taxonID	type	description	language	source
03F1A7289F30991960D1F9ACF3F6FBC8.taxon	description	ReviTec is an ecological rehabilitation approach developed by the Bremen-based partnership KeKo - Kesel, Koehler & partners, biologists, in co-operation with the Centre for Environmental Research and Technology (UFT) of the University of Bremen (Koehler et al. 2006). ReviTec is based on experience from long-term ecological research (Koehler & Müller 2003, Koehler & Melecis 2010). The modular design of ReviTec covers three levels of scale with various functions. The basic module is a bag of degradable fabric for initial erosion control, filled with substrate (30 L). The substrate is amended with abiotic and biotic elements (bioactivation) to initiate and accelerate ecological succession (Koehler 2005, Koehler et al. 2006, Kesel et al. 2006) and to rehabilitate essential ecosystem services of soil. In Cameroon, four demonstration, teaching and research sites have been established since 2012: one on the premises of University of Ngaoundéré (Adamawa region) and three near Maroua (Far North; East Sudanian savanna) (Kesel 2012, Koehler et al. 2013 )). The preparation of the ReviTec site in Ngaoundéré in 2012 included experimental degradation (removal of vegetation and topsoil). Soils capable to deliver the ecosystem services mentioned above are alive. Apart from above-ground vegetation, soil biota offer important information on the state of the soil. Soil biota are vital for life on earth which is based on the ecosystem services that result from their interactions with the abiotic environment, such as soil fertility, biogenic soil stabilization, water infiltration and storage, carbon sequestration. Pressure on the soil biota undermine the provisioning of ecosystem services (Gardi et al. 2013, Wagg et al. 2014). In our study, we focus on predatory mites (Gamasina), which are considered to be valuable bioindicators (Karg & Freier 1995, Koehler 1997, Koehler 1999, Pérez-Velázquez et al. 2011). Gamasina occur in relatively modest abundances, but in high numbers of species (Petersen & Luxton 1982, Coja & Bruckner 2006). They are sensitive to anthropogenic and natural disturbances (Koehler 1999, Coja & Bruckner 2006, Bedano & Ruf 2007). The overarching objective of this study is to contribute to the assessment of the efficiency of the ReviTec approach in a Central African context. The abundance, diversity and ecological roles of microarthropods in Sub Sahara African soil ecosystems are poorly known and understood. Until now there are only a few microarthropod studies of the Sahel and the savannas bordering South of it (e. g. Mosadoluwa & Buny 2000, Iloba & Ekrabene 2008, Gbarakoro et al. 2010, N’Dri & André 2011, Okiwelu et al. 2012, N’Dri et al. 2016). For Cameroonian savanna, the knowledge on soil microarthropods is limited to Oribatida species from the ReviTec site of Ngaoundéré, Adamawa region (Ermilov & Koehler 2017) and to two unpublished master’s theses from the University of Ngaoundéré (Danra 2014, Djoussi 2015). As parameters for this assessment, we use abundance, species diversity and community structure of Gamasina under three selected treatments and two controls. We provide baseline and reference data against which planned future savanna and woodland restoration can be measured. We hypothesize that: (i) compared to the savanna (sav) Gamasina abundance and species composition would be lower in ReviTec control (ctrl 1). The relatively low colonization of ctrl 1 is expected to reflect the experimental degradation of the site. (ii) The compost amendments are expected to have a positive effect on Gamasina abundance and diversity, with a positive effect of the biochar amendments.	en	Danra, Dieudonné Djackba, Nukenine, Elias Nchiwan, Koehler, Hartmut (2018): Soil Gamasina from savanna and ReviTec site of Ngaoundéré (Adamawa, Cameroon): abundance and species diversity. Soil Organisms 90 (3): 187-198, DOI: 10.25674/8FSW-
03F1A7289F34991E6356F94FF159FE59.taxon	description	Thirty-four Gamasina species belonging to fourteen genera and eight families were recorded over the sampling period (Tab. 3). The Gamasina community is dominated by small Rhodacaridae with eleven morphospecies and Ascidaewithtenmorphospecies. ThefamilyHypoaspididae Mean abundance 0 – 10 cm. ind. in tsd. / m 2 2.36 1.48 4.08 10.03 10.27 Species number 17 14 22 30 30 was represented by six morphospecies and the family of Pachylaelapidae by three morphospecies, while the family Ameroseiidae, Phytoseiidae, Gamasiphidae and Macrochelidae were represented by one morphospecies each (Tab. 3). Some individuals representing these families are shown in Fig. 4.	en	Danra, Dieudonné Djackba, Nukenine, Elias Nchiwan, Koehler, Hartmut (2018): Soil Gamasina from savanna and ReviTec site of Ngaoundéré (Adamawa, Cameroon): abundance and species diversity. Soil Organisms 90 (3): 187-198, DOI: 10.25674/8FSW-
03F1A7289F38991160D1FA96F334FDE7.taxon	description	The Gamasina community documented is indicative for the different plots. As control (ctrl 1) mimics degradation, the absence of Afrogamasellus cf. nyinabitabaensis suggests that this species is sensitive to degradation. The compost amendments seem to have facilitated the dominance of Hypoaspis-Geolaelaps spec. 1 (HYGEOA), Rhodacarus cf. matatlanticae (RHOMAT) and Afrogamasellus cf. nyinabitabaensis (AFRNYI), the latter particularly where biochar was added. Hypoaspis-Geolaelaps spec. 1 (HYGEOA), Rhodacarus cf. matatlanticae, 2010 (RHOMAT) and Afrodacarellus spec. 1 (AFROVS) were the omnipresent species as they were recorded in all the investigated plots. Multidentorhodacarus cf. aegypticus - a (MUAEa) is a species from the ReviTec site, which is characterized by being a successional site and by a high vegetation cover, even in ctrl 1 by vegetative plant parts, providing an ameliorated microclimate. Organic amendments with compost in the ReviTec site increased Gamasina abundance and species number considerably when compared to the control (ctrl 1) and also to savanna. It is unlikely that Gamasina possibly imported with the substrate and its amendments survive the typical successional conditions. As was shown by a Bremen ReviTec site (Koehler & Warrelmann 2007), the initial (imported) compost fauna was replaced within half a year by typical successional species. Reactions of Gamasina to organic amendment were reported by Minor & Norton (2004) and Koehler (1997): ephemeral organic materials such as manure or dung initiate colonization by phoretic surface species, e. g. from the families Ascidae, Macrochelidae and Parasitidae. We found five species in the savanna soil as well as in the compost amended soil, indicating that they prefer organic matter with its associated food source. The biochar amended treatments are colonized by seven exclusive species.	en	Danra, Dieudonné Djackba, Nukenine, Elias Nchiwan, Koehler, Hartmut (2018): Soil Gamasina from savanna and ReviTec site of Ngaoundéré (Adamawa, Cameroon): abundance and species diversity. Soil Organisms 90 (3): 187-198, DOI: 10.25674/8FSW-
03F1A7289F38991160D1FA96F334FDE7.taxon	description	Calculations of similarities of the Gamasina communities of the investigated plots confirm the high similarities in the biochar amended treatments, as well as in the compost treatments. The high species identity of the community of savanna with those of the two biochar plots is remarkable: this similarity might be due to the natural pyrogenic carbon in savanna soil from the regular grassland fires. Bedano & Ruf (2007) reported that the choice of similarity measure had a considerable effect on site discrimination. The dominance structure of the Gamasina community was not affected by the habitat differences, due to the prevailing eudominant species.	en	Danra, Dieudonné Djackba, Nukenine, Elias Nchiwan, Koehler, Hartmut (2018): Soil Gamasina from savanna and ReviTec site of Ngaoundéré (Adamawa, Cameroon): abundance and species diversity. Soil Organisms 90 (3): 187-198, DOI: 10.25674/8FSW-
