The impact of decentralised forest management on charcoal production practices in Eastern Senegal

In accordance with Senegal’s decentralisation policy, important forest management tasks, including the right to allocate charcoal production rights, have been transferred to rural councils. This paper investigates the impact of these institutional reforms on charcoal production practices using the environmental entitlement framework developed by Leach et al. [Environmental entitlements: dynamics and institutions in community-based natural resource management. World Development 27 (2) (1999) 225]. The councils have not been able to turn their new endowments into entitlements because they lack sufficient strength and legitimacy. Informal institutions, notably the coalition between merchants, state agents and village chiefs, continue to run the charcoal business and are hardly affected by decentralisation efforts. Most rural people, especially those relying solely on agriculture for sustenance, do not benefit at all from the charcoal trade. They do suffer from the environmental costs it brings with it, however. Although tensions between pro-exploitation actors and pro-conservation actors are evident, the pro-exploitation actors’ firm grip on the informal institutions will probably lead to a prolonged subversion of the laws that seek to enhance local control and to sustain the forest.     

Scientific advice in integrated ocean management: The process towards the Barents Sea plan

It is widely held that integrated management of ocean areas needs to be based on integrated scientific advice. Such advice crosses disciplinary and traditional sector boundaries. This paper aims to provide insight into the role of science and scientific knowledge in a process towards integrated ocean management. It does so by exploring the organization of the process towards the integrated management plan for the Barents Sea-Lofoten area in Norway. It sheds light on the complexity of management questions in a context characterized by uncertainty and political controversy, largely concerning petroleum activity. Scientists were asked to provide a dynamic view on these issues and have delivered important material that furthers the task of policy development. However, there is a persisting lack of understanding about the consequences of human impact on the ecosystem. The paper finishes by pointing at the need for a larger societal discussion on what activities we consider appropriate, considering the limits of science to provide the knowledge base for questions that transcend the environmental domain.     

Changes in structural and functional diversity of nematode communities during a spring phytoplankton bloom in the southern North Sea

The response of nematode communities to the sedimentation of a spring phytoplankton bloom in a sandy, well-oxygenated sediment at a single station (station 330) in the Southern North Sea was investigated monthly from early March to July 1999. Both structural (nematode density, diversity, vertical distribution and community composition) and functional (feeding type distributions, number of species within feeding groups) characteristics showed considerable changes shortly after the arrival of fresh organic material at the sediment surface. The general increase in numerical densities and diversity was related to changes within the groups of selective deposit-feeding and epistrate-feeding nematodes. It is hypothesised that sedimentation and subsequent remineralisation of fresh organic matter during the spring phytoplankton bloom result in an increase of suitable food items (both living and dead). This, combined with the availability of oxygen, creates conditions in which many nematode species can co-exist.     

The uncertainties of precaution: Zero discharges in the Barents Sea

This paper describes and analyzes the application of the precautionary principle in the regulation of operational discharges from offshore petroleum activities. Norway implemented a zero discharge policy in line with international agreements. However, companies are obliged to follow considerably stricter requirements in the Barents Sea compared to other parts of the Norwegian Continental Shelf. This paper follows the development of the zero discharge measure and analyzes what it implies for activities in the Barents Sea. Several “uncertainties of precaution” are discussed, which relate to technological issues, monitoring, compliance and unintended environmental consequences. Precautionary action should be scrutinized for its proportionality: how do the benefits of the measure relate to the technological, financial and environmental costs? It is concluded that the most (cost-) effective solutions that could lead to the lowest total environmental harm are not always the solutions that are most politically feasible.     

Climate and global grain yield variability

Historical grain yields from several countries were analyzed to determine the variability of grain yield. This was accomplished by assuming a linear technology trend and analyzing the deviations from this trend. The deviation was assumed to be primarily an effect of weather. Using 10 percent deviation from trend as a threshold, it was determined that for each of seven countries the probability of a poor yield year ranged from 17 in India and the United States to 33 percent in Canada and the U.S.S.R. The probability of two consecutive poor wheat yield years was highest in Canada (17 percent) and lowest in Argentina (6 percent). The probability of a poor year occurring in the same year in both the United States and the U.S.S.R. was about 7–8 percent. The highest variability in yield has occurred in Canada, but variability in India has increased substantially since the 1960's.     

Impact of discards of beam trawl fishing on the nematode community from the Tagus estuary (Portugal)

The impact of dead discards, originating from beam trawl fishing on the nematode community from the Tagus estuary was investigated in terms of vertical distribution of the dominant nematode groups. Sediment cores were collected from a mud-flat from the Tagus estuary. Crangoncrangon (Linnaeus, 1758) carcasses were added to the surface of the cores, simulating the settling of dead discards on the sediment. The vertical distribution of the dominant nematode groups was determined up to 4 cm deep at four different moments in time post deposition (0, 2, 4 and 6 h) and compared to control cores. The C.crangon addition to the sediment led to the formation of black spots and therefore oxygen depleted areas at the sediment surface. The Chromadora/Ptycholaimellus group, normally dominant at the surface layer, migrated downwards due to their high sensibility to toxic conditions. Sabatieria presented the opposite trend and became the dominant group at the surface layer. Since Sabatieria is tolerant to oxygen stressed conditions and high sulphide concentrations, we suggest that it migrated opportunistically towards an unoccupied niche. Daptonema, Metachromadora and Terschellingia did not show any vertical migration, reflecting their tolerance to anoxic and high sulphidic conditions. Our study showed that an accumulation of dead discards at the sediment surface might therefore alter the nematode community vertical distribution. This effect is apparently closely related to toxic conditions in the sediment, induced by the deposition of C.crangon at the sediment surface. These alterations might be temporal and reflect an adaptation of the nematode community to dynamic intertidal environments.