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Protists, abundant but enigmatic single-celled eukaryotes, are important soil microbiota providing numerous ecosystem functions. We employed high-throughput sequencing of environmental DNA, targeting the V4 region of the 18S rRNA gene, to characterize changes in their abundance, species richness, and community structure with conversion of lowland rainforest into rubber agroforest (jungle rubber), and rubber and oil palm plantations; typical agricultural systems in Sumatra, Indonesia. We identified 5,204 operational taxonomic units (OTUs) at 97% identity threshold of protists from 32 sites. Protists species richness was similar in rainforest, jungle rubber and oil palm plantations but significantly lower in rubber plantations. After standardization, 4,219 OTUs were assigned to five trophic groups, and inspected for effects of land-use change, and potential biotic and abiotic driving factors. The most abundant trophic group was phagotrophs (52%), followed by animal parasites (29%), photoautotrophs (12%), plant parasites (1%), and symbionts (

The potential energy surface and dipole moment surfaces of the ã⁴A2 electronic state of CH+2 are calculated ab initio using an augmented correlation-consistent polarized valence quadruple-ζ (aug-cc-pVQZ) basis set, with the incorporation of dynamical correlation using the coupled cluster method with single and double excitations and perturbatively connected triple excitations [CCSD(T)]. We use these surfaces in the MORBID program system to calculate rotation and rotation–vibration term values for ã-state CH+2 , CD+2 , and CHD+ and to simulate the rotation and rotation–vibration absorption spectrum of CH+2 in the ã⁴A2 electronic state. Our work is motivated by studies of CH+2 that use the Coulomb explosion imaging technique and by the goal of predicting spectra that may be obtained from discharge sources. Although the ˜ a state is the lowest-lying excited state above the ˜X / ˜A ground state pair, it turns out to be relatively high-lying, and we determine that Te( ã) = 30447.5 cm−1. The equilibrium bond angle for ã-state CH+2 is only 77.1◦; as a result the asymmetric top κ value is close to 0, and the molecule is equally far from the oblate and prolate symmetric top limits in this electronic state.

Land-use transitions can enhance the livelihoods of smallholder farmers but potential economic-ecological trade-offs remain poorly understood. Here, we present an interdisciplinary study of the environmental, social and economic consequences of land-use transitions in a tropical smallholder landscape on Sumatra, Indonesia. We find widespread biodiversity-profit trade-offs resulting from land-use transitions from forest and agroforestry systems to rubber and oil palm monocultures, for 26,894 aboveground and belowground species and whole-ecosystem multidiversity. Despite variation between ecosystem functions, profit gains come at the expense of ecosystem multifunctionality, indicating far-reaching ecosystem deterioration. We identify landscape compositions that can mitigate trade-offs under optimal land-use allocation but also show that intensive monocultures always lead to higher profits. These findings suggest that, to reduce losses in biodiversity and ecosystem functioning, changes in economic incentive structures through well-designed policies are urgently needed.