Cedar Creek plots with more planted species had lower mean annual log biomass loss and higher mass loss in 2011–2021
We tested whether planted species richness was linked to smaller annual biomass losses in the Cedar Creek Biodiversity II experiment. We used 154 fixed plots with 1, 2, 4, 8 or 16 planted species and ten annual changes from 2011 to 2021. Loss is the decrease between successive harvests. A change without a decrease has zero loss. Mean annual log loss was 0.152 in 16-species plots and 0.206 in monocultures. Its slope was -0.0148 per doubling of richness (95% plot-bootstrap interval -0.0225 to -0.0072). Mean mass loss was 44.6 versus 19.3 grams per square metre. Its slope was +5.76 grams per square metre per doubling (interval +4.32 to +7.19). Mean biomass was 298.5 versus 102.8 grams per square metre. Thus, smaller log loss occurred with larger mass loss and much more standing biomass. Losses greater than 25% occurred in 21.4% versus 25.0% of changes. That difference was uncertain. The directions of the log-loss and mass-loss slopes held in earlier periods, in mixtures alone, and with one strip per plot. All plots shared ten annual changes. The log-loss interval included zero when single years were sampled independently, but excluded zero with blocks of two to four changes. The result is therefore strongest for the observed plots and years. It does not establish protection against future climate events. We preserve unchanged source data, source hashes, the local analysis plan, code, all results, figures, and independent numerical checks.
plant diversity · grassland · standing biomass · annual loss · temporal stability · Cedar Creek · reproducible analysis
References
6- usesCedar Creek e120, 1997–2021: the richness effect on total live biomass stopped increasing after about 2005, but the effect on planted-species biomass continued to increase sci:sha256:6bc19f30a8ffdf3c8c7098f9e84c102f63c16e650fd3f65e84c7ef82d0da36b4
We reuse its retained source files and harvest convention. We independently rebuild plot means and test annual loss measures in 2011–2021. Its reported late biomass decline informed our question and period.
- usesdoi:10.6073/pasta/87b179ac496a0343e6860b19f33158fc
This version of the Cedar Creek e120 biomass dataset provides the unchanged source observations and metadata.
- doi:10.1038/nature04742
This study found a diversity-stability relation in the same grassland experiment using earlier observations.
- doi:10.1038/nature15374
This study tested resistance to climate events across grassland experiments. Its event-based measure differs from our annual loss measure.
- doi:10.1038/s41559-018-0647-7
This study describes several paths from biodiversity to temporal biomass stability.
- doi:10.1073/pnas.1712874115
This study assesses the value of grassland biomass output, its variation, and species identity.
Cited by
13 publicationsPublic catalog entries on Sciscape.
- usesAnnual biomass growth covariance is less negative across strips than within strips at Cedar Creek in 2010–2021
Its annual-loss result and stated strip-sampling limit informed the present question. We test adjacent growth covariance with separate strips.
- Removal of linear trends reduced the geometric mean variance ratio for CSV-listed plants from 1.33 to 1.07 in 35 Cedar Creek 16-species plots, 2010–2021
Prior comparison of annual biomass loss measures using the same release.
- usesBoth strips had biomass below half their own medians less often at higher planted richness at Cedar Creek in 2010–2021
We use its source discovery and harvest conventions. Our event measures low biomass levels, while that report measures annual losses. The raw observations overlap.
- usesTotal biomass had less relative variation than biomass of sown plants in 154 Cedar Creek plots, 2001–2021
Its comparison of biomass loss measures and source audit informed our question and independent data checks.
- usesTemporal log biomass covariance between strips decreased with planted richness at Cedar Creek in 2010–2021
Its loss analysis and strip-sampling limit informed the question. We use the same source release and number of later plots.
- The link between rain and the biomass advantage of plant richness was uncertain at Cedar Creek in 1997–2021
Prior same-release annual biomass loss analysis. It informed the distinction between annual change and weather sensitivity.
- usesA linear model of the 1997–2021 Cedar Creek data did not show lower rain sensitivity at higher planted richness
Its annual-loss result motivated a separate test of response to measured rain. The measures answer different questions.
- The biomass gain from planted richness had no clear link to April–June rain at Cedar Creek in 1997–2020
It compares annual log and mass losses at the same site. Our analysis tests the rain response of the richness slope.
- usesStrip differences account for 47% of the richness slope in relative biomass variance in 154 Cedar Creek plots, 2011–2021
Its later-period loss analysis and stated spatial-sampling limit motivated this paired-strip variance audit and its primary 2011–2021 period. Our metric differs from its log-loss metric.
- Including other plants reduced the biomass stability benefit of sown diversity at Cedar Creek in 2012–2021
This related study compares annual proportional and mass losses. We test variation around multi-year means.
- Total biomass had a smaller diversity–stability slope than planted biomass at Cedar Creek in 2011–2021
This study measured annual biomass losses in the same period. Our outcome is the mean divided by standard deviation over years.
- Recorded total biomass had a weaker richness–stability relation than biomass of listed plants at Cedar Creek in 2010–2021
Its comparison of loss measures in the same release informed our stability question.
- C4 grass share rose while legume mass fell in 35 Cedar Creek plots assigned 16 species, 2001–2005 versus 2017–2021
This report studies annual biomass loss measures in the same release. It provides context for lower later biomass.