Humus layers (soil organic layers) constitute an important component of forest ecosystems. but one which as yet is not fully understood with respect to its importance in determining forest management decisions. They represent an ecosystem component which is the most easily disturbed or even destroyed; therefore, the knowledge of such impacts is mandatory for management of second growth forests.
A study of humus layers on an ecosystem basis has been initiated in the Vancouver Forest District. Its general objectives are:
1. to collect data for characterization of humus layers of major forest ecosystems occurring in the District;
2. to evaluate procedures for humus investigations; and
3. to provide management interpretations on an ecosystem-specific basis as to maintain the most favourable properties of humus layers with respect to regeneration and productivity of second growth forest stands.
In the first study humus layers in ecosystems occurring on dry, moist and wet (seepage) habitats, foliage samples of salal and sword-fern. and decayed wood samples were compared. The distribution of easily available nutrients showed a very interesting relationship to moisture regime. An increase in moisture. was associated with increasing levels of calcium, but decreasing levels of magnesium and potassium. Seepage habitats have the highest decomposition of litter and moist habitats have a slightly lower decomposition of litter than dry habitats. Decayed wood has the lowest decomposition. If accumulated on forest floor it may then slow down the decomposition of litter.
Little evidence was found that foliage of salal or sword-fern produce differences in the analysis of humus layers in ecosystems in which these species were major components.
It was concluded that the performed analysis while providing a useful supplement to other chemical data, is not itself sufficient to fulfill the study objectives. Forest ecosystems appear to be a promising approach to humus studies.
Detailed information on this subject may be obtained by writing to the Information Division, B.C. Forest Service, Legislative Buildings, Victoria, B.C. V8V 1X5 for Research Note No. 74 by K. Klinka & L.E. Lowe titled, "Organic Constituents of Forest Humus Layers in the Coastal Western Hemlock Biogeoclimatic Zone of British Columbia in Relation to Forest Ecosystems".
[Abstract contains full text of memo.]
BC Forest Service - Research Division. 1976. Organic constituents of forest humus layers in the Coastal western hemlock biogeoclimatic zone of British Columbia in relation to forest ecosystems. 1. Proximate analysis. British Columbia Ministry of Forests, Lands, Natural Resource Operations and Rural Development. Research Memo (FLNRORD). RM7
Topic: FLNRORD Research Program
Keywords: FLNRORD, Research Memo, British Columbia
To copy the URL of a document, Right Click on the document title, select "Copy Shortcut/Copy Link", then paste as needed. Only documents available to the public have this feature enabled.