## 2 Characteristics of the Sectors in Focus
### Ecosystem and Biodiversity Monitoring  
Activities focused on the protection, restoration, and promotion of the sustainable use of terrestrial ecosystems, the sustainable management of forests, combating desertification, halting and reversing land degradation, and halting biodiversity losses are associated with goal #15 of the United Nations (UN) Sustainable Development policy [24]. The policy has been recognized and implemented at regional and state levels. The Bonn Convention on the Conservation of Migratory Species of Wild Animals [25], ratified by 129 states, is focused on wildlife and their habitats on a global scale through the conservation of migratory species across their ranges. The Bern Convention on the Conservation of European Wildlife and Natural Habitats [26], aiming at the conservation of natural heritage in Europe, has been ratified by 45 European countries and 5 from outside Europe. In response to the Bern Convention, the European Communities (EC) have adopted the Habitats Directive (i.e., the conservation of natural habitats and wild fauna and flora) [27], which requires, i.a., regular reporting and assessing of the status of habitats and species conservation at 6-year intervals. The directive has also established a network of protected and conservation areas across the EU to protect species and habitats, the so-called \"Natura 2000\" network. The second pillar of the harmonized EU policy dedicated to the preservation of biodiversity is the Bird Directive (i.e., the conservation of wild birds) [28].  
Biodiversity monitoring is performed through the collection of information, which allows for the determination of the conservation status of current species and habitats in the context of changes due to various anthropogenic and natural impacts and predicted threats, as well as existing protection methods [29]. In the case of natural habitats, it is related to their conditions and changes, changes in their area of coverage, as well as their structure and function. In the case of species, it is related to the conditions and changes in their range, size, and structure of their populations, as well as the area and quality of the habitats with which they are associated. One of the important aspects of biodiversity monitoring is the detection and response to the threats posed by invasive alien species, i.e., animals and plants that have been introduced (either accidentally or deliberately) into an environment where they normally do not occur. Such introductions have serious negative consequences for their new environment and the native plants and animals found there and cause environmental and economic damage (e.g., to agriculture or forests). When implementing the monitoring, one should take into account the necessity to refine and adapt the methodology for the monitored species and habitats, which implies a wide variety. There are, however, two basic approaches to biodiversity monitoring: in situ and remote sensing [30; 31] using satellite- or Unmanned Aerial Vehicle (UAV)-based technologies [32]. It should be mentioned that biodiversity monitoring is not limited to land areas, including inland waters, but also includes seas and oceans. Another element of ecosystem monitoring is the observation of meteorological parameters, as well as air quality, composition, and pollutants (also in urbanized areas with higher spatial resolution). Biodiversity monitoring is also used in cities and suburbs (the aspect of wildlife invasiveness in inhabited areas, especially species that threaten humans).