Comparisons of natural and managed forests suggest that single-focus management of 2nd growth is unlikely to achieve broad conservation goals because biocomplexity is important to ecosystem capacity to produce useful goods and services. Biocomplexity includes species composition, the absolute and relative abundances of those species, and their arrangement in space (for example, trees and shrubs of various species, sizes, vigor, and decay states). Key to high biocomplexity is patchiness at the appropriate spatial scale (for example, 0.1 to 0.5 ha). Passive management (benign neglect) does not necessarily remedy whatever degradation might have occurred under past management or neglect (for example, lack of biological legacies, artificial homogeneity, loss of biodiversity, missing keystone species, presence of diseases, or increased vulnerability to disturbance). Furthermore, not all management is equal. Purposefully managing processes of forest development and landscape dynamics is more likely to be successful in maintaining ecosystem and landscape function (and adaptiveness) than just providing select structural elements in stands and select structural stages in landscapes, as is often suggested for conservation. Deliberate simplification of ecosystems (for example, even-aged, single-species plantations harvested every 15 to 40 y to maximize wood production) runs counter to conservation, even if rotations are extended slightly and conventional thinning is applied. Recent experiments support the importance of biocomplexity to soil organisms, vascular plants, fungi, invertebrates, birds, small mammals, and vertebrate predators. These studies suggest that various techniques used purposefully over time are more likely to be successful than any 1-time intervention, passive management, or traditional timber management. Biocomplexity is promoted by variable-retention harvest systems, planting and precommercial thinning for species diversity, variable-density thinning to create spatial heterogeneity and foster species diversity, managing decadence processes to provide cavity trees and coarse woody debris, and long to indefinite rotations. At the landscape scale, passive management (reserves and riparian corridors) that does not take into account restoration needs may be self-fulfilling prophecies of forest fragmentation and landscape dysfunction. Restoring landscape function entails restoring function to both 2nd growth and riparian areas. Intentional (integrated, holistic, and collaborative) systems management seems to offer the best hope for meeting diverse objectives for forests, including conservation of biodiversity, a sustained yield of forest products, and economic, social, and environmental sustainability.