## 2 Materials and Methods  
### Data Collection  
The research was realized in Scots pine and black pine stands, either pure or mixed with broadleaved trees, installed on degraded lands from the south-east zone of Romania, which are representative of the extent and forms of land degradation as well as of the types of forestry works carried out on degraded lands (Figure 1). They are situated in four permanent experimental perimeters (EP) that are representative of the forest cultures installed on degraded lands (Table 1). In each experimental perimeter, we established a network of research plots (RP) that highlight the nature of the degradation and its intensity. From this network, we selected a total number of 10 representative RPs that cover both the zone of the pure pine stands and the ones mixed with hardwood species. The EP are distributed by phytoclimatic floor as follows:  
1. _The sessile oak and common beech phytoclimatic storey (FD3)_: (i) Vidra Experimental Base, experimental perimeters: Caciu-Barsesti (EP1) (45\({}^{\circ}\)55'19.69'' N, 26\({}^{\circ}\)44'44.74'' E) and Paraul Sarat-Valea Sarii (EP2) (45\({}^{\circ}\)52'35.57'' N, 26\({}^{\circ}\)47'51.97'' E); (ii) Focsani Forest District, experimental perimeter Rosoiu-Andreiaus (EP3) (45\({}^{\circ}\)44'56.24'' N, 26\({}^{\circ}\)49'55.96'' E);
2. _The internal hilly forest-steppe site_ (Ssd): (iii) Ramincu-Sarat Forest District perimeter Livada-Ramincu Sarat (EP4) (45\({}^{\circ}\)23'55.78'' N, 26\({}^{\circ}\)55'29.49'' E). The afforestation works are distinctive due to the black pine and Scots pine plantations mixed with white sea buckthorn and/or other broadleaved species. These are located on very strongly (excessively) eroded lands and were set up/consolidated by special works in order to ensure minimum vegetation conditions. The realized forest cultures from EP1 Caciu-Barsesti, EP2 Paraul Sarat-Valea Sarii, and EP3 Rosoiu-Andreiaus presently have ages between 45-65 years and are located in the sessile oak-common beech phytoclimatic storey (FD3) and fulfill special hydrological and anti-erosion protection functions. The stand aged over 70 years is located in the internal hilly forest-steppe site (Ssd), fulfilling the management goals of protection (soil, water, etc.). The most representative stands are composed of pure pine species or mixed with broadleaved ones (mahaleb cherry, sweet cherry, sycamore, manna, etc.) in different proportions of participation in stand composition, with a maximum of 30%. Due to the fragmented relief from the Curvature Subcarbathians, with steep and strongly inclined slopes, the climate is characterized by torrential rains. Together with the lithological substratum, composed mainly of marls and clays, this leads to the appearance of numerous degradation phenomena, the most frequent being pluvial erosion produced both at the surface and in depth. Figure 1: Location of experimental perimeters: EP1—Caciu–Bärsesti; EP2—Päräul Sarat–Valea Sarii; EP3—Rosoiu–Andreiaus; EP4—Livada–Ränmicu Sarat. The Description of Degradation  
In general, land degradation represents the alteration of soil characteristics so that they becomes inferior in quality, and it includes several degradation processes (erosion, gullying, landslides, etc.). For the research undertaken in this paper, the erosion processes caused by water that generate eroded land are of interest. In relation to the intensity of erosion, three degrees of erosion are distinguished: moderate erosion or 1 st degree (E1); high erosion or 2 nd degree (E2); and very high erosion or 3 rd degree (E3). The significance of the degrees of erosion and the pedological characteristics of the eroded lands are shown in Table 2.  
Removing the fertile soil layer from the surface leads to serious consequences on the plant production capacity. Therefore, many of the lands from this area were declared unproductive or poorly productive, generating ecological, economic, and social imbalances.