Geoscience Reference
In-Depth Information
Table 8.2 (continued)
Ecosystem
Anthropogenic impacts
Causes of impacts
Fresh-
water
ecosystems
Over-exploitation of water sources
in their economic use
Breaking the norms of
fish catch in
the inland water basins
Building of dams in the interests of
irrigation, creation of hydroelectric
power stations, and floods control
Pollution of water basins due to
various factors of economic water
use
Increasing size of population
General de
cit of water and natural
non-uniform distribution of water
resources
Governmental subsidies to maintain
the water use
Inadequate estimate of losses due to
water basins pollution
Poverty and unemployment
Growing needs for hydroenergetics
Intrusion of alien species
Grass
ecosystems
Transformation or fragmentation
due to either agricultural use or
urbanization
Biodiversity losses due to
res,
emissions of stored carbon, and
atmospheric pollution
Reduction of soil fertility and water
pollution by domestic animals
Increasing size of population
Growing needs for agricultural
products, especially for meat
Inadequate information on the state
of ecosystems
Poverty and unemployment
Accessibility and easiness of grass
ecosystems
Unacceptable scales of the use of
animals for entertainment
consumption is an extremely important feature of the growing scales of con-
sumption re
ecting the socio-economic contrasts in the world.
Furthermore, we shall discuss the principal results obtained within the frame-
work of the pilot analysis of the global ecosystems (PAGES) (A Guide
fl
…
2000).
The main dif
cit of the available
information. The PAGES project is focused on the consideration of the three types
of the indicators of impacts on the ecosystems dynamics:
culties of this analysis are connected with the de
(1) anthropogenic loads (increasing size of population, growing level of resources
consumption,
pollutions,
overexploitation
of
natural
and
controlled
ecosystems);
(2)
the spatial extent of ecosystems (size, shapes,
localization, geographical
distribution);
(3) production of economically important products such as agricultural crops,
wood,
sh, etc.
A considerable drawback of each of these indicators and all of them is that they
do not contain information about the thresholds of ecosystems
'
ability to perform
their functions of life support.
Figure
8.4
illustrates the presentation of the expert assessments of the state of
ecosystems and their functioning as the life supporting systems including the
respective trends: increasing ability of ecosystems to perform the life supporting
Search WWH ::
Custom Search