Neighboring tree effect on the survival and growth of <i>Shorea johorensis</i> under a line planting system in a Bornean dipterocarp forest

Abstract

In Indonesia, in recent years, line planting of valuable Shorea species has taken place on logged forest to maintain the timber yield. However, there exists scant information about the effectiveness of such a method. Neighboring trees along the planting lines affect the planted trees. We assessed the survival, growth, and crown exposure of the planted trees to evaluate the effect of neighboring trees in three 1 ha-monitoring plots, in which Shorea johorensis seedlings had been planted at a 5-m spacing along five parallel lines separated by 25 m, all running in a north-south direction within a 3 m-wide strip. The planted trees were monitored for 11 years after planting. The crown exposure was evaluated using a three-dimensional spatial structure model and SExI-FS software. Eleven years after planting, 77.6 % of the planted S. johorensis had survived. The average diameter at breast height (DBH) was 16.7±5.6 cm, ranging widely from 5.3 to 33.6 cm. The initial growth 1 year after planting predicted the variance in DBH 11 years later. Trees showing rapid initial growth exhibited higher survival and subsequent growth rates. The variation in light conditions in the planting lines affects the growth and survival. The spatial structure model illustrated how neighboring tree crowns suppress the growth of the planted tree by casting shade. In a line-planting system, the neighboring tree effect influences the survival and growth of the planted trees, and this can be reduced by treatment of the canopy to ensure exposure of planted trees to sunlight.

Potential of carbon sequestration enhancement through intensive silvicultural techniques using Shorea leprosula plantation in Central Kalimantan, Indonesia

“…The implementation of Sustainable Forest Management (SFM) in PBPH can expedite the ecological restoration of degraded forests, due to its 27-year production cycle compared to the 30-year of logging rotation (Hilwan et al 2012). A study by Inada et al (2015) has shown an increase in the number of trees in the ex-logging areas after 11 years of Shorea spp. plantation.…”

Vegetation diversity of Hemaq Beniung Customary Forest, West Kutai, East Kalimantan

“…Untuk nilai Indeks Kemerataan (e) tergolong hampir merata pada semua tingkat pertumbuhan dengan nilai e antara 0,76 -0,95 (Karmilasanti & Fajri, 2020) (Panjaitan et al, 2012). Kondisi serupa juga ditemukan pada hutan produksi di Kalimantan Tengah yang dijumpai Shorea johorensis (Inada et al, 2015). Penelitian yang dilakukan di Taman Nasional Gunung Leuser, Aceh, juga menemukan bahwa Shorea johorensis masih tumbuh baik di sana (Harnelly et al, 2018).…”

An alternative Silvicultural approach in managing logged-over forests

“…The medium-term silvicultural results of Silin, as applied in PT. Sari Bumi Kusuma, are impressive, with seedling survival rates of about 70% and rates of stem diameter increments consistently averaging about 2 cm per annum, based on 10-14 years of post-planting data from permanent sample plots [1,2]. At first glance, TPTJ seems easy to implement in the field and does not cause many problems.…”