Growth, yield and economics of Pinus patula in the Natal Midlands
Date
1965
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: This thesis deals with the mensurational and economic
studies in plantations of Popatula in the Natal Midlands o
In Chapter I the climate of P.patula areas in Natal
I
is classified with the Thornthwaite method. The present
silvicultural practice in the Natal Midlands is surmnarised o
In Chapter II the construction of Volume Yield tables
is discussed. These tables are based on the measurement of
stand characteristics of temporary sample plots which have been
measured once. The past diameter and the basal area i ncrement
is determined from increment cores o A multiply regression
analysis is used to determine the relationship between basal
increment as dependent variable, stand density» age, sit e index
and their interactions as independent variableso Site index
is deleted l::lltage and stand density are retained as explaining
variables .
Site index curves, based on temporary sample plots
are constructed, but the yield tables are based on the mean
site index of 81 . 9 feet at 20 years.
The volume increment is estimated from separately
determined height and basal area increment equations.,
Four thinning models are introduced and for each
of them a yield table is constructed., For these thinning
regimes the diameter- = , volume--, and log class volume
distributions are investigated .
In Chapter IV the results of the economic analysis are
presented.,Production costs have been investigated through
questionnaires. Various types of rotations are calculated for each
of the four thinning regimes. The profitability of different
rotations and thinning regimes are compared.
The implications of these calculations on the
practice of silviculture and management are discussed.
Description
Thesis (PhD) -- Stellenbosch University, 1965.
Keywords
Pinus patula -- South Africa -- KwaZulu-Natal -- Growth, Forests and forestry -- Economic aspects -- South Africa -- KwaZulu-Natal, Pinus patula -- Planting -- South Africa -- KwaZulu-Natal, Forests and forestry -- Climatic factors -- South Africa -- KwaZulu-Natal, UCTD