DISTRIBUSI SPASIAL DAN DIAMETER POHON BINAAN BEKAS TEBANGAN TPTI DI AREAL HPH PT. DWIMAJAYA UTAMA PROPINSI KALIMANTAN TENGAH

Rawana, Prof.Dr.Ir. H. Djoko Marsono

1998 | Tesis | S2 Ilmu Kehutanan

Pcnclitian ini dilakukan di HPH PT. Dwimajaya Utama Kalimantan T engah. Tujuan penelitian ini adaJah untuk mengetahui komposisi dan kerapatan pohon binaan di areal belcas tcbanga:n TPTI O, 1,4 da:n 8 tahlDI scrta scbaran spasialnya da:n melakuka:n pendekatan secara matematis t ·,adap sebaran diameter pohon binaan bekas teba:nga:n Tm melalui penerapan fungsi eksponensial. Metode yang digunakan adalah metode kuadrat. Plot-plot diletaJdcan dalam jalur, dengan jarak antat plot 50 m, sedangkan jarak antar jalur 200 m. Total plot yang dibuat sebanyak 400 plot. Pertama dicari lokasi tcbangan TPTI pada 0 W\Wl .(calon tebanga:n), 1 iahun setelah tebangan (Et+ 1 ). 4 iahun (Et +4) dan 8 iahun setelah ditebang (Et+S). Kemudian dilal-ukan pengambitan sampel, dengan ukuran plot 20 x 20 m. Setelah itu dilakukan penc:arian pohon binaan sebanyak 8 pohon sctiap plot, tennasuk didalamnya pohon inti. Pohon binaan ini dipi1ih pohon-pohon yang memililci nilai ekonomi tinggi pada wak-ru yang akan datang. Oleh lcarena itu dalam penentuan ini ditakulcan dengan pertimbangan petugaS HPH setempat. Parameter yang diukur meliputi : nama jenis, dan diameter. Untuk menget:ahui komposisi clan kerapatan d.ihitung INP (Tndeks nilai penting) dengan cara menjwnlah nilai keraparan relatif + frekuensi relatif + dominasi relarif. Sedangkan untuk mengeiahui pola disttibusi spasialnya digunakan distribusi Poisson dengan· dilengkapi indeks dispersi Blackman. Adapun persebaran diameter mcn8c,aunakan sebar..n eksponensial. Dari hasil perhitung:m dipm>lch 18 j????is pohon bina:m. setnt!2Ilya tmnasuk famili Dipterocarpaceae, dcngan kerapatan sebagai bcrikut : untuk tegakan sebclum di1a.lcu.1can penebangan (Et+O) kerapatan pohon binaan sebesar 184 pohon /ha Untuk lokasi I tahun setela.'1 tebangan did.2.patkan kerapatan 140 phn /ha. uncuk 4 tahwt dan 8 tahcn setelah teb2:tg.an masing­masing dipc:rntch angka t3 l phn/ba dan 133 phn/ha Dalam pc:nelitian ini kcrapatan dihitung; pada tingkat pohon ( diameter ???? 10 cm) saja Pohon binaan yang mc:mpunyai distribusi ???? random : Shorea seminis, Shorea ova/is, Vatica umbunata, Shorea laevis, Shorea gibbosa. Hopea sangal. Anisoptera sp_ dan Dryohalanaps oblongtfolia. Sedangkan jenis y????g m...-mpunyai persebar.:in mengelompok meliputi : Shorea sp .. Dipterocarpus sp .• Shorea johorensis, Shorea smithiana. Shorea pauciflora. dan Shorea parvifolia. Pohon bin3:lll yang mempuny???? ????b:ira..'l diameter eksponensial adalah Shorea par.ifolia. Shorea ova/i;, Hopea mangarawar.. Drvobalanops oblongifolia, Shorea laevis, Vatica umhunara. Shorea seminis, Shorea smithiar.a, Shorea paucijlora, Shorea johore>.sis, Shorea sp .. Dipterocarpus sp .. dan Shorea lamellcuz

The Study was con????ur!ed in the HPH PT. Dwimajaya Utama, Central Kalimantan. The purpose of the study are to identify the composition and the density of commercial trees in the 0, l, 4 an???? 8-year logged-over forest and their spatial distribution and to make mathematical approach to the diameter distribution of commercial trees in logged-over forest through exponential function application. Quadratic method is used in this study. The plots were located in rows with 50 m distance between rows. Total plots were 400 units. First, the location of the O year (before cutting), I -year (Et+ I), 4-year (Et+4 ), and 8-year (Et+8) after cutting in the TPTI cutting areas were determined. Sampling was conducted in 20 x 20 m plot siz.e. Eight trees of commercial trees from each plot were determined including the core trees. The cotrrr.ercial trees were selected based on future the economic value. Accordingly, local HPH official consideration were used in conducting the selection. The parameter being measured were : the species and the diameter of trees. The composition and the density are obtained from IVI (hnportant Value Index). IVI is calculated by summing up RD (relative density), RF (relative frequency) and RD (relative dominance) values. Whereas the Poisson distribution followed by Blackman dispersion index was used to obtain their spatial distribution. The diameter distribution is obtained using exponential function From this study, 18 species of the commercial trees were obtained, and all of them were Dipterocarpaceae family with the density as follow : before cutting being done (Et+0), the density of the commercial trees was 184 trees/ha For I year after cutting, the density was 140 trees/ha; for 4 and 8-ye.ar after cutting, the density were 13 I trees/ha and 133 trees/ha consecutively. In this study, the density was counted merely the tree stages(???? 10 cm in diameter). The commercial trees in random distribution were : Shorea seminis, Shorea ova/is, Vatica umbunata, Shorea /aevis, Shorea gibbosa, Hopea sanga/, Anisoptera sp., and Dryobalanops oblongifolia. Whereas the species in clump distribution were : ,\'horea sp. , Dipterocarpw, sp., Shorea johorensis, Shorea smithiana, Shorea pauciflora, and Shorea parvifo/ia. The commercial trees in exponential diameter distribution were : Shorea parviflora, Shorea ova/is, Hopea mangarawan, Drydalanops oblongifolia, Shorea lael'is, Vatica umbunata, Shorea seminis, Shorea smithiana, Shorea pauciflora, Shorea johorensis, Shorea sp., Dipterocarpus sp., and Shorea lamellata.

Kata Kunci : Tegakan Bekas Tebang,Hutan Bekas Tebangan TPTI