scholarly journals Experimental warming influences species abundances in a Drosophila host community through direct effects on species performance rather than altered competition and parasitism

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0245029
Author(s):  
Mélanie Thierry ◽  
Nicholas A. Pardikes ◽  
Chia-Hua Lue ◽  
Owen T. Lewis ◽  
Jan Hrček
Keyword(s):  
Host Species ◽  
Indirect Effects ◽  
Global Climate ◽  
Biotic Interactions ◽  
Host Community ◽  
Experimental Warming ◽  
Direct Effects ◽  
Species Abundances ◽  
Species Specific ◽  
Species Performance

Global warming is expected to have direct effects on species through their sensitivity to temperature, and also via their biotic interactions, with cascading indirect effects on species, communities, and entire ecosystems. To predict the community-level consequences of global climate change we need to understand the relative roles of both the direct and indirect effects of warming. We used a laboratory experiment to investigate how warming affects a tropical community of three species of Drosophila hosts interacting with two species of parasitoids over a single generation. Our experimental design allowed us to distinguish between the direct effects of temperature on host species performance, and indirect effects through altered biotic interactions (competition among hosts and parasitism by parasitoid wasps). Although experimental warming significantly decreased parasitism for all host-parasitoid pairs, the effects of parasitism and competition on host abundances and host frequencies did not vary across temperatures. Instead, effects on host relative abundances were species-specific, with one host species dominating the community at warmer temperatures, irrespective of parasitism and competition treatments. Our results show that temperature shaped a Drosophila host community directly through differences in species’ thermal performance, and not via its influences on biotic interactions.

scholarly journals Experimental warming influences species abundances in a Drosophila host community through direct effects on species performance rather than altered competition and parasitism

2020 ◽  
Author(s):  
Mélanie Thierry ◽  
Nicholas A. Pardikes ◽  
Chia-Hua Lue ◽  
Owen T. Lewis ◽  
Jan Hrček
Keyword(s):  
Host Species ◽  
Indirect Effects ◽  
Biotic Interactions ◽  
Host Community ◽  
Experimental Warming ◽  
Direct Effects ◽  
Species Abundances ◽  
Effects Of Temperature ◽  
Species Specific ◽  
Species Performance

AbstractCurrent global warming trends are expected to have direct effects on species through their sensitivity to temperature, as well as on their biotic interactions, with cascading indirect effects on species, communities, and entire ecosystems. To predict the community-level consequences of global change we need to understand the relative roles of both the direct and indirect effects of warming. We used a laboratory experiment to investigate how warming affects a tropical community of three species of Drosophila hosts interacting with two species of parasitoids over a single generation. Our experimental design allowed us to distinguish between the direct effects of temperature on host species performance, and indirect effects through altered biotic interactions (competition among hosts and parasitism by parasitoid wasps). Although experimental warming significantly decreased parasitism for all host-parasitoid pairs, the effects of parasitism and competition on host communities did not vary across temperatures. Instead, effects on host relative abundances were species-specific, with one host species dominating the community at warmer temperatures, independently of parasitism and competition treatments. Our results show that temperature shaped a Drosophila host community directly through differences in species’ thermal performance, and not via its influences on biotic interactions.

The effect of non-native plant invasions on the dispersal of native seeds.

2020 ◽  
pp. 256-269
Author(s):  
Ruben H. Heleno
Keyword(s):  
Seed Dispersal ◽  
Indirect Effects ◽  
Biotic Interactions ◽  
Plant Invasions ◽  
Native Communities ◽  
Native Seed ◽  
Emergent Structure ◽  
Underlying Mechanisms ◽  
Species Specific

Abstract Non-native plants change the communities they integrate in multiple ways, including direct and indirect effects on co-occurring native vegetation. While direct effects are more obvious, indirect effects, i.e. those mediated by biotic interactions with other trophic levels, can also have pervasive consequences for long-term community persistence. Seed dispersal is a critical stage during the life cycle of most plants, as it lays the foundations for plant recruitment patterns and long-term vegetation dynamics. By interacting with seed-dispersing animals, primarily frugivorous birds and mammals, plants can positively or negatively affect the dispersal of co-occurring native seeds. In an increasingly invaded world, it is thus critically important to identify general trends on the direction and magnitude of these effects. This chapter reviews the empirical evidence supporting such changes and the potential underlying mechanisms driving them. While the direct impacts of plant invasions are relatively easy to document, indirect effects are much harder to detect. Nevertheless, the most important consequence of the incorporation of new fruiting plants into native communities seems to be a direct competition for the services provided by the local dispersers, negatively affecting native seed dispersal rates. However, another key message emerging from the literature is that responses are highly idiosyncratic, and usually habitat- and species-specific, and therefore resistant to broad generalizations. Fruiting phenology, and in particular the synchrony/asynchrony between the availability of native and non-native fruits, seems to be a particularly important driver of the direction of the responses (i.e. towards facilitation or competition). However, most evidence is still derived from anecdotal observations and formal community level assessments are largely missing. Similarly, how invasive plants change the emergent structure of seed dispersal networks remains uncertain, with early evidence suggesting that novel seed dispersal networks might be structurally very similar to native ones. Bringing together classic experimental designs and new technical and analytical tools to provide broad synthesis will be vital in the near future to clarify the direction, magnitude and generality of these effects.

scholarly journals Trypanosoma cruzi reservoir—triatomine vector co-occurrence networks reveal meta-community effects by synanthropic mammals on geographic dispersal

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3152 ◽  
Author(s):  
Carlos N. Ibarra-Cerdeña ◽  
Leopoldo Valiente-Banuet ◽  
Víctor Sánchez-Cordero ◽  
Christopher R. Stephens ◽  
Janine M. Ramsey
Keyword(s):  
Trypanosoma Cruzi ◽  
Host Species ◽  
Disease Risk ◽  
Global Climate ◽  
Host Community ◽  
Transmission Risk ◽  
Edge Density ◽  
Public Health Importance ◽  
Mammal Species ◽  
The Impact

Contemporary patterns of land use and global climate change are modifying regional pools of parasite host species. The impact of host community changes on human disease risk, however, is difficult to assess due to a lack of information about zoonotic parasite host assemblages. We have used a recently developed method to infer parasite-host interactions for Chagas Disease (CD) from vector-host co-occurrence networks. Vector-host networks were constructed to analyze topological characteristics of the network and ecological traits of species’ nodes, which could provide information regarding parasite regional dispersal in Mexico. Twenty-eight triatomine species (vectors) and 396 mammal species (potential hosts) were included using a data-mining approach to develop models to infer most-likely interactions. The final network contained 1,576 links which were analyzed to calculate centrality, connectivity, and modularity. The model predicted links of independently registeredTrypanosoma cruzihosts, which correlated with the degree of parasite-vector co-occurrence. Wiring patterns differed according to node location, while edge density was greater in Neotropical as compared to Nearctic regions. Vectors with greatest public health importance (i.e., Triatoma dimidiata,T. barberi,T. pallidipennis,T. longipennis, etc), did not have stronger links with particular host species, although they had a greater frequency of significant links. In contrast, hosts classified as important based on network properties were synanthropic mammals. The latter were the most common parasite hosts and are likely bridge species between these communities, thereby integrating meta-community scenarios beneficial for long-range parasite dispersal. This was particularly true for rodents, >50% of species are synanthropic and more than 20% have been identified asT. cruzihosts. In addition to predicting potential host species using the co-occurrence networks, they reveal regions with greater expected parasite mobility. The Neotropical region, which includes the Mexican south and southeast, and the Transvolcanic belt, had greatest potential activeT. cruzidispersal, as well as greatest edge density. This information could be directly applied for stratification of transmission risk and to design and analyze human-infected vector contact intervention efficacy.

The effect of non-native plant invasions on the dispersal of native seeds.

2020 ◽  
pp. 256-269
Author(s):  
Ruben H. Heleno ◽  
Keyword(s):  
Seed Dispersal ◽  
Indirect Effects ◽  
Biotic Interactions ◽  
Plant Invasions ◽  
Native Communities ◽  
Native Seed ◽  
Emergent Structure ◽  
Underlying Mechanisms ◽  
Species Specific

Non-native plants change the communities they integrate in multiple ways, including direct and indirect effects on co-occurring native vegetation. While direct effects are more obvious, indirect effects, i.e. those mediated by biotic interactions with other trophic levels, can also have pervasive consequences for long-term community persistence. Seed dispersal is a critical stage during the life cycle of most plants, as it lays the foundations for plant recruitment patterns and long-term vegetation dynamics. By interacting with seed-dispersing animals, primarily frugivorous birds and mammals, plants can positively or negatively affect the dispersal of co-occurring native seeds. In an increasingly invaded world, it is thus critically important to identify general trends on the direction and magnitude of these effects. This chapter reviews the empirical evidence supporting such changes and the potential underlying mechanisms driving them. While the direct impacts of plant invasions are relatively easy to document, indirect effects are much harder to detect. Nevertheless, the most important consequence of the incorporation of new fruiting plants into native communities seems to be a direct competition for the services provided by the local dispersers, negatively affecting native seed dispersal rates. However, another key message emerging from the literature is that responses are highly idiosyncratic, and usually habitat- and species-specific, and therefore resistant to broad generalizations. Fruiting phenology, and in particular the synchrony/asynchrony between the availability of native and non-native fruits, seems to be a particularly important driver of the direction of the responses (i.e. towards facilitation or competition). However, most evidence is still derived from anecdotal observations and formal community level assessments are largely missing. Similarly, how invasive plants change the emergent structure of seed dispersal networks remains uncertain, with early evidence suggesting that novel seed dispersal networks might be structurally very similar to native ones. Bringing together classic experimental designs and new technical and analytical tools to provide broad synthesis will be vital in the near future to clarify the direction, magnitude and generality of these effects.

scholarly journals Altered parasitism of a butterfly assemblage associated with a range-expanding species

2020 ◽  
Author(s):  
H. Audusseau ◽  
N. Ryrholm ◽  
C. Stefanescu ◽  
S. Tharel ◽  
C. Jansson ◽  
...  
Keyword(s):  
Host Species ◽  
Land Use Changes ◽  
Biotic Interactions ◽  
Host Community ◽  
Butterfly Species ◽  
Ecological Communities ◽  
Species Assemblage ◽  
Resident Species ◽  
Parasitism Rates ◽  
The Impact

AbstractAimBiotic interactions are an important factor structuring ecological communities but data scarcity limits our understanding of the impact of their response to climate and land use changes on communities. We studied the impact of a change in species assemblage on biotic interactions in a community of closely-related butterflies. Specifically, we examined the impact of the recent range expansion of Araschnia levana on the resident species, with a particular focus on natural enemies, parasitoids, shared with other butterfly species in the assemblage.LocationSweden.Time periodTwo years (2017-2018).Major taxa studiedNettle-feeding butterflies (Aglais urticae, Aglais io, Araschnia levana, and Vanessa atalanta) and their parasitoids.MethodsWe assessed parasitism in 6777 butterfly larvae sampled in the field from 19 sites distributed along a 500 km latitudinal gradient, and every two weeks throughout species’ reproductive seasons. We identified the parasitoid complex of each butterfly species and their overlap, and analysed how parasitism rates were affected by species assemblage, variations in abundance, time, and the arrival of A. levana.ResultsParasitoids caused high mortality, with substantial overlap across the four host species. The composition of the host community influenced parasitism rates and this effect was specific to each species. In particular, the rate of parasitism in resident species was comparatively higher at sites where A. levana has been established for longer.Main conclusionsParasitoid pressure is a significant source of mortality in the nettle-feeding butterfly community studied. Variations in butterfly species assemblages are associated with substantial variations in rates of parasitism. This is likely to affect the population dynamics of their butterfly host species, and, potentially, the larger number of species with which they interact.

Trophic Cascades in Grasslands

2018 ◽  
Author(s):  
Brian J. Wilsey
Keyword(s):  
Indirect Effects ◽  
Prey Species ◽  
Trophic Levels ◽  
Herbaceous Plant ◽  
Direct Effects ◽  
Temperate Grasslands ◽  
Cascading Effect ◽  
Top Predators ◽  
Invertebrate Predators ◽  
Ecology Of Fear

Top predators have effects that can ‘cascade down’ on lower trophic levels. Because of this cascading effect, it matters how many trophic levels are present. Predators are either ‘sit and wait’ or ‘active’. Wolves are top predators in temperate grasslands and can alter species composition of smaller-sized predators, prey, and woody and herbaceous plant species, either through direct effects or indirect effects (‘Ecology of Fear’). In human derived grasslands, invertebrate predators fill a similar ecological role as wolves. Migrating populations of herbivores tend to be more limited by food than non-migratory populations. The phenology and synchrony of births vary among prey species in a way that is consistent with an adaptation to predation. Precocious species have highly synchronous birth dates to satiate predators. Non-precocious species (‘hiders’) have asynchronous births. Results from studies that manipulate both predators and food support the hypothesis that bottom-up and top-down effects interact.

scholarly journals Predictable and host‐species specific humanization of the gut microbiota in captive primates

2021 ◽  
Author(s):  
Jennifer L. Houtz ◽  
Jon G. Sanders ◽  
Anthony Denice ◽  
Andrew H. Moeller
Keyword(s):  
Gut Microbiota ◽  
Host Species ◽  
Species Specific

scholarly journals The Benefits of Combining Global and Local Data—A Showcase for Valuation and Mapping of Mangrove Climate Regulation and Food Provisioning Services within a Protected Area in Pará, North Brazil

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 432
Author(s):  
Robin Gutting ◽  
Ralf-Uwe Syrbe ◽  
Karsten Grunewald ◽  
Ulf Mehlig ◽  
Véronique Helfer ◽  
...  
Keyword(s):  
Global Climate ◽  
Structural Parameters ◽  
Management Strategies ◽  
Small Scale ◽  
Mangrove Forests ◽  
Food Provisioning ◽  
Local Data ◽  
Climate Regulation ◽  
North Brazil ◽  
Species Specific

Mangrove forests provide a large variety of ecosystem services (ES) to coastal societies. Using a case study focusing on the Ajuruteua peninsula in Northern Brazil and two ES, food provisioning (ES1) and global climate regulation (ES2), this paper proposes a new framework for quantifying and valuing mangrove ES and allow for their small-scale mapping. We modelled and spatialised the two ES from different perspectives, the demand (ES1) and the supply (ES2) side respectively. This was performed by combining worldwide databases related to the global human population (ES1) or mangrove distribution and canopy height (ES2) with locally derived parameters, such as crab catches (ES1) or species-specific allometric equations based on local estimates of tree structural parameters (ES2). Based on this approach, we could estimate that the area delivers the basic nutrition of about 1400 households, which equals 2.7 million USD, and that the mangrove biomass in the area contains 2.1 million Mg C, amounting to 50.9 million USD, if it were paid as certificates. In addition to those figures, we provide high-resolution maps showing which areas are more valuable for the two respective ES, information that could help inform management strategies in the future.

scholarly journals Longitudinal zonation of larval Hydropsyche (Trichoptera: Hydropsychidae): abiotic environmental factors and biotic interactions behind the downstream sequence of Central European species

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Márk Ficsór ◽  
Zoltán Csabai
Keyword(s):  
Environmental Factors ◽  
Biotic Interactions ◽  
Life Cycles ◽  
Longitudinal Distribution ◽  
Central European ◽  
European Species ◽  
Longitudinal Gradients ◽  
Species Specific ◽  
Behavioural Aspects ◽  
Abiotic Environmental Factors

AbstractThe aim of this review is to summarize the literature knowledge about how abiotic environmental factors and biotic interactions affect the sequentially overlapping longitudinal distribution of Central European species of the net-spinning freshwater caddisfly larvae of the genus Hydropsyche (Trichoptera: Hydropsychidae). In this relation, several physical and chemical parameters of water are discussed, as well as different species-specific traits, behavioural aspects and the interaction of coexisting species. Longitudinal gradients of river networks, especially annual temperature range, flow velocity and the particle size of suspended food material play a crucial role in forming the downstream succession of characteristic species, while increased levels of organic pollution, nutrients, salinity and heavy metals facilitates the presence of more tolerant ones. Several species-specific traits, such as respiration range, net-building frequency, head capsule size or optimal net-building velocity correlate with the position of a given species in the sequence. Coexistence of species with similar ecological demands in the overlapping zones of distribution is facilitated by differences in feeding and net-building habits, microhabitat preferences and staggering life cycles, but complicated at the same time by means of inter- and intraspecific territorial behaviour, such as fighting for the ownership of larval retreats or the practice of stridulation.

Sign in / Sign up

Export Citation Format

Share Document