Integration of Conservation Strategies of Plant Genetic ... - Genres

eing mainly to local and regional urban centres, but also for external markets]. Similarly, the great
majority of the more than 600 species of medicinal plants imported into the European Community are
collected from the "wild" by a process of scavenging, with no regard for the sustainability of supply from
particular localities (Lewington 1993).
Likewise, much logging in tropical forest is carried out with little or no regard to regeneration of the
timber stock, the conservation of genetic diversity of valuable timber trees or indeed conservation of
forest biological diversity as a whole. It also often disregards the value of existing economic uses of
forest resources by local communities, and the value of 'ecosystems services', such as stabilisation of
soils, the maintenance of soil fertility and catchment protection.
Market forces are such that, both with timber and medicinal plants, traders simply switch to new sources
of supply as shortages occur, leaving behind successive areas of degraded habitats and associated
environmentally impoverished rural communities, one after another.
Threats to conservation of plant genetic resources - Generation of pollution and wastes
Growing levels of pollution and wastes threaten biodiversity. The magnitude of threats from these
sources is rising, as the absolute levels of consumption increase in industrialised nations and as human
population mounts. Injection of greenhouse gases into the atmosphere, through the burning of fossil
fuels and from other man-made sources, will have major impacts on ecosystems during the coming
century, placing the survival of many species and local populations of plants in jeopardy. Ozone
depletion in the upper atmosphere, resulting from CFC emissions, has led to increased levels of ultraviolet
radiation at the Earth's surface, which, in turn, are thought to be damaging to phytoplankton and
which may also have adverse effects on terrestrial plant species. Acid rainfall is causing damage to large
areas of forest in Europe and elsewhere. In Europe alone, the costs of forest damage from pollution has
been estimated at $30 billion each year during the 1980's.
Waste dumping also damages biodiversity. The pollution problems associated with waste disposal are
well-known and include contamination of both land and water, including ground water. Wastes, apart
from their sheer volume, present enormous problems of environmental persistence and toxicity. Many
synthetic chemicals have been developed specifically to be inert and unreactive to other materials and,
once they enter the environment, they tend to be resistance to decay. PCBs, some pesticides and heavy
metals are all examples of such materials. The accumulation of these substances in either the physical
or biological components of ecosystems can cause great damage, even at extremely low concentrations.
Toxic chemicals inhibit growth of more sensitive species, leaving opportunities for invasion by less
sensitive species and consequent ecosystem simplification.
The importance of land planning
The great and increasing human pressure on the Earth makes it essential that land is used efficiently to
produce required quantities of products and services. This means that the use of land must be planned,
a process which cannot be left entirely to individual people, with their sometimes short-term or personal
mercenary interests, but which must involve higher authorities, such as national governments, acting to
achieve objectives of long-term benefit for communities as a whole.
Conservation of biodiversity should be a consideration in all land management plans, from the level of
the homestead or farm upwards. Local land use plans should always consider the wider environmental
context. For example, the presence of a very rare plant on a farm property places a special obligation