The growing debate on issues such as maintaining biological diversity and escalating environmental degradation have highlighted the need for systemic approaches to environmental management. For example, Ulrich (1993) proposes the concept of critical holism as being useful in the debate about designs or applications in the field of ecological thinking. Here, critical systems heuristics has been used to develop a number of boundary judgements which can be used to address the value, power and knowledge bases of particular designs, as well as their basis of legitimisation. Grumbine (1994) has argued that the concept of ecosystem management is an approach which offers a fundamental reframing of how humans work with nature because it "integrates scientific knowledge of ecological relationships within a complex sociopolitical and values framework toward the general goal of protecting native ecosystem integrity over the long term". A number of themes underlie the concept such as the need for environmental managers to seek connections between all levels of the biodiversity hierarchy, to work across ecological and administrative boundaries and to conserve viable populations which also includes the reintroduction of species. Importantly he identifies adaptive management, where management is considered to be a learning process, as a theme and highlights the dominant role that human values play in ecosystem management goals.