Adinandra belukar: an anthropogenic heath forest in Singapore

Adinandra belukar is a species-poor forest dominated by Adinandra dumosa (Theaceae) found in Singapore and southern Peninsular Malaysia. It is the product of secondary succession after exhaustive agricultural exploitation on land cleared of primary lowland rain forest. A high degree of similarity in vegetation between different sites was found for seven 225 m² plots in a dinandra belukar in Singapore. Adinandra dumosa was dominant or codominant in all plots, generally found in association with the woody species Dillenia suffruticosa, Fagraea fragrans, and Rhodamnia cinerea, the climber Gynochthodes sublanceolata, the fern Dicranopteris linearis and the terrestrial orchid Bromheadia finlaysoniana. All sites had extremely acidic (pH 3.3–3.9) surface (0–20 cm) mineral soils with very low total nitrogen (0.06–0.14%) and total phosphorus (11–29 g g^-1) contents and very high carbon/nitrogen ratios (33–48). Adinandra belukar is interpreted as a heath forest because of its floristic and physiognomic similarities with this forest formation.