Promising native tree species for reforestation of degraded tropical
Reference: Forest Ecology and Management
Authors: Lampela, M., Jauhiainen, J., Sarkkola, S., Vasander, H.
Abstract: Tropical peat swamp forests (PSF) of South East Asia are biodiversity hotspots and carbon-rich ecosystems under severe degradation and threat of extinction. Almost yearly recurring ﬁres progressively devastate clear-cut PSFs. The need for both conservation and active restoration together with the appropriate information on the techniques and species is urgent. The aim of this study was to ﬁnd native PSF species that are suitable for reforestation in the open degraded peatlands. We established two planting experiments in degraded peat areas with 21 tree species to study the survival and growth in relation to environmental factors for 2 years. The study sites were located in Central Kalimantan, Indonesia in the degraded peatland of the Ex-Mega Rice area and along the degraded margins of the river Sabangau. Seed material collected from local forests was grown in a ﬁeld nursery and planted 6–11 months later in the ﬁeld. Growth and mortality of the seedlings and environmental variables (water table, temperature) were monitored frequently for two years. The effects of the environmental variables on growth were tested with mixed-effects models and on mortality with Cox regression. As a result, we could derive species-speciﬁc information of the seedlings’ early stage ecology and suitability for restoration. The most promising species based on the analysis were Shorea balangeran, Adenanthera pavonina, Dacryodes rostrata and Lithocarpus dasystachys. The comparison of the two differing areas revealed contrasting challenges: the main obstacle for reforestation in the Ex-Mega Rice area was ﬁre, whereas in the river margin extreme water table ﬂuctuation limited the success of the seedlings.
Key words: Tropical peat, Peat swamp forest, Restoration, Abandoned land
Article access: http://dx.doi.org/10.1016/j.foreco.2016.12.004