Larger aboveground neighbourhood scales maximise similarity but do not eliminate discrepancies with belowground plant diversity in a Mediterranean shrubland

• Published in: Plant and soil 2021-03, Vol.460 (1-2), p.497-509
• Main Authors: Illuminati, Angela, López-Angulo, Jesús, de la Cruz, Marcelino, Chacón-Labella, Julia, S. Pescador, David, Pías, Beatriz, Sánchez, Ana M., Escudero, Adrián, Matesanz, Silvia
• Format: Article
• Language: English
• Subjects: Analysis; Assembly; Biodiversity; Biomedical and Life Sciences; Botany; Compartmental analysis (Biology); Compartments; Composition; Cores; Distribution patterns; Ecology; Environmental aspects; Geographical distribution; Herbivores; Life Sciences; Methods; Plant communities; Plant diversity; Plant ecology; Plant Physiology; Plant Sciences; Plant species; Population distribution; Regular Article; Sampling; Shrublands; Similarity; Soil layers; Soil Science & Conservation; Soils; Spatial distribution; Species richness
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-020-04796-7

Aims An unresolved question in plant ecology is whether diversity of the aboveground and belowground compartments of a plant community is similar at different neighbourhood scales. We investigated how the similarity between both compartments varies with the aboveground sampling grain and if significant discrepancies exist between aboveground and belowground plant diversity at the maximum similarity scale. Methods We fully mapped the aboveground perennial plant community of a 64 m 2 plot in a Mediterranean shrubland and analysed this compartment by assessing diversity in 5 to 50 cm radii circles centred in soil cores. We sampled 2.5 cm radius root cores at two different depths and identified plant species by using DNA metabarcoding to characterise the belowground compartment. We quantified differences in species richness, composition and species’ spatial distribution above- and belowground. Results The differences between aboveground and belowground communities were affected by the size of the aboveground sampling grain and were minimised when considering a circle of 20 cm radius in the aboveground. We found a significant dissimilarity in richness and composition between the two compartments, with larger differences when considering the deeper soil layer only. Conclusions Our results showed that the spatial grain selected to sample a plant community aboveground and belowground is critical to characterise them in a comparable manner. Although their composition is related, species distribution patterns strongly differ, suggesting the simultaneous action of different assembly mechanisms. Our results call for caution when studying community assembly considering only the standing vegetation, since total plant diversity can be underappreciated.