bioRxiv Science⌕ Search

Biology subjects

Ruprecht, E.

Publications and source records attributed to Ruprecht, E..

2 recordsLinked to original sources

The 'false transience' hypothesis: Do we need to reconsider the seed persistence classifications of soil seed bank studies?

Background and Aims Seed bank persistence data is typically indirect, inferred from the presence and distribution of seeds in the soil. However, this approach frequently underestimates seed longevity, because dormant and low-abundance seeds can remain undetected. Here, we introduce and test the 'false transience' hypothesis which proposes that a subset of species classified as having transient seeds based on soil seed bank (SSB) studies actually possess the capacity for long-term persistence. Their perceived transience stems from methodological limitations and ecological filters, rather than physiological constraints. We also aimed to assess how the seed mass and seed production of 'false transient' species compare to the full range of tested species. Methods We focused on species considered to have transient seeds based on SSB studies. We conducted a germination experiment with 103 species using dry-stored seeds aged 10-29 years. We then assessed how the seed mass and seed number of germinating species relate to the full range of tested species. Key Results From the 103 tested species, eight species (~8%) germinated. The majority of species germinating after >10 years had large seeds and low seed numbers compared to the full range of species, and all germinating species had seed numbers below the median of the tested species. Conclusions Our results provide partial support for the proposed 'false transience' hypothesis, showing that nearly 10% of supposedly transient species can persist after more than a decade of ex situ storage. Our results also suggest that 'false transients' are frequently large-seeded with low seed production, therefore being more likely to be missed in SSB studies and erroneously classified as transient. We can conclude that relying solely on field SSB data to infer seed persistence can be misleading, suggesting that the widely observed negative relationship between seed size and persistence may also require reconsideration.

ecology↗

Scale dependency of taxonomic and functional diversity in old-growth and secondary loess steppic grasslands.

Widespread campaigns on forest restoration and various tree planting actions lower the awareness of the importance of grasslands for carbon sequestration or biodiversity conservation. Even lower attention is given to the conservation of biodiversity and ecosystem functioning in remnants of ancient, so called old-growth grasslands. Old-growth grasslands in general harbour high biodiversity and even small patches of these can act as important refuges for many plant and animal species in urbanised or agriculture driven landscapes. Spontaneous succession of grassland is frequently viewed as a cost-effective tool for grassland restoration, but its applicability is strongly dependent on many local to landscape-scale factors and the recovery often slow. Thus, for the assessment of the effectiveness of spontaneous succession as a restoration tool, it is essential to compare the species diversity and functional attributes of old-growth and secondary grasslands. We studied the taxonomic and functional diversity in thirteen loess steppic grasslands (8 old-growth and 5 secondary) using differently sized plots ranging from 0.01 to 100m2. Our results indicated that there are remarkable differences in taxonomic and functional diversity between old-growth grasslands and secondary ones. We also point out that during secondary succession there is a likely functional saturation of the species assembly in the first few decades of recovery, and while patterns and structure of secondary grasslands became quite similar to those of old-growth grasslands, the species richness and diversity remains still much lower. Old-growth grasslands support considerable plant diversity, and species composition is slow to recover if destroyed for agricultural land use. This underlines the priority of protecting existing old-growth grassland remnants over restoration actions and the recovery of secondary grasslands.

ecology↗