Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Dec;16(12):2635-2643.
doi: 10.1038/s41396-022-01286-9. Epub 2022 Aug 18.

Ecosystem size-induced environmental fluctuations affect the temporal dynamics of community assembly mechanisms

Raven L Bier #  1   2 , Máté Vass #  3 , Anna J Székely  3   4 , Silke Langenheder  3
Affiliations

Ecosystem size-induced environmental fluctuations affect the temporal dynamics of community assembly mechanisms

Raven L Bier et al. ISME J. 2022 Dec.

Abstract

Understanding processes that determine community membership and abundance is important for many fields from theoretical community ecology to conservation. However, spatial community studies are often conducted only at a single timepoint despite the known influence of temporal variability on community assembly processes. Here we used a spatiotemporal study to determine how environmental fluctuation differences induced by mesocosm volumes (larger volumes were more stable) influence assembly processes of aquatic bacterial metacommunities along a press disturbance gradient. By combining path analysis and network approaches, we found mesocosm size categories had distinct relative influences of assembly process and environmental factors that determined spatiotemporal bacterial community composition, including dispersal and species sorting by conductivity. These processes depended on, but were not affected proportionately by, mesocosm size. Low fluctuation, large mesocosms primarily developed through the interplay of species sorting that became more important over time and transient priority effects as evidenced by more time-delayed associations. High fluctuation, small mesocosms had regular disruptions to species sorting and greater importance of ecological drift and dispersal limitation indicated by lower richness and higher taxa replacement. Together, these results emphasize that environmental fluctuations influence ecosystems over time and its impacts are modified by biotic properties intrinsic to ecosystem size.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1
Fig. 1. Temporal patterns of alpha diversity metrics for bacterial communities in dispersal sources (air and rain) (DNA), source media (sediment and water) (DNA) and mesocosm water (RNA).
Error bars are standard error. Diversity metrics for large mesocosms are greater than for both small and medium mesocosms (repeated measures ANOVA, pairwise t-test with Bonferroni correction, p < 0.05). Source media n = 3, mesocosm sizes n = 16, air and rain n = 1. Note the difference in y-axis scales.
Fig. 2
Fig. 2. Path analysis diagrams of factors shaping bacterial communities in mesocosms of different sizes.
Panels show the small (A), medium (B), and large (C) mesocosm sizes. The influence of spatial distances (Δspace), temporal distances (Δtime), environmental distances (ΔEnvi), mean community size (<CommSize >), absolute difference in community size (ΔCommSize) and species richness (ΔRich) on community dissimilarity (βBray-Curtis) was quantified following Jabot et al.’s framework (2020). Arrow width represents, and increases proportionally with, standardized estimate strength. Arrows with positive estimate strength are solid lines and negative estimates are dashed lines. For environmental variables, the absolute values of standardized estimates were added. Effects shown have p < 0.05. SRMR = Standardized Root Mean Square Residual. See Tables S4–S6 for standardized estimate values.
Fig. 3
Fig. 3. Association networks and the relative abundances of the 50 most abundant bacteria in mesocosms of different sizes.
Panels show the small (A), medium (B), and large (C) mesocosm size categories (n = 16). All significant (p ≤ 0.01 and Q ≤ 0.01) pairwise local similarity correlations (LS ≥ 0.5) are shown as edges in the networks. Each node represents an ASV (ellipse) or an environmental factor (rectangle). Edge transparency is proportional to the association strength (based on LS values). Solid lines refer to positive associations while dashed lines to negative ones. Edge colors indicate delayed (blue) and non-delayed (black) associations between ASVs and/or environmental variables. Arrows point toward the lagging node. For clarity, nodes of environmental variables were moved to the side.
Fig. 4
Fig. 4. Conceptual figure for the interpretation of statistical results and patterns based on path analysis, network analysis, and the partitioning of beta-diversity.
In our study, the dominant deterministic force was the applied salinity press disturbance. Ecosystem size was manipulated by different volumes of mesocosms. Darker shading in bars indicates greater influence of the process.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Vellend M. Conceptual synthesis in community ecology. Q Rev Biol. 2010;85:183–206. - PubMed
    1. Leibold MA. Chase JM Metacommunity Ecology. Levin SA, Horn HS, editors: Princeton University Press, Princeton; 2018.
    1. Logue JB, Mouquet N, Peter H, Hillebrand H, Declerck P, Flohre A, et al. Empirical approaches to metacommunities: A review and comparison with theory. Trends Ecol Evol. 2011;26:482–91.. - PubMed
    1. Hanson CA, Fuhrman JA, Horner-Devine MC, Martiny JB. Beyond biogeographic patterns: Processes shaping the microbial landscape. Nat Rev Microbiol. 2012;10:497–506. - PubMed
    1. Lindström ES, Langenheder S. Local and regional factors influencing bacterial community assembly. Environ Microbiol Rep. 2012;4:1–9. - PubMed

Publication types