## 1 Introduction  
The evaluation of the state of ecosystems, as the fundamental structural and functional unit of living matter, is a constant concern of global and European policies, in order to establish guidelines for preventing the loss of their functions. The assessment of the condition of ecosystems necessitates extensive analysis of their physical, chemical and biological quality at a particular moment and measurement of the impacts of major pressures that are arising. Natural ecosystems are constantly exposed to pressures from over-exploitation of resources, extensive hunting, climate change and pollution [1, 2]. Some authors consider that the highest direct impact on an ecosystem's state is represented by anthropogenic pressures (overharvesting and land use change) leading to biodiversity loss [3]. To accurately evaluate the ecosystem services provided by a particular area, first, the state of the ecosystem must be studied. The state of the ecosystem is the first level in the flow of services from nature to society [4], and it defines the ability of the ecosystem to provide services. Pressures from human activity, such as pollution or overuse, can have an impact on the state of the ecosystem, thus reducing its ability to provide services to society [5; 6]. The good condition of ecosystems is not considered a service itself; however, it is indispensable as it is an essential condition for human activity. The ecosystem is degraded when the viability of natural processes and relationships within it are removed or disturbed by anthropogenic activity or the action of natural factors [7]. It is also a process with multiple effects on climate change, biodiversity changes and ecosystem services [8]. Europe is facing a continuing loss of biodiversity, and natural ecosystems are diminishing, especially wetlands, by about 50% [9]. As a member of the European Union (EU), Romania promotes and supports the protection of ecosystems, being part of the United Nations Convention on Biological Diversity (\"Convention on Biological Diversity\", 1992). However, like most European countries, Romania is experiencing an increase in its share of degraded ecosystems [10; 11]. The restoration of the geological environment and the affected terrestrial ecosystems involves bringing them as close as possible to their natural state, by applying complementary and compensatory cleaning, remediation and/or reconstruction measures and by eliminating any significant risk according to the category of land use. To do this it is necessary to properly evaluate their degradation state and the drivers of this degradation. Changes in ecosystems are frequently identified on the basis of satellite imagery [12; 13]. Most methods focus on biomass evaluation [14; 15; 16], leaf area index (LAI) [17] or productivity [18; 19; 20]. The Global Climate Observing System (GCOS), promotes LAI as an essential climate variable (ECV), being a key parameter used in woody ecosystems [21]. In many studies, the health of the ecosystem is analyzed based on GPP (gross primary production) or NPP (net primary production) indices and a vegetation index, such as the normalized-difference vegetation index (NDVI). The high value of these indices does not necessarily mean a good state of health [22], as it may be due to invasive species. In the same way, primary productivity is related not only to variations in CO\({}_{2}\) in the atmosphere but also to climate change. Globally, productivity has increased in the last 20 years [23]. Machine learning algorithms such as Random Forest (RF) and Support Vector Machine (SVM) are used to identify and monitor vegetation types within forest [24] and grassland ecosystems [25]. Moreover, the SVM image classification method is useful in identifying invasive plant species [26; 27], one of the important criteria in the evaluation of grassland ecosystems [27]. Some authors used satellite imagery (Sentinel 2, Landsat 8) and machine learning processes to locate forest treatments over large spatial extents [28].