Conservation must be set in a context in which it is recognized that:

(i) Overall human impact on The Biosphere is the product of the number of people on Earth multiplied by the average impact per person. Both of these factors are continuing to increase although there is already compelling evidence that the present level of impact is exceeding the carrying capacity of the planet.

(ii) The ability of the Earth's natural systems to tolerate different types of impacts varies from place to place. Not surprisingly it is in the world's tropical and arid regions, where rapid population-growth often coincides with ecological systems which are less able than most others elsewhere to tolerate intensive utilization, that many of the world's most intractable ecological problems are found.

(iii) All countries must endeavour to minimize population growth and reduce the environmental impact per person until the overall global impact is reduced to a level at which all peoples can expect to be able to have a comparable but ecologically sustainable level of impact.

(iv) Achieving sustainable levels of impact will require an unprecedented degree of international cooperation. This will involve at its core due recognition that ecologically sustainable development can best be achieved in conjunction with continued economic and social development. It will also require due recognition of how new, ecologically sustainable, technologies will often be the key to ensuring that such continued development is indeed ecologically sustainable.

(v) There is at present insufficient recognition in the industrialized, i.e. ‘developed’, countries that their failure to pay ecologically realistic prices makes it extremely difficult, if not impossible, for commodity producers to follow ecologically sustainable practices. The consequence is land degradation in countries that are dependent on commodity exports, and a diminished or degraded global environment overall.

(vi) There is a strong case for preserving Antarctica from development because of its importance in influencing global weather and climate, and because of its ecological fragility and biological uniqueness. To preserve it as a wilderness will be an important test of international resolve to manage such resources as are still accessible in the rest of the world in an ecologically sustainable manner.

Our world of Mankind and Nature is becoming more and more seriously threatened as human populations and profligacy increase. Yet short of near-future calamity, there should be hope in global environmental education as a basis for countering such threats as those of world hunger, acidic precipitation, increasing desertification, nuclear proliferation, ‘greenhouse’ warming, and stratospheric ozone depletion. We need to educate people throughout the world to see these dangers in their global context and to act always within this perspective — be they decision-makers, legislators, or mere private citizens. For their actions and effects compound to make up those of their pandominant species, the likes of which our unique planet Earth can surely never have experienced before, and consequently its all-important Biosphere, constituting virtually the whole of our and Nature's lifesupport, is totally unprepared to withstand.

The above means that decisions and concomitant actions at the personal level can and often do affect the globe, to however infinitesimal a degree, and of this all people on Earth should be forewarned, acting on it with clear understanding and due responsibility. Particularly North Americans should realize that their effect is disproportionately large, as they use some 36% of the world's resources although comprising only about 6% of its population. Towards remedying such anomalies and effecting an improved sharing of responsibility among all the world's human inhabitants, an urgent need is, clearly, effective global environmental education. We need a world of concerned people with the knowledge that personal decisions and local actions can affect others very widely, and that each individual human being thus has a role in furthering solutions to environmental, as well as political and social problems.

With the need for such thinking and action so clear, and the stakes so very high, why is it that global perspectives are not better integrated into today's educational system? ‘The answer is that the barriers to such integration and concomitant action are many and strong, and due understanding of holism's fundamental importance is barely beginning to sweep our prejudice-bound world.’ These barriers include lack of student interest and pertinent enrolment, lack of international perspective among teachers and in the general press, and lack of television and other news-media coverage of such real world affairs. A general obstacle lies in the tendency of educational efforts to emphasize differences rather than similarities — scarcely conducive to fostering an interdependent, one-world ethic. Yet global issues should be our ultimate consideration, and holistic practice our means of furthering them for lasting survival.

It is clear that we humans no longer have the option of foregoing a global perspective, and that there is dire need for widely-increased global environmental education to inculcate greatly-increased respect and concern for the world environment. This is brought starkly to mind on realization that practically all the horrors which now beset our world were known fairly widely already twenty years ago — including threats to the stratospheric ozone shield, the ‘greenhouse effect’ on world climate, the effects of deforestation and devegetation with ever-increasing human population pressures, and many more — and that new ones keep on emerging. These latter include build-up of nuclear-waste and other pollutions, AIDS, everincreasing acidic deposition and salinization, flooding of lowlands and other effects of climatic changes, and further foreseeable problems that are likewise of our own making in being due to human overpopulation, ignorance, and/or profligacy.

Jordan lies at a meeting-point of three zoogeographical areas: the Palaearctic, the Afrotropical, and the Oriental—circumstances which were conducive to habitat diversity in Jordan and hence the diversity and often abundant occurrence of different floral and faunal elements.

The present paper gives information about the history and past occurrence of large mammalian species and their populations in Jordan, while also focusing on the present status of the large mammalian species, and gives the reasons for extinctions and the preventive measures that are being taken to conserve the populations remaining. In addition, this study gives a future prospective outlook for habitat and mammalian conservation, and the reintroduction programme that is being implemented in Jordan.

The first part of the paper sheds light on the past existence of large mammals in Jordan. The historical sequence of events starting from the Upper Palaeolithic and continuing right up to the present, and the succession of civilizations, had a negative impact on the large mammalian populations. This section gives tabulated data on the past occurrence of 26 species, supported by evidence of their past existence such as bone remains, rock drawings, engravings, mosaics, and frescos, found in various archaeological sites in Jordan.

The second part of the paper deals with the present status of large mammalian populations, their distribution being reflected through maps indicating recent sightings in some outstanding cases. Among those are reintroduced species such as the Arabian Oryx and the Syrian Wild Ass, and highly threatened species such as the Nubian Ibex. This part also investigates the reasons for extinction, which mainly link the destruction of habitats with the direct deterioration of mammalian populations. Habitat destruction was chiefly due to the rapid decline of the natural pasture areas, overgrazing, urban expansions, unorganized construction plans, human impact, mismanagement of the highlands, fire, and hunting. All of these factors led to deforestation and soil erosion, resulting in a patchy, fragile ecocomplex. The decrease of rainfall assisted the severe deterioration of natural forests.

The future outlook of this study includes plans to restore ecosystems and, with them, much of the overall ecocomplex. For this and other reasons it also stresses the urgent need to establish more reserves, both grazing and natural. This concluding part of the paper encourages the improvement of national parks, and urges the authorities to look seriously at the often disastrous effects of mismanagement. The importance of collaboration between Jordan and the various international agencies is emphasized, as well as the need to speed up work on the National Conservation Strategy of Jordan.

Human interactions with rain-forest on the Australian continent have played, and will continue to play, a vital role in their distribution and survival. The presence and significance of rain-forest in Australia lies in the evolutionary history of the Australian plate since the break-up of the Gondwanan supercontinent. Its continued survival and distribution illustrates and encapsulates the history of plant evolution and biogeography in Australia.

Since human arrival in Australia at least 40,000 years ago, human interactions with rain-forest have been marked by a number of phases — ranging from Aboriginal use of rain-forest resources to the impetus given by the hunt for the prized Red Cedar, and from the early European settlement on the east coast of Australia in the midto late-19th century to the wholesale clearing of rain forests for agricultural settlement and dairying in the late 19th century. In more modern times, human interactions with rain-forest have focused on adapting forest management techniques to rain-forest logging, restructuring the native forest timber industry in the face of mechanization, changing markets and resource constraints, convulsions as a result of conservationist challenges in Terania Creek and Daintree, and finally the implications of conserving rain-forests in the context of natural processes including fire, climate change, and the impact of human visitors and their recreation.

The course of the controversies over rain-forest conservation in Australia has meant that rain-forest logging either has been dramatically curtailed or is in the process of generally ceasing. The protection of rainforests from logging and forestry operations in the future seems secure, given the widespread community support for rain-forest conservation. Threats to rain-forest conservation in the future are likely to be found in more subtle processes: the impact of fire regimes on the spread and contractions of rain-forests, the impacts of exotic species such as Lantana (Lantana camara) and Camphor Laurel (Cinnamomum camphora), the impacts of human uses through tourism and recreation, the diminution of the viability of isolated pockets by ‘edge effects’, and the damage to the remaining stands on freehold property by conflicting land-uses.

Overlying all of these potential threats is the impact of global climate change. Climate change since the Tertiary has reduced the once widespread rain-forest communities of Australia practically to the status of relicts in refugia. Will the remaining rain-forests be able to withstand the projected human-induced climate changes of the future?

Remote sensing is being widely used in the fields of resource management, planning, and wildlife habitat evaluation. Canopy cover-type mapping has been done in most of the bioclimatic zones of India and widely abroad, using aerial photointerpretation techniques. In the present study an attempt has been made to develop a methodology for mapping understorey vegetation in part of Kanha National Park, using 1:10,000-scale black-and-white aerial photographs.

The Park, one of the best for Tiger (Felis tigris) visibility and observation of other large carnivores and herbivores, has been mapped, with subdivision into 11 vegetation cover-classes and four density-classes, using aerial photographs, and each class has been visited in the field for understorey information concerning different physiographic units. Each category of canopy-cover was sampled in the field, and tree base-cover per hectare has been estimated.

Vertical profiles have also been drawn in the main vegetation classes in order to understand the occurrence of understorey vegetation. It was found that a physiographic analysis coupled with canopy-cover type and density, with appropriate sampling in the individual vegetation strata, have together proved indicative of understorey vegetationtype. When the relationship between understorey vegetation and canopy-cover type is established, one can directly depict understorey limits spatially in conjunction with the main vegetation cover. Such an approach of mapping understorey vegetation using aerial photographs could be of immense value for wildlife habitat evaluation and park management.

Although most of the lowland endemic forests of the mountainous Indian Ocean island of La Réunion have been converted by Man to other land-uses, relatively intact ecosystems still survive at higher elevations. Given the particular conservational value of these remnants of primary forest, detailed knowledge of the threats faced by these native ecosystems was urgently needed. Accordingly we conducted field surveys through the various plant communities on the island in order to answer particular questions regarding the vulnerability of native vegetation remnants to invasive, introduced plant species.

Our results indicated that most invaders colonize human-disturbed sites most successfully. However, such alien plants are also frequent in the Réunion primary forest remnants, with at least 62 species penetrating into areas which have experienced no or little human disturbance. Nevertheless, the forest remnants were still mainly dominated by indigenous or endemic plant species and maintain what is, presumably, their original vegetational structure.

The most threatening plant invaders are the trees Psidium cattleianum and Ligustrum robustwn, the bramble Rubus alceifolius, the shrubs Fuchsia magellanica and Lantana camara, and the herbaceous Hedychium gardnerianum, Boehmeria macrophylla, and Boehmeria penduliflora.

We found the early stages of primary succession on young volcanic sites to be dominated by aggressively expanding populations of alien species. It appears very unlikely that native species will replace the invaders as the succession proceeds, and furthermore the survival of many indigenous species probably hinges on the active control of alien species.

In order for alien plant management efforts to be successful, we propose a priority ranking based on the current and potential future extent of specific infestation, the rate of spread, the difficulty with which a species can be controlled, and its ecological impact on the areas invaded.

Finally, the long-term survival of the Réunion ecosystems depends largely upon the drawing up and implementation of an adequate overall conservation policy regarding human-caused invasions by alien plants in the native vegetation.

Climate issues reach far beyond the atmospheric and oceanic sciences, affecting every aspect of life on this planet. The issues are increasingly pivotal in determining future environmental and economic well-being. Variations of climate have profound effects on natural and managed systems, the economies of nations, and the wellbeing of people everywhere. A clear scientific consensus has emerged on estimates of the range of global warming which can be expected during the 21 st century. If the increase of concentrations of ‘greenhouse’ gases is not limited, the predicted climate change would place stresses on natural and social systems unprecedented in the past 10,000 years.

At the First World Climate Conference, in 1979, nations were urged ‘to foresee and to prevent potential man-made changes in climate that might be adverse to the well-being of humanity’. The Second World Climate Conference concludes that, notwithstanding scientific and economic uncertainties, nations should now take steps towards reducing sources and increasing sinks of ‘greenhouse’ gases through national and regional actions, with due negotiation of a global convention on climate change and related legal instruments. The long-term goal should be to halt the build-up of ‘greenhouse’ gases at a level that minimizes risks to society and natural ecosystems. The remaining uncertainties must not be the basis for deferring societal responses to these risks. Many of the actions that would reduce risk are also desirable on other grounds.

A major international observational and research effort will be essential to strengthen the knowledge-base on climate processes and human interactions, and to provide the basis for operational climate monitoring and prediction.