## 1 Introduction
In this country, the concept of ES remains little studied, and only a few forest ecosystems have been the subject of studies on ES. We cite, among others, the forests of Chrea and Senalba (2011-2016) [24] and the national park of El Kala studied by [PERSON]. (2016) [25]. To assess potential ES, i.e., the general capacity of our study area to provide ES, we used botanical data and remote sensing for the delineation of \"ES Provisioning Units\" (SPU) [26]. Geospatial Data from Remote Sensing for Ecosystem Services Characterization Earth remote sensing in general and the resulting geospatial data offer multiple potentialities for assessing ecosystem services [27,28]. Indeed, the spatially exhaustive character of all these techniques helps assess a territory continuously and at different scales of analysis. The temporal scale is also apprehended by the repetitiveness of the satellite'spassage, providing time series capable of evaluating the seasonal and/or inter-annual variations in the remotely sensed information [29]. Schematically, there are two main approaches to mapping the supply of ES using remotely sensed data. The oldest and simplest approach uses land cover (LC) categories produced by satellite image classification as indirect support [27; 30]. Each thematic land cover class is thus assumed to qualitatively represent a biophysical or other value (economic, social) of one or more ecosystem services [28; 31]. Although criticized because of the standardization of ecosystem qualities or conditions simplified by a single cartographic representation [27; 31], this approach nevertheless retains the major interest in integrating the concept of ES at the geographical level of the landscape [32]. A landscape assessment of ES is not necessarily limited to land-use/land-cover information (LULC) but allows for the integration of other environmental descriptors, such as soil, climate, surface geomorphology, substrate nature, or hydrological characteristics [32; 33], which can be modeled by various geospatial data [28; 34]. In this sense, the geographic dimensions of the landscape constitute a Service Provision Area (SPA) [33] or Service Provision Unit (SPU) [26] that has ecological significance at the scale considered. The concept of service providers was conceived as a continuum including different organizational ecological levels from populations of a single species to biomes, passing through communities, habitat types, or landscapes, among others. This multiscalar notion implies questioning the level of the aggregation of the cartographic unit used to spatially assess the supply of ES [33; 35]. Does the map unit correspond to the minimum area for estimating a homogeneous and constant supply of ES over the dimensions of this area, or should all these minimum units be aggregated to evaluate the supply of ES over a spatial unit of greater dimension [36]? The answer to this question logically depends on the type of ES to be mapped and the purpose of the assessment. For some ES, the pixel size will be considered relevant, whereas for others, it will be necessary to opt for a more integral mapping unit such as a watershed or an ecoregion [33]. This constraint on the spatial suitability of mapping units is not only restricted to the indirect qualitative approach to estimating ES provision, but it also applies to the quantitative measurement of ES by remote sensing, which is the most credible and currently recommended methodological alternative [27; 31]. The variety of sensor types used in satellite imagery, each with its own acquisition characteristics, implies a disparity of spatial resolutions that must necessarily be adapted according to the ES to be quantified. Nevertheless, under this condition of spatial adequacy between the satellite data and the mapping unit of the ES, there is currently a wide range of quantitative remote sensing products that can be directly or indirectly related to ecological and ecosystem processes and, more particularly, to their associated functions [27; 31; 37]. In particular, [PERSON] et al.