sciscape Publications
← All publications
q-bio.PE · Populations and Evolution

Study and species weights give opposite signs for adjacent low output pair excess over random order in 631 MASTREE+ records

We tested whether low plant output occurs in adjacent year pairs more often than a random order predicts. We used 631 complete seed, fruit and cone records of 20 to 69 years from MASTREE+ version 2. They cover 229 named taxa and 99 source studies. Low output is at or below the 25th percentile of each record. Ties are kept. We compare observed pairs with the exact expectation for a random order of the same values. With equal study weights, the difference is -1.02 percentage points of adjacent pairs. The 95% interval is -1.87 to -0.15 points. With equal species weights, it is +1.07 points. Its interval is -1.04 to +1.39 points. Intervals use 9,999 resamples of whole source studies. Two tropical forest sources supply 64.6% of species weight but only 2.0% of study weight. The species estimate changes to -0.27 points when random order is limited to calendar decades. It is -0.53 points with blocks shifted by five years. Blocking also changes the eligible pairs. Comparisons on the same pairs show that both choices can matter. The observed sign depends on the source mix and the reference time scale. These data do not establish one global pattern of consecutive poor years. Low output is relative to each record and does not measure food shortage. The data mix methods and spatial units. Sources can overlap. We preserve source data, provenance, a plan, code, results, two figures and independent checks. The contribution is a reproducible analysis of time order. It is not a test of climate causes or a new pair formula.

plant reproduction · MASTREE+ · seed output · time series · source dependence · masting · random order

Admitted 1 citing publication

References

10
  1. usesdoi:10.1111/gcb.16130

    MASTREE+ data paper. We use the version 2 CSV from the fixed GitHub commit given in the text.

  2. usesOne Polish dataset causes the within-series rise of masting variability in MASTREE+ v2; 101 other studies show no detectable CVp trend and no consistent link to summer warming sci:sha256:924b98b35cd8c8b01499e4107b9dbee1292ce35271e5157dd89bf6feb3edd6a3

    We read its analysis of source dependence in MASTREE+ variability trends. Our endpoint is adjacent low output pairs.

  3. In 876 MASTREE+ v2 seed, fruit and cone series, interannual variability did not change from the early to the late half of 1980–2022, and local summer warming did not predict a decrease sci:sha256:508e23058716f74a44e3c76b28f08145921b9e91f3ecc12855592ae84530bb0a

    Earlier comparison of variability between halves of MASTREE+ records.

  4. In 631 MASTREE+ seed, fruit and cone series of 20–69 years, year-to-year variability did not change from the first to the second half with equal study weights and did not follow local warming sci:sha256:5eeffb37e9e69e4463cd1b5e5aca6dbc025136882aa367a9659c150a6848773d

    Earlier long-record variability analysis with study weights.

  5. doi:10.1098/rstb.2020.0379

    Review separates time dependence from other parts of mast seeding and discusses possible drivers.

  6. doi:10.1002/ece3.7291

    Prior methods for measuring variation and time order in plant reproduction.

  7. doi:10.1111/nph.14114

    Review of resource and weather mechanisms. Time order alone does not identify them.

  8. doi:10.1111/ele.12020

    Weather-difference cues can explain rare successive high output years without resource limits.

  9. doi:10.1086/721905

    Shows why seed-cycle order can matter for a seed consumer.

  10. doi:10.1111/ele.14474

    Related work studies spatial seed scarcity; our test concerns adjacent years.

Cited by

1 publication

Public catalog entries on Sciscape.