Monodominance of Parashorea chinensis on fertile soils in a Chinese tropical rain forest

• Published in: Journal of tropical ecology Vol. 30; no. 4; pp. 311 - 322
• Main Authors: van der Velden, Nic, Ferry Slik, J. W., Hu, Yue-Hua, Lan, Guoyu, Lin, Luxian, Deng, XiaoBao, Poorter, Lourens
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.07.2014
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Dipterocarpaceae; diversity; Diversity indices; Edaphic factors; Forest ecology; Forest soils; Fundamental and applied biological sciences. Psychology; guyana; Manganese; mechanisms; mexico; Mixed forests; phosphorus; Plant populations; Rain; Rainforests; responses; Saplings; size distributions; Soil fertility; Soil nutrients; Soil properties; Species diversity; Synecology; Terrestrial ecosystems; tree species composition; Trees; Tropical environments; Tropical forests; Tropical rain forests; vegetation; Water balance; xishuangbanna; diversity; population structure; monodominance; Parashorea chinensis; tropical forest; soil fertility; manganese; Soil fertility; Tropical rain forest; Tropical forest
• ISSN: 0266-4674; 1469-7831
• DOI: 10.1017/S0266467414000212

Monodominance in the tropics is often seen as an unusual phenomenon due to the normally high diversity in tropical rain forests. Here we studied Parashorea chinensis H. Wang (Dipterocarpaceae) in a seasonal tropical forest in south-west China, to elucidate the mechanisms behind its monodominance. Twenty-eight 20 × 20-m plots were established in monodominant and mixed forest in Xishuangbanna, Yunnan province. All individuals ≥1 cm stem diameter and 16 soil variables were measured. Parashorea chinensis forest had a significantly higher mean tree dbh compared with mixed forest. Diversity did not differ significantly between the two forest types. However, within monodominant patches, all diversity indices decreased with an increase in P. chinensis dominance. Floristic composition of P. chinensis forest did differ significantly from the mixed forest. These differences were associated with more fertile soils (significantly higher pH, Mn, K and lower carbon pools and C:N ratio) in the P. chinensis forest than the mixed forest. In contrast to current paradigms, this monodominant species is not associated with infertile, but with fertile soils. Parashorea chinensis seems to be especially associated with high manganese concentrations which it can tolerate, and with edaphic conditions (water, K) that allow this tall and exposed emergent species to maintain its water balance. This is in contrast with most previous studies on monodominance in the tropics that found either no effect of soil properties, or predict associations with nutrient-poor soils.