Land and soil in Europe — Ever-sprawling urban concrete?

In 2018, the EU’s Earth observation programme, Copernicus, completed another round of a Europe-wide mapping exercise, which formed the basis of a detailed analysis by the EEA of land cover and, partly, land use in EEA member and cooperating countries. According to these Corine (Coordination of information on the environment) monitoring results, Europe’s land cover has remained relatively stable since 2000, with about 25 % covered by arable land and permanent crops, 17 % by pastures and 34 % by forests. However, on closer inspection of recent land cover changes, two noteworthy trends emerge.

First, cities and concrete infrastructures continue to expand. Although artificial surfaces cover less than 5 % of the wider EEA territory, a sizeable area — slightly smaller than Slovenia — still became sealed (covered by concrete or asphalt) between 2000 and 2018. The good news is that the rate of increase in artificial surface areas has slowed down, from 1 086 km² per year between 2000 and 2006 to 711 km² per year between 2012 and 2018.

Second, the largest losses were observed in agricultural land, due mainly to urban expansion and farming withdrawal, while the total forest area remained stable. The area of cropland, pastureland and natural grasslands lost was similar in size to the increase in area of artificial surfaces. And, as most of Europe’s cities were built on and surrounded by fertile land, it is often productive agricultural land that gets taken and covered by artificial surfaces. Fortunately, the loss of agricultural land appears to have slowed down significantly and came close to halting in the period 2012-2018.

Urban population and cities continue to grow

Today, almost three quarters of Europeans live in urban areas. Europe’s urban population is expected to continue to grow by up to 30 million additional people by 2050. Additional housing and infrastructure (e.g. roads, schools, water treatment networks and waste facilities) will need to be built to accommodate Europe’s growing total population as well as its urban population.

Population growth is not the only driver behind urban expansion and the land take and soil degradation associated with it. Rising income levels also play a role, as they often translate into bigger houses, more holiday homes and resorts along the coast, and more commercial and industrial facilities to meet rising consumer demand. In many ways, the expansion of urban areas and their infrastructure extensions go hand in hand with the increasing number of socio-economic benefits that many Europeans have been able to enjoy in recent decades. But some of these lifestyle changes have long-lasting negative impacts not only on the countryside and natural landscapes but also on urban landscapes.

Increasingly fragmented landscapes

Despite slowing down between 2012 and 2015, landscape fragmentation is still increasing across the 39 EEA countries, affecting rural and sparsely populated areas in particular.

Roads and railways connect people, and urban and rural areas, but they often constitute real barriers for wildlife and plant dispersal. As urban areas and their supporting infrastructures expand across the landscape, they fragment habitats into smaller patches. Species living in these increasingly smaller areas may be forced to live with fewer resources and a more limited gene pool. When the size of an animal population falls below a critical level, species can become extinct in that particular area. This is why many species are found only in rural or protected areas. Many wild animals are also injured or killed trying to cross barriers such as motorways.

Landscape fragmentation is addressed by a number of EU policies, including the overarching EU biodiversity strategy to 2020 aimed at halting the decline in biodiversity. On the ground, this strategy is supported by tangible measures, such as establishing a green infrastructure — a strategically planned network of natural and semi-natural areas to help species move and spread across the landscape. In this context, many European countries are building wildlife crossings — tunnels or bridges enabling species to move across motorways and canals. Depending on the location of the crossing and the species in the area, these crossings can make a real difference locally. Hedges and rows of trees in open landscapes also promote habitat connectivity, while reducing other threats such as soil erosion by wind.

Landscape fragmentation occurs even in protected areas. However, compared with unprotected areas, the increase in fragmentation appears to be noticeably lower in protected areas that are part of the EU’s Natura 2000 network, indicating that well-implemented nature protection measures have positive impacts.

When farmland is abandoned

Like many other environmental policy questions, landscape fragmentation presents a dilemma. On the one hand, the expansion of transport networks fragments the landscape and introduces additional pressures on ecosystems, including pollution. On the other hand, transport networks also bring economic opportunities (e.g. jobs in tourism, industry or the bioeconomy) to rural communities, often heavily dependent on agriculture and affected by land abandonment.

For some rural communities, land abandonment is a pertinent concern, especially in remote regions where the local economy relies heavily on the agricultural activities of often small-scale farms with low agricultural productivity. In such communities, younger generations also tend to move to cities and small-scale farming struggles to compete economically with a more structured, intensive agricultural market. In the next 20 to 30 years, significant areas of agricultural land are expected to be abandoned in parts of Europe.

When left uncultivated, vegetation — including forests — will grow and take over the abandoned area. However, after centuries of extensive land management, such as grazing by sheep or goats, natural revegetation often results in ecosystems with fewer species. To preserve EU habitats and species, it is often better, therefore, to support farmers to practise extensive, high-nature-value agriculture. New incentives, such as diversification of income sources (e.g. tourism) or premium prices for high-quality food products, can help change these trends.

Intensive land use affects soil and its functions

Urbanisation, a growing population and a growing economy on the one hand and land abandonment on the other have resulted in more people living and relying on a smaller area in Europe. While some areas face depopulation and a decline in agricultural and economic activities, other areas — urban and agricultural alike — are subject to increasingly intensive use.

Soil represents an almost invisible interaction between a huge diversity of soil-dwelling organisms, organic matter from plants and roots, and material from weathered rock and sediments. This sensitive biomineral layer on top of the Earth’s crust can be viewed as an ecosystem of its own. Intensive use of land can affect soil and its functions significantly and in several ways, including through soil sealing, erosion, compaction and contamination.

When sealed — covered by buildings, asphalt or concrete — soil loses, among others, its ability to absorb and retain water or to produce food. Use of heavy machinery can change soil structure and make it more compact, reducing air and water in the parts of the soil where plant roots take up water and nutrients and where soil animals and microorganisms decompose organic material. Sealed or heavily compacted soil absorbs less rain water, which in turn increases surface run-off, soil erosion and the risk of flooding.

Higher productivity often relies on synthetic fertilisers and crop protection products, as well as certain agricultural practices, which may lead to erosion and contamination. For example, maize monocropping tends to increase erosion. The erosion of topsoil reduces yields and, hence, can affect farmers’ incomes. Erosion can also affect biodiversity as top soils tend to shelter the highest diversity and density of soil organisms. According to some estimates, the current mean soil erosion rate by water is 1.6 times higher than the average rate of soil formation in the EU. Wind and harvest losses are also major sources of soil erosion.

Similarly, the excessive use of mineral fertilisers can contaminate the soil with cadmium (see Interview — Soil contamination: the unsettling legacy of industrialisation) and affect the way soil ecosystems function (see Interview — Soil: the living treasure under our feet). Through soil erosion or flooding, pollutants can enter water streams, leach into groundwater and spread farther. Or, waste management practices — such as landfilling or spreading waste water on land — can introduce contaminants, including microplastics, to soil. In Europe, pollution from industry is regulated by EU legislation and as a result has been declining significantly. Despite this, industrial facilities also release some of their pollutant emissions to land. For the 30 000 facilities and 91 pollutants included, all information on how much and what pollutants each facility releases is made public through a web portal (European Pollutant Release and Transfer Register) managed by the EEA and the European Commission. In addition to known and regulated pollutants, in recent years there has been a growing concern of new pollutants, such as persistent organic chemicals used in plant protection, contaminating in Europe’s soils. Depending on their potential impacts, new measures are very likely to be needed to protect the environment and human health.

Contamination is not always linked to local sources of pollution. Wind and rain can transport and deposit air pollutants even in the most inaccessible parts of the world. Similar to what happens in lakes and oceans, once they enter soil, pollutants can accumulate over time and affect these ecosystems.

Preserve and connect natural areas, reuse and recycle urban areas

With resources as valuable and limited as land and soil, the only viable option is to prevent their degradation and use them sustainably.

The EU aims to achieve ‘no net land take by 2050’ in line with the global Sustainable Development Goals. One clear way of limiting urban expansion is to make better use of the existing urban space. Today, land recycling and densification (e.g. using an old industrial site for infrastructure or urban expansion) account for only a fraction — 13 % — of new developments (see EEA indicator[x] and land recycling viewer), and land take continues to be a problem (see the land take data viewer). Europe’s spatial, especially urban, planners will need to play a key role in limiting urban expansion by designing compact but green cities, with key amenities within walkable distances or mobility systems designed to reduce travel distances and times, or an extensive green infrastructure network that connects all natural areas across the continent.

To turn such plans into reality, a wide range of stakeholders needs to be involved and key governance questions need to be addressed (see Governance — Acting together for sustainable land management).