CASCADE had six study sites spread across the entire Euro-Mediterranean (Figure 1).
Figure
The main characteristics of these sites are summarised in Table 1 and are further described in
- »Várzea Portugal: Description of site and main causes of degradation
- »Albatera, Spain: Description of site and main causes of degradation
- »Ayora, Spain: Description of site and main causes of degradation
- »Castelsaraceno, Italy: Description of site and main causes of degradation
- »Messara, Greece: Description of site and main causes of degradation
- »Randi Forest, Cyprus: Description of site and main causes of degradation
Table 1: Main characteristics of the CASCADE study sites, partly after Tsanis and Daliakopoulos (2015)
As can be seen from Figure 1 and Table 1, the sites cover several ranges, such as a West-East range (Varzea to Randi), and a range in amount of precipitation and aridity index (Albatera to Castelsaraceno). Together the study sites cover conditions typical for the Mediterranean. Different types of land degradation and desertification are found across the study sites. While forested areas (Ayora and Varzea) are susceptible to repeated wildfires, rangelands face soil erosion owing to poor vegetation cover (Albatera, Messara and Randi) or shrub encroachment (Castelsaraceno), due to overgrazing and insufficient grazing management (leading to undergrazing in Castelsaraceno). Both forest and rangelands are affected by drought and abandonment.
The main causes of degradation for each CASCADE study site are also different, but they are always associated with the accumulated impact of a driver: forest fires, marginal agriculture and grazing, and long-term poor land management. Less often, the causes are related to climate, which nevertheless acts as a catalyst by making the system more vulnerable to disturbance. This accumulated impact might cause sudden ecosystem shifts, which may be one of the factors that causes abandonment. In the Mediterranean, land abandonment is a widespread and increasing issue (Bielsa et al., 2005; Duarte et al., 2008; Sluiter and de Jong, 2007), also in the CASCADE study sites. After abandonment, the land might not supply the same ecosystem services as before. All study sites are affected by droughts in summer. The historical development and land use are described in Daliakopoulos and Tsanis (2013), and has resulted in current land use being either wood production or marginal grazing.