Environmental Engineering Reference
In-Depth Information
mycorrhiza are not consumed themselves, they are essential for the growth
of many timber species that are harvested and they are necessary to
support the production process that produces goods and services that are
consumed directly.
Similarly, the importance of bird species used as a biological control
agent can be captured from increased timber sales associated with insect
pest reduction. Takekawa and Garton (1984) used the substitution
method to determine the value of a bird species, the evening grosbeak
(
Hesperiphona vespertina
) in controlling spruce budworm populations
af ecting stands of Douglas i r
(
Pseudotsuga menziesii
)
in Washington.
They substituted the costs of insecticide to produce the same mortality
that birds cause and established that it would cost at least $1820 per square
km per year over a 100-year rotation.
Biodiversity in managed landscapes: policy issues
Earlier sections indicated why markets may fail to protect biodiversity and
give some examples of how economic tools can provide a useful means by
which to measure the non-benei ts and costs associated with biodiversity
and thereby go some way towards dealing with market failure. A further
solution is to develop economic incentives and instruments that correct for
market failure. In the section that follows we consider the importance of
policy with respect to biodiversity conservation.
The aims of a society may be formulated within the framework of
national environmental policy. Policy can be regarded as 'the compendium
of statements, laws and other actions concerning government's intentions
for a particular human activity under its jurisdiction' (Miller, 1999).
Objectives concerning natural resources are not necessarily static.
History indicates that environmental policies have changed progressively
with time in response to changes in society. This has led to changes in the
public demands placed on environmental resources. Human populations
are concerned with using environmental resources as a means of survival
but also increasingly to meet recreation and conservation goals.
In managed landscapes there is also public concern about the impor-
tance of ecological functions - water quality, biodiversity, aesthetic values
and international and national organizations are under increasing public
pressure to take action to develop economic incentives to protect public
values on privately managed land (WCED, 1987).
Economic instruments
In what follows we outline two types of policy instruments of relevance to
land managers - economic incentives and command and control regula-
tions. We discuss economic incentives i rst.
