scholarly journals Environment affects specialisation of plants and pollinators

2019 ◽  
Author(s):  
E. Fernando Cagua ◽  
Audrey Lustig ◽  
Jason M. Tylianakis ◽  
Daniel B. Stouffer

AbstractWhat determines whether or not a species is a generalist or a specialist? Evidence that the environment can influence species interactions is rapidly accumulating. However, a systematic link between environment and the number of partners a species interacts with has been elusive so far. Presumably, because environmental gradients appear to have contrasting effects on species depending on the environmental variable. Here, we test for a relationship between the stresses imposed by the environment, instead of environmental gradients directly, and species specialisation using a global dataset of plant-pollinator interactions. We found that the environment can play a significant effect on specialisation, even when accounting for community composition, likely by interacting with species’ traits and evolutionary history. Species that have a large number of interactions are more likely to focus on a smaller number of, presumably higher-quality, interactions under stressful environmental conditions. Contrastingly, the specialists present in multiple locations are more likely to broaden their niche, presumably engaging in opportunistic interactions to cope with increased environmental stress. Indeed, many apparent specialists effectively behave as facultative generalists. Overall, many of the species we analysed are not inherently generalist or specialist. Instead, species’ level of specialisation should be considered on a relative scale depending on where they are found and the environmental conditions at that location.

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.


2016 ◽  
Author(s):  
Sara F. Paver ◽  
Angela D. Kent

AbstractSpecies interactions, environmental conditions, and stochastic processes work in concert to bring about changes in community structure. However, the relative importance of specific factors and how their combined influence affects community composition remain largely unclear. We conducted a multi-factorial experiment to 1) disentangle the direct and interaction-mediated effects of environmental conditions and 2) augment our understanding of how environmental context modulates species interactions. We focus on a planktonic system where interactions with phytoplankton effect changes in the composition of bacterial communities, and light and temperature conditions can influence bacteria directly as well as through their interactions with phytoplankton. Epilimnetic bacteria from two humic lakes were combined with phytoplankton assemblages from each lake (“home” or “away”) or a no-phytoplankton control and incubated for 5 days under all combinations of light (surface, ∼25% surface irradiance) and temperature (5 levels from 10°C to 25°C). Observed light effects were primarily direct while phytoplankton and temperature effects on bacterial community composition were highly interdependent. The influence of temperature on aquatic bacteria was consistently mediated by phytoplankton and most pronounced for bacteria incubated with “away” phytoplankton treatments, likely due to the availability of novel phytoplankton-derived resources. The effects of phytoplankton on bacterial community composition were generally increased at higher temperatures. Incorporating mechanisms underlying the observed interdependent effects of species interactions and environmental conditions into modeling frameworks may improve our ability to forecast ecological responses to environmental change.


2020 ◽  
Vol 29 (13) ◽  
pp. 3609-3634 ◽  
Author(s):  
Cristian Dambros ◽  
Gabriela Zuquim ◽  
Gabriel M. Moulatlet ◽  
Flávia R. C. Costa ◽  
Hanna Tuomisto ◽  
...  

Abstract To determine the effect of rivers, environmental conditions, and isolation by distance on the distribution of species in Amazonia. Location: Brazilian Amazonia. Time period: Current. Major taxa studied: Birds, fishes, bats, ants, termites, butterflies, ferns + lycophytes, gingers and palms. We compiled a unique dataset of biotic and abiotic information from 822 plots spread over the Brazilian Amazon. We evaluated the effects of environment, geographic distance and dispersal barriers (rivers) on assemblage composition of animal and plant taxa using multivariate techniques and distance- and raw-data-based regression approaches. Environmental variables (soil/water), geographic distance, and rivers were associated with the distribution of most taxa. The wide and relatively old Amazon River tended to determine differences in community composition for most biological groups. Despite this association, environment and geographic distance were generally more important than rivers in explaining the changes in species composition. The results from multi-taxa comparisons suggest that variation in community composition in Amazonia reflects both dispersal limitation (isolation by distance or by large rivers) and the adaptation of species to local environmental conditions. Larger and older river barriers influenced the distribution of species. However, in general this effect is weaker than the effects of environmental gradients or geographical distance at broad scales in Amazonia, but the relative importance of each of these processes varies among biological groups.


2019 ◽  
Author(s):  
Matthieu Barbier ◽  
Claire de Mazancourt ◽  
Michel Loreau ◽  
Guy Bunin

AbstractThe coexistence of many competing species is a long-standing puzzle in ecology. Classic niche theory explains coexistence by trade-offs between a few essential species traits. Here we study an unexplored frontier of this theory: we assume that coexistence is intrinsically high-dimensional, arising from many traits and trade-offs at once. Species interactions then appear almost random, but their disorder hides a diffuse statistical structure: competitors that become successful start by subtly favoring each other, and partitioning their impacts on other species. We validate our quantitative predictions using data from grassland biodiversity experiments. We conclude that a high biodiversity can be attained through a pattern of collective organization that cannot be understood at the species level, but exhibits the fingerprint of high-dimensional interactions.


2015 ◽  
Author(s):  
Ignasi Bartomeus ◽  
Dominique Gravel ◽  
Jason Tylianakis ◽  
Marcelo Aizen ◽  
Ian Dickie ◽  
...  

Species interactions, ranging from antagonisms to mutualisms, form the architecture of biodiversity and determine ecosystem functioning. Understanding the rules responsible for who interacts with whom, as well as the functional consequences of these interspecific interactions, is central to predicting community dynamics and stability. Species traitssensu latomay affect different ecological processes determining species interactions through a two-step process. First, ecological and life-history traits govern species distributions and abundance, and hence determine species co-occurrence, which is a prerequisite for them to interact. Second, morphological traits between co-occurring potential interaction partners should match for the realization of an interaction. Moreover, inferring functioning from a network of interactions may require the incorporation of interaction efficiency. This efficiency may be also trait-mediated, and can depend on the extent of matching, or on morphological, physiological or behavioural traits. It has been shown that both neutral and trait-based models can predict the general structure of networks, but they rarely accurately predict individual interactions, suggesting that these models may be predicting the right structure for the wrong reason. We propose to move away from testing null models with a framework that explicitly models the probability of interaction among individuals given their traits. The proposed models integrate both neutral and trait-matching constraints while using only information about known interactions, thereby overcoming problems originating from under-sampling of rare interactions (i.e. missing links). They can easily accommodate qualitative or quantitative data, and can incorporate trait variation within species, such as values that vary along developmental stages or environmental gradients. We use three case studies to show that they can detect strong trait matching (e.g. predator-prey system), relaxed trait matching (e.g. herbivore-plant system) and barrier trait matching (e.g. plant-pollinator systems). Only by elucidating which species traits are important in each process, i.e. in determining interaction establishment, frequency, and efficiency, can we advance in explaining how species interact and the consequences for ecosystem functioning.


2016 ◽  
Vol 371 (1694) ◽  
pp. 20150267 ◽  
Author(s):  
Ulrich Brose ◽  
Helmut Hillebrand

The relationship between biodiversity and ecosystem functioning (BEF) and its consequence for ecosystem services has predominantly been studied by controlled, short-term and small-scale experiments under standardized environmental conditions and constant community compositions. However, changes in biodiversity occur in real-world ecosystems with varying environments and a dynamic community composition. In this theme issue, we present novel research on BEF in such dynamic communities. The contributions are organized in three sections on BEF relationships in (i) multi-trophic diversity, (ii) non-equilibrium biodiversity under disturbance and varying environmental conditions, and (iii) large spatial and long temporal scales. The first section shows that multi-trophic BEF relationships often appear idiosyncratic, while accounting for species traits enables a predictive understanding. Future BEF research on complex communities needs to include ecological theory that is based on first principles of species-averaged body masses, stoichiometry and effects of environmental conditions such as temperature. The second section illustrates that disturbance and varying environments have direct as well as indirect (via changes in species richness, community composition and species' traits) effects on BEF relationships. Fluctuations in biodiversity (species richness, community composition and also trait dominance within species) can severely modify BEF relationships. The third section demonstrates that BEF at larger spatial scales is driven by different variables. While species richness per se and community biomass are most important, species identity effects and community composition are less important than at small scales. Across long temporal scales, mass extinctions represent severe changes in biodiversity with mixed effects on ecosystem functions. Together, the contributions of this theme issue identify new research frontiers and answer some open questions on BEF relationships in dynamic communities of real-world landscapes.


2011 ◽  
Vol 279 (1733) ◽  
pp. 1588-1596 ◽  
Author(s):  
Anna Eklöf ◽  
Matthew R. Helmus ◽  
M. Moore ◽  
Stefano Allesina

Explaining the structure of ecosystems is one of the great challenges of ecology. Simple models for food web structure aim at disentangling the complexity of ecological interaction networks and detect the main forces that are responsible for their shape. Trophic interactions are influenced by species traits, which in turn are largely determined by evolutionary history. Closely related species are more likely to share similar traits, such as body size, feeding mode and habitat preference than distant ones. Here, we present a theoretical framework for analysing whether evolutionary history—represented by taxonomic classification—provides valuable information on food web structure. In doing so, we measure which taxonomic ranks better explain species interactions. Our analysis is based on partitioning of the species into taxonomic units. For each partition, we compute the likelihood that a probabilistic model for food web structure reproduces the data using this information. We find that taxonomic partitions produce significantly higher likelihoods than expected at random. Marginal likelihoods (Bayes factors) are used to perform model selection among taxonomic ranks. We show that food webs are best explained by the coarser taxonomic ranks (kingdom to class). Our methods provide a way to explicitly include evolutionary history in models for food web structure.


2016 ◽  
Author(s):  
Thijs Janzen ◽  
Adriana Alzate ◽  
Moritz Muschick ◽  
Fons van der Plas ◽  
Rampal S. Etienne

ABSTRACTThe African Great Lakes are characterized by an extraordinary diversity of endemic cichlid fish species. The cause of this diversity is still largely unknown. Most studies have tried to solve this question by focusing on macro-evolutionary processes, such as speciation. However, the ecological processes determining local cichlid diversity have so far been understudied, even though knowledge on these might be crucial for understanding larger scale biodiversity patterns.Using trait, environmental and abundance data of cichlid fishes along 36 transects, we have studied how differences in local environmental conditions influence cichlid community assembly in the littoral of Lake Tanganyika, Zambia. We investigated changes in average trait values and in trait-based community assembly processes along three key environmental gradients.Species diversity and local abundance decreased with increasing sand cover and diet-associated traits changed with depth. Analyses on within-community trait diversity patterns indicated that cichlid community assembly was mainly driven by stochastic processes, to a smaller extent by processes that limit the similarity among co-existing species and least by filtering processes that limit the range of species traits occurring in an environment. Despite, the low impact of habitat filtering processes, we find community dissimilarity to increase with increasing environmental difference.Our results suggest that local environmental conditions determine cichlid abundance, while the predominance of stochastic community assembly across all environments explains why the communities with the highest abundances contain most species.


2020 ◽  
Author(s):  
Beth M. L. Morrison ◽  
Berry J. Brosi ◽  
Rodolfo Dirzo

AbstractDetermining linkage rules that govern the formation of species interactions is a critical goal of ecologists, especially considering that biodiversity, species interactions, and the ecosystem processes they maintain are changing at rapid rate worldwide. Species traits and abundance play a role in determining plant-pollinator interactions, but we illustrate here that linkage rules of plant-pollinator interactions change with disturbance context, switching from predominantly trait-based linkage rules in undisturbed, natural habitats, to abundance-based linkage rules in intensive agricultural habitats. The transition from trait-based to abundance-based linkage rules corresponds with a decline in floral trait diversity and an increase in opportunistic interaction behavior as agricultural intensification increases. These findings suggest that agricultural intensification is changing the very rules determining the realization of interactions and the formation of communities, making it challenging to use the structure of undisturbed systems to predict interactions within disturbed communities.


2013 ◽  
Vol 75 (3) ◽  
pp. 194-201 ◽  
Author(s):  
Jennifer L. Hopwood ◽  
Susan K. Flowers ◽  
Katie J. Seidler ◽  
Erica L. Hopwood

Invasive species are a substantial threat to biodiversity. Educating students about invasive species introduces fundamental concepts in biology, ecology, and environmental science. In the Race to Displace game, students assume the characteristics of select native or introduced plants and experience first hand the influences of species interactions and changing environmental conditions on community composition as they advance across a game board. Through game play, students learn about ways in which species can interact, as well as attributes of successful invaders and the impacts of invasion on communities.


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