bluuebunny/crossref_metadata_2025_split huggingface dataset:
The El Kala National Park and Environs, Algeria: An Ecological Evaluation
Authors: Stevenson Anthony C. , Skinner Jamie , Hollis G. Edward , Smart Michael 
Published: August 2009

The structure of the El Kala National Park, its aims, zonation scheme for conservation and development, and boundaries, are described. Those ecobiomes and ecosystems which merit the highest classification and protection within the National Park are described and evaluated along with the numerous sites of similar importance outside the Park. A summary evaluation table (Table III) of the habitats, the species, and the resources for sustainable utilization, is presented.Three wetlands within the Park—Lake Oubeïra (perennial freshwater lake: a Ramsar Convention site important for wintering waterfowl), Lake Tonga (semi-perennial freshwater lake with surrounding marsh and earn a Ramsar Convention site with significant numbers of breeding waterbirds), and the Bou Redim marsh (freshwater carr with open water and a breeding colony of herons) are placed in the highest category of protection for the National Park. Four wetlands outside the National Park—the Mkhada marsh (8,900 ha of seasonally-flooded freshwater marsh), Lake Fetzara (15,000 ha freshwater lake now refilled with water in winter), Lac des Oiseaux (40 ha perennial freshwater lake), and the Cheffia Reservoir (3,000 ha)—are considered as important and consequently deserving of legislative protection. A marine section of the Park needs further study.The highest level of protection is recommended for the coastal dunes, including alder carrs, within and outside the Park; for the pristine low-montane Cork Oak woodlands, including the last remnants of Pinus pinaster ssp. renoui in Algeria; for the rare Lusitanian Oak forests including the small and declining Algerian population of Barbary Deer (Cervus elephas barbarus); and for some of the last remaining riverine woodland in North Africa. In addition, the healthy and diverse population of raptors is noted. The megalithic and later archaeological remains are extensive, valuable, and little-known.MEcological improvements to Lakes Tonga and Fetzara, which were drained in the 1930s, have recently developed from the operation of the old sluices to hold water back in the lakes, although at Lake Tonga some of the marginal vegetation and alder forest appears to be suffering from the prolonged inundation. The construction of the large Mexanna Dam within the National Park will desiccate the Mkhada Marsh, and Lake Oubeïra may have its ecological character changed if it is used for regulatory storage. The dune ecosystems are being affected by agriculture, groundwater pumping, industrial forestry (including perhaps a pulp mill), and the new road which is being driven into the heart of the dunes. Fishing and aquaculture may further reduce the suitability of Lakes Oubeïra and Melah for wintering waterfowl, and deliberate fires continue to ravage the Cork Oak forests.
Environmental, Economic, and Social Aspects of Marine Aggregates' Exploitation
Authors: Charlier Roger H. , Charlier Constance C. 
Published: August 2009

The progressive depletion of land sources of construction materials poses increasingly acute supply problems to the building industry. Stricter rules than currently exist in relation to environmental concerns and their effective enforcement, while undoubtedly laudable, would exacerbate the situation and preclude opening, in many instances, new land-quarries. The search for alternative sources led naturally to exploitation of marine deposits. Beaches and near-shore areas have long been tapped for relatively small amounts of sand and gravel, but the new, greatly-increased demands for these materials poses a serious threat to many shores. Tourism and mining, unavoidably, have come into conflict. Beach protection, and, with increasing frequency, ‘renourishment’, is antipodal to granulates' mining. Offshore dredging has in some cases triggered accelerated beach erosion. The general rise of sea-level, and the consequences of exceptional-strength storms, have worsened erosion and greatly disturbed — occasionally irreversibly — the local sedimentary budget and transit. Technological progress, and more and more sophisticated equipment, permit greater efficiency in, and greater depth of, dredging operations.Besides their use for construction materials, the search for minerals in the marine domain also affects sands and gravels: placers and ores are available here, and mining in the coastal zone is no longer a marginal undertaking. Exploitation of ‘granulates’ ranks today as the second most important marine mining activity after oil extraction. Hence it is a top-priority topic for Quaternary economic geologists and environment specialists alike, while public awareness has henceforth to be reckoned with. Communication and information techniques must consequently be designed and vigorously propagated.
Land-use Changes and Resource Degradation in South–West Masailand, Tanzania
Authors: Mwalyosi Raphael B.B. 
Published: August 2009

This study uses sequential aerial photography to identify environmental changes. The interpreted aerial photos constitute a data-bank of past and present land cover/uses.* Substantial changes have been observed in the areas of cultivation, woody cover, and bare ground.An increased 449.9% of the surveyed area has been cleared for cultivation during the last 30 years, while 77.2% of the former woodland has been destroyed during the same period, contributing to a 15.6% increase in grassland. Bare ground increased by 33.1%. Increased cultivation is caused by increase in the population of subsistence farmers and mechanization. Expansion of cultivation and overexploitation of woody resources (fuel-wood and building materials) are the causes of decline in the woody vegetation. As consumption of woody resources exceeds natural regeneration, woody cover is gradually replaced by grasslands.Diminution of the woody vegetation results in shortage of fuel-wood and building materials and consequent misery to the local people. Expansion of cultivation reduces grazing-land, leading to overstocking and overgrazing. Extensive cultivation, based on soil ‘mining’, subjects more and more land to physical and chemical soil degradation, leading in turn to decline in soil fertility and crop yields. Both overgrazing and extensive cultivation accelerate soil erosion in the area, reducing available cropland, while siltation and flooding cause serious damage to property and infrastructure.Lack of effective land-use planning, uncontrolled population growth, and introduction of the Tanzanian village agricultural production system in a semi-arid area, have contributed to the present deplorable state of affairs. In general, the area shows increasing environmental degradation and resource depletion, while very little conservation effort is being made to reverse the trend. These results indicate that a sustainable resource management plan is urgently needed for the area.
Present and Future Use of Fencing in the Management of Larger African Mammals
Authors: Hoare Richard E. 
Published: August 2009

The varying reasons are outlined for needing to control the movements or otherwise manage a wide range of African animal wildlife species by means of fencing. In all cases there is an underlying conflict of interest between people and animals — principally the larger mammals. Fencing is seen as the most powerful tool in this process of land-use division, and high expectations of fences are held by people who are adversely affected by wildlife activities and similarly by many conservationists. To date the main determinants in the siting and construction of fences have been political pressure or the availability of funds; wildlife fencing is perhaps the only factor having a substantial influence on ecosystems and animal populations that has remained virtually devoid of any serious input of ecological knowledge, of systematic investigation, or of environmental legislation.The wild species requiring management are many and varied in individual size, group size, and dispersal patterns; they also exhibit an array of special behaviours when confronted with a barrier. This means that any barrier will come under very variable levels and types of challenge, and that the effects of it on the biology of both target and non-target species must be carefully considered.Research on the behaviour of animals at fences has been limited, being mostly confined to domestic species or non-African wildlife. Certainly, very little systematic investigation has been carried out to determine whether fences have achieved their objectives or been economically justified, and to what extent they have caused environmental side-effects on the population dynamics of animals or the disturbance of plant communities.Current evidence suggests that electric or power fences are an increasingly efficient way of managing wild mammals and that fencing programmes should become more deflecting than encircling. Fences create ‘hard edges’ between dissimilar forms of land-use and cause long-term inflexibility that limits planning and forecloses options. As the pressure for land becomes more and more acute, the control of wildlife with the help of fences needs to develop into a specialized field of its own, based on sounder ecological, sociological, and economic, principles than hitherto, within the expanding scope of adaptive wildlife management.
Tree–Habitat Relationships in Urban Hong Kong
Authors: Jim Chi Yung 
Published: August 2009

Trees, as welcome and necessary components of Nature and functional landscape elements in cities, provide a worth-while theme for applied ecological study. Of the different approaches, the micro-scale evaluations of tree—habitat interactions can throw light on practical tree management. The roadside trees in Hong Kong, generally dwelling in a stressful physical and physiological environment, have been surveyed in detail in the field with regard to species composition, tree structure, tree defects, and habitat characteristics.Despite a diversified floristic composition, the street-tree population is dominated by a small number of common species, of which 12 have been chosen for in-depth evaluations. The recent emphasis on exotic and fast-growing species with limited final dimensions will modify the treescape in the long run. Many existing large specimens have been sacrificed to urban redevelopments. The differential performance of different species with reference to the occurrence of defects has been interpreted. Almost all the trees are inflicted by some structural or physiological problems, and large trees are practically collectors of diverse maladies.The urban tree habitats of Hong Kong are characterized by gravely cramped and stressful conditions from the soil-level upwards and especially as regards headroom. Tree-habitat correlations and associations suggest a need to plant rapid-growing, tall but narrow-canopied species that are able to resist a maximum proportion of the inevitable tree defects and diseases. The shortage of good-quality habitats with space for tree-growth, and the accompanying unfavourable ecological niches, are crucial factors for tree existence. The prospects of street trees in the long-term urban planning and upgrading for environmental quality, with special reference to the provision and preservation of proper habitats, are elaborated, with Hong Kong as a practical example.
Designing for Nature in Cities: A Case-study of the Hill Area of the Summer Villa Estate, Chengde, China
Authors: Jiang Gaoming , Huang Yinxiao , Lin Shunhua 
Published: August 2009

The Summer Villa estate was famous for its wildness, preservation of Nature, pleasant climate, and beautiful scenery in the Qing Dynasty when the natural ecosystems were strictly conserved by the Emperors Kangxi and Qianlong (1703–93). Plants on the estate played an important role in this embellishment, 28 out of the 72 noted scenic sites being named after plants or plant etc. materials. The estate has been seriously destroyed in the last 150 years by wars, fires, and natural disasters, before the foundation of the new China. The damage was especially serious in the Hill Area, comprising some 80% of the estate.The present vegetation in the Hill Area is the result of reafforestion in the 1950s. Seven different plant communities, composed of natural and artificial elements, are now found there, most extensive of which is the Pinus tabulaeformis artificial forest with Vitex chinensis dominating the shrub layer. Some of these communities are unsuitable for the scenic spots on which they stand, some are not adaptable to the habitats, some have problems such as consisting of single species — so resulting in susceptibility to pests and offering little possibility for birds to make their nests and mammals to colonize.The natural environment in the estate is becoming widely degraded, with serious SO2 and Pb pollution caused by tourism and urbanization. Plants — especially needleleaf trees — are sensitive to these pollutants.This paper discusses the process of designing for Nature in the Hill Area of the Summer Villa estate, much of the work being concerned with problems of the present vegetation and the best approach to deal with them. To create Nature for the City of Chengde and at the same time recover the natural beauty in the Summer Villa estate, much attention is paid to the natural characteristics of suitable plants — especially those ‘historical’ natural species which can adapt to the present habitats. Five subsidary landscape areas with different plant characteristics in different habitats have been designed. Maps of the ‘historical’ natural vegetation, the present vegetation, and designs for Nature in the Hill Area, have been drawn and are here reproduced for practical use.
Biological Conservation Implications of Water-level Fluctuations in a Wetland of International Importance: Lake Kerkini, Macedonia, Greece
Authors: Pyrovetsi Myrto , Papastergiadou Evanthia 
Published: August 2009

Kerkini Lake in Greece, a reservoir maintained principally for agricultural irrigation purposes on the Strymon River, has been classified as a ‘Wetland of International Importance’ according to the Ramsar Convention. Hydrological conditions favoured the formation of a shallow, very productive lake, rich in species diversity and biotic abundance. The importance of the wetland lay in its complex zonation of various habitats which mainly consisted of: shallow open water with sand-strips, beaches, and mud-flats; shallow-water areas with communities of emergent vegetation; a lowland hardwood riparian forest mainly ofSalixandTamarixspecies; a shrub-swamp; and extensive wet meadows. The diversity of habitats supported a rich waterbird fauna for breeding, stationing during migration, and wintering.Nevertheless, in 1982 a new high-dam was constructed, higher embankments along the banks of the Lake were established, and other works were carried out (to increase the water capacity of the reservoir), in response to irrigation demands. No consideration was given to the wetland resources. Operation of the new dam resulted in changes in the flooding etc. regime, with severe impact on the biotic resources of the wetland, especially by waterlevel increases of more than 5 m in less than 4 months during spring — the critical growing- and breedingseason. Wetland heterogeneity and the mosaic structure of water-land-vegetation were thereby lost.Now the riparian forest is diminishing in area and declining in productivity, the reed-swamp with emergent macrophytes has been lost, and wet meadows have also disappeared. Deep flooding and the loss of these habitats is reflected in marked decline in the densities of migratory waterbird populations and, most important, in drastic shrinkage in the populations of breeding species. Similar impact is observed in the dramatic decline of fish species diversity and abundance. In general, nowadays, Kerkini presents an alarming example of loss of biodiversity and accelerating impoverishment of its former biotic resources.In view of the projected plans to increase further the water-storage capacity of the Lake by raising its waterlevel, measures are urgently needed: (a) for preventing such actions; (b) for restoring and maintaining marsh conditions, and (c) for ecologically sound management and sustainable use of the wetland resources.
The Exxon Valdez Oil-spill: Ecological and Social Consequences
Authors: Shaw David G. 
Published: August 2009

Major oil-spills, such as occurred following the grounding of the tanker Exxon Valdez in March 1989 in Prince William Sound, Alaska, account for only a small fraction of the total anthropogenic input of petroleum to the marine environment. Yet major spills can result in significant and even acute impacts, trigger ecological changes requiring decades for recovery, and command considerable public attention. Thus catastrophic oil-spills in general, and the Exxon Valdez spill in particular, differ from other chronic human alterations of coastal marine systems.Estimates of the fate of the 38,000 metric tons of crude oil lost by the Exxon Valdez are imprecise, but perhaps 30–40% evaporated, 10–25% was recovered, and the rest remains in the marine environment. Roughly 1,500 km of coastline were oiled in varying degrees. Much of this coastline consists of gravel beaches into which oil penetrated to depths as great as 1 m.The ecological effects of the spill on the marine environments of Prince William Sound and adjacent coastal areas of the Gulf of Alaska were extensive, but natural recovery, aided by clean-up efforts, is expected. Judging by the consequences of other oil-spills affecting rocky shorelines, as well as previous natural and anthropogenic disturbances to Prince William Sound, it appears likely that most affected biotic communities and ecosystems will recover to approximately their pre-spill functional and structural characteristic within from five to twenty-five years.This oil-spill had major social effects. Many individuals, whether personally present or viewing the spill around the world on television, were saddened by the environmental damage, and felt that an important public trust had been broken. These feelings, together with dissatisfaction with the results of early clean-up efforts, gave rise to popular sentiment in favour of every possible clean-up and mitigation effort — regardless of cost, effectiveness, or possible negative consequences.The response to the Exxon Valdez oil-spill by government and the oil industry revealed serious inadequacies in the plans and institutions for dealing with major marine oilspills in the United States. Attempts to recover spilled oil, and to respond to the spill's environmental consequences, were hampered by a low level of preparedness and lack of clear agreement about the goals of response efforts. Attempts are under way to improve oil-spill prevention and response capabilities in Alaska and the rest of the United States. However, these efforts are not yet complete, and it remains to be seen whether an improved response will be made to the next major oil-spill.
Sustainable Development and Biotechnology
Authors: Mannion Antoinette M. 
Published: August 2009

Sustainable development requires that resources are used as conservationally and as optimally as possible in order to maintain an adequate resource-base for future generations. It is not an easily-defined concept, nor is there any single way of achieving it. It does, however, focus on the environment, as this provides the resource-base that supports all society. Among the recently-evolved scientific developments, biotechnology has many applications that can improve resource-use. It involves the manipulation of organisms to undertake specific processes and includes genetic manipulation or ‘engineering’.In an environmental context, biotechnology has its greatest contribution to make in agriculture — especially by improving crop-yields. It offers opportunities to design crops for specific environments and to make crops more efficient producers of food-energy than otherwise. Biotechnology can thus manipulate primary energy-flows; it can also reduce fossil-fuel energy inputs into agricultural systems. It could also contribute to the mitigation of environmental problems such as deforestation and soil erosion. Both food- and fuel-energy resources are key components of sustainability. Sources produced biotechnologically, e.g. SCPs and biomass fuels, can supplement those produced conventionally.Resource recovery and recycling, and hazardous-waste disposal, are other environmentally-beneficial facets of biotechnology. These are equally pertinent to sustainable development because they extend the resource-base. In this context, biotechnology constitutes a vehicle for the improved manipulation of biogeochemical cycles.There are, however, potentially significant drawbacks in the use of biotechnology. These focus on technology transfer between the Developed and Developing World; this is economic and political, and relates to intellectual property rights, etc. Environmentally, the disadvantages concern the potential creation of ‘ecological ogres’ which could generate ecological disasters. Moreover, biotechnology relies heavily on the availability of a sustainable genepool, i.e. on biodiversity; indeed the two are interdependent. The high rates of extinction of plant and animal species that are currently occurring are thus limiting biotechnological opportunities for the future.
Carbon Storage and Land-use in Extractive Reserves, Acre, Brazil
Authors: Brown I. Foster , Nepstad Daniel C. , Pires Ivan de O. , Luz Leda M. , Alechandre Andréa S. 
Published: August 2009

Large-scale forest conversion in Brazil, primarily to cattle pasture, contributes significantly to the global anthropogenic emission of CO2 into the atmosphere. An alternative land-use, namely extractive reserves for forest residents, may serve as one means of using Amazonian forests sustainably and of maintaining carbon in living matter rather than adding it to that in the atmosphere.In the Seringal (former rubber estate) Porongaba (6,800 ha) of the Chico Mendes Extractive Reserve, Acre, Brazil, primary forest still covers more than 90% of the area. Total biomass in primary forest is estimated at 426 tons per ha, equivalent to 213 t C per ha. Rubber tappers effectively maintain about 60,000 tons of carbon per household (family unit) in forest biomass and thus out of the atmosphere. Deforestation of primary forest was less than 0.6% per yr — much less than rates of natural disturbances for other neotropical forests.Slash-and-burn agriculture in the Seringal Porongaba releases carbon at a gross rate of some 200 t C per yr per household. Net releases are much less, as regrowth forests absorb carbon at rates of about 9 t C per ha per yr. The net areal flux of carbon to the atmosphere from land-use in Seringal is much less than one ton of carbon per ha per yr, which is equivalent to less than 0.3% per yr of the carbon stock in forest biomass. If Seringal Porongaba is typical of the three million hectares in extractive reserves in Brazilian Amazonia, then these reserves are calculated to retain 0.6 Gigatons of carbon in the terrestrial biota.Adverse changes in income patterns for rubber tappers could lead to abandonment of extractive reserves or increased deforestation within them. Diversification and improvement of income from non-timber forest products are needed to maintain rubber tappers in extractive reserves. Most beneficiaries of carbon storage in these and other reserves live outside Brazil; devising means of recompensation for these benefits is a challenge for the global society.