Agricultural Threats

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[ Agricultural Threats ] Climate Change & Agriculture ] Change in Habitats ] Change in Species ] Basic Conservation Measures ] GMO's ]

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Stripper harvesting of rice in the Philippines

Changes in farming practices that have been identified as causing declines in biodiversity include:

bulletConcentration on winter crops with a consequent loss of spring crops, 
bulletIncreased farm specialisation with a decline in livestock and grass enterprises in arable areas
bulletChanges in cultivation dates
bulletLoss of semi-natural habitat in farmland, including field margins.

 The Countryside Survey 1990 showed that not only have hedgerows declined in length, but the botanical diversity of many field margins has also declined through nutrient enrichment and/or herbicide drift.

Historically, most farming practices  have maintained the patchwork of fields and field boundaries. Modern farming techniques have often weakened, and/or destroyed these patterns. Without agriculture, the landscape would take on a different appearance, often reverting over time to scrub and eventually woodland. This would smother the patterns and boundaries  characteristic of the English landscape. 

Pause for thought.... List the 5 aspects of the British countryside which you find most appealing

The specific agricultural threats will be examined later in the course. The general change in agricultural practice and its effects on the landscape and ultimately, flora and fauna are listed below.

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Agricultural intensification

Loss of permanent grassland to arable cultivation:

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Loss of traditionally managed landscape character and biodiversity in mixed farming areas.

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Introduction of monoculture, therefore less diversity in landscape patterns and reduced biodiversity.

Intensive grassland through higher inputs

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Less visually harmonious landscape, bright green swards.

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Earlier harvesting (silage) prevents seed from setting resulting in reduced species diversity of swards 

The area of semi-natural grassland continues to decline in the UK.  The Countryside Survey 2000 showed an decrease of 280,000 hectares in the area of neutral, acid and calcareous grassland from 1990 to 1998.  The data also showed a continuing decline in the species diversity of these infertile grasslands.

Intensification of arable land

Intensive arable cropping

 

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Increased field size to facilitate the use of larger machinery often leads to the loss of hedges and ditches, reducing visual integrity of the landscape and range of wildlife habitats

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Increased ploughing depth and subsoiling operations enhance the potential for soil erosion and nutrient loss

Pause for thought...... Can you remember how much of the UK has grassland as its main groundcover? List 3 reasons why it may be difficult to encourage the reversion of arable land in the East of England back to grass

Intensified upland grazing management

Upland livestock

 

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Changes in land management are the main cause of environmental degradation

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Increased stocking densities on upland grazing resulting in sward damage and reduction or loss of species

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Intrusion of farming activities disturbing plant and wildlife, domestication of landscape (i.e. feed troughs, hardcore tracks etc.)

bulletIncreased competition for grazing between domestic and wild species.           

 

Drainage

 
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Loss of watercourses and ditches equates to loss of habitat for aquatic plants and animals.

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Loss of wetlands having a direct effect on wading bird populations.

The reduction in mixed farming systems

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Increased monoculture and a shift away from traditional crop rotations.

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Abandonment of marginal land around specialized farms.

Pause for thought.......List 3 advantages associated with mixed farming. 

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[ Agricultural Threats ] Climate Change & Agriculture ] Change in Habitats ] Change in Species ] Basic Conservation Measures ] GMO's ]

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