Relation between soil physico-chemical properties and the distribution of Rhododendron species in China

S. Wang, L. Leus, M.-C. Van Labeke, J. Van Huylenbroeck
Rhododendron is one of the most important ornamental plant genera. Its species are distributed in Asia, Europe and North America. In China 571 Rhododendron species, 180 botanical varieties and 72 subspecies are reported. The Chinese Virtual Herbarium (CVH, ), an online portal, contains about 90,000 Rhododendron specimens. For more than 30,000 specimens, detailed information on location is present which allows geocoding into GPS data. Data on soil properties are present in the Harmonized World Soil Database (HWSD). In the presented study we related the GPS data of 31,146 Rhododendron specimens and 525 taxa to 60 soil units as defined in the HSWD. Soil physical properties, such as gravel content, sand/silt/clay fraction, bulk density, and chemical properties like organic carbon content, pH, cation exchange capacity, base saturation, total exchangeable bases, calcium carbonate, gypsum, sodicity and salinity in each soil unit and their correlation with the number of specimens and species were analyzed. The results indicated that Haplic Luvisols (LVh) is the dominant soil unit (31.7% of all specimens) for the distribution of Rhododendron species. Five other soil units, Chromic Cambisols (CMx), Haplic acrisols (ACh), Haplic Alisols (ALh), Cumulic Anthrosols (ATc), and Humic Acrisols (ACu), could also be linked with at least 2,000 specimens. Through principal components analysis, we found that pH is one of the main properties that effect the distribution of rhododendrons. Besides the distribution maps of the six soil units were generated. These data provide information which is useful for Rhododendron breeding programs and enable us to identify interesting species and genotypes adapted to specific soil physico-chemical properties.
Wang, S., Leus, L., Van Labeke, M.-C. and Van Huylenbroeck, J. (2020). Relation between soil physico-chemical properties and the distribution of Rhododendron species in China. Acta Hortic. 1283, 121-130
DOI: 10.17660/ActaHortic.2020.1283.16
soil, physico-chemical property, Rhododendron, principal components analysis

Acta Horticulturae