Early Growth of 11 Native and Three Alien Tree Species in Northeastern Mindanao, Philippines

Conrado Marquez,Renato Bacsal,Henry Adornado,Maricar Aguilos,Rustum Aguilos

doi:10.3390/f12070909

Abstract

Early growth performances of 11 native tree species were investigated in three different sites in Mindanao, Philippines, to evaluate their adaptability and potential for plantation development. Three alien species were added to assess how native species could potentially compete with these alien species based on survival rate, diameter growth rate (DGR), and height growth rate (HGR). A year after planting, the native species common to all sites that obtained >80% survival rate were Casuarina equisetifolia L. Alstonia macrophylla Wall. ex. G.Don., Alstonia scholaris (L.) R.Br., and Parkia javanica (Lam.) Merr. and were comparable to an alien species Acacia mangium Willd. The species with the lowest survival rate (30%) across all sites was Duabanga moluccana Blume. Native species P. javanica, Eucalyptus deglupta Blume, and A. macrophylla all had a DGR of 34 mm year−1 and were comparable with the alien species Schizolobium parahyba (Vell.) S.F.Blake with 38 mm year−1. However, the HGR of native species E. deglupta (245 cm year−1) and Melia dubia Cav. (230 cm year−1) were higher than an alien species S. parahyba (222 cm year−1). No native species can compete with the DGR (52 mm year−1) and HGR (384 cm year−1) of A. mangium. Rainfall significantly explained 13%–97% of DGR, HGR and survival rate of >70% of the species while air temperature explained about 17%–96% of the variations of similar variables. This early assessment provides a strong basis to better predict the early performances of native species in the Philippines. Through this, appropriate silvicultural intervention can be recommended towards improving the growth and survival of the native seedlings as alternative industrial tree plantation species in the country.

Highlights

Foresters, environmental researchers, and tree farmers face challenges in revitalizing our native tree species in degraded forest lands in the quest to manage productive, profitable, and fully functional ecosystems
The highest survival rate was attained by an alien species A. mangium (95%), the survival rate of native species such as A. scholaris (93%), C. equisetifolia (93%), P. javanica (91%), and B. javanica (90%) were close and did not differ significantly (p > 0.05)
For example our previous study showed that P. javanica and B. javanica achieved 80%–90% surviva rates 5 years after planting, which proved the ability of these native species to survive wel as that of A. mangium

Summary

Introduction

Environmental researchers, and tree farmers face challenges in revitalizing our native tree species in degraded forest lands in the quest to manage productive, profitable, and fully functional ecosystems. The Philippines was one of the major exporters of logs of native trees from natural stands [1]. Dubbed as the Timber Capital of the country, the Caraga Region provides 58%–72% of the country’s log requirement [4] due to social inclination to tree planting, favorable climate, and existing wood processing plants. Tree farmers focus on planting alien species due to their excellent growth productivity, market availability, short rotation, absence of government administrative constraints in marketing, and availability of seedlings [6]. The use of a greater variety of reforestation species will reduce the risk of species invasion, improve ecosystems’ resilience, promote plant biodiversity, and amend soil condition [15,16]. From a socio-economic point of view, increasing the species options may enhance adaptability to changing market opportunities and offer a wider variety of products and services [17]

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Conclusion