Forming foci of transmission: the effects of resource utilization, species interaction, and parasitism on molluscan movement

2009 ◽  
Vol 87 (11) ◽  
pp. 1024-1031 ◽  
Author(s):  
T. T. Gray ◽  
J. T. Detwiler ◽  
D. J. Minchella
Keyword(s):  
Species Interactions ◽  
Animal Movement ◽  
Interspecific Interactions ◽  
Behavioral Responses ◽  
Single Species ◽  
Species Interaction ◽  
Snail Species ◽  
Parasite Transmission ◽  
Biotic Factor ◽  
Environmental Stimuli

Animal aggregation to environmental cues provides opportunities for parasite transmission between individual hosts of the same or different species. Better characterization of host behavioral responses to environmental stimuli in the absence and presence of parasites will improve our understanding of how foci of transmission form. The behavioral response patterns of two co-occurring freshwater snail species ( Lymnaea elodes (Say, 1821) and Helisoma trivolvis (Say, 1817) (=  Planorbella trivolvis (Say, 1817))) were assessed in response to three environmental stimuli (crayfish (genus Orconectes  Cope, 1872) carrion, vegetation, or temperature gradient). Experiments were conducted with single species and species interactions. In addition, parasitized L. elodes were included in a single-species experiment and a species-interaction experiment. Snail species differed in the direction and magnitude of their responses to the environmental stimuli. Species interactions did not affect the responses to two of the stimuli for either species; however, interspecific interactions affected the response to high temperature in both species. Behavioral responses were altered in the presence of parasites for both the infected and uninfected hosts, suggesting parasitism is an important biotic factor in animal movement. This experimental study indicates co-occurring species respond to environmental factors in different ways. Furthermore, species interactions and parasitism within a guild can have strong effects on animal movement and potentially on parasite transmission.

scholarly journals Temperature drives asymmetric competition between alien and indigenous freshwater snails (Physa acuta vs. Physa fontinalis)

2015 ◽  
Author(s):  
Denise Früh ◽  
Peter Haase ◽  
Stefan Stoll
Keyword(s):  
Alien Species ◽  
Species Interactions ◽  
Field Data ◽  
Single Species ◽  
Freshwater Snail ◽  
Species Interaction ◽  
Snail Species ◽  
Indigenous Species ◽  
Physa Acuta ◽  
The Impact

Biological invasion represent one of the major threats to global biodiversity as alien species often displace indigenous species. However, knowledge of the mechanisms behind such displacements and the driving factors of the competitive superiority of the alien species still remain rare. In our study we combined analysis of field data and laboratory experiments examining species interactions, to investigate the impact of temperature in the case of the alien freshwater snail Physa acuta that is held responsible for the decline of indigenous snail Physa fontinalis in Europe. From field data, we identified higher temperature as the most important difference between sites populated by alien P. acuta and those where indigenous P. fontinalis occurred. Results of the species interaction experiment conducted at 15, 20, and 25°C confirmed the hypothesis that the competitive superiority of P. acuta over P. fontinalis increases at warmer temperatures. In single species treatments, increasing temperature stimulated both species to grow faster and reach greater shell heights. Coexistence treatments revealed an asymmetric competitive interaction between the two snail species. In both species, the density of conspecifics did not affect snail growth; however, density of heterospecifics affected the growth. At 15°C, the presence of heterospecifics stimulated the growth of both species, while at higher temperatures the presence of heterospecifics stimulated the growth in P. acuta, but inhibited in P. fontinalis. Our study shows that temperature can be a powerful driver of the outcomes of alien and indigenous species’ competition by driving asymmetric interaction. Further our results point up that the environmental context cannot be disregarded when investigating the interaction between alien and indigenous species, and predict alien species success and impact.

scholarly journals Temperature drives asymmetric competition between alien and indigenous freshwater snails (Physa acuta vs. Physa fontinalis)

2015 ◽  
Author(s):  
Denise Früh ◽  
Peter Haase ◽  
Stefan Stoll
Keyword(s):  
Alien Species ◽  
Species Interactions ◽  
Field Data ◽  
Single Species ◽  
Freshwater Snail ◽  
Species Interaction ◽  
Snail Species ◽  
Indigenous Species ◽  
Physa Acuta ◽  
The Impact

Biological invasion represent one of the major threats to global biodiversity as alien species often displace indigenous species. However, knowledge of the mechanisms behind such displacements and the driving factors of the competitive superiority of the alien species still remain rare. In our study we combined analysis of field data and laboratory experiments examining species interactions, to investigate the impact of temperature in the case of the alien freshwater snail Physa acuta that is held responsible for the decline of indigenous snail Physa fontinalis in Europe. From field data, we identified higher temperature as the most important difference between sites populated by alien P. acuta and those where indigenous P. fontinalis occurred. Results of the species interaction experiment conducted at 15, 20, and 25°C confirmed the hypothesis that the competitive superiority of P. acuta over P. fontinalis increases at warmer temperatures. In single species treatments, increasing temperature stimulated both species to grow faster and reach greater shell heights. Coexistence treatments revealed an asymmetric competitive interaction between the two snail species. In both species, the density of conspecifics did not affect snail growth; however, density of heterospecifics affected the growth. At 15°C, the presence of heterospecifics stimulated the growth of both species, while at higher temperatures the presence of heterospecifics stimulated the growth in P. acuta, but inhibited in P. fontinalis. Our study shows that temperature can be a powerful driver of the outcomes of alien and indigenous species’ competition by driving asymmetric interaction. Further our results point up that the environmental context cannot be disregarded when investigating the interaction between alien and indigenous species, and predict alien species success and impact.

scholarly journals Interaction capacity underpins community diversity

2020 ◽  
Author(s):  
Masayuki Ushio
Keyword(s):  
Interspecific Interactions ◽  
Experimental Studies ◽  
Interaction Strength ◽  
Single Species ◽  
Species Interaction ◽  
Community Diversity ◽  
Ecological Communities ◽  
Total Dna ◽  
Mathematical Equations ◽  
The Mean

AbstractHow patterns in community diversity emerge is a long-standing question in ecology. Theories and experimental studies suggested that community diversity and interspecific interactions are interdependent. However, evidence from multitaxonomic, high-diversity ecological communities is lacking because of practical challenges in characterizing speciose communities and their interactions. Here, I analyzed time-varying causal interaction networks that were reconstructed using 1197 species, DNA-based ecological time series taken from experimental rice plots and empirical dynamic modeling, and show that species interaction capacity, namely, the sum of interaction strength that a single species gives and receives, underpins community diversity. As community diversity increases, the number of interactions increases exponentially but the mean species interaction capacity of a community becomes saturated, weakening interaction among species. These patterns are explicitly modeled with simple mathematical equations, based on which I propose the “interaction capacity hypothesis”, namely, that species interaction capacity and network connectance are proximate drivers of community diversity. Furthermore, I show that total DNA concentrations and temperature influence species interaction capacity and connectance nonlinearly, explaining a large proportion of diversity patterns observed in various systems. The interaction capacity hypothesis enables mechanistic explanations of community diversity, and how species interaction capacity is determined is a key question in ecology.

scholarly journals Harnessing multilayer networks to predict metacommunity responses to global environmental change

2020 ◽  
Author(s):  
Tyler McFadden ◽  
Rodolfo Dirzo
Keyword(s):  
Environmental Change ◽  
Species Interactions ◽  
Interspecific Interactions ◽  
Global Environmental Change ◽  
Spatial Dynamics ◽  
Species Interaction ◽  
Data Availability ◽  
Multilayer Networks ◽  
Ecological Data ◽  
Pollinator Community

Species interact both within and across communities, forming complex networks of biotic interactions and spatial links that underpin ecosystem functioning. However, while recent technological advances permit the analysis of increasingly complex and realistic ecological networks, data availability remains a major challenge. Here, we present a novel approach that uses readily available ecological data to build spatially-structured species interaction networks and predict metacommunity responses to environmental change. Predictive Multilayer Networks (PMNs) model the distributions, interspecific interactions, and spatial connectivity of multiple species across a landscape and quantify network structure and stability. We provide a proof-of-concept using a simulated plant-pollinator community, measure network centrality to identify areas of high functional connectivity, and compare land cover scenarios to predict effects of forest loss and restoration on PMN connectance and robustness. PMNs synthesize network approaches from community and landscape ecology and offer a flexible, predictive approach for examining the spatial dynamics of species interactions.

scholarly journals Evaluating Coexistence of Fish Species with Coastal Cutthroat Trout in Low Order Streams of Western Oregon and Washington, USA

Fishes ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Kyle D. Martens ◽  
Jason Dunham
Keyword(s):  
Pacific Northwest ◽  
Species Interactions ◽  
Coho Salmon ◽  
Cutthroat Trout ◽  
Single Species ◽  
The Pacific ◽  
Small Streams ◽  
Coastal Cutthroat Trout ◽  
Multiple Species ◽  
Low Order

When multiple species of fish coexist there are a host of potential ways through which they may interact, yet there is often a strong focus on studies of single species without considering these interactions. For example, many studies of forestry–stream interactions in the Pacific Northwest have focused solely on the most prevalent species: Coastal cutthroat trout. To examine the potential for interactions of other fishes with coastal cutthroat trout, we conducted an analysis of 281 sites in low order streams located on Washington’s Olympic Peninsula and along the central Oregon coast. Coastal cutthroat trout and juvenile coho salmon were the most commonly found salmonid species within these streams and exhibited positive associations with each other for both presence and density. Steelhead were negatively associated with the presence of coastal cutthroat trout as well as with coho salmon and sculpins (Cottidae). Coastal cutthroat trout most frequently shared streams with juvenile coho salmon. For densities of these co-occurring species, associations between these two species were relatively weak compared to the strong influences of physical stream conditions (size and gradient), suggesting that physical conditions may have more of an influence on density than species interactions. Collectively, our analysis, along with a review of findings from prior field and laboratory studies, suggests that the net effect of interactions between coastal cutthroat trout and coho salmon do not appear to inhibit their presence or densities in small streams along the Pacific Northwest.

scholarly journals Topographic Effects on the Spatial Species Associations in Diverse Heterogeneous Tropical Evergreen Forests

2021 ◽  
Vol 13 (5) ◽  
pp. 2468
Author(s):  
Nguyen Hong Hai ◽  
Yousef Erfanifard ◽  
Van Bac Bui ◽  
Trinh Hien Mai ◽  
Any Mary Petritan ◽  
...  
Keyword(s):  
Species Interactions ◽  
Species Coexistence ◽  
Spatial Scales ◽  
Interspecific Interactions ◽  
Spatial Association ◽  
Topographic Effects ◽  
Habitat Association ◽  
Important Species ◽  
Evergreen Forests ◽  
Partial Overlap

Studying spatial patterns and habitat association of plant communities may provide understanding of the ecological mechanisms and processes that maintain species coexistence. To conduct assessments of correlation between community compositions and habitat association, we used data from two topographically different plots with 2 ha area in tropical evergreen forests with the variables recorded via grid systems of 10 × 10 m subplots in Northern-Central Vietnam. First, we tested the relationship between community composition and species diversity indices considering the topographical variables. We then assessed the interspecific interactions of 20 dominant plant species using the nearest-neighbor distribution function, Dij(r), and Ripley’s K-function, Kij(r). Based on the significant spatial association of species pairs, indices of interspecific interaction were calculated by the quantitative amounts of the summary statistics. The results showed that (i) community compositions were significantly influenced by the topographic variables and (ii) almost 50% significant pairs of species interactions were increased with increasing spatial scales up to 10–15 m, then declined and disappeared at scales of 30–40 m. Segregation and partial overlap were the dominant association types and disappeared at larger spatial scales. Spatial segregation, mixing, and partial overlap revealed the important species interactions in maintaining species coexistence under habitat heterogeneity in diverse forest communities.

scholarly journals Sustainable exploitation of temperate fish stocks

2009 ◽  
Vol 6 (1) ◽  
pp. 124-127 ◽  
Author(s):  
Henrik Sparholt ◽  
Robin M. Cook
Keyword(s):  
Species Interactions ◽  
Fishery Management ◽  
Regional Scale ◽  
Single Species ◽  
Fishing Effort ◽  
Theoretical Concept ◽  
Maximum Sustainable Yield ◽  
Production Model ◽  
The Status ◽  
Long Time

The theory of maximum sustainable yield (MSY) underpins many fishery management regimes and is applied principally as a single species concept. Using a simple dynamic biomass production model we show that MSY can be identified from a long time series of multi-stock data at a regional scale in the presence of species interactions and environmental change. It suggests that MSY is robust and calculable in a multispecies environment, offering a realistic reference point for fishery management. Furthermore, the demonstration of the existence of MSY shows that it is more than a purely theoretical concept. There has been an improvement in the status of stocks in the Northeast Atlantic, but our analysis suggests further reductions in fishing effort would improve long-term yields.

Complex environments alter competitive dynamics in fungi

2021 ◽  
Author(s):  
Justin Chan ◽  
Stephen Bonser ◽  
Michael M. Kasumovic ◽  
Jeff Powell ◽  
William Kirkham Cornwell
Keyword(s):  
Interspecific Interactions ◽  
Fungal Species ◽  
Wood Block ◽  
Complex Environments ◽  
Biotic Factor ◽  
Pairwise Interactions ◽  
Agar Media ◽  
Contextual Environment ◽  
Natural Settings ◽  
Natural Communities

Competition is a key biotic factor that often structures natural communities. Many attempts to disentangle how competition shapes natural communities have relied on experiments on simplified systems or through simple mathematical models. But these simplified approaches are limited in their ability to represent the complexity seen in more natural settings. Here, we considered the competitive pairwise dynamics between four saprotrophic fungal species. We tested whether the contextual environment changed these dynamics, repeating competitive experiments in a simple agar media and a more ecologically realistic wood block setting. We found that the competitive outcomes on agar media differed from those within the wood blocks. While superior competitors were identified across all pairwise interactions on agar, within the wood blocks, two of six interactions resulted in deadlock, where neither competitor could breach territory of the other, and one interaction resulted in a reversed competitive outcome. These results suggest that the complexity within natural substrates can alter the strength of interspecific interactions and may contribute to coexistence and the resulting high diversity of fungi often observed within wood.

scholarly journals Facilitation costs and benefits function simultaneously on stress gradients for animals

2018 ◽  
Vol 285 (1885) ◽  
pp. 20180983 ◽  
Author(s):  
Olivier Dangles ◽  
Mario Herrera ◽  
Carlos Carpio ◽  
Christopher J. Lortie
Keyword(s):  
Conceptual Framework ◽  
Environmental Conditions ◽  
Species Interactions ◽  
Stress Gradient ◽  
Species Interaction ◽  
Positive Interactions ◽  
Costs And Benefits ◽  
Strong Basis ◽  
Stress Gradients ◽  
High Resource

Understanding the variation in species interactions along environmental stress gradients is crucial for making robust ecological predictions about community responses to changing environmental conditions. The facilitation–competition framework has provided a strong basis for predictions (e.g. the stress-gradient hypothesis, SGH), yet the mechanisms behind patterns in animal interactions on stress gradients are poorly explored in particular for mobile animals. Here, we proposed a conceptual framework modelling changes in facilitation costs and benefits along stress gradients and experimentally tested this framework by measuring fitness outcomes of benefactor–beneficiary interactions across resource quality levels. Three arthropod consumer models from a broad array of environmental conditions were used including aquatic detritivores, potato moths and rainforest carrion beetles. We detected a shift to more positive interactions at increasing levels of stress thereby supporting the application of the SGH to mobile animals. While most benefactors paid no significant cost of facilitation, an increase in potato moth beneficiary's growth at high resource stress triggered costs for benefactors. This study is the first to experimentally show that both costs and benefits function simultaneously on stress gradients for animals. The proposed conceptual framework could guide future studies examining species interaction outcomes for both animals and plants in an increasingly stressed world.

scholarly journals Do syntopic host species harbour similar symbiotic communities? The case ofChaetopterusspp. (Annelida: Chaetopteridae)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2930 ◽  
Author(s):  
Temir A. Britayev ◽  
Elena Mekhova ◽  
Yury Deart ◽  
Daniel Martin
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Host Species ◽  
Interspecific Interactions ◽  
Single Species ◽  
Intraspecific Interactions ◽  
Mean Intensity ◽  
Species Dominance ◽  
High Species Richness ◽  
Symbiotic Community

To assess whether closely related host species harbour similar symbiotic communities, we studied two polychaetes,Chaetopterussp. (n = 11) andChaetopteruscf.appendiculatus(n = 83) living in soft sediments of Nhatrang Bay (South China Sea, Vietnam). The former harboured the porcellanid crabsPolyonyxcf.heokandPolyonyxsp., the pinnotherid crabTetriassp. and the tergipedid nudibranchPhestillasp. The latter harboured the polynoid polychaeteOphthalmonoe pettiboneae, the carapid fishOnuxodon fowleriand the porcellanid crabEulenaios cometes, all of which, exceptO. fowleri, seemed to be specialized symbionts. The species richness and mean intensity of the symbionts were higher inChaetopterussp. than inC.cf.appendiculatus(1.8 and 1.02 species and 3.0 and 1.05 individuals per host respectively). We suggest that the lower density ofChaetopterussp. may explain the higher number of associated symbionts observed, as well as the 100% prevalence (69.5% inC.cf.appenciculatus). MostChaetopterussp. harboured two symbiotic species, which was extremely rare inC.cf.appendiculatus, suggesting lower interspecific interactions in the former. The crab and nudibranch symbionts ofChaetopterussp. often shared a host and lived in pairs, thus partitioning resources. This led to the species coexisting in the tubes ofChaetopterussp., establishing a tightly packed community, indicating high species richness and mean intensity, together with a low species dominance. In contrast, the aggressive, strictly territorial species associated withC.cf.appendiculatusestablished a symbiotic community strongly dominated by single species and, thus, low species richness and mean intensity. Therefore, we suggest that interspecific interactions are determining species richness, intensity and dominance, while intraspecific interactions are influencing only intensity and abundance. It is possible that species composition may have influenced the differences in community structure observed. We hypothesize that both host species could originally be allopatric. The evolutionary specialization of the symbiotic communities would occur in separated geographical areas, while the posterior disappearance of the existing geographical barriers would lead to the overlapped distribution.

Sign in / Sign up

Export Citation Format

Share Document