Geoscience Reference
In-Depth Information
uses (Daily et al. 2000). Land-cover change challenges the capacity of many ecosys-
tems and landscapes to deliver the expected goods and services for specifi ed land
management systems, ranging from seed stocks to water fi ltration (Daily et al.,
2000; DeFries et al., 2004; MEA, 2005). Fragmentation of ecosystems or land bar-
riers to the fl ow biota may disrupt or reduce the movement of biota across landscape
and regions, especially along ecoclines or involving keystone species, with implica-
tions for the functioning of ecosystems. Increasing research examines this relation-
ship for nature reserves, especially in regard to land changes beyond the reserve
(Homewood et al., 2001; Terborgh et al., 2002).
In addition to these immediate feedbacks, land uses are affected by those operat-
ing through climate and other atmospheric changes. For example, regional-to-
continental scale, ground-level ozone from industrial-urban regions spreads across
prime croplands worldwide, interacting with nitrous oxide released from fertilizers
to reduce crop yields (Chameides et al., 1994; Matson et al., 1997; Tilman et al.,
2002). Climate change in conjunction with land changes also threatens such sensi-
tive land covers as tropical forests (Nobre et al., 1991; Laurance, 1998) as well as
the functioning of terrestrial ecosystems and their land covers everywhere (Walther
et al., 2002).
Observing-monitoring land change
Perhaps no part of land change science has advanced more than that dealing with
observation and monitoring as the use of satellite remote sensing has become
increasingly fi ne-grain in spatial and temporal resolution and employed in novel
ways (Walsh and Crews-Meyer, 2002; Fox et al., 2003; Wulder and Franklin,
2006). Seamless global data of different types of land cover can now be produced
that address a large number of vegetative attributes (Defries et al., 2000; Loveland,
2000), such as their functional properties (e.g., DeFries et al., 1995), improving
datasets for various kinds of global models.
Advances have been made as well in a large array of remote sensing data
assessments for specifi c kinds of land change detection-assessment. Examples
include the temporal patterns of landscape burning and their implications for
cultivation and burning policies (Laris, 2005); attempts to separate climate from
land management impacts on vegetation in order to assess the consequences of
stocking strategies (Archer, 2004); detection of 'cryptic' deforestation by way of
selective logging (Nepstad et al., 1999; Asner et al., 2005); mapping and monitor-
ing 'hot spots' of biological diversity (Myers et al., 2000), although such efforts
perhaps should be directed at populations (Ceballos and Ehrlich, 2006); observing
land changes to urbanisation and peri-urban uses (Seto et al., 2002; Seto and
Kaufman, 2003); and linking successional states of forest growth to household
lifecycles (Moran et al., 1994; McCrackin et al., 1999), participatory mapping
(Mapedza et al., 2003), ethnology (Nyerges and Green, 2000) and disasters (Lupo
et al., 2001).
While each project tends to design its own land classifi cation suited to the obser-
vational instrument and the aims of the project, headway has been made on meta-
classifi cation, complete with software, in order to permit individual project products
to be compared (Di Gregorio 2005). In addition, land classifi cations and monitoring
are now used as accounting mechanisms for differing governing units (e.g., EEA,
2006).
