THE SLOSS DILEMMA - A BUTTERFLY CASE-STUDY

Butterfly species richness is examined on simulated archipelagoes of 2 , 3, 4 and 5 holm oak forest fragments in the Guadalajara Province (ce ntral Spain). It is shown that there are more species on several small 'islands' than on a single island. Also, species number increases wit h the number of fragments that form the archipelago, and with the aver age distance between islands within the archipelago. Thus, we conclude , at least for butterflies in a system of fragmented helm oak forests in central Iberia, that the best strategy in order to maximize the con servation of species richness is the creation of a net of some small a nd scattered reserves.