The most significant direct impacts of beef
production on habitat are the conversion of forest habitat to
pasture, the alteration of the composition of native plant
communities in grasslands, and the wholesale removal of native
vegetation (e.g., forests, scrublands, and grasslands) as
habitat is converted to seeded or planted pasture.
Rendering large tracts of land useless
Currently two-thirds of the world's agricultural land is used
for maintaining livestock. One-third of the world's land is
suffering desertification due in large part to deforestation,
overgrazing, and poor agricultural practices.
Mounting damages
An area of the world's rainforest larger than New York State is
estimated to be destroyed each year to create grazing land. This
not only alters the composition or existence of native plant
communities but also the species of wildlife that existed in
those plant communities.
Plant communities are altered over much of the
world, often as a result of direct intervention such as
ploughing native grassland vegetation and establishing either
single-species or mixed-species pastures of introduced species.
The species composition of natural grasslands is transformed by
continuously overstocking native rangeland with livestock,
enrichment planting (e.g., sowing seeds of introduced species in
native grassland), and eliminating intentional burning.
Pastures - damaging local biodiversity
of converted lands
Pasture can be created from temperate or tropical forests or
savannas. This often involves converting native habitat and
introducing grass and forage species that provide more food for
cattle. In natural grasslands the biggest impact is the
alteration of the native plant communities and the associated
impacts on wildlife and other biodiversity.
In addition, cattle are increasingly fed hay and grains to supply food during the dry or winter seasons, or to fatten them before slaughter. While forests have been cleared to make way for livestock throughout the world, the most significant impacts recently have been in the Amazon, where massive clearing of tropical forests has had a tremendous impact on biodiversity, ecosystem functions, and even local climate.
Maintaining desired pasture composition in created pastures often requires tillage, chemical fertilisers, and pesticides. Continuous grazing causes plants to produce more leaf biomass and less root biomass. This reduces their ability to survive during periods of stress (e.g., extended cold, hot, or dry spells).
Watershed protection also suffers as plant cover and leaf litter diminish, leaving the soil exposed and erodible. In areas where pastures are not maintained, woody plants tend to dominate over time, not only affecting ecological balance but also reducing the carrying capacity for cattle.
Irreversible damages to degraded
agricultural land
Another source of pasture is degraded agricultural land. In many
areas, once land can no longer produce agricultural crops, it is
used for livestock. Such land is already degraded. However,
converting it to pasture degrades it even further, virtually
ensuring that it will not return to anything near its natural
state.
Displacing rural poor
Cattle production can cause habitat conversion indirectly as
well. In some instances cattle are a "push" factor, displacing
the rural poor into fragile areas. In Central America, for
example, the conversion of labour-intensive, cash crop-producing
areas to cattle production caused many landless poor to move
into and clear tropical forest areas for subsistence production.
In a variation on this pattern, the rural poor and landless in
the Amazon often clear land, grow a crop or two and then plant
the land to pasture to sell to ranchers.