and is used in many higher-end acoustic guitars and violins, as well as musical soundboard. The sap can be used to make spruce gum. Leafy red spruce twigs are boiled with sugar and flavoring to make spruce beer. Also it can be made into spruce pudding. It can also be used as construction lumber and is good for millwork and for crates. Red spruce is the provincial tree of Nova Scotia. Damaging factors Like most trees, red spruce is subject to insect parasitism. Their insect enemy is the spruce budworm, although it is a bigger problem for white spruce and balsam fir. Other issues that have been damaging red spruce has been the increase in acid rain and current climate change. One of the consequences of acid rain deposition is the decrease of soil exchangeable calcium and increase of aluminum. This is because acid precipitation disrupts cation and nutrition cycling in forest ecosystems. Components of acid rain such as H+, NO3−, and SO42- limit the uptake of calcium by trees and can increase aluminum availability. Calcium concentration is important for red spruce for physiological processes such as dark respiration and cold tolerance, as well as disease resistance, signal transduction, membrane and cell wall synthesis and function, and regulation of stomata. Conversely, dissolved aluminum can be toxic or can interfere with root uptake of calcium and other nutrients. At the ecosystem and community levels, Calcium availability is associated with community composition, mature tree growth, and ecosystem productivity. One study testing the effects of added aluminum to soil, found that P. rubens mortality rate increased under these conditions. During the 1980s, increased acid deposition contributed to a loss of high-elevation red spruce trees, due to leached calcium and decreased freezing tolerance. Additionally, the structure of the spruce needle enhances the capture of water and particles, which has been shown to add to soil acidification, nutrient leaching, and forest decline. However, more recently, reductions in acid deposition have contributed to red spruce resurgence in some mountain areas in the northeastern United States. This increase in red spruce growth has been associated with an increase in rainfall pH, which reduces bulk acidic deposition. This suggests that policies aiming to reduce atmospheric pollution in this area have been effective, although other species sensitive to soil acidification, such as sugar maple, are still continuing to decline. Conservation The Central Appalachian Spruce Restoration Initiative (CASRI) seeks to