Silviculture: Various silvicultural systems may be used to manage red spruce. Single tree selection, group selection, shelterwood, and strip clearcut are all practical harvesting methods. Red spruce is subject to windthrow; partial cuttings are recommended not to exceed half of the basal area, and a lighter harvest is usually better. Seed tree cuts are not recommended [6,9]. Frank and Blum  recommend a selection silviculture where net growth is maximized by a 10-year, intensive selection system. Clearcuts are contraindicated for many soil types and fertility levels . Postharvest red spruce regeneration is entirely dependent on advance reproduction. If seedlings are not present at the time of logging, any new spruce seedlings will be quickly overtopped and suppressed by faster growing hardwoods . The presence of leaf litter may beenefit for regeneration. Harvesting during the dormant season or allowing harvested trees to dry on site has been recommended to increase litter . Loucks  noted that in the Maritime Provinces of Canada, red spruce regeneration is usually good following partial cuts but may be lacking in clearcuts. The extent of red spruce forests has decreased following extensive logging practices and subsequent fire . In the mountains of central West Virginia, it is estimated that approximately 500,000 acres (200,000 ha) of red spruce present in the late 19th century had been reduced to less than 60,000 acres (24,000 ha) by 1975, and as little as 17,500 acres (7,000 ha) in 1978 [10,73]. Management for wildlife: Harvest practices have an effect on the resulting stand structure, and therefore on the numbers and species of birds that use red spruce habitats. Crawford and Titterington  identified five seral stages and the corresponding bird species, and made associated recommendations for management of spruce-fir stands. They also determined that spruce budworm infestation increases both the number and diversity of birds. Dense, young stands of red spruce support a higher population of birds but with less diversity than in older forests. Insects and disease: Red spruce is relatively free from insects and diseases until it is mature. Mature trees are susceptible to the following insects: spruce budworm (Choristoneura fumiferana), eastern spruce beetle (Dendroctonus rufipennis), European spruce sawfly (Diprion hercyniae), yellowheaded spruce sawfly (Pikonema alaskensis), and eastern spruce gall adelgid (Adelges abietis) [9,22,23,30]. Diseases of red spruce have been detailed [9,22,23,30,47]. Red spruce decline: Throughout its range, growth rates of red spruce have declined and mortality has increased . This decline is apparently more severe at higher elevations, in older stands, and on more exposed sites. This decline is not limited to red spruce; balsam fir and associated white and black spruce appear to be affected also . A number of studies on the causes of red spruce decline have failed to make a definitive case for any single cause. There may be no single cause or the complexity of the situation may not lend itself to a clear cause-effect relationship [36,42,47]. The combination of climatic stress and atmospheric pollution is probably the major cause of this decline, according to a number of researchers [19,36,41,42]. Numerous other causes have been proposed as well, including a natural cycle of dieback and recovery [3, 36,]. A survey of the extent and identifiable causes of mortality and decline was published in 1985 .