Rubber (Hevea brasiliensis): Growth, Allometry and Carbon Potential

Updated 2026-11-02 · 4 min read · By the akar.earth specialist team

Rubber tree carbon sequestration in Indonesia: range, tapping life and replanting cycle, wood density, allometry, jungle rubber agroforestry, EUDR and risks.

Rubber trees store a moderate amount of carbon over a productive life of roughly 25 to 30 years before they are felled and replanted, so their carbon value is a time-averaged stock rather than a permanent one. In Indonesia the bigger carbon story is how rubber is grown: diverse jungle rubber agroforests hold far more carbon and biodiversity than clonal monocultures.

Identity and range

The Pará rubber tree (Hevea brasiliensis) is in the spurge family, Euphorbiaceae. In Indonesia it is called karet or para. Smallholder agroforests are known as hutan karet or kebun karet campur (jungle rubber).

Rubber is native to the Amazon basin in South America. It was introduced to Southeast Asia in the late 19th century. Indonesia is one of the world’s largest producers, and most of its rubber comes from smallholders. Main producing provinces include South Sumatra, Jambi, North Sumatra, Riau and West Kalimantan.

Growth habit and rotation

Rubber is a fast-growing deciduous tree that drops leaves annually (“wintering”). Trees are tapped for latex once the stem reaches a minimum girth, usually after about 5 to 7 years. Tapping continues for roughly 20 to 25 years, until yields fall, and plantations are then felled and replanted. Total cycles of around 25 to 30 years are common. The felled timber is sold as rubberwood for furniture and panels.

Jungle rubber is different. Farmers plant rubber seedlings in a slash-and-burn or cleared plot and let secondary forest regrow around them, creating a multi-species agroforest that may be tapped for decades with low inputs. Reported growth and yield vary widely between clonal estates and jungle rubber.

Wood density and biomass estimation

Reported basic density for rubberwood is roughly 0.50 to 0.65 g/cm³. Wood density varies with clone, age and site, so record the value used.

The default above-ground biomass model is Chave et al. 2014:

AGB (kg) = 0.0673 × (ρ × D² × H)^0.976

where ρ is wood density (g/cm³), D is DBH (cm) and H is height (m). Rubber-specific allometric equations have been published from plantations in Southeast Asia and elsewhere, usually as functions of girth or DBH. Tapping panels sit at about breast height, so measure DBH carefully just above or below the panel and record where. For jungle rubber, measure other trees in the plot with the generic model. See the allometric equations guide.

Convert to carbon with the IPCC default 0.47 and to CO2 with 44/12.

Carbon role in ARR and agroforestry

• Jungle rubber and agroforestry. Diversifying rubber with fruit and timber trees raises carbon stock, income stability and biodiversity. See rubber agroforestry and the agroforestry hub.
• ARR on degraded land. Rubber planted on eligible non-forest land adds biomass, but VM0047 credits harvested systems only up to the long-term average carbon stock. A 25 to 30 year cycle averages roughly half its peak.
• Avoided conversion. Keeping old jungle rubber rather than converting it to oil palm or clonal monoculture avoids carbon loss, though this is harder to credit.

Co-benefits and livelihoods

Rubber supports millions of smallholder households in Sumatra and Kalimantan. Tapping provides weekly cash. Jungle rubber also gives fruit, timber, medicinal plants and habitat for wildlife.

Risks and cautions

• Replanting cycles. Felling and replanting drops the stock to near zero every few decades. Model it explicitly.
• Price swings. Low rubber prices have led many farmers to convert rubber to oil palm. That is a real permanence risk.
• Leaf diseases. Leaf-fall disease outbreaks have hit Indonesian plantations in recent years, cutting yields. South American leaf blight is absent from Asia but would be severe if introduced.
• Monoculture. Clonal blocks store less carbon and biodiversity than jungle rubber.
• EUDR. Rubber is an EUDR commodity. Exporters need plot geolocation and proof that rubber was not grown on land deforested after 31 December 2020. See EUDR rubber.

Planning notes for project developers

• Stratify by system. Separate clonal monoculture, jungle rubber and new agroforestry plots in sampling.
• Record replanting dates. Old rubber due for replanting within the crediting period will drop to near zero stock.
• Measure non-rubber trees. In jungle rubber, other trees can hold a large share of biomass.

Worked example

A tapped rubber tree with DBH 25 cm, height 16 m and wood density 0.55 g/cm³:

1. ρ × D² × H = 0.55 × 625 × 16 = 5,500
2. AGB = 0.0673 × 5,500^0.976 ≈ 301 kg
3. Carbon = 301 × 0.47 ≈ 141 kg C
4. CO2e = 141 × 44/12 ≈ 519 kg CO2e (above-ground only)

Try your own plots with the tree CO2 calculator.