LAND USE - LAND & HEALTH

What are the major types of land use changes?

• Deforestation and aforestation

• Agricultural expansion - wildland/grasslands→grazing or crops

• agricultural change - converting from livestock to arable (or vice versa)

• agricultural land loss - through rewilding or cropland abandonment

• urbanisation - permanent destruction of natural landscapes to build cities

How has anthropogenic land use changed through space and time?

• roughly 70% of ice free land on Earth has been altered by humans

• Most extensive land cover change - Europe, North America and India

• most untouched areas are the worlds hot and cold desert regions - Arctic, Antarctic, Sahara, central Australia

• Land use change through history model

• creation of designated protected areas in UK in 1950s

• land has been changed from wild spaces, to agricultural and then to urban as the land becomes less productive and populations have increased

• land use not equal globally - Global north, increased afforestation and cropland abandonment while Global south has seen increased deforestation and agricultural expansion

What are the stages of land use change model?

• pre-settlement - 100% natural environment

• frontier clearing

• small style agriculture - subsistence & small farms, some urban areas

• growth of Urban and intensification of agriculture

Problems in modern food system

• roughly 15% of global population lack sufficient dietary protein & energy

• many sufferers of micronutrient malnourishments

• predicted that increased population and increased global wealth will lead to increased demands on land for food resources and energy - increased ‘purchasing power’ from individuals

• climate change a key factor in how food system is and will be shaped

• demands for food increased but land used hasn’t increased at same rate - intensification of farming - probably unsustainable, soil degredation

• possible future issues of land loss through urbanisation, desertification and salinasation

How is land use change linked to the economy?

• global economic and food crisis 2007-2009

• pre crisis - increased demand for food, animal feed and biofuel which stimulated agricultural production

• Global norths demands met by global south (e.g oil crops in Ghana, Argentina, Brazil and Indonesia)

• post crisis - slowed agricultural expansion in global south

case study - land use change in South America

• increased biofuel production in global south during the financial crisis - Argentina plays role in bioethanol production produced by corn and sugarcane

• mass deforestation in South America, especially Brazil

• substantial urbanisation

case study - changes to UK land use

• fractional change over 75 year period with greatest losses in grassland areas

• causes of change - urbanisation, regional woodland increases, north/south split on arable farming

Changes to grasslands

• causes for change - use of artificial fertilisers, changes to cutting regimes/schedules, drainage

• benefits of grasslands - water management, erosion control, climate regulation, fodder for animals, polination, biological pest control, biodiversity

Things associated with poor land use/management

• changes to climate

• food insecurity

• poor economic development

• air, water and land pollution

• reduced water availability / desertification

What are environmental services (examples?)

• environmental services are benefits that ecosystems provide to people either directly or indirectly

• examples - purification of air, ensuring plant pollination

socioeconomic impacts of land use change

• urbanisation reduces land avaliable for resources and food

• enhanced agriculture and deforestation → soil erosion, salinization, desertification reduce quality and productivity

• monoculture can lead to consumption of certain produce less possible (local scale)

• urbanisation disrupts social dynamics and organisation

• increased land value makes housing less affordable

• reduces open space for public

• private ownership threatens public interests

environmental impacts of land use change

• pollution from runoff

• reduced carbon storage and biodiversity

• water cycle and ground water levels altered by irrigation

• degredation of soil through intensive farming and deforestation

• deforestation adds to greenhouse effect

• urban development increases emissions, pollution and runoff/flooding

• habitat loss, fragmentation and alteration

Important factors to consider relating to climate

• evotranspiration

• albedo effect

• Net Ecosystem Production

• carbon stores