Perbandingan Teknik Pengukuran Diameter Pohon Bakau (Rhizophora spp.) di Taman Wisata Alam Angke Kapuk, Jakarta.

Abstract

Pengukuran diameter pohon menjadi parameter penting dalam kegiatan inventarisasi hutan. Namun, morfologi khas pada Rhizophora spp. dengan akar tunjang yang kompleks menimbulkan tantangan untuk pengukuran diameter. Perlu adanya penentuan titik pengukuran diameter yang sesuai dan alat ukur akurat. Penelitian ini bertujuan membandingan teknik pengukuran diameter menggunakan phiband, Criterion RD1000, dan aplikasi Trees pada beberapa titik ukur pada Rhizophora di Taman Wisata Alam Angke Kapuk, Jakarta. Pengambilan sampel menggunakan metode purposive sampling sebanyak 60 sampel pohon dengan tinggi akar tunjang >1,3 meter. Analisis meliputi perhitungan korelasi antar titik ukur, Mean Error (ME), Percentage Error (PE), Root Mean Square Error of Prediction (RMSEP), dan uji t-berpasangan. Korelasi sangat kuat (r > 0,98) terjadi pada titik 20 cm dan 30 cm diatas akar tunjang, sehingga dapat dijadikan pilihan titik pengukuran. Criterion RD1000 memiliki nilai bias rendah, PE < 1%, RSMEP rendah serta tidak berbeda signifikan dengan phiband. Sementara aplikasi Trees menunjukkan bias tinggi, PE hingga ±8% dan hasil berbeda signifikan. Kata kunci: aplikasi trees, Criterion RD1000, diameter, Rhizophora spp.

Tree diameter measurement is an important parameter in forest inventory activities. However, the unique morphology of Rhizophora spp. with complex stilt roots poses challenges for diameter measurement. It is necessary to determine appropriate diameter measurement points and use accurate measuring tools. This study aims to compare diameter measurement techniques using phiband, Criterion RD1000, and the Trees app at several measurement points on Rhizophora in Taman Wisata Alam Angke Kapuk, Jakarta. Sampling was conducted using purposive sampling, with 60 tree samples selected based on stilt root height >1,3 meters. Analysis included calculating correlations between measurement points, Mean Error (ME), Percentage Error (PE), Root Mean Square Error of Prediction (RMSEP), and paired t-tests. Very strong correlations (r > 0.98) were observed at the 20 cm and 30 cm points above the stilt root, making these points suitable for measurement. The RD1000 Criterion RD1000 showed low bias, PE < 1%, low RMSEP, and no significant difference from the phiband method. Meanwhile, the Trees application exhibited high bias, PE up to ±8%, and results that differed significantly. Keywords: Criterion RD1000, diameter, Rhizophora spp., tress application