Screening Potential Bioenergy Production of Tree Species in Degraded and Marginal Land in the Tropics
Center for International Forestry Research, Jalan CIFOR, Situ Gede, Sindang Barang, Bogor 16115, Indonesia
Natural Resources Institute Finland (Luke), Plant Production, 00790 Helsinki, Finland
Ruhr-University Bochum, Institute of Geography, Soil Science/Soil Ecology, Universitätsstrasse 150, 44801 Bochum, Germany
Institute of Plant Production and Agroecology in the Tropics and Subtropics, University of Hohenheim, 70593 Stuttgart, Germany
National Institute of Forest Science, 57 Heogi-ro, Dongdaemu-gu, Seoul 02455, Korea
Author to whom correspondence should be addressed.
Forests 2018, 9(10), 594; https://doi.org/10.3390/f9100594
Received: 2 August 2018 / Revised: 15 September 2018 / Accepted: 18 September 2018 / Published: 23 September 2018
(This article belongs to the Section Forest Ecology and Management)
Bioenergy can produce at least 25% of the global energy demand to combat climate change through reducing emissions in the energy sector. However, information on the bioenergy production potential of woody species and their suitability for silviculture on various soils in the humid tropics is limited. This review aims to identify tree species suitable for bioenergy production under these conditions. Data were compiled from 241 publications and nine freely available databases to assess environmental and silvicultural information on tropical tree species. Energy outputs were derived from the estimated productivity of the reviewed species and ranged from 0.2 to 24.0 Mg biomass ha−1 yr−1, 0.1 to 9.0 Mg bio-oil ha−1 yr−1, and 0.2 to 20.0 Mg sugar ha−1 yr−1, equivalent to an energy yield between 2 and 444 GJ ha−1 yr−1. As such, these bioenergy yields are within the range reported for the lignocellulosic biomass of energy crops cultivated in Europe, the USA, and Brazil. Our review identified some high-yielding species (e.g., Dyera polyphylla (Miq.) Steenis, Metroxylon sagu (Rottb.), Pongamia pinnata (L.)) and leguminous species that could be beneficial in mixed stands (e.g., Elaeis oleifera (Kunth) and Pongamia pinnata) or are suitable species to grow on wet or re-wetted peatland (Dyera polyphylla). However, there are limitations to cultivate woody bioenergy species on wet peatland. Sustainable methods for managing and harvesting forests, particularly on wet or re-wetted peatland, need to be developed.