Table 1. Cohesion predicts community turnover in six long-term time series.
Lake | Taxon pers. cutoff a | Adjusted R2 | Positive cohesion P-value | Negative cohesion P-value | Positive cohesion direction b | Negative cohesion direction b | Days between samples | Number of samples |
---|---|---|---|---|---|---|---|---|
Mendota (phyto) | 5% | 0.465 | 0.405 | <1 × 10−20 | NS | Stronger is stabilizing | 36–48 | 186 |
Monona | 5% | 0.355 | 0.413 | <1 × 10−15 | NS | Stronger is stabilizing | 36–48 | 166 |
Peter | 10% | 0.357 | 0.062 | <1 × 10−3 | NS | Stronger is stabilizing | 39–45 | 121 |
Paul | 10% | 0.500 | <1 × 10−11 | <1 × 10−19 | Weaker is stabilizing | Stronger is stabilizing | 39–45 | 125 |
Tuesday | 10% | 0.374 | 0.355 | <1 × 10−8 | NS | Stronger is stabilizing | 39–45 | 72 |
Mendota (16S) | 5% | 0.378 | 0.0039 | <1 × 10−5 | Weaker is stabilizing | Stronger is stabilizing | 25–41 | 54 |
Stands for ‘taxon persistence cutoff’, which was the minimum proportion of presences across the data set that we used as a cutoff for including taxa in the connectedness and cohesion metrics. Other cutoffs may give higher model-adjusted R2 values (see the Supplementary Online Material), but we wanted to use the same cutoff for data sets collected within the same sampling program. We also applied a mean abundance cutoff to the Lake Mendota 16S rRNA gene data set, where we removed taxa with a mean abundance <1 × 10−7.
These columns indicate the direction of a significant relationship between cohesion and Bray–Curtis dissimilarity. For example, ‘stronger is stabilizing’ means that greater cohesion is related to lower Bray–Curtis dissimilarity. Nonsignificant relationships are denoted ‘NS’.