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Safe wild-seed harvest depends on generation time

Across 280 species, annuals can spare only about 2% of seeds each year, while long-lived plants can lose far more without collapsing.

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How many species’ matrices were simulated?

280 angiosperms from five continents in COMPADRE.

What trait best predicted harvest vulnerability?

Generation time, explaining more than 50% of vulnerability on its own.

What is the safe annual harvest for annuals/biennials?

About 2.3% of seeds (95% CI 0.5–4.1).

What does a US 20% annual rule do to annuals?

It would drive all annual plants to extinction within a few decades in the 30-year annual-harvest scenario.

How does harvesting less often change the safe fraction for annuals?

Every 10 years: 30.3%; every 2 years: 5.3%.

Are German 2% annual rules for annuals about right?

Yes; 2.3% is close to Germany’s 2% guideline.

Is plant growth type a good harvest rule?

No; herbaceous perennials span large declines to no effect at 10–20% harvest.

Why is 30% combine-harvest risky in grasslands?

60% of grassland species in the dataset have generation times below 15 years, the threshold for safe 30% annual take.

What extreme scenario did the models assume?

Harvest every growing season for 30 consecutive years from the same population.

What do the authors say restoration still needs?

Professional large-scale seed production in orchards, because wild harvest cannot meet UN Decade demand.