Geography Reference
In-Depth Information
Table 7.7
The forest area and biomass stock in Brazil from 1990 to 2005
Categories
1990
2000
2005
Forest area (10
6
hectares)
Primary
460.51
433.22
415.89
Modified natural
54.44
54.71
56.42
Productive plantation
5.07
5.28
5.38
Total
520.03
493.21
477.70
Biomass stock (10
3
million metric tonnes oven-dry weight)
Above ground biomass 86.09 82.68 79.22
Below ground biomass 24.43 22.86 22.02
Dead wood 6.88 6.56 6.36
Total 117.40 112.10 107.60
Note This table shows a dramatic reduction in both forest quantity and quality. The data is
obtained from the website of Food and Agriculture Organization of the United Nations, global
forest resources assessment, 2005. For more information, please refer to
http://www.fao.org/
The Amazonia tropical forest with an area of 6 million km
2
, nearly 80 % of its
original area, covers half of the global remaining tropical forests, and approxi-
mately 60 % is located in the Brazilian Amazon region. The annual average forest
clearing rate in Brazil has accelerated during the period from 1994 to 2005 and
showed a decreasing trend in recent years, increased from 1.3 9 10
4
km
2
in
1990-1994 to above 2.0 9 10
4
km
2
in the next two years, then slightly declined to
1.9 9 10
4
km
2
until 2005 and less than 0.7 9 10
4
km
2
in 2011 (Duchelle et al.
2013
). Meantime, the quality of forest has also experienced a significant loss, which
can be illustrated by the figures in Table
7.7
. Given the massive ecological services
in water maintaining and climate regulation, the annual average precipitation in
Amazon reaches 2,500 mm, and it can discharge over a trillion m
3
of water into the
ocean. Without these tropical forest featured by low albedo, great radiative forcing,
and high evapotranspiration rate, the local residents should not have had such
habitable zones with a cool and wet boundary (Werth and Avissar
2002
). Although
the tropical forests are an indispensable component of regional ecological system
and humanity, anthropogenic activities have caused the shift of climatic states by
disturbing and clearing the tropical forests (Ramos da Silva et al.
2008
). This land
surface change would destabilize regional climatic and hydrometerological vari-
ability (Baidya Roy and Avissar
2002
), and then induce the climate anomalies, such
as change in precipitation and temperature (Schneider et al.
2004
).
Numerous researches have been conducted to assess the potential climatolog-
ical changes of tropical deforestation in (Brazilian) Amazon using the global or
regional climate models (Ke et al.
2012
), and shared a common view that the vast
tropical forest plays a pivotal role in changing climatic conditions. But these
studies are lacking thorough and profound investigation due to the demerits of
numerical models and data availability. As to the Global Climate Models (GCMs),
