Newly discovered landscape traps produce regime shifts in wet forests

Abstract

We describe the "landscape trap" concept, whereby entire landscapes are shifted into, and then maintained (trapped) in, a highly compromised structural and functional state as the result of multiple temporal and spatial feedbacks between human and natural disturbance regimes. The landscape trap concept builds on ideas like stable alternative states and other relevant concepts, but it substantively expands the conceptual thinking in a number of unique ways. In this paper, we (i) review the literature to develop the concept of landscape traps, including their general features; (ii) provide a case study as an example of a landscape trap from the mountain ash (Eucalyptus regnans) forests of southeastern Australia; (iii) suggest how landscape traps can be detected before they are irrevocably established; and (iv) present evidence of the generality of landscape traps in different ecosystems worldwide.

Fig. 1.

Conceptual model of a landscape trap. The trap results from the reinforcing feedback loop shown in red.

Fig. 2.

Photo montage showing historical logging in extensive stands of old-growth forest (A–C) and extensive clear-cut areas of forest cut in the past 10 y (D and E) in the mountain ash forest in the central highlands of Victoria. (Photos courtesy of National Archives of Australia, State Library of Victoria and D.B.L.)

Fig. 3.

Development of a landscape trap in the mountain ash forests of the central highlands of Victoria.

Fig. 4.

Conceptual model highlighting signals and interventions required to reverse the development of a landscape trap.