Promoting environmental-friendly restoration methods in Indonesia
Deforestation and forest degradation threaten the sustainability of natural resources, both flora and fauna in Indonesia due to the combined effects of factors such as illegal logging, fire, mining, natural hazards, etc. According to the data from the Ministry of Environment and Forestry (2019), Indonesia’s critical land area is 14.01 million ha, with a rate of forest degradation estimated at 450,000 ha per year. At the present, forest and landscape restoration (FLR) in Indonesia generally uses containerized (polybag) media seedlings with topsoil as the main media. While a high economic cost of the methods (including the costs for seedling production, transportation, and human power) especially in remote areas with low accessibility is the main reason to find more profitable alternative methods for FLR. In general, direct seeding and bare-root seedlings have been widely applied in many locations and can be an alternative to accelerate the FLR programs. In practice, the development of direct seeding and the bare-root seedling is often less successful due to the low seed vigour, making it less tolerant of drought or other environmental stresses. From this aspect, the application of bio-fertilizers (e.g. Mycorrhiza (arbuscular mycorrhizae fungi) and dark septate endophyte) could be an environmentally-friendly option to deal with the above-mentioned issues and improve the success of reforestation and restoration.

Figure. (a) Nursery performance of polybag seedling of Ocroma pyramidale,
(b) bare-root seedling of O. pyramidale, (c) polybag seedling of Swietenia macrophylla, and (d) bare-root seedling of S. macrophylla
In 2020, APFNet launched the Small Research Grant Program of the Sino-ASEAN Network of Forestry Research Institutes (SANFRI) to help young forestry researchers from China and ASEAN economies to transfer their innovative scientific ideas to the ground. As one of the first-batch grant programs, the research project “Alternative Methods for Reforestation Using Seed Briquette and Bare-root Seedling Based on AMF and DSE Bio-fertilizers” was implemented by Mr Dede Jajat Sudrajat’s group and under support from APFNet and the Forest Research, Development and Innovation Agency of Indonesia. Some key findings are yielded from this research project in the following:
a) Some tree species (e.g. C. inophyllum,  Swietenia macrophylla, E. cyclocarpum, P. pinnata, and H. verrucose) are appropriately recommended for direct seedling by using seed briquette;
b) The right time of direct seeding (rainy season) is crucial to increase the probability of success and to ensure the accuracy of sowing time is suggested to coordinate with the local agro-climate office. In general, on the Jawa island, direct seeding is suggested to conduct in December;
c) The use of bio-fertilizers (e.g. DSE) is recommended as an additional treatment to increase the success of direct seeding using seed briquettes;
d) The selection of suitable species is critical during the application of bare-root seedlings in tropical areas like Indonesia especially affected by climate obstacles (e.g. irregular precipitation and high temperature), and species such as C. inophyllum showed good prospects in this regard;
e) Similar to direct seeding, DSE inoculation has good prospects for improving the quality of seedlings – the applications in either polybag seedlings and bare-root seedlings;
f) From the cost-effective perspective of this study, direct seeding using seed briquettes can be an alternative method to accelerate the FLR program. On an operational scale, the application of seed briquettes can be applied by using an aero-seeding system (e.g. helicopter and drone).
Although the growth of seedlings will be further influenced by various factors (e.g. climate), the current research outcomes can show an increased ability in seeds and seedlings by the application of bio-fertilizers and this funded project can be regarded as pioneering research efforts on forest restoration in Indonesia. The long-term observation will be taken to track the growth of target seedlings of selected superior species by the project group and more research in this aspect will be required in the future. More importantly, the young forestry professionals’ innovative research ideas can be transferred to the ground and this further improves their research capacity.