The design of nature reserves in the face of habitat loss

- Selecting the given area of suitable habitats from the center of a fragmented landscape, we investigate whether several large or many small reserves should be established.
- When the carrying capacity is intermediate, the effects of both habitat loss and migration must be considered.
- When the environmental carrying capacity is intermediate: if migration is allowed between reserves and habitat loss is not severe, many small reserves are better; otherwise, several large reserves are optimal; increasing the migration mortality rate tends to favor the implementation of several large reserves.

When designing nature reserves, it is very difficult to find an intact landscape because of the prevalence of habitat loss. The FLOMS debate - should we have Few Large Or Many Small reserves - is a focus of the design of nature reserves. Thus, habitat loss may greatly influences the FLOMS debate. Selecting the given area of suitable habitats from the center of a fragmented landscape (caused by habitat loss), we present a theoretical model and Cellular Automata simulation is used to investigate whether several large or many small reserves should be established in these suitable habitats. The results suggest that if the environmental carrying capacity is high, many small reserves are optimal; if it is low, several large reserves are optimal. When the carrying capacity is intermediate, the effects of both habitat loss and migration must be considered, and the following apply. (1) If migration is not allowed between reserves, several large reserves are better. (2) If migration is allowed between reserves and habitat loss is not severe, many small reserves are optimal. (3) If habitat loss is severe, few large reserves are beneficial, regardless of whether migration exists between reserves. (4) Increasing the migration mortality rate tends to favor the implementation of several large reserves.