The Full Picture

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Moreover, such colonization initiates unpredictable

ecological interactions between new organisms and the

surrounding environment, fosters new ecosystems

(Hobbs et al., 2006),

and potentially reduces the origi-

nal variability of natural habitats.

Bridging scaling gaps

Limitations relating to generalization are inherent to

experiments carried out under scale-limited laboratory

or field conditions. Such small-scale experimental design

is unable to reveal the complex spatial and temporal char-

acter of larger scale ecosystems and their biodiversity

response to accelerated climate change.

Nature’s complexity is successively scaling various

structures, states and processes over time and space. The

chain of scales starts at the ultra-cellular structure of plant

membranes, accommodating instantaneous biochemical

processes (occurring in fractions of seconds), that are

scaled through cellular tissues, leaves, shoot/branches,

crown canopies, habitats and ecosystems up to biomes,

ending with the global biogeochemical cycles (having

response times of several years). The latest state-of-the-art

science in Earth observation related remote sensing (RS)

enables the bridging of these scales and processes using

radiative transfer based models, data assimilation and

evidential reasoning (Schaepman, 2007a).

Various air- and space-borne Earth observation instru-

ments are currently in use for regular large-scale and

long-termmonitoring as well as regional, high spatial and

forced to either adapt to these new climatic regimes and run the risk

of extinction, or migrate into more suitable environments.

An average temperature change of one degree Celsius can trigger a

shift of ecological zones by up to 160 kilometres. The predicted

temperature increase of four degrees Celsius over the next century

may therefore cause the migration of certain Northern Hemisphere

species by up to 500 kilometres (Thuiller, 2007).

Such rapid and

extreme changes in environmental conditions combined with physi-

cal-geographical barriers may overwhelm the ability of species to

modify their physiological-seasonal strategies, or follow shifting

climate by colonizing new territories; thus lowering their survival rate.

Alternatively, extreme events or shifting climate could trigger an inva-

sion of opportunistic species, which may to some extent cause a

biodiversity increase.

Apart from ecosystem disruption due to climatic change, biodiver-

sity is also facing direct negative impact from anthropogenic and global

human activities motivated by rapid, often economical, benefits. A

prominent anthropogenic impact is large-scale wood logging in the

tropical rain forest. This results in myriad negative effects, such as soil

degradation and biodiversity loss.

It has been observed that land-use change in the year 2100 forced

by climate change alone, will be the largest influence on biodiversity

decline (Sala et al., 2000).

The strongest negative impact from biodi-

versity loss is currently predicted in Arctic, alpine and boreal

ecosystems. Steadily growing long-distance transportation and trade

globalization is further fostering the dispersal of exotic invasive species.

Due to their progressive life strategies, these invaders manage to

occupy the niches of the original conservative species, resulting in

biodiversity homogenization and/or loss.

Pan-European land cover map

Source: CORINE, PELCOM and GLC2000

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