Tropical peatlands are fragile ecosystems with an important role in conserving biodiversity, water quality and availability, preventing floods, soil intrusion, erosion and sedimentation, and providing a livelihood for people. However, due to illegal logging, fire and conversion into other land use, the peatlands in Indonesia are under serious threat. Efforts to restore Indonesia’s tropical peatlands have been accelerated by the establishment of the Peatland Restoration Agency in early 2016. The restoration action policy includes the rewetting, revegetation and revitalisation of local livelihood (known as the 3Rs). This paper summarises the regulatory, institutional and planning aspects of peatland restoration, in addition to the implementation of the 3Rs in Indonesia, including failures, success stories, and the criteria and indicators for the success of peatland restoration.

Tropical forests are among the most diverse ecosystems in the world, completed by huge biodiversity. An expansion in natural resource extraction through open-pit mining activities leads to increasing land and tropical forest degradation. Proper science-based practices are needed as an effort to reclaim their function. This paper summarizes the existing practice of coal mining, covering the regulatory aspects and their reclamation obligations, the practices of coal mining from various sites with different land characteristics, and the reclamation efforts of the post-mining landscapes in Indonesia. The regulations issued accommodate the difference between mining land inside the forest area and outside the forest area, especially in the aspect of the permit authority and in evaluating the success rate of reclamation. In coal-mining practices, this paper describes starting from land clearing activities and followed by storing soil layers and overburden materials. In this step, proper handling of potentially acid-forming materials is crucial to prevent acid mine drainage. At the reclamation stage, this paper sequentially presents research results and the field applications in rearranging the overburden and soil materials, controlling acid mine drainage and erosion, and managing the drainage system, settling ponds, and pit lakes. Many efforts to reclaim post-coal-mining lands and their success rate have been reported and highlighted. Several success stories describe that post-coal-mining lands can be returned to forests that provide ecosystem services and goods. A set of science-based best management practices for post-coal-mine reforestation is needed to develop to promote the success of forest reclamation and restoration in post-coal-mining lands through the planting of high-value hardwood trees, increasing trees’ survival rates and growth, and accelerating the establishment of forest habitat through the application of proper tree planting technique. The monitoring and evaluation aspect is also crucial, as corrective action may be taken considering the different success rates for different site characteristics.

This paper provides an overview of the implementation and obstacles of watershed management, and the alternative solutions based on a synoptic review of related studies and experiences across Indonesia. The review found that problems in the institutional aspect were hierarchical confusion, discrepancy, and asynchrony among regulations, and weak (participation, synchronization, and coordination) among watershed management stakeholders. The weaknesses in the planning stage are integration among sectors, a lack of community participation, and limited readiness to integrate watershed planning into regional planning. Stakeholders’ involvement is also a critical factor in successful implementation of degraded watershed rehabilitation, including in peatland and mangrove areas. Failure should be minimized by providing adequate information on degraded watershed characteristics, appropriate species choices, and effective mechanical construction for soil and water conservation. Community participation as the main factor in driving watershed management should be achieved by strengthening public awareness of the importance of a sustainable watershed and providing access for the community to be involved in each stage of watershed management. Another problem is data gaps which are essential to address from the planning to evaluation stages. The gaps can be bridged by using remotely sensed data and by applying hydrological-based simulation models. Simplified criteria for watershed assessment may also be required, depending on site-specific issues and the watershed scale.

No abstract

Degraded tropical peatlands lack tree cover and are often subject to seasonal flooding and repeated burning. These harsh environments for tree seedlings to survive and grow are therefore challenging to revegetate. Knowledge on species performance from previous plantings represents an important evidence base to help guide future tropical peat swamp forest (TPSF) restoration efforts. We conducted a systematic review of the survival and growth of tree species planted in degraded peatlands across Southeast Asia to examine (1) species differences, (2) the impact of seedling and site treatments on survival and growth and (3) the potential use of plant functional traits to predict seedling survival and growth rates. Planted seedling monitoring data were compiled through a systematic review of journal articles, conference proceedings, reports, theses and unpublished datasets. In total, 94 study‐sites were included, spanning three decades from 1988 to 2019, and including 141 indigenous peatland tree and palm species. Accounting for variable planting numbers and monitoring durations, we analysed three measures of survival and growth: (1) final survival weighted by the number of seedlings planted, (2) half‐life, that is, duration until 50% mortality and (3) relative growth rates (RGR) corrected for initial planting height of seedlings. Average final survival was 62% and half‐life was 33 months across all species, sites and treatments. Species differed significantly in survival and half‐life. Seedling and site treatments had small effects with the strongest being higher survival of mycorrhizal fungi inoculated seedlings; lower survival, half‐life and RGR when shading seedlings; and lower RGR and higher survival when fertilising seedlings. Leaf nutrient and wood density traits predicted TPSF species survival, but not half‐life and RGR. RGR and half‐life were negatively correlated, meaning that slower growing species survived for longer. Synthesis and applications. To advance tropical peat swamp reforestation requires expanding the number and replication of species planted and testing treatments by adopting control vs. treatment experimental designs. Species selection should involve slower growing species (e.g. Lophopetalum rigidum, Alstonia spatulata, Madhuca motleyana) that survive for longer and explore screening species based on functional traits associated with nutrient acquisition, flooding tolerance and recovery from fire.

No abstract

Indonesia has the second-largest biodiversity of any country in the world. Deforestation and forest degradation have caused a range of environmental issues, including habitat degradation and loss of biodiversity, deterioration of water quality and quantity, air pollution, and increased greenhouse gas emissions that contribute to climate change. Forest restoration at the landscape level has been conducted to balance ecological integrity and human well-being. Forest restoration efforts are also aimed at reducing CO2 emissions and are closely related to Indonesia’s Nationally Determined Contribution (NDC) from the forestry sector. The purpose of this paper is to examine the regulatory, institutional, and policy aspects of forest restoration in Indonesia, as well as the implementation of forest restoration activities in the country. The article was written using a synoptic review approach to Forest Landscape Restoration (FLR)-related articles and national experiences. Failures, success stories, and criteria and indicators for forest restoration success are all discussed. We also discuss the latest silvicultural techniques for the success of the forest restoration program. Restoration governance in Indonesia has focused on the wetland ecosystem such as peatlands and mangroves, but due to the severely degraded condition of many forests, the government has by necessity opted for active restoration involving the planting and establishment of livelihood options. The government has adapted its restoration approach from the early focus on ecological restoration to more forest landscape restoration, which recognizes that involving the local community in restoration activities is critical for the success of forest restoration.

Dominated by mountainous topography, high rainfall, and erosion-sensitive soil types, and with the majority of its population living in rural areas as farmers, most of Indonesia’s watersheds are highly vulnerable to erosion. In 1984, the Government of Indonesia established 22 priority watersheds to be handled, which marked the start of formal soil and water conservation activities. Although it has not fully succeeded in improving watershed conditions from all aspects, something which is indicated by fluctuations in the area of degraded land, over the past 40 years the Indonesian government has systematically implemented various soil and water conservation techniques in various areas with the support of policies, laws and regulations, and research and development. These systematic efforts have shown positive results, with a 40% reduction in the area of degraded land over the last 15 years from 2004–2018. This paper reviews policy, implementation, and research and development of soil and water conservation activities in Indonesia over the last 40 years from the 1980s to 2020 and explores the dynamics of the activities.