Danish Yield Tables in the Past Century

Frederiksberg

Royal Veterinary and Agricultural University

1989

94 S.

20 Abb., 4 Tab., zahlr. Lit. Ang.

Bandaufführung

47473

Meddelelser fra Skovbrugsinstituttet. Series 2: Research ; (23), 94 S.
; (23), 94 S.

All Danish yield tables produced over the last century are analyzed and classified according to the methodology used in construction of the tables. More recent yield tables are all divided into 3 main sections showing growth- , treatment- and yield figures. It is shown how a yield table with a single site class, containing the above-mentioned 3 sections, can be constructed when 6 basic factors are known. The 6 basic factors are: totel yield (P), height of remaining crop (H3), basal area of remaining crop (G3), diameter of remaining crop (D3), the ratio between diameter of remaining crop called the thinning quotient (Q=D2/D3) and thinning intervals (C). When the construction of a yield table is not based on data from permanent sample plots, figures for total yield (P) will be lacking and must accordingly be reconstructed. As total yield is considered to be the most important of the 6 basic factors in a yield table, an extensive review of methods used for determining cumulative volume production in all Danish yield tables is given. It is further shown how yield tables with several site classes are constructed. Through the use of growth functions, treatment functions and yield functions, a total yield table with several site classes may be derived. The 3 types of functions determine the relationship between the basic factors and site class. Finally, the concept of "the graphical matrix" is introduced as a quick visual method of analyzing, amongst other things, the growth-, treatment- and yield functions used in constructing the yield table.