Page 260 - Materials Chemistry, Second Edition

246 R.K. Rosenbaum et al.

arises. This drives continuous changes in land uses. Croplands, pastures, urban
areas and other land-use-intensive, human activities have expanded worldwide in
the last decades at the expense of natural areas to satisfy our growing society’s
needs for food, fibre, living space and transport infrastructure. Such changes
transform the planet’s land surface and lead to large and often irreversible impacts
on ecosystems and human quality of life (EEA 2010). For example, forest clearing
contributes to climate change with the release of carbon from the soil to the at-
mosphere. The loss, fragmentation and modification of habitats lead to biodiversity
decline. Land use change alters the hydrological cycle by river diversion and by
modifying the portion of precipitation into runoff, infiltration and evapotranspira-
tion flows (Foley et al. 2005). After soil surface conversion, inappropriate man-
agement practices on human-dominated lands can also trigger a manifold of
environmental effects on soil physical properties. In agricultural lands, mechanised
farming can induce soil compaction, which affects aquifer recharge and the natural
capacity of the soil to remove pollutants. Erosion is also a spread environmental
concern of intensive agricultural practices. In urban and industrial areas, soil has
been replaced by concrete surfaces and all its functions annulled.
The Millennium Ecosystem Assessment (2005) provides a comprehensive
description of how human land-use activities affect biodiversity and the delivery of
ecological functions. Some ecological effects of land use are:
• Biodiversity decrease at the ecosystem, species and genetic levels
• Impacts on local and regional climate regulation due to changes in land cover
and albedo, e.g. tropical deforestation and desertification may locally reduce
precipitation
• Regional decline in food production per capita due to soil erosion and deser-
tification, especially in dry lands
• Rise in flood and drought risks through loss of wetlands, forests and mangroves
• Change in the water cycle by river diversion and by greater appropriation of
freshwater from rivers, lakes and aquifers to be used for irrigation of areas
converted to agriculture
To sum up, land-use activities (including land conversion and land use itself)
cause noticeable damages on biodiversity and on the performance of soil to provide
ecological functions as illustrated in Fig. 10.23. These ecological functions upon
which human well-being depends are also referred to as ecosystem services
(Millenium Ecosystem Assessment 2005), and together with biodiversity loss are
the focus of the LCIA land-use impact category.

10.14.2 Environmental Mechanism

The LCIA land-use impact category covers a range of consequences of human land
use, being a receptacle (or ‘bulk’) category for many impact indicators. It does not