173
Southeast Asia from the Ganges Valley to the
Malaysian Peninsula and South-Central China still
remain among the plant geographical regions in the
most serious conditions where the spatial distribution of surviving endemic flora does not exceed
8%. Biological diversity in these areas are threatened by the rapidly increasing population, the poverty of the majority of the inhabitants and thus the
exploitation (= destruction) of all natural values.
In Africa natural woodlands of Kenya,
Tanzania and Madagascar are close to total
destruction, and the eastern coast of South
America is in a similar situation. Economic utilisation of the areas close to the coast had an
important role in retreating natural wildlife in all
four areas. Cities grew rapidly especially in the
eastern coast of Brazil. The situation is somewhat
better in the central areas (Cerrado) with 20% of
remaining natural vegetation but in absolute values the fate of the original vegetation is depressing. The main reason for destruction is advancing
agriculture and associated deforestation.
The most endangered areas of the natural
wildlife of the whole planet are the islands.
Table 4.16 reveals that 11,600 endemic plant species and 1018 endemic vertebrate species exist on
Madagascar and the islands of the Indian Ocean.
According to registered data 45 species out of
them went extinct. Only 5% survived considering
the original vegetation of Indo-Burma. The
majority of the 7000 endemic plant species and
1046 vertebrate species living here are threatened
by extinction due to high population density. The
situation is similar in the Philippines as well.
New Zealand, Polynesia and the Caribbean are
listed first for extinct species.
The biological value of all areas included in
Fig. 4.67 and Table 4.16 is proved by the fact that
44% and 35% of endemic plant and vertebrate
animal species on the Earth respectively exist in
those areas. In contrast, only 38% of these
“hotspots” are under nature protection. The ratio
of protected areas should be increased by all
means in all regions because the number of
species—according to the estimation of biologists—falls rapidly: the number of species existing on Earth is 70–300 less each day.
The situation of natural woodlands has to be
discussed separately as tropical rain forests
among them are the richest ecosystems in species. Hansen et al. (2013) studied the global
extension, growth and decline of forests between
2000 and 2012 using Landsat satellite images
with 30 m resolution. They found that total loss
in this time period was 2.3 million km
2
and 0.8
million km
2
new forest was either planted or
spontaneously regenerated. The global balance
for the studied period was the loss of 1.5 million
km
2
forest. Loss was greatest in tropical areas,
especially in rainforests. Around 32% of the total
forest loss was rainforest area. The greatest ratio
of loss and gain can also be detected in tropical
areas (3.6 for >50% of tree cover) indicating the
predomination of deforestation dynamics.
Figure 4.68 illustrates the annual decline of
forests in the Amazon Basin. The degree of
destruction strongly undulated in the studied
period; however, promisingly it decreased continuously between 2004 and 2012. It cannot be
decided yet whether the increase of destruction in
2013 is another reversed trend or just a single
deviation. It is doubtless, however, that the degree
of tropical deforestation still increases in several
countries, like Indonesia, Malaysia, Paraguay,
Bolivia, Zambia, Angola. In South America tropical dry forests (in the Chaco region) suffer from
most damage. Subtropical forests are frequently
utilised extensively, trees are harvested like crop.
Exception is, for example, the south-eastern subtropical region of the USA where planting and
harvesting short cycle trees are typical. Here disturbance rate is four times that of South America.
In the moderate climate zone forest management determines fundamentally the ratio of loss
and gain (1.6 for >50% of tree cover) which can
be regarded low.
In boreal forests fire and forestry cause greatest changes. Here the ratio of loss and gain (2.1
for >50% of tree cover) is very high due to slow
regrowth dynamics. Figure 4.69 presents the spatial distribution of all changes. Studies involved
changes in tree cover as well which is important
because the tree cover of new planted forests is
much smaller than that of developed forests;
therefore, the value for tree cover gives information on the state of forests as well.
Regarding all forests on Earth, however, the
trend of decreasing destruction rate is clear:
4.4 Changes in the Biosphere
Southeast Asia from the Ganges Valley to the
Malaysian Peninsula and South-Central China still
remain among the plant geographical regions in the
most serious conditions where the spatial distribution of surviving endemic flora does not exceed
8%. Biological diversity in these areas are threatened by the rapidly increasing population, the poverty of the majority of the inhabitants and thus the
exploitation (= destruction) of all natural values.
In Africa natural woodlands of Kenya,
Tanzania and Madagascar are close to total
destruction, and the eastern coast of South
America is in a similar situation. Economic utilisation of the areas close to the coast had an
important role in retreating natural wildlife in all
four areas. Cities grew rapidly especially in the
eastern coast of Brazil. The situation is somewhat
better in the central areas (Cerrado) with 20% of
remaining natural vegetation but in absolute values the fate of the original vegetation is depressing. The main reason for destruction is advancing
agriculture and associated deforestation.
The most endangered areas of the natural
wildlife of the whole planet are the islands.
Table 4.16 reveals that 11,600 endemic plant species and 1018 endemic vertebrate species exist on
Madagascar and the islands of the Indian Ocean.
According to registered data 45 species out of
them went extinct. Only 5% survived considering
the original vegetation of Indo-Burma. The
majority of the 7000 endemic plant species and
1046 vertebrate species living here are threatened
by extinction due to high population density. The
situation is similar in the Philippines as well.
New Zealand, Polynesia and the Caribbean are
listed first for extinct species.
The biological value of all areas included in
Fig. 4.67 and Table 4.16 is proved by the fact that
44% and 35% of endemic plant and vertebrate
animal species on the Earth respectively exist in
those areas. In contrast, only 38% of these
“hotspots” are under nature protection. The ratio
of protected areas should be increased by all
means in all regions because the number of
species—according to the estimation of biologists—falls rapidly: the number of species existing on Earth is 70–300 less each day.
The situation of natural woodlands has to be
discussed separately as tropical rain forests
among them are the richest ecosystems in species. Hansen et al. (2013) studied the global
extension, growth and decline of forests between
2000 and 2012 using Landsat satellite images
with 30 m resolution. They found that total loss
in this time period was 2.3 million km
2
and 0.8
million km
2
new forest was either planted or
spontaneously regenerated. The global balance
for the studied period was the loss of 1.5 million
km
2
forest. Loss was greatest in tropical areas,
especially in rainforests. Around 32% of the total
forest loss was rainforest area. The greatest ratio
of loss and gain can also be detected in tropical
areas (3.6 for >50% of tree cover) indicating the
predomination of deforestation dynamics.
Figure 4.68 illustrates the annual decline of
forests in the Amazon Basin. The degree of
destruction strongly undulated in the studied
period; however, promisingly it decreased continuously between 2004 and 2012. It cannot be
decided yet whether the increase of destruction in
2013 is another reversed trend or just a single
deviation. It is doubtless, however, that the degree
of tropical deforestation still increases in several
countries, like Indonesia, Malaysia, Paraguay,
Bolivia, Zambia, Angola. In South America tropical dry forests (in the Chaco region) suffer from
most damage. Subtropical forests are frequently
utilised extensively, trees are harvested like crop.
Exception is, for example, the south-eastern subtropical region of the USA where planting and
harvesting short cycle trees are typical. Here disturbance rate is four times that of South America.
In the moderate climate zone forest management determines fundamentally the ratio of loss
and gain (1.6 for >50% of tree cover) which can
be regarded low.
In boreal forests fire and forestry cause greatest changes. Here the ratio of loss and gain (2.1
for >50% of tree cover) is very high due to slow
regrowth dynamics. Figure 4.69 presents the spatial distribution of all changes. Studies involved
changes in tree cover as well which is important
because the tree cover of new planted forests is
much smaller than that of developed forests;
therefore, the value for tree cover gives information on the state of forests as well.
Regarding all forests on Earth, however, the
trend of decreasing destruction rate is clear:
4.4 Changes in the Biosphere