Limited Carrying Capacity Research Articles

Korean household waste management and recycling behavior

The rapid industrial and economic development in the recent several decades has caused serious environmental problems in Korea. The country has very limited carrying capacity; the population density in Korea is 481 people per km 2, ranking the third-highest in the world [1]. In 1995, the Korean government implemented a volume-based waste fee system (unit pricing system) that required every household to purchase certified plastic bags for waste disposal [2]. Consequently, since the introduction of this regulation, household solid waste in Korea has been substantially decreased, and household recycling has been increased. This study is to examine current Korean household recycling and waste management behavior and explore factors that affect those behaviors. Data was gathered though a survey conducted in Seoul, Korea. For the data analysis, 196 responses were used. The impacts of several factors on recycling and waste management behaviors including NEP (New Environmental Paradigm), attitudes for recycling and waste management, and the respondents’ demographic variables were examined. To analyze the data, correlations and multiple regressional analyses were conducted using SPSS 16. The results showed that environmental attitudes affected recycling and waste management behaviors significantly along with several demographic variables.

Long-term climate-related changes in somatic growth and population dynamics of Hokkaido chum salmon

We used multiple regression and path analysis to examine the effects of regional and larger spatial scales of climatic/oceanic conditions on the growth, survival, and population dynamics of Hokkaido chum salmon (Oncorhynchus keta). Variability in the growth of chum salmon at ages 1 to 4 was estimated from scale analysis and the back-calculation method using scales of 4-year-old adults returning to the Ishikari River in Hokkaido, Japan, during 1943–2005. Growth of chum salmon at age 1 was less during the period from the 1940s to the mid-1970s compared to the period from the mid-1980s to the present. On the other hand, growth of chum salmon at ages 2, 3, and 4 has declined since the 1980s. Path analysis indicated that growth at age 1 in the Okhotsk Sea was directly affected by warmer sea surface temperatures associated with global warming. The increased growth at age 1 led directly to higher survival rates and indirectly to larger population sizes. Subsequently, in the Bering Sea, the larger population size was directly associated with decreased growth at age 3 and indirectly associated with shorter adult fork lengths despite the lack of relationships among sea surface temperature, zooplankton biomass, and growth at ages 2 to 4. Therefore, higher growth at age 1 related to global warming positively affected the survival rate of juvenile chum salmon in the Okhotsk Sea. The higher survival rates in turn appear to be causing a population density-dependent effect on growth at ages 2 to 4 and maturation in the Bering Sea due to limited carrying capacity.

Specialisation versus diversification: A simple model for tourist cities

By developing a simple general equilibrium structure, this paper compares the welfare effects of tourism specialisation and economic diversification in tourist cities. We discovered that tourist cities with limited carrying capacity easily suffer from side effects, particularly Dutch disease, when faced with rapid tourism growth. Therefore, such cities should actively use revenue that is generated from the booming tourism sector to pursue economic diversification for the sake of sustainable urban development.

Views on peak oil and its relation to climate change policy

Definitions of fossil fuel reserves and resources and assessed stock data are reviewed and clarified. Semantics explain a large stake of conflict between advocate and critical voices on peak oil. From a holistic sources–sinks perspective, limited carrying capacity of atmospheric sinks, not absolute scarcity in oil resources, will impose tight constraints on oil use. Eventually observed peaks in oil production in nearby years will result from politically imposed limits on carbon emissions, and not be caused by physical lack of oil resources. Peak-oil belief induces passive climate policy attitudes when suggesting carbon dioxide emissions will peak naturally linked to dwindling oil supplies. Active policies for reducing emissions and use of fossil fuels will also encompass higher energy end-use prices. Revenues obtained from higher levies on oil use can support financing energy efficiency and renewable energy options. But when oil producers charge the higher prices they can pump new oil for many decades, postponing peak oil to occur while extending carbon lock-in.

Evaluating the Tourism Potential of Public Museums in Hangzhou: A Supply-Side Perspective

ABSTRACT This is a qualitative study to evaluate the tourism potential of public museums from a supply-side perspective. Nine specialized public museums in Hangzhou were evaluated based on six criteria: cultural, physical, product, experiential, marketing, and leadership. The overall tourism potential was rated as moderate for the museums in Hangzhou. Poor accessibility, isolation from tourism nodes, lack of complementarity with peripheral attractions, and limited carrying capacity impair the museums' appeal to tourists. The local government's proactive intention to develop cultural tourism and the innovative marketing efforts adopted by a few museums certainly help to enhance the museums' tourism potential.

A bio-friendly and economical technique for chronic implantation of multiple microelectrode arrays

Many neurophysiological experiments on rodents and non-human primates involve the implantation of more than one multi-electrode array to record from many regions of the brain. So called ‘floating’ microelectrode arrays are implanted in cortical regions of interest and are coupled via a flexible cable to their connectors which are fixed to the skull by a cement cap or a titanium pedestal, such as the Cereport system, which has been approved for human use. The use of bone cement has several disadvantages including the creation of infection prone areas at the interface with the skull and surrounding skin. Alternatively, the more biocompatible Cereport has a limited carrying capacity and is far more expensive. In this paper, we describe a new implantation technique, which combines the biocompatibility of titanium, a high carrying capacity with a minimal skull footprint, and a decreased chance of infection, all in a relatively inexpensive package. This technique utilizes an in-house fabricated ‘Nesting Platform’ (NP), mounted on a titanium headpost to hold multiple connectors above the skin, making the headpost the only transcutaneous object. The use of delrin, a durable, lightweight and easily machinable material, allows easy customization of the NP for a wide variety of floating electrodes and their connectors. The ultimate result is a longer survival time with superior neural recordings that can potentially last longer than with traditional implantation techniques.

Giant panda conservation science: how far we have come

The giant panda is a conservation icon, but science has been slow to take up its cause in earnest. In the past decade, researchers have been making up for lost time, as reflected in the flurry of activity reported at the symposium Conservation Science for Giant Pandas and Their Habitat at the 2009 International Congress for Conservation Biology (ICCB) in Beijing. In reports addressing topics ranging from spatial ecology to molecular censusing, from habitat recovery in newly established reserves to earthquake-induced habitat loss, from new insights into factors limiting carrying capacity to the uncertain effects of climate change, this symposium displayed the vibrant and blossoming application of science to giant panda conservation. Collectively, we find that we have come a long way, but we also reach an all-too-familiar conclusion: the more we know, the more challenges are revealed. While many earlier findings are supported, many of our assumptions are debatable. Here we discuss recent advancements in conservation science for giant pandas and suggest that the way forward is more direct application of emerging science to management and policy.

Fuzzy comprehensive evaluation model for water resources carrying capacity in Tarim River Basin, Xinjiang, China

This paper explores the method of comprehensive evaluation of water resources carrying capacity and sets up an evaluation model applying the fuzzy comprehensive evaluation method. Based on the data of nature, society, economics and water resources of the Tarim River Basin in 2002, we evaluated the water resources carrying capacity of the basin by means of the model. The results show that the comprehensive grades are 0.438 and 0.454 for Aksu and Kashi prefectures respectively, where the current water resources exploitation and utilization has reached a relative high degree and there is only a very limited water carrying capacity, 0.620 for Kizilsu Kirgiz Autonomous Prefecture, where water resources carrying capacity is much higher, and in between for Hotan Prefecture and Bayingolin Mongolian Autonomous Prefecture. As a whole, the comprehensive grade of the Tarim River Basin is 0.508 and the current water resources exploitation and utilization has reached a relative high degree. Thus, we suggest that the integrated management of the water resources in the basin should be strengthened in order to utilize water resources scientifically and sustainably.

Variation in migratory history of Japanese eels, Anguilla japonica, collected in the northernmost part of its distribution

In order to examine the variation of migratory histories in the Japanese eel, Anguilla japonica, we measured otolith strontium (Sr) and calcium (Ca) concentrations by X-ray electron microprobe analysis in A. japonica collected in a coastal brackish water lake in the northernmost part of its distribution. Two migratory types that were categorized as river eels and estuarine eels were found. Estuarine eels were dominant (85%), while ordinary diadromous eels that had entered the freshwater habitat made up only 15% of the population. The low proportion of river eels suggested that the estuarine eels that inhabit the nearby coastal areas might make a larger reproductive contribution to the next generation in this area. There was no significant difference in growth between the river and estuarine eels, which suggested that the limited carrying capacity of the adjacent river and geographical features might be more effective in determining the habitat use of the Japanese eel than the genetic feature and food abundance at the northern edge of its distribution.

Costs and Benefits of Flue Gas Desulfurization for Pollution Control at the Mae Moh Power Plant, Thailand

I. Introduction Southeast Asia has experienced a massive increase in electricity consumption over the last decade. This trend looks set to continue as industry develops and the region's population rises. Although renewable sources of energy production such as wind and solar can play in meeting energy demand, large-scale fossil-fuel-fired power stations will provide the bulk of the region's power needs for the foreseeable future. Such power stations can have massive environmental and social impacts. The need for cost-effective pollution control technologies and approaches for such plants is therefore vital. Thailand's Mae Moh power plant, with its 2,625 megawatt (MW) installation capacity, is the largest thermal lignite-fired (1) power plant in Southeast Asia, meeting approximately 18 per cent of the national power demand. There have been substantial environmental and social concerns regarding the operation of the plant, especially after the first incidence of air pollution caused by it in 1992. At that time, the plant reached its capacity of 2,025 MW--and apparently hit the ecological carrying limit of the surrounding environment. An all-time high reading of the hourly average ground level of ambient sulfur dioxide (S[O.sub.2)] concentration of 3,418 micrograms per cubic metre ([micro]g/[m.sup.3]) was observed as compared with the then hourly average Thai standard of 1,300 [micro]g/[m.sup.3]. This S[O.sub.2] level caused people in several villages near the power plant to suffer from coughs, asthmatic attacks, chest tightness and wheezing. Many of them were hospitalized. In addition to the health impacts, damage to crops, trees and livestock was also reported. Damage to rice, field crops and vegetables was obvious; the leaves of many trees withered and dropped overnight. Negative reactions from the public accelerated the decision to retrofit Flue Gas Desulfurization systems (FGDs) to the eight remaining power generation units (units 4 to 11), starting in 1994. This has resulted in substantially improved ambient air quality since the year 2000. However, the decision to install these emission control systems was undertaken without a cost-benefit analysis, i.e., the authorities had no basis to know whether the value of the damages avoided by reducing emissions would be sufficient to justify the cost of installing and operating the controls. This paper provides such an analysis, ex post. II. Background II.1 Study Site The Mae Moh power plant is located in the Mac Moh valley of Lampang province in northern Thailand, roughly 600 kilometres north of Bangkok. Lampang has an area of about 12,500 square kilomctres, of which 70 per cent is forested. Mining contributes about 17 per cent of Lampang's GDR Agriculture contributes about 8 per cent but accounts for 52 per cent of the total labour force. Half of the total farmland is devoted to paddy rice, while 23 per cent and 17 per cent area are under fruit trees and field crops, respectively. The Mae Moh District covers 855 square kilometres, of which about 70 per cent are mountainous. Most of it is situated within the national forest reserves. II.2 The Mae Moh Power Plant and Flue Gas Desulfurization Technology Owned and operated by the Electricity Generating Authority of Thailand (EGAT), the first generation unit of the Mae Moh power plant was first operated in 1978 and gradually expanded until it reached the capacity of 2,025 MW with eleven operating units in 1992, when the aforementioned S[O.sub.2] incident occurred. Shortly after the incident, EGAT installed high investment, wet scrubbing FGD systems to reduce S[O.sub.2] emissions to permissible levels. The Mae Moh power plant's expansion to units 12 and 13 had to be equipped with FGD systems at the time of construction in 1993. EGAT's plan to set up a new Lampang power plant with an additional installed capacity of 2,400 MW was aborted due to the limited carrying capacity of the environment and the negative impacts on human health and the environment. …

The Ethical Rational of Business for the Poor – Integrating the Concepts Bottom of the Pyramid, Sustainable Development, and Corporate Citizenship

The first United Nations Millennium Development Goal calls for a distinct reduction of worldwide poverty. It is now widely accepted that the private sector is a crucial partner in achieving this ambitious target. Building on this insight, the ‘Bottom of the Pyramid’ concept provides a framework that highlights the untapped opportunities with the ‘poorest of the poor,’ while at the same time acknowledging the abilities and resources of private enterprises for poverty alleviation.This paper connects the idea of business with the poor to sustainable development and especially to the notions of inter- and intragenerational justice. These principles of justice can be linked with the ‘Bottom of the Pyramid’ approach directly through the Rawlsian principles to foster holistic thinking. On this basis, the paper offers a normative-ethical reasoning of corporations’ possible responsibilities for the poorest of the poor. Today’s state of worldwide inequalities is likely to generate future tensions between the privileged western world and the uncounted mass of poor (let alone the ethical dubiousness of this status). However, it is at the same time problematic if not even impossible to improve the situation of the poor by simply copying the resource intensive western way of living to the ‘Bottom of the Pyramid’ due to the limited carrying capacity of the earth. After highlighting possible moral dilemmas which may occur through such a potential trade off, this paper concludes with an outlook on how the concepts ‘Bottom of the Pyramid’ and sustainable development could be combined.

Asian Energy and Environmental Policy: Promoting Growth While Preserving the Environment

Asia has truly experienced spectacular economic growth over the past 15 years. However, this economic progress has come at a high cost. It has led to unprecedented environmental consequences. Ecological footprint shows that, despite the fact that one-fifth of the population in Asia still lives on less than US$ 1 per day (PPP-adjusted), the region is already living beyond its ecological carrying capacity. The region is facing a dilemma. On the one hand, continued economic growth is needed to alleviate the poverty of the two-thirds of the world's poor living in this region. On the other hand, that economic growth will further place tremendous strains on the natural environment. In order to extricate itself from this difficult position, the region needs to shift the conventional pattern of develop first and then treat the pollution to a different trajectory of sustainable development. To that end, this paper examines a variety of policy responses, at national, regional and international levels, to deal with growing concerns about the environmental challenges in Asia in order to help to put the region on a more sustainable development path. In the context of national responses, special attention is paid to the following issues: coordination between the central and local governments, market-based environmental instruments and industrial policies, tougher emissions standards for mobile and stationary sources and fuel quality, policies to promote energy efficiency and the use of clean energy and biofuels, the integration of environmental policies with economic and sectoral policies, and engagement of the private sector through e.g., ecolabelling, green government procurement, corporate ratings and disclosure programs, and drawing the support of financial institutions to promote improved corporate environmental performance. It is concluded that having the right policy mix, coupled with strengthened cooperation at national, local and regional levels, will ensure continuing economic growth in the region without compromising its limited ecological carrying capacity and environmental quality.

The Manhattan Metaphor

Fixed operating costs draw a sharp distinction between endogenous growth based on horizontal and vertical innovation: a larger number of product lines puts pressure on an economy’s resources; greater productivity of existing product lines does not. Consequently, the only plausible engine of endogenous growth is vertical innovation whereby progress along the quality or cost ladder does not require the replication of fixed costs. Is, then, product variety expansion irrelevant? No. The two dimensions of technology are complementary in that using one and the other produces a more comprehensive theory of economic growth. The vertical dimension allows endogenous growth unconstrained by endowments, the horizontal provides the mechanism that translates changes in aggregate variables into changes in product-level variables, which ultimately drive incentives to push the technological frontier in the vertical dimension. We show that the potential for exponential growth due to an externality that makes entry costs fall linearly with the number of products, combined with the limited carrying capacity of the system due to fixed operating costs, yields logistic dynamics for the number of products. This desirable property allows us to provide a closed-form solution for the model’s transition path and thereby derive analytically the welfare effects of changes in parameters and policy variables. Our Manhattan Metaphor illustrates conceptually why we obtain this mathematical representation when we simply add fixed operating costs to the standard modeling of variety expansion.

Are fine roots of both shrubs and perennial grasses able to occupy the upper soil layer? A case study in the arid Patagonian Monte with non-seasonal precipitation

We tested whether both shrubs and grasses are able to develop similar active fine-root systems in the upper soil layer of the arid Patagonian Monte ecosystem with non-seasonal precipitation. We selected in the field shrub patches consisting of one isolated modal plant of the dominant shrub Larrea divaricata Cav., grass patches formed by one or more bunches of the dominant grass Stipa tenuis Phil. (15 cm diameter), and mixed patches consisting of one individual of L. divaricata with bunches of S. tenuis under its canopy. We assessed the biomass, regrowth, and activity of fine roots (diameter <1.4 mm) of each species in the upper soil (50 cm depth) of each patch type at 3-month intervals. We also measured the N concentration in fine roots to estimate the relative contribution of each species to fine-root biomass of mixed patches. We injected Li+ in the soil as a chemical tracer to detect fine-root activity of each species in the upper soil. Fine-root biomass was higher in mixed patches than in grass patches while fine-root biomass in shrub patches did not differ from the two former. We did not find differences in fine-root regrowth among patch types. Li+ injection provided evidence of active fine roots of both species in the upper soil when it was wet. N concentration in fine roots suggested the prevalence of fine roots of L. divaricata in the upper soil of mixed patches. Our results support evidence of the ability of fine roots of both the shrub and the grass species to occupy the upper soil. These findings did not support the two-layer model (H Walter, Ecology of tropical and subtropical vegetation, Oliver and Boyd, Edinburgh, 1971) and provide evidence of this model would be less applicable to arid ecosystems with non-seasonal precipitation. Further, our results highlighted some issues deserving more research such as the outcome of belowground competition between neighboring plants of both contrasting life forms, the eventual limited fine-root carrying capacity of the upper soil, and differences in fine-root lifespan between species of both contrasting life form.

Empire of Scrounge: Inside the Urban Underground of Dumpster Diving, Trash Picking, and Street Scavenging

70 Social Control, Deviance, and Law From an occupational perspective, gang units seem to afford officers less structure, greater independence, and more excitement, along with special status. Officers often joined a gang unit with this expectation, hop- ing to be real “crime fighters,” while those stakeholders in the officers’ institutional envi- ronment often placed greater emphasis on functions such as intelligence and preven- tion. And while the great expectation was that gang units would embed themselves solidly in the community policing approach, this study provided little evidence of that. In- stead, the authors found, overall, poor train- ing and only a general appreciation for com- munity policing, without any significant and meaningful integration of gang policing and community policing (ironically, Inglewood’s gang unit was somewhat of an exception to this, even though the department had not formally implemented community policing!). Worse, the study produced some evidence of racial profiling, harassment, falsification of records, and fabrication of pretexts for ag- gressive enforcement actions. Such tactics, according to this study, rose to the level of Standard Operating Procedures CSOPS) in two of the four study sites. Predictably, such tactics fueled gang resentment, with the un- intended consequence of enbancing gang solidarity and cohesion. The authors found that most of these units were physically and organizationally disconnected and did not engage in the kind of problem-oriented com- munity policing that was widely expected. Instead, they adopted a much more tradi- tional style of interacting with the communi- ty. Although the representativeness of these four gang units cannot be assumed, the find- ings of this study generally parallel other scholarly studies of attempts to implement and sustain reforms in traditional police or- ganizations. Contemporary Sociology 36, 1 Empire of Scrounge: Inside tbe Urban Underground of Dumpster Diving, Trasb Pic/eing, and Street Scavenging, by Jeff Ferrell. New York, NY: NYU Press, 2005. 235 pp. $22.00 paper. ISBN: 0814727987. JACK KATZ University of California, Los Angeles For about eight months in 2002, Jeff Ferrell was a “Dumpster diver and trash picker” in Fort Worth, Texas. He began scrounging af- ter resigning from one tenured sociology job and before nailing down the next. Ferrell could rely on a modest house, a working partner, and a trickle of royalties from previ- ous books, but he mainly “survived” by trans- forming what he found into personal posses- sions or cash at junk/antique stores and re- cycling centers. Ferrell weaves carefully detailed fieldnotes into 200 continuously compelling pages. He reveals the distinctive practical activities re- quired to scrounge successfully; provides subtle appreciations of how scroungers inter- act with others, such as other scroungers, res- idents, police, and managers of recycling centers; and he conveys the sensual-aesthet- ic dimensions of trash picking in a stream of surprisingly inspiring sociological reveries. Labeling his analysis ethnomethodologi- cal, Ferrell details how the distinctive prac- tices of scrounging are based on routine cog- nitions, which in turn are the product of the scrounger’s uniquely crafted folk sociology. Seeing trash within an approaching time horizon defined by the garbage collector, scroungers discipline themselves tightly to the calendar. Scroungers interpret as they dig, inferring a move, divorce, or death in a given trash pile, picking up much more about abruptly abandoned social lives than they take away physically, As an interaction analyst, Ferrell appreci- ates how scroungers interact with versions of themselves at different points in time and with others they never directly meet. Every scrounger, whether Ferrell on his bicycle, an apparently homeless man pushing a shop- ping cart, or the driver of a pickup truck, has a limited carrying capacity; thus all must con- stantly choose. Anticipating the journey ahead, scroungers “dress” the items they pick up, discarding less useful and heavier parts,

Cancer dissemination: A consequence of limited carrying capacity?

Assuming that there is feedback between an expanding cancer system and its organ-typical microenvironment, we argue here that such local tumor growth is initially guided by co-existence rather than competition with the surrounding tissue. We then present a novel concept that understands cancer dissemination as a biological mechanism to evade the specific carrying capacity limit of its host organ. This conceptual framework allows us to relate the tumor system's volumetric growth rate to the host organ's functionality-conveying composite infrastructure, and, intriguingly, already provides useful insights into several clinical findings.

DISPERSAL PER RECRUIT: AN EFFICIENT METHOD FOR ASSESSING SUSTAINABILITY IN MARINE RESERVE NETWORKS

Marine reserves are an increasingly important tool for the management of marine ecosystems around the world. However, the effects of proposed marine reserve configurations on sustainability and yield of populations are typically not estimated because of the computational intensity of direct simulation and uncertainty in larval dispersal and density-dependent recruitment. Here we develop a method for efficiently assessing a marine reserve configuration for persistence and yield of a population with sedentary adults and dispersing larvae. The method extends the familiar sustainability criteria of individual replacement for single populations based on eggs-per-recruit (EPR) to spatially distributed populations with sedentary adults, a dispersing larval phase, and limited carrying capacity in the settlement-recruit relationship. We refer to this approach as dispersal-per-recruit (DPR). In some cases, a single DPR calculation, based on the assumption that post-settlement habitat is saturated (i.e., at maximum recruitment), is sufficient to determine population persistence, while in other cases further iterative calculations are required. These additional calculations reach an equilibrium more rapidly than a full simulation of age- or size-structured populations. From the DPR result, fishery yield can be computed from yield-per-recruit (YPR) at each point. We assess the utility of DPR calculations by applying them to single reserves, uniformly distributed systems of reserves, and randomly sized and spaced systems of reserves on a linear coastline. We find that for low levels of EPR in fished areas (e.g., 10% or less of the natural, unfished EPR when post-settlement habitats are saturated by 35% of natural settlement), a single DPR calculation is sufficient to determine persistence of the population. We also show that, in uniform systems of reserves with finite reserve size, maximal fisheries yield occurs when the density of reserves is such that all post-settlement habitat is nearly saturated with settlers. Finally, we demonstrate the application of this approach to a realistic proposed marine reserve configuration.

Regional scale analysis of the altimetric stream network evolution

Abstract. Floods result from the limited carrying capacity of stream channels when compared to the discharge peak value. The transit of flood waves - with the associated erosion and sedimentation processes - often modifies local stream geometry. In some cases this results in a reduction of the stream carrying capacity, and consequently in an enhancement of the flooding risk. A mathematical model for the prediction of potential altimetric stream network evolution due to erosion and sedimentation processes is here formalized. It works at the regional scale, identifying the tendency of river segments to sedimentation, stability, or erosion. The model builds on geomorphologic concepts, and derives its parameters from extensive surveys. As a case study, tendencies of rivers pertaining to the Valle d'Aosta region are analyzed. Some validation is provided both at regional and local scales of analysis. Local validation is performed both through a mathematical model able to simulate the temporal evolution of the stream profile, and through comparison of the prediction with ante and post-event river surveys, where available. Overall results are strongly encouraging. Possible use of the information derived from the model in the context of flood and landslide hazard mitigation is briefly discussed.

An island approach to industrial ecology: towards sustainability in the island context

Many fields of study have employed geophysical islands in experimental design with a great deal of success. An island is a closed and bounded system in many respects and presents a manageable unit of study. The island microcosm has been the basis for significant advances in areas such as evolutionary biology, ecosystem ecology and physical anthropology. The same properties that make islands so useful to scientists present island populations with pressing sustainability challenges of limited resource availability and natural carrying capacity. This paper discusses the characteristics of the island context to show the severity and immediacy of these challenges. Based on this discussion, it is apparent that new approaches are needed to address sustainable development on islands. Island systems and the study of industrial ecology, which examines industry embedded within the finite natural environment, have much to gain from one another in this respect. Several industrial ecology case studies, primarily drawn from research in Puerto Rico, are presented to illustrate the compatibility of islands as a study unit in this field. Industrial ecology presents new solutions to the challenges of sustainable island development, while well‐defined island systems offer a unique opportunity for the approach of industrial ecology.

A survey of traditional beef cattle farmers in Southern Botswana: Demographic parameters and adoption of certain improved management practices

The aims of this survey were to characterise traditional beef cattle farmers and evaluate the adoption of certain improved management practices by these farmers in southern Botswana. The study was carried out over a period of 8 months i.e. March to October 2002. Demographic data, marital status, level of education, use of vaccination, record keeping, breeding system in use and management system used were collected from randomly chosen farmers using a formal questionnaire. A total of 71 beef cattle farmers were interviewed in 50 different villages of Kgatleng, Kweneng and Southern Districts of Botswana. Data were analysed using Procedure Frequency in Statistical Analysis System. The majority of the farmers were males (87%), aged over 35 years (83%), married (75%) and with either primary or no education (62%). The majority of the farmers (86%) practiced extensive management and did not keep production records (83%). Most farmers (99%) supplementary feed their animals and all farmers (100%) vaccinate their animals against certain diseases. The majority of the farmers (94%) did not control the breeding season of their herds and the majority (87%) also let bulls run with cows all year round. Most of the sampled farmers (56%) used artificial insemination (AI) to improve the genetic quality of their cattle. The constraints, which prevented farmers from using AI were long distances (over 60 km) between cattle post and AI camp centre, limited carrying capacity of the AI camps, small numbers of cows permitted per farmer per breeding season (5) and cows which were pregnant during stocking at the beginning of the breeding season. Farmers should be encouraged to know how to read and write to enable them to communicate better. Farmers should also be taught the benefits of controlling breeding and use of modern management practices such as use of AI and keeping production records. More AI camps should be set up to reduce the distance travelled by those farmers who are far way from an AI camp centres and also to accommodate more cows. SA Jnl. Agric. Ext. Vol. 33 2004: 11-19