Micro-decomposer communities and decomposition processes in tropical lowlands as affected by land use and litter type
We investigated how the land-use change from rainforest into jungle rubber, intensive rubber and oil palm plantations affects decomposers and litter decomposition in Sumatra, Indonesia. Litterbags containing three litter types were placed into four land-use systems and harvested after 6 and 12 months. Litter mass loss and litter element concentrations were measured, and different microbial groups including bacteria, fungi and testate amoebae were studied. After 12 months 81, 65, 63 and 53% of litter exposed in rainforest, jungle rubber in oil palm and rubber plantations was decomposed. In addition to land use, litter decomposition varied strongly with litter type and short-term effects differed markedly from long-term effects. After 6 months, oil palm and rubber litter decomposed faster than rainforest litter, but after 12 months, decomposition of rainforest litter exceeded that of oil palm and rubber litter, reflecting adaptation of bacteria and fungi to decompose structural compounds in rainforest litter but not (or less) in rubber and oil palm litter. Bacterial and fungal community composition and testate amoeba species number and density varied strongly with litter type, but little with land use. However, community composition of testate amoebae was mainly affected by land use. Generally, changes in bacteria, fungi and testate amoebae were linked to changes in litter element concentrations, suggesting that element ratios of litter material as basal resource for the decomposer food web shape the structure of decomposer communities and decomposition processes via bottom-up forces. Overall, changing rainforest to monoculture plantations shifts the decomposer community structure and negatively affects litter decomposition.
KeywordsTransformation system Microorganisms Protists Testate amoebae Plantation
Financial support was provided by the German Research Foundation (DFG) in the framework of the collaborative German—Indonesian research project CRC990 (EFForTS). We thank the State Ministry of Research and Technology of Indonesia (RISTEK), the Indonesian Institute of Sciences (LIPI), Ministry of Forestry (PHKA) and Restoration Ecosystem Indonesia Harapan for the permits. Testate amoebae analysis was supported by the Russian Science Foundation (grant 14-14-00891). We thank many Indonesian organizations for granting us access to the sampling plots and use of their properties. We thank the many colleagues and helpers for their support in the field and assistance in the laboratory.
Author contribution statement
VK, SS and MM designed the study. VK and BK prepared and installed litterbags. VK, EM, YM and RW performed the research in the laboratory. VK analysed the data. VK and SS wrote the paper.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Allen SE (1974) Chemical analysis of ecological material. Blackwell Scientific Publications, OxfordGoogle Scholar
- Berg B, McClaugherty C (2003) Plant litter. Decomposition, humus formation, carbon sequestration. Springer, Berlin, HeidelbergGoogle Scholar
- Crawley JM (2013) The R Book, 2nd edn. Wiley, ChichesterGoogle Scholar
- FAO (2015) FAOSTAT production statistics. Food and agricultural organization of the United Nations, RomeGoogle Scholar
- Gilbert D, Amblard C, Bourdier G et al (2000) Le regime alimentaire des thecamoebiens (Protista, Sarcodina). L’Année Biol 39:57–68Google Scholar
- González G, Seastedt TR (2001) Soil fauna and plant litter decomposition in tropical and subalpine forests. Ecology 82:955–964. https://doi.org/10.1890/0012-9658(2001)082[0955:SFAPLD]2.0.CO;2 CrossRefGoogle Scholar
- Klarner B, Winkelmann H, Krashevska V et al (2017) Trophic niches, diversity and community composition of invertebrate top predators (Chilopoda) as affected by conversion of tropical lowland rainforest in Sumatra (Indonesia). PLoS One 12:e0180915. https://doi.org/10.1371/journal.pone.0180915.s010 CrossRefPubMedPubMedCentralGoogle Scholar
- Krashevska V, Klarner B, Widyastuti R et al (2016) Changes in structure and functioning of protist (testate amoebae) communities due to conversion of lowland rainforest into rubber and oil palm plantations. PLoS One 11:e0160179. https://doi.org/10.1371/journal.pone.0160179 CrossRefPubMedPubMedCentralGoogle Scholar
- Mazei YA, Tsyganov AN (2006) Fresh water testate amoebae. KMK, MoscowGoogle Scholar
- Perakis SS, Matkins JJ, Hibbs DE (2012) Interactions of tissue and fertilizer nitrogen on decomposition dynamics of lignin-rich conifer litter. Ecosphere 3:art54 https://doi.org/10.1890/es11-00340.1
- Pereira e Silva MC, Dias ACF, van Elsas JD, Salles JF (2012) Spatial and temporal variation of archaeal, bacterial and fungal communities in agricultural soils. PLoS One 7:e51554 https://doi.org/10.1371/journal.pone.0051554
- Ter Braak CJF, Šmilauer P (2012) Canoco reference manual and user’s guide: software for ordination, version 5.0. Microcomputer Power, Ithaca, USAGoogle Scholar