Von Hippel and von Hippel (1998) suggested that Viagra had the potential to replace an existing demand for certain wildlife species used in traditional Chinese medicine (TCM) to treat erectile dysfunction (ED). Von Hippel and von Hippel (2002) attempted to show that this potential is becoming a reality.

Feral swine (Sus scrofa) adversely affect the environment in many of the places where they have been introduced. Such is the case in Florida, but quantification and economic evaluation of the damage can provide objective bases for developing strategies to protect habitats. Swine damage to native wet pine-flatwoods at three state parks in Florida was monitored from winter 2002 to winter 2003. Economic valuations of damage were based on the US dollar amounts that wetland regulators have allowed permit applicants to spend in attempts to replace lost resources. The parks had different swine management histories and the damage patterns differed among them over time. Swine were intensively removed in 2000 from the first park, and it initially had the lowest habitat damage at 1.3%, but as a result of natural and artificial population growth this damage rose to 5.4% by the conclusion of the study, and was valued at US$ 19 193–36 498 ha−1. The second park had no history of swine harvest and, over the monitoring period, damage escalated from 2.6%–6.4%, with an associated value of US$ 22 747–43 257 ha−1. Swine were managed as game animals in the third park prior to its inclusion into the state parks system in 2000. Within this park, the proportion of area damaged decreased from 4.3%–1.5%, valued at US$ 5 331–10 138 ha−1. This decrease may be a result of human activities associated with development of the park's infrastructure causing dispersal of animals conditioned to avoid humans by hunting. Damage was highly scattered in each park, as evidenced by a much higher proportion of sampling sites showing damage than the actual proportion of land area damaged. The dispersed nature of small amounts of damage would increase the effort required to recover habitat and thus damage value estimates are probably conservative. It was also impossible to incorporate values for such contingencies as swine impact to state and federally listed endangered plants in the parks, some of which are found nowhere else in the world.

Slash-and-burn is a widespread agricultural system practised by more than 250 million people in tropical regions. It is sustainable when fallow periods allow for the restoration of organic matter and nutrient losses that occur during the cropping phase. However, fallow periods have been reduced in most slash-and-burn systems as population density has increased. The consequent landscape structure modification occurring throughout this process can affect several ecological processes. As a first step in understanding these modifications, the present study aimed to test the effects of fallow period reduction on landscape structure by examining a total of 34 lots of 25–250 ha each in the north-east of the Brazilian Amazon. Sixteen lots with long fallow periods (about 10 years) were compared with 18 lots where fallow periods were reduced to c. four years. The reduction in fallow period created a more homogeneous landscape, largely dominated by agricultural and young secondary vegetation. The main mechanism leading to this homogenization was a more intensive use of initial secondary vegetation for agriculture. On average, the percentage of land used more intensively for agriculture was four times higher in short fallow period areas than in long-period areas. The increase in agricultural area is related to both an increase in the number of agricultural fields and also to an increase in the area of these fields. The proportions of forest and old secondary vegetation in the landscape were reduced as a consequence of a reduction in patch size, without significant fragmentation or patch losses. These structural changes appeared to be more usual in large properties belonging to several families. Further studies are needed to understand the consequences of these modifications for landscape functioning, but it is possible to speculate, based on previous studies, that these structural changes can lead to a reduction in the speed of regeneration processes.

In recent years, wildlife policies that consider the participation of stakeholders have been promoted. An understanding of the stakeholders' attitudes towards conservation and existing policies are critical in designing new policies or sustainable conservation strategies. This paper examines stakeholders' (local people, park staff and professional hunter guides) attitudes, towards the Bénoué Wildlife Conservation Area (BWCA) and towards Cameroonian wildlife policy. The BWCA encompasses the Bénoué National Park and its surrounding hunting concessions that also include some villages. Both the Park and the hunting concessions are two categories of protected areas. Data were collected using informal interviews and questionnaires administered to 114 households from three communities, 17 park staff and seven professional hunter guides. Local people's attitudes towards protected areas depended on the management category of the particular protected area. Local people were positive towards the existence of the Park, but negative towards the system of hunting concession areas. There was local variation between communities concerning these attitudes. Local people were generally positive to maintaining the present Park area, but preferred a reduction in the size of the hunting concessions. Both Park staff and professional hunter guides expressed concern about present management strategies and the extent of illegal resource exploitation. Despite having poor knowledge of the current Cameroonian wildlife policy, most of the local households expressed support for it, but called for increased local involvement in management, off-take and the harvesting of benefits from both Park and hunting concession activities. The Park staff were sceptical about local participation in this context and saw such endeavours as a threat to a sound biodiversity management scheme. The findings indicate the need to strengthen current wildlife policy, promote the involvement of local people and empower the Park staff, both in terms of resources and in terms of skills in interacting with local people. The revised policy should be designed so as to vary according to the category of protected area and allow site-specific adaptations. Local people must experience reduced incurred costs and increased incomes from the Park. An environmental education programme is recommended to extensively disseminate the policy to user groups in the area.

There are many environmental and socio-economic concerns about the shrimp aquaculture industry. This study, based on interviews, direct observations and literature reviews, shows that the Indian hatchery industry is heavily dependent upon the continuous support of natural resources and ecosystem services generated by marine, freshwater and terrestrial ecosystems. The mangrove ecosystem support area (‘ecological footprint’) needed to supply the hatcheries with Penaeus monodon shrimp broodstock, and the aquaculture grow-out ponds with postlarvae, exemplify the dependence on external ecosystems. Each hectare of mangrove in the Godavari River delta generated an annual fisheries catch of 0.8–1.5 P. monodon spawners (gravid females), valued at US$ 92–184. The entire Godavari mangrove delta had a partial gross economic value of US$ 3.0–6.0 million per year for the provision of shrimp spawners alone. The average hatchery, producing 75 million postlarvae annually, had an ecological footprint of 534 ha mangrove for the life-support input of shrimp spawners. The ecological footprint of intensive shrimp ponds was up to 11 times the pond area for postlarval input alone. The shrimp ponds in the State of Andhra Pradesh needed 35 000–138 000 ha of mangroves to satisfy the spawner requirement to hatcheries, and this implied a need to appropriate mangroves in other regions. Hatcheries were prepared to pay up to US$ 2000 for a single shrimp spawner, which also illustrated that the mangrove support areas regionally available were too small. Other concerns about the industry are the net loss of employment if hatcheries replace wild postlarvae collection, the extensive use of groundwater creating direct resource-use conflicts, by-catch problems in broodstock fisheries, and pollution by effluents. The risk of hatcheries introducing, amplifying and propagating disease affecting both cultured organisms and wild biota is another concern that can, and should, be addressed.

Reactivation of sand drift is a common phenomenon in arid areas and needs suitable surface vegetation in association with overstorey trees for better stabilization. Regeneration and survival of Cassia angustifolia seedlings were studied in relation to different adult neighbours and soil water content with a view to developing effective surface vegetation and control of sand drift. Acacia tortilis, Prosopis juliflora and Calligonum polygonoides were the experimental adult neighbours. Observations were recorded at distances of 0–1.0 m (inner canopy [IC] zone), 1.0–1.5 m (outer canopy [OC] zone) and 1.5–2.5 m (outside the canopy [OS] zone) from the neighbours. Seeds and regenerated seedling densities were higher in the C. polygonoides plot than the other two neighbours and the control plots. The density was higher in the OC zone of the C. polygonoides and P. juliflora plots, the OS zone of the A. tortilis plot and the IC zone of the control plot. Both inter- and intraspecific competition resulted in high mortality during July–October in A. tortilis and P. juliflora plots. Seedling survival decreased in February and June, but the density, which was greater in the IC zone, was positively correlated with that in July and with the soil water content (SWC). The ultimate survival of seedlings was higher in the neighbour inclusion than control plots. The soil water content (SWC) was generally higher in the Calligonum polygonoides plot than that in the A. tortilis and P. juliflora plots. With distance from the adult neighbours, the SWC increased in the 25–50 cm and 50–75 cm and decreased in the 0–25 cm soil depth layers. Shoot height and biomass of one-year-old C. angustifolia seedlings were higher in the C. polygonoides plot than in the plots of other neighbours. A negative relative neighbour effect for most of the growth variables suggests that the adult neighbours facilitated regeneration, survival, growth and biomass of C. angustifolia seedlings. C. polygonoides was the best neighbour, with better soil water content at depth and the most positive influence on seedling growth; it is therefore a suitable planting partner for C. angustifolia in promoting the effective stabilization of dunes.

Selective logging applied in tropical forests is based on one universal criterion: a minimum diameter cutting limit for all commercial timber species. Minimum diameter cutting limits in mixed dipterocarp forests of the Malesia region lead to high felling intensities (10–20+ trees ha−1). Such extraction rates create massive stand damage (>50% of the remaining tree population), which has a negative impact on the regeneration and growth of many harvested dipterocarp species. As such, the minimum diameter cutting limit approach is seldom compatible with sustainable forest management. Where basic ecological characteristics of the commercial species are considered in timber harvesting prescriptions, mixed dipterocarp forests appear capable of sustained timber yields, habitat conservation, and providing other goods and services. This paper first presents the main silvicultural systems developed in mixed dipterocarp forests of Western Malesia and then reviews current knowledge of dipterocarp biology to finally develop guidelines aimed at improving the ecological sustainability of production forests of Western Malesia. These guidelines, a pragmatic reflection of science and ‘best guess’ judgement, include: (1) integration of reduced-impact logging practices into normal management operations; (2) cutting of eight trees ha−1 or less (with a felling cycle of 40–60 years to be determined according to local conditions); (3) defining minimum diameter cutting limits according to the structure, density and diameter at reproduction of target species; (4) avoiding harvesting species with less than one adult tree ha−1 (diameter at breast height [dbh] ≥ 50 cm over an area of 50–100 ha); (5) minimizing the size and connectivity of gaps (<600 m2 whenever possible); (6) refraining from treatments such as understorey clearing; and (7) providing explicit protection for key forest species and the ecological processes they perform. Further refinement is encouraged to allow for local conditions, and for other forest types.

Despite the vast destruction caused by recent fires in Sumatra's forested areas, there have been few analyses of their spatial variability and causes. Various combinations of predisposing and land-use factors in space and time may cause fires. For each variable, fire densities were calculated to assess the spatial and temporal association between natural and cultural landscape variables and fire occurrence in four provinces in Sumatra, Indonesia for a non-dry year (1999) and a dry year (1997). This was complemented by a single multivariate logistic regression for the two years over the four provinces with fires as the dependent variable and land use and predisposing factors as independent variables. The provincial analyses showed that fires are determined by multiple, interacting factors and that these factor interactions are not the same in all provinces. In the non-dry year, the factors were only weak determinants of fires and only few determinants were common to all provinces (presence of undisturbed forests, elevation, smallholder area, land allocation to production area). In the dry year, more determinants of fires were found to be common to all provinces (presence of undisturbed forests, elevation, land allocation to production or conversion areas, presence of plantations, distance from roads). This led to the identification of pathways that increased fire probability. The first step was the allocation of land to different land-use types and stakeholders by national policies. If allocated to large-scale landowners, fires were more likely to occur in plantations, especially in the dry year. Logging concessions did not play a major role in increasing the incidence of fire. However the strongest increase in fire probability was outside the areas under use, in undisturbed forests. We conclude that areas not yet used by large-scale landowners were more prone to fire, indicating a serious threat to the remaining forests in this region.

Marine sanctuaries are increasingly being promoted as tools for conservation and fisheries management. This study investigates the effects of protection over 19 years on substrate composition and fish communities in four marine sanctuaries and corresponding non-sanctuary areas in the Philippines and examines the importance of community support, management measures and enforcement of regulations on these ecological effects. Between 1981 and 2000, substrate cover variables were measured using line transects with scuba and snorkel surveys, and fish censuses (identification to family level) were conducted using scuba within a 500 m2 area. Semi-structured interviews collected data on community support for the sanctuaries, and observations and interviews established management and enforcement aspects of the sanctuaries. Over time, all sanctuaries showed improvements, or maintenance of, ecological variables compared with pre-enforcement times, with maintenance of hard coral cover and average increases of 8.3% in fish species richness and 54.9% in fish abundance. In comparison, non-sanctuary areas showed maintenance of the status quo or declines in ecological variables. However hard coral cover, fish abundances and fish species richness showed significant declines as well as increases in sanctuary areas. Community, management and enforcement factors were significantly related to positive ecological trends in sanctuary areas; management and enforcement were related to a wider variety of ecological factors than community score. Community support was significantly related to an increase in hard coral cover in deep areas. Enforcement of regulations was significantly related to an increase in abundance of fishery target fish species in sanctuary areas, and simple management measures were significantly related to an increase in abundance of large predators. Supportive communities that voluntarily implemented sanctuary regulations, improved enforcement, and small discrete cohesive communities may have facilitated the process of building this community support. Well-enforced sanctuaries that showed an increase in abundance of target species may have contributed to the maintenance of fish yields in adjacent non-sanctuary areas. The effects of sanctuary implementation varied on a case-by-case basis, influenced by environmental, biological, physical and human factors. However, a combination of community support, management measures and enforcement of regulations contributed towards positive ecological trends in sanctuary areas.