106 Ecology and Applied Environmental Science
examples. Fires, grazing and the expansion of cultivations have been
major factors.
The current phyto- and zoocoenoses of the terrestrial Mediterranean
space are the result of a lasting action of geological, paleoclimatic and
anthropogenic factors. The presence of a large number of endemic species in
certain areas is associated with the existence of many isolated mountains and
islands and is to a great extent due to the significant ecological perturbations
that were caused by the glaciers and other climatic changes. It is estimated
that in the Mediterranean area there are approximately 12,000 species of
endemic anthophytes.
5.5 biodivErSity and landScaPE
The concept of biodiversity includes the genetic variety among individuals of the same species, the variety among species and the variety among
ecosystems (ecological niches and landscapes). The biological species variety in ecosystems and indeed in the biosphere has been one of the main
objects of the efforts for environmental protection on the part of international organizations. At the International Rio de Janeiro Convention for
the Environment and Development in 1992, biodiversity was one of the
most important discussion issues, and the convention concluded with the
signing of an international agreement for its protection.
The conservation of biodiversity is very important, mainly because the
extinction of one flora or fauna species constitutes irreparable environmental loss, since neither any natural mechanism nor technology can re-create it.
Recent estimations give great emphasis to the economic value of bio diversity
as well. Many wild flora and fauna species could be useful in the preparation
of new medicines, the improvement of agricultural and livestock farming
production, the utilization of new biotechnology achievements etc.
The estimated number of biosphere species fluctuates between 5 and
100 million, with a most probable value around 8.7 million, while over
1.2 million species have been described by science and already catalogued in
central databases. The current species extinction rate is somewhere between
50 and 1000 times greater than the natural rate. In 1996, 25% of mammals
were considered endangered, 11% of birds, more than 25% of freshwater
fish and a significantly higher percentage of invertebrate animals.
The most significant factors for the global biodiversity decrease are
the following:
• The destruction or fragmentation of ecological habitats (feeding and
breeding sites etc.)
• Over-exploitation (fishing, timber felling, trade etc.)
• Introduction of alien species into ecosystems
examples. Fires, grazing and the expansion of cultivations have been
major factors.
The current phyto- and zoocoenoses of the terrestrial Mediterranean
space are the result of a lasting action of geological, paleoclimatic and
anthropogenic factors. The presence of a large number of endemic species in
certain areas is associated with the existence of many isolated mountains and
islands and is to a great extent due to the significant ecological perturbations
that were caused by the glaciers and other climatic changes. It is estimated
that in the Mediterranean area there are approximately 12,000 species of
endemic anthophytes.
5.5 biodivErSity and landScaPE
The concept of biodiversity includes the genetic variety among individuals of the same species, the variety among species and the variety among
ecosystems (ecological niches and landscapes). The biological species variety in ecosystems and indeed in the biosphere has been one of the main
objects of the efforts for environmental protection on the part of international organizations. At the International Rio de Janeiro Convention for
the Environment and Development in 1992, biodiversity was one of the
most important discussion issues, and the convention concluded with the
signing of an international agreement for its protection.
The conservation of biodiversity is very important, mainly because the
extinction of one flora or fauna species constitutes irreparable environmental loss, since neither any natural mechanism nor technology can re-create it.
Recent estimations give great emphasis to the economic value of bio diversity
as well. Many wild flora and fauna species could be useful in the preparation
of new medicines, the improvement of agricultural and livestock farming
production, the utilization of new biotechnology achievements etc.
The estimated number of biosphere species fluctuates between 5 and
100 million, with a most probable value around 8.7 million, while over
1.2 million species have been described by science and already catalogued in
central databases. The current species extinction rate is somewhere between
50 and 1000 times greater than the natural rate. In 1996, 25% of mammals
were considered endangered, 11% of birds, more than 25% of freshwater
fish and a significantly higher percentage of invertebrate animals.
The most significant factors for the global biodiversity decrease are
the following:
• The destruction or fragmentation of ecological habitats (feeding and
breeding sites etc.)
• Over-exploitation (fishing, timber felling, trade etc.)
• Introduction of alien species into ecosystems