Site productivity depends both on natural factors inherent to the site and on management-related factors. Although gross productivity Forest site productivity is the capacity of a forest to generate products (e.g., wood or biomass) on a certain site with a given tree species and a specified management regime. USDA Forest Service, Pacific Northwest Forest and Range Experiment Station, Gen. Ecological characteristics of old-growth Douglas-fir forests. Jr., Denison, W., McKee, A., Maser, C., Sedell, J., Swanson, F., Juday, G. The amount of leaf area and biomass that is needed for photosynthetic production is generally large and intact in old growth forests ( Franklin et al., 1981 Franklin, J.F., Cromack, K. Old trees are a major site for photosynthesis, or production of the food base, on which the rest of the old growth forest system depends. The process of carbon storage in trees, which is eventually transferred to snags and logs, begins with photosynthesis. More, downed woody debris (logs, branches, and twigs), and below-ground in roots, fungi, soil microbiota, forest floor and mineral soil. Ferns are considered advanced cryptogams because they reproduce by spores but are differentiated into roots, stems and leaves. They include mosses, liverworts, and lichens. Carbon in forests is stored above-ground in live and dead trees (stems, bark, branches, leaves), understory vegetation including shrubs, herbs and cryptogams Cryptogams are plants that have no true flowers or seeds and reproduce by spores. Land use strategies to mitigate climate change in carbon dense temperate forests. Forests are of particular interest for offsetting atmospheric carbon dioxide because they do not require new technologies or infrastructure to mitigate climate change ( Law et al., 2018 Law, B.E., Hudiburg, T.W., Berner, L.T., Kent, J.J., Buotte, P.C., Harmon, M.E. Proceedings of the National Academy of Science104:18866-18870. Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks. More Canadell et al., 2007 Canadell, J.G., Le Quéré, C., Raupach, M.R., Field, C.B., Buitenhuis, E.T., Ciais, P., et al. Forest carbon sinks in the northern hemisphere. More and are accumulating carbon in large enough quantities to affect the global carbon budget ( Goodale et al., 2002 Goodale, C.L., Apps, M.J., Birdseye, R.A., Field, C.B., Heath, L.S., Houghton, R.A., et al. Conversely, if a forest produces more carbon than it absorbs it is a carbon source. A forest is a carbon sink if it absorbs more carbon than it produces. Forests also produce carbon dioxide through respiration, decay or when they burn. Temperate forests represent one-third of the global forest carbon sink Forests absorb carbon dioxide from the air through photosynthesis and the carbon is stored in trees and other components of the ecosystem. Organic matter and carbon steadily accumulate in the forest floor and mineral soil horizons as stand age.įorests take in carbon dioxide from the atmosphere and convert it into stored carbon, thus they have an important role to play in reducing atmospheric carbon dioxide levels and thereby lessening the degree of climate change. During stand development, part of the carbon sequestered by trees and other vegetation is transferred to the carbon stock of the soil in the form of litterfall and root turnover.For a second growth stand to recover the amount of carbon stored in a 300-year-old stand (i.e., to get back to the same carbon density per hectare) could take 200 years or more, therefore crucial short-term greenhouse gas mitigation objectives will not be met by converting old growth to second growth.Logging old-growth forests releases 40–65% of the ecosystem carbon to the atmosphere, even when off-site storage of carbon in wood products is factored in.As forests age, the rate of net carbon uptake by trees levels off or decreases but they still remove carbon dioxide from the air and total storage continues to increase unless a stand-replacing disturbance occurs.Productive coastal old forests can store up to six times more carbon than old forests in drier climatic areas. On sites like Fairy Creek, old forests are estimated to store twice as much carbon as mature forests and six or more times as much as clearcuts.BC’s old coastal forests store huge amounts of carbon (up to 1,300 Mg ha -1) which is more than in tropical or boreal areas and second in the world only to old multi-layered Australian temperate moist mountain ash forests.
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