Growth Increments of Indigenous Species Planted in Secondary Forest Area

Background

Appropriate species selection for reforestation of degraded lands in the tropics makes a great difference in survival rates and success in establishing secondary forest. Indigenous species used in reforestation are not always able to survive in their native landscapes based on the degree of site degradation. This paper reports on growth increments of five tree species indigenous to Malaysia five years after planting.

Research goals & methods

Single-species blocks of Azadirachta excelsa, Cinnamomum iners, Hopea pubescens, Intsia palembanica and Shorea leprosula were planted at 2x2m spacing in a 42-ha experimental plot on logged over forest in Pasoh Forest Reserve. A. excelsa had the highest diameter increment in the study period at 1.06 cm yr^-1 while I. palembanica had the lowest (0.97 cm yr^-1). A. excelsa also had the highest height increment at 1.38 m yr^-1. While in other studies A. excelsa had a higher survival rate, in this study its survival rate (74.1%) was secondary to C. iners (76.3%), which had diameter and height increments secondary to A. excelsa.

Conclusions & takeaways

Of the five species studied, only A. excelsa and C. iners had survival rates greater than 50% as well as rapid growth, suggesting suitability for reforestation on similar sites in Malaysia. Growing conditions such as close spacing and full sun were likely limitations on survivability for other species; the two species with highest mortality were shade-demanding.