Performance of Anthocephaluschinensis in Puerto Rico

Abstract

The growth of kadam (Anthocephaluschinensis (Lam.) A. Rich. ex Walp.), a fast-growing Asiatic species, was studied under different soil and climatic conditions in Puerto Rico. Plantings included a 10-year-old line planting, a 12.5-year-old plantation, 12 localities with 20-year-old single tree plots, and 1 locality with four 52-year-old trees. Over 600 trees were measured in all. Growth rates were comparable to those of fast-growing species elsewhere in the tropics; e.g., the 12.5-year-old plantation had a volume growth of 27.8 m3•ha−1•year−1 (77% was merchantable wood), a basal area growth of 1.82 m2•ha−1•year−1, and a total aboveground biomass production of 11.5 t•ha−1•year−1. Trees grew well both in plantations and in lines under natural forest. The 20-year-old single tree plots averaged up to 1 m•year−1 in height growth and 53 cm2•year−1 in basal area growth. Highest rates were observed in localities with high annual rainfall (>2500 mm) and with phosphorus- and silt-rich soils of high bulk density and low pH. After 10 years, basal area growth of trees was fastest in volcanic deep clay locations, followed, in order, by trees on volcanic shallow loams, calcareous soils, and plutonic sandy loams. However, basal area growth during the first 5 years was fastest in the plutonic sandy loams and slowest in the calcareous soils. After 20 years, volcanic deep clay soils still supported the fastest basal area growth rate (about 100 cm2•year−1), while the other locations converged at about 30 cm2•year−1. Trees reached maximum height after 20 years (average, 19 m; maximum, 26.5 m). Kadam growth was limited by close spacings (below 2.5 × 2.5 m). Trees exhibited excellent form (ratio of diameter at 1.3 m to diameter at 4.9 m > 0.8). We found no evidence of pest or disease attacks on trees, but noted severe tapering and stem twist in localities having poor growth rates. Results underline the need for caution when making species adaptability assessments in the tropics with short-term (<10 years) data.