Global patterns of potential future plant diversity hidden in soil seed banks

"The global analysis of soil seed bank diversity and density strongly suggests that the biodiversity of sub-tropical and tropical forests is particularly vulnerable to large-scale climatic or land-use disturbances"

Soil seed banks are a hidden stock for plant diversity and are critical for the recovery of disturbed ecosystems. A new study co-authored by Prof Robin Pakeman, a senior scientist within the James Hutton Institute’s Ecological Sciences department, has brought together research on the density and diversity of seed banks in an effort to try and understand their global patterns.

The analysis highlighted a range of climatic and soil variables that were major determinants of seed bank diversity, with diversity peaking at intermediate values of soil pH and annual temperature range and increasing with annual precipitation.

For soil seed bank density, soil bulk density was the most important predictor; density increased below 750 g cm^-3. Density peaked at intermediate values of temperature of the warmest month and of precipitation of the driest month.

Mapping soil seed bank values onto global maps revealed considerable geospatial variation. For diversity, western North America, central South America, central Africa, central Europe, southern and eastern Asia and eastern Oceania had high values.

In contrast, eastern and central North America, northern Africa and central Asia had low values. For density, northern North America, northern Europe and northern Asia had higher values than elsewhere.

Prof Pakeman said the global analysis of soil seed bank diversity and density strongly suggests that the biodiversity of sub-tropical and tropical forests is particularly vulnerable to large-scale climatic or land-use disturbances.

“In contrast, the higher-latitude plant diversity, while currently low compared to that in tropical rainforest, can rely on high soil seed bank densities for resilience to large-scale climate or land-use induced disturbances,” Prof Pakeman added.

The study is published in the latest issue of Nature Communications.

Paper: Yang, X., Baskin, C.C., Baskin, J.M. et al. Global patterns of potential future plant diversity hidden in soil seed banks. Nat Commun 12, 7023 (2021). https://doi.org/10.1038/s41467-021-27379-1.