Thirty years of land-cover change in bolivia

Solo disponible en BuenasTareas
  • Páginas : 27 (6700 palabras )
  • Descarga(s) : 0
  • Publicado : 15 de agosto de 2012
Leer documento completo
Vista previa del texto

Timothy J. Killeen, Veronica Calderon, Liliana Soria, Belem Quezada, Marc K. Steininger,
Grady Harper, Luis A. Solorzano and Compton J. Tucker

Thirty Years of Land-cover Change in Bolivia
Land-cover change in eastern lowland Bolivia was
documented using Landsat images from five epochs for
all landscapes situated below the montane tree line at
approximately 3000 m, includinghumid forest, inundated
forest, seasonally dry forest, and cloud forest, as well as
scrublands and grasslands. Deforestation in eastern
Bolivia in 2004 covered 45 411 km2, representing ;9%
of the original forest cover, with an additional conversion
of 9042 km2 of scrub and savanna habitats representing
17% of total historical land-cover change. Annual rates of
land-cover change increasedfrom ;400 km2 yÀ1 in the
1960s to ;2900 km2 yÀ1 in the last epoch spanning 2001
to 2004. This study provides Bolivia with a spatially
explicit information resource to monitor future land-cover
change, a prerequisite for proposed mechanisms to
compensate countries for reducing carbon emissions as
a result of deforestation. A comparison of the most recent
epoch with previous periods shows thatpolicies enacted
in the late 1990s to promote forest conservation had no
observable impact on reducing deforestation and that
deforestation actually increased in some protected areas.
The rate of land-cover change continues to increase
linearly nationwide, but is growing faster in the Santa
Cruz department because of the expansion of mechanized agriculture and cattle farms.

INTRODUCTIONLand-cover change in tropical ecosystems is one of the most
important ecological challenges facing modern society; potential
global-scale impacts include catastrophic losses of biodiversity
(1), increased global warming (2), and changes in weather
patterns that could reduce agricultural production in the
world’s poorest countries (3). Despite numerous policy initiatives and multilateralassistance programs designed to decrease
deforestation, countries in the developing world continue to
experience high levels of deforestation because of economic and
social phenomena that drive the expansion of the agricultural
frontier (4–7). Proposals are now being advanced within the
context of the United Nations Framework Convention on
Climate Change (UNFCC) to compensate developing countriesfor conserving tropical forest; most proposals are based on
lowering carbon emissions by reducing current deforestation
rates (8). Whatever mechanism is eventually approved, parties
to the agreement(s) will require baseline data on historical
deforestation rates at the national level, whereas information at
the subnational level will be a requisite for individual initiatives.
Inevitably,countries will need to conduct a methodologically
robust annual survey to document and certify any future
reductions in the annual deforestation rate.
Currently, very few countries have access to reliable statistics
on current and historical deforestation rates. Global deforestation is at near historical levels with an annual rate of ;130 000
km2 yÀ1; between 34 000 km2 yÀ1 and 44 000 km2 yÀ1of this
occurs in the Amazon (9). Brazil accounts for about 60% of
Amazonian deforestation, with an annual rate of deforestation
that has trended upward since monitoring began in 1988, with
peaks in 1995 and 2004. The Brazilian rate has decreased the


past two consecutive years, falling from a near high of 27 429
km2 yÀ1 in 2004 to 18 793 km2 yÀ1 in 2005 (10) and an
unvalidated rateof only 13 100 km2 yÀ1 for 2006 (11). The
Brazilian government contends that the recent reduction in
deforestation is due to policy initiatives (12), but reduced
demand for the commodities that drive deforestation may also
be responsible. Similar data for the Andean Amazon is lacking
because multitemporal measurements based on satellite imagery
have not been systematically collected. This...
tracking img