Limits...
Autogenic succession and deterministic recovery following disturbance in soil bacterial communities

View Article: PubMed Central - PubMed

ABSTRACT

The response of bacterial communities to environmental change may affect local to global nutrient cycles. However the dynamics of these communities following disturbance are poorly understood, given that they are often evaluated over macro-ecological time scales and end-point measurements. In order to understand the successional trajectory of soil bacterial communities following disturbances and the mechanisms controlling these dynamics at a scale relevant for these organisms, we subjected soil microcosms to a heat disturbance and followed the community composition of active bacteria over 50 days. The disturbance imposed a strong selective pressure that persisted for up to 10 days, after which the importance of stochastic processes increased. Three successional stages were detected: a primary response in which surviving taxa increased in abundance; a secondary response phase during which community dynamics slowed down, and a stability phase (after 29 days), during which the community tended towards its original composition. Phylogenetic turnover patterns indicated that the community experienced stronger deterministic selection during recovery. Thus, soil bacterial communities, despite their extreme diversity and functional redundancy, respond to disturbances like many macro-ecological systems and exhibit path-dependent, autogenic dynamics during secondary succession. These results highlight the role of autogenic factors and successional dynamics in microbial recovery.

No MeSH data available.


Variation in diversity during secondary succession.Richness (A) measured as the number of observed OTUs and evenness (B), calculated using Pielou’s J. A lowess fit of the data is shown in black.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5382530&req=5

f2: Variation in diversity during secondary succession.Richness (A) measured as the number of observed OTUs and evenness (B), calculated using Pielou’s J. A lowess fit of the data is shown in black.

Mentions: Disturbance affected the potentially active bacterial community, with both richness (χ2 = 44.32, p = 0.012) and evenness (χ2 = 51.18 p < 0.001) decreasing after heating (Fig. 2). The mean OTU richness dropped by 28%, from 838 (±65.9 sd) in the undisturbed soils, to 602 (±148 sd) one day after disturbance. These differences persisted for over three weeks (χ2 post-hoc test; p < 0.005 for the comparison between T0 and T1-24), but subsequently began to recover. By T25 OTU richness was not significantly different from that of the C49. Evenness also decreased following disturbance (Fig. 2), with differences between disturbed communities and both T0 and C49 controls for up to 24 days post-disturbance (Tukey post-hoc test; p < 0.01 for all comparisons between T1-24 and T0, and T1-24 and C49). Evenness also fully recovered with respect to controls by T29.


Autogenic succession and deterministic recovery following disturbance in soil bacterial communities
Variation in diversity during secondary succession.Richness (A) measured as the number of observed OTUs and evenness (B), calculated using Pielou’s J. A lowess fit of the data is shown in black.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5382530&req=5

f2: Variation in diversity during secondary succession.Richness (A) measured as the number of observed OTUs and evenness (B), calculated using Pielou’s J. A lowess fit of the data is shown in black.
Mentions: Disturbance affected the potentially active bacterial community, with both richness (χ2 = 44.32, p = 0.012) and evenness (χ2 = 51.18 p < 0.001) decreasing after heating (Fig. 2). The mean OTU richness dropped by 28%, from 838 (±65.9 sd) in the undisturbed soils, to 602 (±148 sd) one day after disturbance. These differences persisted for over three weeks (χ2 post-hoc test; p < 0.005 for the comparison between T0 and T1-24), but subsequently began to recover. By T25 OTU richness was not significantly different from that of the C49. Evenness also decreased following disturbance (Fig. 2), with differences between disturbed communities and both T0 and C49 controls for up to 24 days post-disturbance (Tukey post-hoc test; p < 0.01 for all comparisons between T1-24 and T0, and T1-24 and C49). Evenness also fully recovered with respect to controls by T29.

View Article: PubMed Central - PubMed

ABSTRACT

The response of bacterial communities to environmental change may affect local to global nutrient cycles. However the dynamics of these communities following disturbance are poorly understood, given that they are often evaluated over macro-ecological time scales and end-point measurements. In order to understand the successional trajectory of soil bacterial communities following disturbances and the mechanisms controlling these dynamics at a scale relevant for these organisms, we subjected soil microcosms to a heat disturbance and followed the community composition of active bacteria over 50 days. The disturbance imposed a strong selective pressure that persisted for up to 10 days, after which the importance of stochastic processes increased. Three successional stages were detected: a primary response in which surviving taxa increased in abundance; a secondary response phase during which community dynamics slowed down, and a stability phase (after 29 days), during which the community tended towards its original composition. Phylogenetic turnover patterns indicated that the community experienced stronger deterministic selection during recovery. Thus, soil bacterial communities, despite their extreme diversity and functional redundancy, respond to disturbances like many macro-ecological systems and exhibit path-dependent, autogenic dynamics during secondary succession. These results highlight the role of autogenic factors and successional dynamics in microbial recovery.

No MeSH data available.