Land in limbo: Nearly one third of Indonesia's cleared old- growth forests left idle

• 成果类型: Article
• 署名作者: Parker, Diana; Tosiani, Anna; Yazid, Muhammad; Sari, Inggit L.; Kartika, Tatik; Kustiyoc; Firmansyah, Rizky; Said, Zuraidah; Wijaya, Arief; Potapov, Peter; Tyukavina, Alexandra; Stehman, Stephen V.; Zalles, Viviana; Pickens, Amy; Pickering, Jeffrey; Turubanova, Svetlana; Hansen, Matthew C.
• 署名单位: University System of Maryland; University of Maryland College Park; Ministry of Environment & Forestry; National Research & Innovation Agency of Indonesia (BRIN); State University of New York (SUNY) System; State University of New York (SUNY) College of Environmental Science & Forestry
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10239
• DOI: 10.1073/pnas.2318029121
• 发表日期: 2024-07-09
• 关键词: tropical peatlands; fires; kalimantan; RESOURCES; cover

摘要

Indonesia has experienced rapid primary forest loss, second only to Brazil in modern history. We examined the fates of Indonesian deforested areas, immediately after clearing and over time, to quantify deforestation drivers in Indonesia. Using time- series satellite data, we tracked degradation and clearing events in intact and degraded natural forests from 1991 to 2020, as well as land use trajectories after forest loss. While an estimated 7.8 Mha (SE = 0.4) of forest cleared during this period had been planted with oil palms by 2020, another 8.8 Mha (SE = 0.4) remained unused. Of the 28.4 Mha (SE = 0.7) deforested, over half were either initially left idle or experienced crop failure before a land use could be detected, and 44% remained unused for 5 y or more. A majority (54%) of these areas were cleared mechanically (not by escaped fires), and in cases where idle lands were eventually converted to productive uses, oil palm plantations were by far the most common outcome. The apparent deliberate creation of idle deforested land in Indonesia and subsequent conversion of idle areas to oil palm plantations indicates that speculation and land banking for palm oil substantially contribute to forest loss, although failed plantations could also contribute to this dynamic. We also found that in Sumatra, few lowland forests remained, suggesting that a lack of remaining forest appropriate for palm oil production, together with an extensive area of banked deforested land, may partially explain slowing forest loss in Indonesia in recent years. Significance Indonesia has lost 25% of its old- growth forest since 1990, with its intact forest area (natural forest undisturbed by human activity) declining by 45%. Nearly half (44%) of Indonesia's deforested land had no detectable land use for 5+ y after clearing. This was caused by fires, long assumed to be Indonesia's principal idle land driver, and by deliberate mechanical clearing, an understudied phenomenon despite its large deforestation footprint. When idle areas were converted to productive uses, the majority were planted with oil palms, which covered 28% of Indonesia's deforested land by 2020. Oil palms were the only major land use for which lagged conversion was the norm; other major drivers such as smallholder agriculture were typically established immediately after clearing.