APH. Moreover, we found that rodent dynamics had stronger effects on ptarmigan in colder regions. Our study highlights how species interactions play an important role for the population dynamics of species at higher latitudes and suggests that they can become even more important in the most climatically harsh regions.


2015 ◽  
Vol 73 (6) ◽  
pp. 1659-1667 ◽  
Author(s):  
S. M. Garcia ◽  
J. Rice ◽  
A. Charles

Abstract Balanced harvesting has been proposed as a way for fisheries management to achieve the requirements of both the Law of the Sea Convention (LOSC)—to maintain stocks at the level at which they could produce MSY—and the Convention on Biological Diversity (CBD)—to maintain ecosystem structure and functioning. This paper examines these requirements and briefly presents four system-level relationships (spectra), representing ecosystem structures that might guide management decision-making aiming to meet both requirements. These spectra would fit in the widely accepted frameworks of the Ecosystem Approach enshrined in the CBD and adopted by FAO for Fisheries. A size spectrum, relating biomass to body length, is used as an example to illustrate its potential to support management decision-making—much like present stock-based harvest control rules—in more ecosystem-compliant fishing strategies at a sector or ecosystem level, as a complement to those currently used at a stock/population level.


2019 ◽  
pp. 266-284
Author(s):  
Gary G. Mittelbach ◽  
Brian J. McGill

Just as the dispersal of individuals may link the dynamics of populations in space, the dispersal of species among communities may link local communities into a metacommunity. Four different perspectives characterize how dispersal rates, environmental heterogeneity, and species traits interact to influence diversity in metacommunities. These perspectives are: patch dynamics, species sorting, mass effects, and the neutral perspective. The neutral perspective stands in stark contrast to the other three perspectives in that it assumes that niche differences between species are unimportant and that species are demographically identical in terms of their birth, death, and dispersal rates. Under the neutral perspective, species diversity is maintained by a balance between speciation, extinction, and dispersal. Although neutral theory is incompatible with realistic modes and rates of speciation, it has been enormously influential in focusing our attention on the linkages between species interactions on local scales, and evolutionary and biogeographic processes occurring on large scales.


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