The Conservation Paradox - Biodiversity Conservation and Environmental Change - page 4

off-take of populations was below the rate of replenishment, then nature's balance would
survive. In this view, nature is resilient and will recover from disturbance; therefore the wise
use of natural resources was considered to provide a rationale for good nature management
and conservation (Figure 1.2).
The balance of nature?
Though apparently very different, both the preservation and utilization approaches to con-
servation rest on the same idea of nature in balance (Egerton 1973, Wu and Loucks 1995, Ladle
and Gillson 2009). This idea was pervasive in western philosophy, and was the prevailing
paradigm (underlying world view) of early ecology (Wu and Loucks 1995). For example,
Clements seminal 1916 paper on succession described how vegetation in a particular climate
would undergo a predictable series of stages (termed seres) until it reached equilibrium with
climate (Clements 1916). Each climatic zone would therefore be associated with a particular
climax vegetation assemblage, and was expected to recover to this state after disturbance.
The preservation movement found its scientific soulmate in the theory of succession,
which predicted a stable, though fragile, balance that could be conserved through strict pro-
tection. Preventing disturbance and change was therefore seen as good conservation, and
indigenous people were often moved out of reserves in an effort to restore (or sometimes cre-
ate) a feeling of wilderness and untouched nature (Cronon 1996, Weddell 2002). Because of
the exclusion of people from reserves and the perceived barricading of nature into protected
areas, this approach has been called 'Fortress Conservation' (Brockington 2002).
At the same time, other biologists concerned with the sustainable harvesting of resources,
predicted logistic growth of populations to a steady state, known as the carrying capacity.
Based on a constant rate of supply of resources and a fixed intrinsic rate of population growth,
populations would initially grow exponentially, to a point where resources become limiting,
at which point the rate of population growth would begin to slow (Pearl and Reed 1920).
A stable population at carrying capacity is reached when resources are used at the same rate
as they are supplied, and mortality and birth rate are equal. Harvesting populations to half of
carrying capacity would, in theory, maximize the rate of population growth, giving the max-
imum sustainable yield. Thus, harvesting of populations was seen as a management ideal
(Gillson and Ladle 2009).
Over the years, managers learned from practical experience that far from being stable
and predictable, many ecosystems changed, despite or because of their best efforts,
because climate is always changing and disturbance is inevitable (Pickett 1995, Wu and
Loucks 1995, Gillson et al. 2003, Rogers 2003). On the preservationist side, attempts to sup-
press natural disturbances were often futile (Holling 1996b). Furthermore, many appar-
ently pristine landscapes had in fact been managed by people for millennia, and without
human intervention, many ecosystems began to change, with the loss of heterogeneity and
disturbance-adapted taxa (Gillson and Willis 2004). On the utilitarian side, many popula-
tions did not behave as expected. Far from being stable, resources like water, and hence
biomass, forage, and prey abundance varied from year to year; annual rainfall, disturbance