A stem taper equation compatible to volume equation forParaserianthes falcatariain Pare, East Java, Indonesia: its implications for the plantation management

Abstract

A stem taper equation compatible to the volume equation was derived from the data of 172 trees sampled in the three plantations of Paraserianthes falcataria in Pare, East Java. The stem taper equation in this study was based on a conventional logarithmic volume equation, with the addition of one free parameter that minimized the standard errors of estimate to the observed diameter of stems at 1.0-m intervals. The derived equation was able to predict the stem taper of P. falcataria reasonably well, while it was not flexible enough to describe delicate changes of the taper in the upper portion of stem. The equation was able to predict bole length and the volume up to the top diameter 20 cm, the diameter size merchantable for sawn timber in Indonesia, with reasonable accuracy. An appropriate rotation age for sawn-timber production was found to be 8-9 years old, at which the mean annual increment of sawn timber would be maximized.

Model Volume Pohon Sengon Untuk Menilai Kehilangan Keuntungan Petani Hutan Rakyat

“…Misalnya, Bustomi (1995) et al menyusun model penduga volume pohon sengon untuk hutan tanaman di Jonggol, Jawa Barat. Kurinobu (2007) menyusun persamaan ta-et al per untuk menduga volume pohon sengon pada hutan tanaman di Pare, Jawa Timur. Namun untuk hutan rakyat, model-model penduga volume pohon sengon belum banyak dikembangkan sesuai dengan karakteristik tiap lokasi hutan rakyat yang pengelolaannya cenderung beragam (Bramasto & Tiryana 2013).…”

Validation of strength and flexibility of sengon (Paraserianthes falcataria) by experimental tree-pulling test and numerical simulation

“…As mentioned in the previous section, the sengon tree in general has a straight bole. The tapering is generally identifi ed mostly in the upper portion of the stem [30]. In this experiment, as the rope attachment was made at slightly over the midway point of the stem's height, it is tolerable to model the sengon tree as a non-tapered cylindrical cantilever beam with a static lateral load applied to the tip of the free-end.…”

Paraserianthes falcataria (L.) Nielsen: Ecology, silviculture and productivity

“…The stem taper equation was based on a logarithmic volume equation with the addition of 1 free parameter that minimised the standard errors of estimate to the observed diameter of stems at 1-m intervals. The derived taper equation, according to Kurinobu et al (2007b), is able to predict the stem taper of P. falcataria with reasonable accuracy, although it is not flexible enough to describe changes in the upper portion of the stem. They stated that the volume equation is able to predict the volume up to 20 cm in diameter reasonably well.…”

“…Several stem volume equations have been produced for P. falcataria in Indonesia (e.g. Bustomi et al 1995, Kurinobu et al 2007b. Bustomi et al (1995) developed a single stem volume equation for P. falcataria using 93 sample trees from plantations in Jonggol, West Java (Table 3).…”

“…These models were used to construct stem volume tables (V 5 and V c ), either one-way tables in which volumes were given for a particular DBH, or 2-way tables that provide estimates for a DBH for a range of height measurements. Kurinobu et al (2007b) developed a total stem volume equation that is compatible with a stem taper equation using a sample of 172 P. falcataria trees from plantations in Pare, East Java (Table 3). The stem taper equation was based on a logarithmic volume equation with the addition of 1 free parameter that minimised the standard errors of estimate to the observed diameter of stems at 1-m intervals.…”