Ecological Sustainability as a Conservation Concept

Neither the classic resource management concept of maximum sustainable yield nor the concept of sustainable development are useful to contemporary, nonanthropocentric, ecologically informed conservation biology. As an alternative, we advance an ecological definition of sustainability that is in better accord with biological conservation: meeting human needs without compromising the health of ecosystems. In addition to familiar benefit-cost constraints on human economic activity, we urge adding ecologic constraints. Projects are not choice-worthy if they compromise the health of the ecosystems in which human economic systems are embedded. Sustainability, so defined, is proffered as an approach to conservation that would complement wildlands preservation for ecological integrity, not substitute for wildlands preservation.     

Justifying Sustainability

In the framework of ethical social choice theory, sustainability is justified by efficiency and equity as ethical axioms. These axioms correspond to the Suppes–Sen grading principle. In technologies that are productive in a certain sense, the set of Suppes–Sen maximal utility paths is shown to equal the set of non-decreasing and efficient paths. Since any such path is sustainable, efficiency and equity can thus be used to deem any unsustainable path as ethically unacceptable. This finding is contrasted with results that seem to indicate that an infinite number of generations cannot be treated equally.     

Sustainability of Nations

SUMMARY

A method is presented to interrelate the development of economy, environment and social quality in communities. Economy and environment, in initial development stages, oppose each other. Social welfare and economy generally develop simultaneously. To assess overall progress in sustainable development, an integrated and quantifiable framework is presented which defines five levels of sustainability. Increasing sustainability is characterized by growing responsibility for the impacts of man's actions in space and time. Through increased eco-efficiency and changed awareness, nations and companies arrive at a synergistic relationship between environment and economy. It is indicated that social security benefits expenditure increases by a factor 3.5 and carbon dioxide emissions per capita decreases by a factor 3 at each higher level of sustainability. Quantified differences in sustainability levels of 24 nations are shown. Priorities for improving and safeguarding sustainability are indicated.     

Biological Sustainability of Live Shearing of Vicuña in Peru

Abstract:  The vicuña's ( Vicugna vicugna ) fiber is highly valued as an export product that is made into luxury fabric and clothing. The price of fiber in 2004 was $566/kg, which makes the fiber a potentially important source of income for Andean agropastoral communities and serves as an incentive to allow vicuña grazing on high-elevation Andean landscapes. It is presumed that a shorn vicuña has little value for poachers, so shearing vicuñas could serve as a disincentive to poaching. Thus, the supply of vicuña fiber may be sustainable if it is procured through live shearing, which should serve as a powerful conservation tool. We evaluated the effects of capture and shearing on the demography of vicuña in one site located in the Salinas Aguada Blanca Reserve, Arequipa, Peru, where vicuñas were captured and shorn in spring and then returned to the wild. We conducted fixed-width line-transect censuses from 1997 to 2003 of this population. We compared the proportion of young born to females that were shorn versus females that were unshorn for the 3 years in which shearing occurred. We evaluated the effect of capture and shearing on proportion of young born to shorn and unshorn females at a second site, Picotani, Puno. The wild population in Arequipa that underwent capture and shearing showed a steady increase in total population and average density between 1997 and 2003. No significant difference was found between the proportion of young per female for shorn and unshorn females at either site. We conclude that in spring, capture and live shearing of vicuñas can be biologically sustainable. Further research is needed to determine whether shearing during winter months is biologically sustainable.     

Assessing Sustainability at Multiple Scales in a Rotational Bushmeat Hunting System

Abstract: Results of many studies show unsustainable levels of bushmeat hunting across West/Central Africa. Nevertheless, these results are usually derived from snapshot sustainability indices in which critical parameters are often taken from the literature. Simple, more informative tools for assessing sustainability are needed. We evaluated the impact of bushmeat hunting across a range of temporal, spatial, and taxonomic scales in a comparison of different measures of sustainability. Over 15 months in 2002–2004 in and around a village close to Equatorial Guinea's Monte Alén National Park, we collected data via a village offtake survey, hunter‐camp bushmeat‐consumption diaries, hunter interviews, and following hunters during hunts. We compared 2003 data with a previous offtake survey (1998–1999) and interview reports back to 1990. In the past 14 years, average distance from the village at which hunters operated remained constant, with hunters switching back and forth between long‐established camps, although trapping effort increased. In the past 5 years, overall offtake and number of active hunters did not change substantially, although catch per unit effort (CPUE) decreased slightly. Although the proportion of the two most commonly trapped species (Cephalophus monticola and Atherurus africanus) and gun‐hunted primates increased in the offtake, species presumably less robust to trapping decreased slightly. Apparent sustainability in economic terms may be masking gradual local extirpation of more vulnerable species before and during this study. Our results suggest that changes in prey profiles and CPUE may be the most accurate indicators of actual sustainability; these indices can be monitored with simple village‐based offtake surveys and hunter interviews to improve community management of bushmeat hunting.     

Sustainability and the Scientist's Burden

Natural scientists are being encouraged by environmental and developmental agencies to define and operationalize the concept of sustainability in a "scientific" manner. Such an approach is fraught with dangers because values, opinions, and social influences are an inextricable part of science, especially applied science. Natural scientists' attempts to define sustainability, particularly to decide what should be sustained, cannot therefore be value-neutral. They simply end up shifting value judgments to different levels by choosing either a single obvious objective, an arbitrary range of objectives, or an arbitrary method of aggregating different preferences. This lack of self-reflectiveness on the part of scientists has important consequences for the direction of research and its political implications. Natural scientists should heed lessons from earlier cases of scientists' involvement in policy and redefine the terms of reference before shouldering their social burden. The dilemma of pursuing objective science in a value-loaded and socially charged discourse can be resolved by properly understanding the role of analysis and by pursuing a socially grounded pluralistic approach to problem definition and research methodology.