Model Hubungan Diameter–Tinggi Pohon Sengon pada Hutan Rakyat di Desa Condong, Kabupaten Probolinggo: Diameter–Height Relationship Model of Sengon Trees in Smallholder Forests in Condong Village, Probolinggo Regency

Wahyu Nazri Yandi; Maulida Oktaviarini

doi:10.22437/jurnalsilvatropika.v10i1.57589

Authors

Wahyu Nazri Yandi 1Fakultas Pertanian, Jurusan Kehutanan, Universitas Jambi
Maulida Oktaviarini Fakultas Kehutanan dan Lingkungan, Jurusan Manajemen Hutan, IPB University

DOI:

https://doi.org/10.22437/jurnalsilvatropika.v10i1.57589

Keywords:

Falcataria moluccana, non-linear model, smallholder forest, diameter, tree height

Abstract

ABSTRACT

Smallholder forests in Condong Village, Probolinggo, play a vital role in providing Sengon timber, yet farmers often face challenges in accurately estimating tree height, leading to low bargaining power in timber transactions. This study aims to develop a site-specific diameter-height (D-H) relationship model as a practical height estimation instrument for farmers. Data were collected from 130 Sengon trees, categorized into modeling (70%) and validation (30%) datasets. Seven models, including linear and non-linear models (such as Power, Weibull, and Naeslund), were evaluated using Root Mean Square Error (RMSE), Adjusted R-Squared (R²adj), and Akaike Information Criterion (AIC). This model accurately represents the asymptotic biological growth characteristics of Sengon, where height growth slows as diameter increases. The implication of this study is the availability of an accurate self-inventory tool for farmers to enhance transparency and bargaining power in bulk timber sales.

Keywords: Falcataria moluccana, non-linear model, smallholder forest, diameter, tree height.

ABSTRAK

Hutan rakyat di Desa Condong, Probolinggo, memiliki peran vital dalam penyediaan kayu sengon, namun petani sering menghadapi tantangan dalam mengestimasi tinggi pohon secara akurat, yang berdampak pada rendahnya posisi tawar dalam transaksi kayu. Penelitian ini bertujuan untuk membangun model hubungan diameter-tinggi (D-H) yang spesifik lokasi sebagai instrumen praktis penduga tinggi pohon bagi petani. Data dikumpulkan dari 130 pohon sengon yang dibagi menjadi data pemodelan (70%) dan validasi (30%). Tujuh model, termasuk model linear dan non-linear (seperti Power, Weibull, dan Naeslund), dievaluasi menggunakan kriteria Root Mean Square Error (RMSE), Adjusted R-Squared (R²adj), dan Akaike Information Criterion (AIC). Model ini secara akurat merepresentasikan karakteristik biologis pertumbuhan sengon yang bersifat asimtotis, di mana pertambahan tinggi melambat seiring meningkatnya diameter. Implikasi dari penelitian ini adalah tersedianya alat inventarisasi mandiri yang akurat bagi petani untuk meningkatkan transparansi dan posisi tawar dalam penjualan kayu secara borongan.

Katakunci: Falcataria moluccana, model non-linear, hutan rakyat, diameter, tinggi pohon.

References

Abedi R, Abedi T. 2020. Some non-linear height-diameter models performance for mixed stand in forests in Northwest Iran. J Mt Sci. 17(5):1084–1095.

Ardelina A, Tiryana T, Muhdin M. 2015. Model volume pohon sengon untuk menilai kehilangan keuntungan petani hutan rakyat. J Penelit Hutan Tanam. 12(2):131–139.

BPS Kabupaten Probolinggo. 2024. Kecamatan Gading dalam Angka 2024. Probolinggo (ID): BPS Kabupaten Probolinggo.

Burnham KP, Anderson DR. 2002. Model Selection and Multimodel Inference: A Practical Information-Theoretic Approach. Ed ke-2. New York (US): Springer-Verlag.

Chave J, Réjou-Méchain M, Búrquez A, Chidumayo E, Colgan MS, Delitti WB, Vieilledent G. 2014. Improved allometric models to estimate the aboveground biomass of tropical trees. Global Change Biology 20(10):3177–3190.

Gao X, Li Z, Yu H, Jiang Z. 2015. Modeling of height–diameter relationship using allometric equation model. Journal of Forestry Research 27(2):339–347.

Heru DR, Susi A, Ragil BWM P. 2009. Kajian sengon (Paraserianthes falcataria) sebagai pohon bernilai ekonomi dan lingkungan. Jurnal Penelitian Hutan Tanaman 6(3):201–208.

Hossain MS, Oluwajuwon TV, Ludgen AN, Hasert DP, Sitanggang M, Offiah C. 2023. Formulating biomass allometric model for Paraserianthes falcataria (L.) Nielsen (Sengon) in smallholder plantations, Central Kalimantan, Indonesia. Journal of Sustainable Forestry 43(3):268–284.

Huang S, Titus SJ, Wiens DP. 2003. Comparison of nonlinear height–diameter functions for major Alberta tree species. Canadian Journal of Forest Research 33(11):2135–2147.

Husch B, Miller CI, Beers TW. 2002. Forest Mensuration. Ed ke-4. New York (US): John Wiley & Sons.

Kozak A, Kozak R. 2003. Does cross-validation provide additional information in the evaluation of regression models? Canadian Journal of Forest Research 33(11):2148–2160.

Liu S, Liu Y, Li G, Mou C. (2024). Disentangling interspecific and intraspecific variability in height–diameter allometry of dominant tree species in the Rocky Mountains across broad spatial scales. Forestry 97(3):363–375.

Mehtätalo L, de-Miguel S, Gregoire TG. (2015). Modeling height–diameter curves for prediction. Canadian Journal of Forest Research 45(7):826–837.

Nirmalasari N, Sihab MA, Cheren A, Dinillah R, Aidah RS, Azrai P. 2024. Pengukuran tinggi pohon menggunakan klinometer di Taman Margasatwa Ragunan Bagian Utara. J Ilm Ecosyst 24(1):39–46.

Parresol BR. 1999. Assessing tree and stand biomass: A review with examples and critical comparisons. Forest Science. 45(4):573–593.

Peng C, Zhang L, Liu L. 2001. Developing and validating nonlinear height-diameter models for major species of Ontario's boreal forests. Northern Journal of Applied Forestry 18(3):87–94.

Polyanina K, Korjus H, Jogiste K, Kiviste A, Stanturf JA. 2021. The possibility of using the Chapman–Richards and Näslund functions to model height–diameter relationships in hemiboreal old-growth forest. Forests 12(2):210.

Pretzsch H. 2009. Forest Dynamics, Growth and Yield: From Measurement to Model. Berlin (DE): Springer-Verlag.

Schumacher FX. 1939. A new growth curve and its application to timber-yield studies. Journal of Forestry 37(11):819–820.

Sharma RP, Vacek Z, Vacek S, Kučera M, Cukor J. (2019). A nonlinear mixed-effects height-to-diameter ratio model for several tree species based on Czech National Forest Inventory data. Forests 10(1): 70.

Sinaga WIT, Prijono A, Andayani ST. 2025. Kesehatan dan pertumbuhan tanaman sengon (Falcataria moluccana) di Desa Pleret, Kecamatan Pleret, Kabupaten Bantul, Provinsi Daerah Istimewa Yogyakarta. Agroforetech 3(3):1941–1948.

Van Laar A, Akça A. 2007. Forest Mensuration. Dordrecht (NL): Springer.

Wahyudi I, Pamoengkas P. 2013. Model pertumbuhan polinomial tanaman sengon (Paraserianthes falcataria (L.) Nielsen) di lahan hutan rakyat. J Penelit Hutan Konserv Alam 10(2):211–218.

Xu Q, Lei X, Zang H, Zeng W. (2022). Climate change effects on height–diameter allometric relationship vary with tree species and size for larch plantations in northern and northeastern China. Forests 13(3):468.

Yandi WN, Nahlunnisa H, Dinanty F, Darsono BS. 2025. Pendugaan stok karbon tegakan sengon (Albizia falcataria) di hutan rakyat Desa Gading Wetan Kabupaten Probolinggo. J Silva Samalas 8(1):1–7.

Yang RC, Kozak A, Smith JHG. 1978. The potential of Weibull-type functions as flexible growth curves. Canadian Journal of Forest Research 8(4):424–431.