The value of older forest for biodiversity conservation is thought to greater than younger forest, and therefore they need particular consideration in sustainable forestry planning. In Latvia sustainable forest management is a primary goal set by the State Stock Company “Latvijas valsts meži”. Landscape-level sustainability is also the goal for the North Vidzeme Biosphere Reserve (NVBR), which was chosen as a study area. We used stand age as a criterion for selection of stands of the common tree species – pine, birch, spruce, black alder, aspen, oak and ash. Forest inventory data from 2011 were used as the main source of information. This study utilized an analytical approach to the assessment of spatial patterns of mature and overmature stands. Overmature stands might be considered as having high potential value for conservation, thus promoting one of the biodiversity as one of key aspects for sustainable forest. Mature stands, which are those that have reached legal cutting age, represent a reserve for the overmature stands, thus ensuring integrity of biodiversity structures. The results showed various potential of mature forest to facilitate biodiversity in the nearest decades from the aspect of stand spatial pattern properties. From the forestry target species, overmature spruce and birch stands over time can be supplemented from the reserve of mature stands, but old aspen woodland was evaluated has having the least potential for continuity in both state and private forest.

Keywords: overmature forest, landscape pattern, landscape metrics