Structuring Interaction Networks Between Epiphytic Bryophytes and Their Hosts in Yunnan, SW China

Ecological networks are commonly applied to depict general patterns of biotic interactions, which provide tools to understand the mechanism of community assembly. Commensal interactions between epiphytes and their hosts are a major component of species interactions in forest canopies; however, few studies have investigated species assemblage patterns and network structures of epiphyte–host interactions, particularly non-vascular epiphytes in different types of forest. To analyze the characteristics of network structures between epiphytes and their hosts, composition and distribution of epiphytic bryophytes were investigated from 138 host individuals using canopy cranes in a tropical lowland seasonal rain forest (TRF) and a subtropical montane moist evergreen broad-leaved forest (STF), in Southwest China. We structured binary networks between epiphytic bryophytes and their hosts in these two forests, which presented 329 interactions in the TRF and 545 interactions in the STF. Compared to TRF, the bryophyte–host plant networks were more nested but less modular in the STF. However, both forests generally exhibited a significantly nested structure with low levels of specialization and modularity. The relatively high nestedness may stabilize the ecological networks between epiphytic bryophytes and their hosts. Nevertheless, the low modularity in epiphyte–host networks could be attributed to the lack of co-evolutionary processes, and the low degree of specialization suggests that epiphytes are less likely to colonize specific host species. Vertical distribution of the bryophyte species showed structured modules in the tree basal and crown zones, probably attributing to the adaptation to microclimates within a host individual. This study highlights the nested structure of commensal interaction between epiphytic bryophytes and host trees, and provides a scientific basis to identify key host tree species for conservation and management of biodiversity in forest ecosystems.

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Introduction: Special issue on species interactions, ecological networks and community dynamics – Untangling the entangled bank using molecular techniques

Molecular Ecology ◽

10.1111/mec.14974 ◽

2019 ◽

Vol 28 (2) ◽

pp. 157-164 ◽

Cited By ~ 6

Author(s):

Tomas Roslin ◽

Michael Traugott ◽

Mattias Jonsson ◽

Graham N. Stone ◽

Simon Creer ◽

...

Keyword(s):

Species Interactions ◽

Community Dynamics ◽

Ecological Networks ◽

Molecular Techniques ◽

Special Issue

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Genotype-Species Interactions in Neighbourhoods of Forest Tree Communities

Silvae Genetica ◽

10.1515/sg-2007-0016 ◽

2007 ◽

Vol 56 (1-6) ◽

pp. 101-110 ◽

Cited By ~ 5

Author(s):

Chr. Wehenkel ◽

F. Bergmann ◽

H.-R. Gregorius

Keyword(s):

Species Interactions ◽

Species Coexistence ◽

Biotic Interactions ◽

Forest Tree ◽

Target Species ◽

Species Identity ◽

Enzymatic Function ◽

Genotype Frequencies ◽

Tree Communities ◽

Large Survey

Abstract Studies on plant communities of various annual species suggest that there are particular biotic interactions among individuals from different species which could be the basis for long-term species coexistence. In the course of a large survey on species-genetic diversity relationships in several forest tree communities, it was found that statistically significant differences exist among isozyme genotype frequencies of conspecific tree groups, which differ only by species identity of their neighbours. Based on a specific measure, the association of the neighbouring species with the genotypes of the target species or that of the genotypes with the neighbouring species was quantified. Since only AAT and HEK of the five analysed enzyme systems differed in their genotype frequencies among several tree groups of the same target species, a potential involvement of their enzymatic function in the observed differences was discussed. The results of this study demonstrate a fine-scale genetic differentiation within single tree species of forest communities, which may be the result of biotic interactions between the genetic structure of a species and the species composition of its community. This observation also suggests the importance of intraspecific genetic variation for interspecific adaptation.

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The effects of seasonality on host–bat fly ecological networks in a temperate mountain cave

Parasitology ◽

10.1017/s0031182016002390 ◽

2016 ◽

Vol 144 (5) ◽

pp. 692-697 ◽

Cited By ~ 9

Author(s):

KARINA D. RIVERA-GARCÍA ◽

CÉSAR A. SANDOVAL-RUIZ ◽

ROMEO A. SALDAÑA-VÁZQUEZ ◽

JORGE E. SCHONDUBE

Keyword(s):

Species Composition ◽

Host Species ◽

Rainy Season ◽

Ecological Networks ◽

Host Interactions ◽

Bat Flies ◽

Bat Fly ◽

Low Prevalence ◽

Host Parasite

SUMMARYChanges in the specialization of parasite–host interactions will be influenced by variations in host species composition. We evaluated this hypothesis by comparing the composition of bats and bat flies within a roost cave over one annual. Five bat and five bat fly species occupied the cave over the course of the study. Bat species composition was 40% different in the rainy season compared with the dry–cold and dry–warm seasons. Despite the incorporation of three new bat species into the cave during the rainy season, bat fly species composition was not affected by seasonality, since the bats that arrived in the rainy season only contributed one new bat fly species at a low prevalence. Bat–bat fly ecological networks were less specialized in the rainy season compared with the dry–cold and dry–warm seasons because of the increase of host overlap among bat fly species during this season. This study suggests that seasonality promote: (1) differences in host species composition, and (2) a reduction in the specialization of host–parasite ecological networks.

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Composition patterns and network structure of epiphyte–host interactions in Chilean and New Zealand temperate forests

10.26686/wgtn.14399225.v1 ◽

2021 ◽

Author(s):

A Taylor ◽

A Saldaña ◽

G Zotz ◽

C Kirby ◽

I Díaz ◽

...

Keyword(s):

New Zealand ◽

Host Species ◽

Species Interactions ◽

Temperate Forests ◽

Null Model ◽

Host Interactions ◽

Host Trees ◽

Specific Host ◽

Random Patterns ◽

Epiphyte Species

Ecological networks are becoming increasingly used as a framework to study epiphyte–host interactions. However, efforts to quantify the properties of epiphyte–host networks have produced inconsistent results. Epiphyte–host interactions in New Zealand and Chilean temperate forests were quantified to test for non-random patterns in nestedness, negative co-occurrences, number of links, and network specialisation. Results showed that three out of five New Zealand networks were significantly more nested than null model expectations, compared with just one out of four Chilean networks. Epiphytes co-occurred more often than null model expectations in one New Zealand network and one in Chile. In all cases, the number of links maintained by each epiphyte and host species was consistent with null model expectations. Lastly, two New Zealand networks and one in southern Chile were significantly less specialised than null model expectations, with all remaining networks returning low specialisation scores. As such, aside from the tendency for greater nestedness in New Zealand networks, most epiphyte species were distributed on their host trees at random. We attribute the result of nestedness in New Zealand to the abundance of large nest epiphytes (Astelia spp. in particular), which may facilitate the sequential colonisation of epiphyte species on developing host trees. The lack of negative co-occurrences suggests that negative species interactions are not an important determinant of species assemblage structure. Low network specialisation scores suggest that epiphytes are selecting for specific host traits, rather than specific host species for colonisation.

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Multiple feedbacks due to biotic interactions across trophic levels can lead to persistent novel conditions that hinder restoration.

Plant invasions: the role of biotic interactions ◽

10.1079/9781789242171.0402 ◽

2020 ◽

pp. 402-420

Author(s):

Stephanie G. Yelenik ◽

Carla M. D'Antonio ◽

Evan M. Rehm ◽

Iain R. Caldwell

Keyword(s):

Species Interactions ◽

Native Species ◽

Biotic Interactions ◽

Terrestrial Ecosystems ◽

Trophic Levels ◽

Native Grasses ◽

Positive Feedbacks ◽

Mesic Forest ◽

Management Context ◽

Multiple Challenges

Abstract Unlike traditional successional theory, Alternate Stable Equilibrium (ASE) theory posits that more than one community state is possible in a single environment, depending on the order that species arrive. ASE theory is often invoked in management situations where initial stressors have been removed, but native-dominated communities are not returning to degraded areas. Fundamental to this theory is the assumption that equilibria are maintained by positive feedbacks between colonizers and their environment. While ASE has been relatively well studied in aquatic ecosystems, more complex terrestrial systems offer multiple challenges, including species interactions across trophic levels that can lead to multiple feedbacks. Here, we discuss ASE theory as it applies to terrestrial, invaded ecosystems, and detail a case study from Hawai'i that exemplifies how species interactions can favour the persistence of invaders, and how an understanding of interactions and feedbacks can be used to guide management. Our system includes intact native-dominated mesic forest and areas cleared for pasture, planted with non-native grasses, and later planted with a monoculture of a native nitrogen-fixing tree in an effort to restore forests. We discuss interactions between birds, understorey fruiting native species, understorey non-native grasses, soils and bryophytes in separate feedback mechanisms, and explain our efforts to identify which of these feedbacks is most important to address in a management context. Finally, we suggest that using models can help overcome some of the challenges that terrestrial ecosystems pose when studying ASE.

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Biotic rescaling reveals importance of species interactions for variation in biodiversity responses to climate change

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2003377117 ◽

2020 ◽

Vol 117 (37) ◽

pp. 22858-22865 ◽

Cited By ~ 4

Author(s):

Vigdis Vandvik ◽

Olav Skarpaas ◽

Kari Klanderud ◽

Richard J. Telford ◽

Aud H. Halbritter ◽

...

Keyword(s):

Climate Change ◽

Species Interactions ◽

Community Dynamics ◽

Biotic Interactions ◽

Plant Interactions ◽

Climate Gradients ◽

Climate Change Responses ◽

Local Extinctions ◽

Future Work ◽

Underlying Processes

Generality in understanding biodiversity responses to climate change has been hampered by substantial variation in the rates and even directions of response to a given change in climate. We propose that such context dependencies can be clarified by rescaling climate gradients in terms of the underlying biological processes, with biotic interactions as a particularly important process. We tested this rescaling approach in a replicated field experiment where entire montane grassland communities were transplanted in the direction of expected temperature and/or precipitation change. In line with earlier work, we found considerable variation across sites in community dynamics in response to climate change. However, these complex context dependencies could be substantially reduced or eliminated by rescaling climate drivers in terms of proxies of plant−plant interactions. Specifically, bryophytes limited colonization by new species into local communities, whereas the cover of those colonists, along with bryophytes, were the primary drivers of local extinctions. These specific interactions are relatively understudied, suggesting important directions for future work in similar systems. More generally, the success of our approach in explaining and simplifying landscape-level variation in climate change responses suggests that developing and testing proxies for relevant underlying processes could be a fruitful direction for building more general models of biodiversity response to climate change.

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Ecological Interactions and Macroevolution: A New Field with Old Roots

Annual Review of Ecology Evolution and Systematics ◽

10.1146/annurev-ecolsys-011720-121505 ◽

2020 ◽

Vol 51 (1) ◽

pp. 215-243 ◽

Cited By ~ 2

Author(s):

David H. Hembry ◽

Marjorie G. Weber

Keyword(s):

Species Interactions ◽

Interspecific Interactions ◽

Biotic Interactions ◽

Evolutionary Change ◽

Future Research ◽

Ecological Interactions ◽

Open Questions ◽

Work Done ◽

Lineage Diversification

Linking interspecific interactions (e.g., mutualism, competition, predation, parasitism) to macroevolution (evolutionary change on deep timescales) is a key goal in biology. The role of species interactions in shaping macroevolutionary trajectories has been studied for centuries and remains a cutting-edge topic of current research. However, despite its deep historical roots, classic and current approaches to this topic are highly diverse. Here, we combine historical and contemporary perspectives on the study of ecological interactions in macroevolution, synthesizing ideas across eras to build a zoomed-out picture of the big questions at the nexus of ecology and macroevolution. We discuss the trajectory of this important and challenging field, dividing research into work done before the 1970s, research between 1970 and 2005, and work done since 2005. We argue that in response to long-standing questions in paleobiology, evidence accumulated to date has demonstrated that biotic interactions (including mutualism) can influence lineage diversification and trait evolution over macroevolutionary timescales, and we outline major open questions for future research in the field.

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Functional Genomics Differentiate Inherent and Environmentally Influenced Traits in Dinoflagellate and Diatom Communities

Microorganisms ◽

10.3390/microorganisms8040567 ◽

2020 ◽

Vol 8 (4) ◽

pp. 567 ◽

Cited By ~ 2

Author(s):

Stephanie Elferink ◽

Uwe John ◽

Stefan Neuhaus ◽

Sylke Wohlrab

Keyword(s):

Signal Transduction ◽

Functional Traits ◽

Species Interactions ◽

Marine Ecosystem ◽

Biotic Interactions ◽

Sulfur Cycle ◽

Functional Responses ◽

Physiological Importance ◽

Metabolic Interactions ◽

Lysine Degradation

Dinoflagellates and diatoms are among the most prominent microeukaryotic plankton groups, and they have evolved different functional traits reflecting their roles within ecosystems. However, links between their metabolic processes and functional traits within different environmental contexts warrant further study. The functional biodiversity of dinoflagellates and diatoms was accessed with metatranscriptomics using Pfam protein domains as proxies for functional processes. Despite the overall geographic similarity of functional responses, abiotic (i.e., temperature and salinity; ~800 Pfam domains) and biotic (i.e., taxonomic group; ~1500 Pfam domains) factors influencing particular functional responses were identified. Salinity and temperature were identified as the main drivers of community composition. Higher temperatures were associated with an increase of Pfam domains involved in energy metabolism and a decrease of processes associated with translation and the sulfur cycle. Salinity changes were correlated with the biosynthesis of secondary metabolites (e.g., terpenoids and polyketides) and signal transduction processes, indicating an overall strong effect on the biota. The abundance of dinoflagellates was positively correlated with nitrogen metabolism, vesicular transport and signal transduction, highlighting their link to biotic interactions (more so than diatoms) and suggesting the central role of species interactions in the evolution of dinoflagellates. Diatoms were associated with metabolites (e.g., isoprenoids and carotenoids), as well as lysine degradation, which highlights their ecological role as important primary producers and indicates the physiological importance of these metabolic pathways for diatoms in their natural environment. These approaches and gathered information will support ecological questions concerning the marine ecosystem state and metabolic interactions in the marine environment.

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Evaluating insect-host interactions as a driver of species divergence in palm flower weevils

Communications Biology ◽

10.1038/s42003-020-01482-3 ◽

2020 ◽

Vol 3 (1) ◽

Author(s):

Bruno A. S. de Medeiros ◽

Brian D. Farrell

Keyword(s):

Species Interactions ◽

Population Divergence ◽

Insect Host ◽

Flower Visitors ◽

Host Interactions ◽

Isolation By Environment ◽

Insect Populations ◽

Evolutionary Consequences ◽

Antagonistic Interactions

AbstractPlants and their specialized flower visitors provide valuable insights into the evolutionary consequences of species interactions. In particular, antagonistic interactions between insects and plants have often been invoked as a major driver of diversification. Here we use a tropical community of palms and their specialized insect flower visitors to test whether antagonisms lead to higher population divergence. Interactions between palms and the insects visiting their flowers range from brood pollination to florivory and commensalism, with the latter being species that feed on decaying–and presumably undefended–plant tissues. We test the role of insect-host interactions in the early stages of diversification of nine species of beetles sharing host plants and geographical ranges by first delimiting cryptic species and then using models of genetic isolation by environment. The degree to which insect populations are structured by the genetic divergence of plant populations varies. A hierarchical model reveals that this variation is largely uncorrelated with the kind of interaction, showing that antagonistic interactions are not associated with higher genetic differentiation. Other aspects of host use that affect plant-associated insects regardless of the outcomes of their interactions, such as sensory biases, are likely more general drivers of insect population divergence.

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The Coupled Influence of Thermal Physiology and Biotic Interactions on the Distribution and Density of Ant Species along an Elevational Gradient

Diversity ◽

10.3390/d12120456 ◽

2020 ◽

Vol 12 (12) ◽

pp. 456

Author(s):

Lacy D. Chick ◽

Jean-Philippe Lessard ◽

Robert R. Dunn ◽

Nathan J. Sanders

Keyword(s):

Observational Data ◽

Species Interactions ◽

Phylogenetic Signal ◽

Environmental Filtering ◽

Null Model ◽

Biotic Interactions ◽

Elevational Gradient ◽

High Elevation ◽

Elevational Range ◽

Stressful Environments

A fundamental tenet of biogeography is that abiotic and biotic factors interact to shape the distributions of species and the organization of communities, with interactions being more important in benign environments, and environmental filtering more important in stressful environments. This pattern is often inferred using large databases or phylogenetic signal, but physiological mechanisms underlying such patterns are rarely examined. We focused on 18 ant species at 29 sites along an extensive elevational gradient, coupling experimental data on critical thermal limits, null model analyses, and observational data of density and abundance to elucidate factors governing species’ elevational range limits. Thermal tolerance data showed that environmental conditions were likely to be more important in colder, more stressful environments, where physiology was the most important constraint on the distribution and density of ant species. Conversely, the evidence for species interactions was strongest in warmer, more benign conditions, as indicated by our observational data and null model analyses. Our results provide a strong test that biotic interactions drive the distributions and density of species in warm climates, but that environmental filtering predominates at colder, high-elevation sites. Such a pattern suggests that the responses of species to climate change are likely to be context-dependent and more specifically, geographically-dependent.

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