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Ecosystem units, their classification, interpretation and mapping in the University of British Columbia research forest

University of British Columbia

A synecological study was conducted at the University of British Columbia Research Forest, Haney, British Columbia. The objectives of the" study were to classify and map forest ecosystems occurring in the area and to provide interpretations as to their use for land and silvi-cultural management. One hundred and fifty eight sample plots were established, each plot representing a sample of an ecosystem individual—biogeocoenosis. Following an analysis of the vegetation and its environment by the phytosociological techniques of the Zürich-Montpellier School as applied by Krajina, and the associated soils, a synthesis of similar plots into abstract units was carried out. The ecosystems were classified according to the system of synecological classification developed by Krajina and his students. Biogeoclimatic and synsystematic units were floristically and environmentally described emphasizing environmental factors and processes which control their distribution and development. Lower synsystematic units were grouped to form management units for which relatively uniform management procedures and techniques could be proposed. By analyzing the properties of vegetation and soils, suitability of ecosystems for wood production was assessed along with suggested silvicultural systems for thirteen management units. The classification was verified by investigations to substantiate ecological significance of the differentiated units. These involved chemical analysis of seepage water, foliage samples of under-story vegetation, and humus layers in the Coastal western hemlock biogeoclimatic zone. Chemical concentrations in foliage of understory vegetation increased progressively along moisture and nutrient gradients. Characteristic species for the Pseudotsugetalia menziesii had the lowest concentrations, those for the Tsugetalia heterophyllae had the intermediate concentrations and finally those for the Thujetalia plicatae had the highest concentrations of metallic elements and nitrogen. The characteristic species for the ecosystem units appear to have a high indicative value in assessing their edatopes. Chemical concentrations in seepage water were found to vary with the season, forest stand type (based on age) and biogeocoenotic units. Seepage water, supplying the ecosystems with additional moisture and nutrients, affects soil development through increased decomposition and mineralization of organic matter. These habitats consequently support very productive ecosystems of the Thujetalia plicatae. Thus, seepage water can be considered as a part of the ecosystem which counteracts leaching. The results of these analyses supported the applied methods of synecological classification. The distinguished ecosystem units can be further characterized by specific indices of properties which were not used in the original classification procedure. On the basis of these synecological studies a synecological map of the 5,151 ha UBC Research Forest at the scale 1:12,000 was prepared by a combination of ground survey and aerial photographic interpretation. Ecosystem type was employed as a mapping unit. The mapping units were designated by selected colors and numerical symbols. In conclusion, it became apparent that the classification of ecosystems into the system of synecological classification, using the described methods, can provide not only a better understanding of forest ecosystems but also a basis on which to differentiate management practices.

Text

2010-02-11

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http://hdl.handle.net/2429/20119

Forestry

University of British Columbia

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