Tree species-area and species-diameter relationships at three lowland rain forest sites in Sumatra

Rennolls Keith, Laumonier Yves. 1999. Tree species-area and species-diameter relationships at three lowland rain forest sites in Sumatra. Journal of Tropical Forest Science, 11 (4) : 784-800.

Titre autre : Kaitan antara spesies dan luas pokok dengan spesies dan garis pusat pokok di tiga tapak hutan hujan tanah pamah di Sumatera

Résumé : Data from three forest sites in Sumatra (Batang Ule, Pasirmayang and Tebopandak) have been analysed and compared for the effects of sample area cut-off, and tree diameter cut-off. An 'extended inverted exponential model' is shown to be well suited to fitting tree-species-area curves. The model yields species carrying capacities of 680 for Batang Ule, 380 species for Pasirmayang, and 350 for Tebopandak (tree diameter ≥ 10 cm). It would seem that in terms of species carrying capacity, Tebopandak and Pasirmayang are rather similar, and both less diverse than the hilly Batang Ule site. In terms of conservation policy, this would mean that rather more emphasis should be put on conserving hilly sites on a granite substratum. For Pasirmayang, with tree diameter ≥ 3 cm, the asymptotic species number estimate is 567, considerably higher than the estimate of 387 species for trees with diameter ≥ 10 cm. It is clear that the diameter cut-off has a major impact on the estimate of the species carrying capacity. A conservative estimate of the total number of tree species in the Pasirmayang region is 632 species! In sampling exercises, the diameter cut-off should not be chosen lightly, and it may be worth adopting field sampling procedures which involve some subsampling of the primary sample area, where the diameter cut-off is set much lower than in the primary plots.

Résumé (autre langue) : Data daripada tiga tapak hut.an di Sumatera (Batang Ule, Pasirmayang dan Tebopandak) dianalisis dan dibandingkan untuk mendapatkan kesan sampel bagi potongan kawasan dan potongan garis pusat pokok. Model eksponen songsang diperluas didapati sangat sesuai dengan lengkuk kawasan spesies pokok. Model ini menghasilkan spesies dengan daya muat membawa sebanyak 680 spesies bagi Batang Ule, 380 spesies bagi Pasirmayang, dan 350 spesies bagi Tebopandak (garis pusat pokok ≥ 10 cm). Nampaknya dari segi keupayaan spesies, Tebopandakdan Pasirmayang lebih kurang sama, dan kedua-duanya kurang kepelbagaiannya berbanding dengan tapak Batang Ule yang berbukit. Dari segi polisi pemuliharaan, ini bermakna bahawa penekanan perlulah diberikan untuk memulihara tapak berbukit di atas substrata granit. Bagi Pasirmayang, dengan garis pusat ≥ 3 cm, anggaran bilangan spesies asimtot ialah 567, lebih tinggi daripada anggaran 387 spesies bagi pokok bergaris pusat ≥ 10 cm. Jelas bahawa potongan garis pusat mempunyai kesan utama terhadap anggaran daya muat membawa spesies tersebut. Satu anggaran konservatif mengenai jumlah spesies pokok di kawasan Pasirmayang ialah 632 spesies! Dalam pensampelan, potongan garis pusat mestilah dipilih dengan berhati-hati. Penggunaan prosedur pensampelan yang melibatkan beberapa subpensampelan kawasan sampel primer, iaitu potongan garis pusat disediakan jauh lebih rendah daripada plot primer.

Auteurs et affiliations

• Rennolls Keith
• Laumonier Yves, CIRAD-FORET-FORETS NATURELLES (IDN)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/479689/)

Métriques

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