Fresh waters offer intricate diversity, from small hot springs to huge floodplain systems, from temporary pools to big lakes, each containing significant proportions of the world's stock of inland water. In this collection is a great diversity of organisms, and of interesting relationships amongst them and with traditional peoples. There is thus every reason to value the diversity of freshwater systems and reasons for conserving them, from the ethical to the economic, can be listed no less than for terrestrial systems.

The approaches currently used to conserve the diversity of terrestrial systems, however, may be counter-productive for the conservation of freshwater systems. These approaches include emphasis on individual, often charismatic species, or on areas of high quality that can be boundaried and protected (fortress conservation) and rest on arguments that all species must be maintained for the system to function. The current decline in world biodiversity under our increasing impact suggests that these are failing approaches even for terrestrial systems. They may be disastrous for freshwater ones.

A general decrease in abundance of wild plant species used as sources of fuel suggests that more detailed information is urgently needed on species-level trends and their conservation. Such studies have not been carried out so far in India and elsewhere; we therefore quantified the species-wise extraction of fuel from a site (Gori Ganga Valley) in Askot Wildlife Sanctuary in the Kumaun Himalaya. In all, 31 species (26 trees and 5 shrubs) were used as fuel, of which 14 were native to the Himalaya. Utilization patterns, distributions, probabilities of use (PU), resource use indices (RUI), preferences and availabilities in forest communities of these species were determined. Use pattern did not vary much amongst low altitude villages (Similarity: 52–74%), whereas along the vertical (elevational) gradient it varied considerably (Similarity: 15–31%). Woodfordia fruticosa (L.) Kurz, Pinus roxburghii Sarg., Quercus leucotrichophora A.Camus, Macaranga pustulata King ex Hk. f., Quercus lanuginosa Don, Engelhardtia spicata Bl. and Mallotus philippensis (Lamk.) Muell. contributed most to collections, while Pyracantha crenulata (Don) Roem., Syzygium cuminii (L.) Skeels, Alnus nepalensis Don and Bauhinia vahlii Wt. & Arn. were in lesser demand. W. fruticosa, P. roxburghii, M. pustulata, Casearia elliptica Willd., E. spicata, M. philippensis, Q. leucotrichophora and Phoebe lanceolata (Nees) Nees showed high values of PU and RUI, indicating high pressure. High density of P. roxburghii, Rhododendron arboreum Sm., Q. lanuginosa, Q. leucotrichophora, Lyonia ovalifolia (Wall.) Drude, C. elliptica and M. pustulata amongst trees and Maesa indica A.DC., P. crenulata and W. fruticosa amongst shrubs exhibited high density but the remaining species showed low density indicating their possible depletion. Intensive management of natural habitats of species highly-preferred for fuel, diversification of choice of species from natives to non-natives, large scale propagation of highly preferred taxa and plantation of seedlings in the degraded, uncultivated and marginal lands through peoples’ participation should promote conservation and management of fuel resources.

Coastal sand dunes are considered to be amongst the most fragile natural systems, however they may be subject to high-intensity recreational stresses. The aim of this study was to assess the response of soil and annual plants of stabilized Mediterranean coastal dunes in Israel to various short-duration pedestrian and motorcycle traffic intensities. A standard experimental procedure was used comprising of 0, 50, 100, 300 and 500 pedestrian passes, and 0, 20, 50, 100, 200 straight and 150 turn motorcycle passes. The response of annual plants was assessed by determining ground cover, height, species richness and diversity, and soil penetrable depth, organic matter and moisture content. The pedestrian traffic did not affect the cover of annual plants, however; mean annual height, species richness and species diversity were significantly but temporarily affected by 500 passes. Conversely, motorcycle passage had an immediate significant impact on annual plants at all traffic intensities. The maximum effect on plants was observed in the wheel tracks and in the turn lanes. The mean annual ground cover and height were less sensitive measures than species richness and diversity for determining the overall impact of motorcycles on the area. Impact of pedestrian and motorcycle traffic on soil was detected only as an increase in penetrable depth, which was significant at 300 and 500 pedestrian passes, and at 100, 200 straight and 150 turn motorcycle passes. The soil and herbaceous vegetation of Mediterranean stabilized coastal dunes is relatively resistant and shows recovery potential to recreational impacts.

Riparian vegetation is vulnerable to human impact worldwide, and this is especially so in arid areas, yet there have been few quantitative studies and this is especially so in Spain. The state of the riparian vegetation along three major rivers and seasonal watercourses of south-eastern Spain was evaluated during 1992–93, using the species composition and community structure in watercourses of different sizes under different management. Reaches of the watercourses were classified using five vegetation indices, namely percentage cover, species richness, degree of connectivity between patches of the plant communities, number of exotic species, and evidence of natural regeneration. With the integration of these into one index, the degradation state of the riparian vegetation in each reach was quantified. In addition, types of human activities exerting the greatest impact were noted, and a scale to evaluate the intensity of each impact was established. The indications are that agriculture has very substantially altered the natural vegetation, and this index has served to highlight the most altered zones, and thus those in most urgent need of restoration. Less-degraded zones could serve as models and sources of plant species for future restoration. The degradation index made it possible to establish quickly, easily, and with a high degree of accuracy, the state of conservation of the riparian vegetation in the study area.

Reform of the European Union's Common Agricultural Policy (CAP), especially through Regulation 2078/92, provided a dual role for farmers as food producers and stewards of the environment and the countryside. Implementation of integrated pest management (IPM) in greenhouse enterprises in Greece is a part of this effort. In this study, the effectiveness of the adoption and implementation of IPM practices in greenhouse vegetable cultivation in Central Macedonia (Greece) was assessed. Eighty-six farmers enrolled in an IPM programme and 28 conventional greenhouse farmers were selected and interviewed in 1997, using a questionnaire designed to assess their behaviour in the greenhouse and examine their attitudes towards the environment. Wide adoption of IPM was found still to face many hindrances, mainly due to the lack of appropriate technical and advisory support by the agricultural local services, and farmers' low level of knowledge of IPM. Comparisons between IPM and conventional farmers revealed that: (1) the two groups' behaviour did not differ significantly in greenhouse production practices, but (2) IPM farmers were more aware of the new environmental dimension of the CAP, and (3) they expressed more concern about the negative effects of modern agriculture on nature, than conventional farmers.

Conflicts between local people and protected area managers are a common problem in developing countries, but in many cases there has been little attempt to comprehensively characterize the underlying problems. Resource uses, management practices, economy and people's perceptions of problems and likely solutions were analysed in two villages near and two villages away from the core zone of Nanda Devi Biosphere Reserve in the Indian Himalaya. Agriculture, although practised on less than 1% of the area, was the primary occupation of local people. Six annual crops of a total of 22 and all four horticultural crops on private farms were damaged by wildlife, but Reserve management provided compensation only for livestock killing by wildlife and compensation amounted to only 4–10% of the total assessed monetary value of killed livestock. A variety of wild plant products were used locally but 27 were marketed by more than 50% of surveyed families; income from wild products was substantially lower than that from crops and livestock. A sociocultural change from a subsistence to a market economy, together with changes in traditional land/resource rights and institutions, has led to a number of changes in land-use and management practices. The livestock population has declined, agricultural area has remained the same and people have started cultivating medicinal species in the last 20 years. These changes seem complementary to the goal of conservation. However, changes such as abandonment of some traditional food crops and stress on cash crops lacking fodder value, requiring substantial manure inputs derived from forest litter and livestock excreta, and causing severe soil erosion, seem to counter the goal of environmental conservation. Some government-managed Reserve Forest sites were similar to the Community Forests in terms of species richness, basal area and soil physico-chemical properties. Two Reserve Forest sites showed basal areas of 160.5–191.5 m2/ha, exceeding the highest values reported so far from the region. The formal institutional framework of resource management seems to be not as effective as the traditional informal system. The Reserve Management Plan lays more emphasis on legal protection than on the sustainable livelihood of local communities and has led to conflicts between local people and reserve managers. Plantation of fodder and medicinal species in degraded forest lands, suppression of economic exploitation of local people in the market, enhancement of local knowledge of the economic potential of biodiversity, incentives for cultivation of crops with comparative advantages and lesser risks of damage by wildlife, and rejuvenation of the traditional involvement of the whole village community in decison-making, could be the options for resolving conflicts between people and protected areas in this case.

Human occupation and development of alluvial river floodplains are adversely affected by river channel lateral migration, which may range as high as several hundred metres per year. Reservoirs that reduce the frequency and duration of high flows typically reduce lateral migration rates by factors of 3 to 6. The ecology of riverine corridors is dependent upon the processes of erosion and sedimentation, which lead to lateral migration. Multiple-objective use of floodplains adjacent to active rivers therefore requires tools for assessing the probability and magnitude of channel movements. Existing approaches for predicting river channel movement may be classified as empirical or mechanistic, and are inadequate for widespread application. The Missouri River downstream from Fort Peck Dam in Montana, a major alluvial river with flow highly perturbed by regulation, was selected for case study. Maps and aerial photographs were available before and after dam construction. This imagery was analysed by digitizing channel centrelines at successive coverages under pre-dam and post-dam conditions, and mean migration rates were computed by bend and by reach. The mean rate of channel centreline migration fell from 6.6 m yr-1 to 1.8 m yr-1 after impoundment. Bend-mean channel activity rates were only weakly correlated with variables describing channel form and geometry. Results indicate that flow regulation for flood control and hydropower production typical of the study reach had profound effects on river corridor dynamism, with implications for habitat type distribution and ecosystem integrity.

While some researchers suggest that higher taxon richness be used for setting conservation priorities, others claim that even data on ‘accepted species’ are inadequate, and that documentation of the finest patterns of differentiation is needed. The significance of taxonomic resolution was assessed using distributional data for 798 Andean bird species, which were recorded in 15′ × 15′ grid cells. This dataset was used because of the fine spatial resolution and the complex biogeographic patterns in this region. The primary database served as a template for creating three new databases, namely for genera, broadly defined biospecies and phylogenetic species. With this spatial resolution, the taxic richness ‘hotspots’ were roughly the same on all taxonomic levels, but the ratio between generic and species richness increased towards the biologically-poor high plateaus. Richness ‘hotspots’ covered only a small fraction of the endangered species. ‘Hotspots of endemism’ provided better guidance, and complementarity was decidedly best, but with generic data neither of these approaches were effective. On the other hand, the recognition of phylogenetic species revealed few new areas of endemism which were not also apparent using ‘accepted’ species. The analyses drew attention to aggregates of endemic species which are often sited in areas immediately adjacent to areas with dense human populations, possibly because traditional human settlements relied on ecoclimatic conditions which also determined the peaks of endemism. Since data are available for some taxonomic groups for detailed analysis of species data, there is little reason to base the conservation planning on coarser surrogates.

The East Usambara mountains are globally important for biodiversity conservation. The work reported here aimed to clarify whether plantations of Maesopsis eminii, an introduced pioneer tree, are a source of alien tree invasion or a temporary element in a protected conservation forest ecosystem in these mountains. The natural regeneration dynamics of M. eminii and indigenous primary tree species were assessed in M. eminii plantations which were up to 35 years old, using clustered systematic sampling. A total of 103 and 95 woody species were observed in the sapling and lower canopy layers, respectively. Both layers showed an abundance of Cephalosphaera usambarensis, a local species also used in plantations. M. eminii was virtually absent in the sapling layer, and its frequency decreased in the lower canopy with time. Abundant spontaneous regeneration of native primary forest species occurred under M. eminii. The sapling density of Allanblackia stuhlmannii, Beilschmiedia kweo and Greenwayodendron suaveolens increased, and that of Newtonia buchananii decreased, with time. In the lower canopy, the density of G. suaveolens, Parinari excelsa and Strombosia scheffleri increased in relation to plantation age. Therefore, no active, risky eradication of Maesopsis is needed in the conservation area, but a priority management task should be to avoid canopy gaps.