Geoscience Reference
In-Depth Information
Examining one part of the answer within the evolving nature-society interface
may help to understand how yield increases can be achieved in some still basically
agricultural economies and societies, while not in others. This requires the black-
case of the agrarian system to be open in order to look carefully into its agro-
ecological engine to understand how matter, water and energy were processed into
fertile soil allowing plants to grow. When applied to organic agrarian economies,
the quantitative reconstruction of energy and biophysical
ows requires that they be
located carefully within the territory. It must be noted that almost all energy or
biophysical
fl
ows mobilized by past agrarian societies were highly dependent on
their land-use pattern. Land usage became pivotal, in those organic economies, for
any socio-metabolic exchange with nature.
The importance of an integrated management of the three main components of
any agrarian system, that is, cropland, woodland, pastureland and the key role
played by livestock in linking the three, are readily apparent to all agrarian histo-
rians studying pre-industrial societies. However, until recently, very few attempts
had been made to connect the energy and material
fl
ow analysis with land-use
systems. Today the most important research programme seeking to relate socio-
metabolic
fl
ow analysis with land usages is that being undertaken by the Institute of
Social Ecology at the University of Vienna (
http://www.iff.ac.at/socec/
). Many
studies and publications on the changing face of human colonization of terrestrial
ecosystems come from the extensive international research programme Land-Use
Land-Cover Change (
http://www.geo.ucl.be/LUCC/lucc.html
)
. The LUCC exam-
ines the transformations undergone by Earth
'
s vegetal cover over the centuries, in
order to identify the main driving forces behind global socio-environmental change,
and also to assess its socio-ecological impact. Perhaps environmental and economic
historians, working together to understand economic growth in past agrarian
societies and present industrial ones, can help merge these two approaches, i.e. the
accounting of biophysical
fl
ows combined with a closer and more analytical
examination of the land-use systems in which they take place.
Thanks to the energy balances calculated by many scholars from the mid 1970s
onwards, we now know that energy returns on energy inputs were higher in earlier
organic agricultures than those attained following the widespread adoption of the
'
fl
as wee see in schemes b and c in
Fig.
2.4
. However, there is an important element to this seemingly paradoxical
discovery which should focus our attention on the land-use system: How were these
pre-industrial societies able to attain such a high energy performance, while being
so heavily dependent on livestock bioconversion which is so inef
green revolution
'
after the Second World War
—
cient? Why has
industrialized agriculture become so inef
cient in processing energy and material
fl
cient
converters? Some recent results obtained analysing the link between energy-use
performance and land-use management in some Mediterranean local case studies
suggest that a great deal of the answer lies in the loss of landscape ef
ows, and thus so pollutant, having at its disposal a wider range of more ef
ciency.
62
62
Tello et al. (
2006
) and Marull et al. (
2010
).
