Calcifuge and soil-indifferent Proteaceae from south-western Australia: novel strategies in a calcareous habitat

• Published in: Plant and soil Vol. 496; no. 1-2; pp. 95 - 122
• Main Authors: Hayes, Patrick E., Clode, Peta L., Lambers, Hans
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.03.2024; Springer; Springer Nature B.V
• Subjects: Acidic soils; Agriculture; Analysis; Australia; Biomedical and Life Sciences; Calcareous soils; calcifuges; Calcium; Carboxylates; Ecology; family; geographical distribution; growth retardation; habitats; Life Sciences; nutrient deficiencies; Nutrient deficiency; phosphorus; Plant growth; Plant Physiology; Plant Sciences; Proteaceae; Research Article; root growth; Roots (Botany); Seeds; soil; Soil microbiology; Soil Science & Conservation; Species; Toxicity; Australia; Soil-indifferent; Calcifuge; Calcareous; Calcium-enhanced phosphorus sensitivity; Phosphorus; Proteaceae; Jurien Bay chronosequence
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-023-06297-9

Background and aims Proteaceae are a prominent plant family in south-western Australia. Most Proteaceae are ‘calcifuge’, occurring exclusively on old phosphorus (P)-impoverished acidic soils, with a few ‘soil-indifferent’ species also found on young P-richer calcareous soils. Calcium (Ca)-enhanced P toxicity explains the calcifuge habit of Proteaceae. However, previous research has so far been focused exclusively on the roles of Ca and P in determining Proteaceae distribution, and consequently there is little knowledge on how other soil-based strategies influence this distribution. We aimed to study the effects of young calcareous soils on four soil-grown Proteaceae and assess differences between calcifuge and soil-indifferent Proteaceae to better understand their natural distribution. Methods Two calcifuge and two soil-indifferent Proteaceae from south-western Australia were grown in six contrasting soils, including young calcareous, and old acidic soils. Results When grown in calcareous soils all species showed root growth inhibition, micronutrient deficiency, Ca-enhanced P toxicity, and negative impacts on physiology. Calcifuge species were more sensitive to calcareous soils than soil-indifferent ones, although this varied between genera. Soil-indifferent species tended to produce more cluster roots, release more carboxylates per root mass, and allocate less Ca to their leaves, compared with calcifuges; they also had smaller seeds and were less sensitive to Ca-enhanced P toxicity. Conclusion We surmise that a combination of these traits allows soil-indifferent species to tolerate calcareous soils. This study provides insight into how Proteaceae respond to young calcareous soils and how this influences their distribution.