Landscape elements such as hedges and windbreaks in rural areas can reduce the emission of particulate pollution (PM10) and ammonia from livestock. That is one of the outcomes of a recent research project by scientists from Wageningen University and Research Centre in The Netherlands. Biologist Fred Tonneijck was one of the research workers, he explains:

“We have shown that landscape elements are relatively effective in removing pollution from the surrounding air. At present, society beliefs that management of green elements in the landscape only costs money. This is not true. This management should be regarded as an investment since green elements have a positive effect on the environment.”

The conclusion? Plant more landscape elements.

Fred Tonneijck worked almost thirty years as a scientist at Wageningen University and Research Centre in the field of air pollution and plants. Recently he joined the team of Triple E in Arnhem as a senior consultant. He was involved in a recent study to assess the importance of landscape elements in removing PM10 and ammonia from cattle husbandry. One of the outcomes is that landscape elements with trees and shrubs are relatively efficient in capturing both pollutants as compared to short vegetations.

“Elevated concentrations of PM10 occur throughout the country and high concentrations can be measured in the vicinity of emission sources and in cities. PM10 is the abbreviation for particulate matter having an aerodynamic diameter of less than 10 µm. PM10 is a serious threat to our health and more people are killed prematurely by the effects of this pollutant. Intensively managed livestock is a well-known emission source of particulate matter as well as of ammonia in rural areas. That is why we have considered both components in our study.”

The pilot area

A pilot area of one square kilometres was selected circa 20 kilometres east of Utrecht near Woudenberg. The area was situated just north of highway A12. This is a very busy highway and an important emission source of PM10 in the region. The net emission of the selected area was investigated. “Circa 200 kilograms of PM10 is emitted in the area while not taking into account the emission of the highway. That is a lot of times less than is removed by the vegetation in this area. The capacity of total vegetation in the pilot area to take up PM10 is about as large as the emission in the area plus that of the busy A12. For ammonia it is the other way around; the emission is considerably larger than the existing vegetations can remove from the air.”

Landscape elements cover about 3% of the area surface. However, these elements accounted for 10% of the total removal of PM10 and 8% of that of ammonia. “Thus, we must plant more landscape elements, especially since these elements remove the air pollutants more effectively than other types of vegetation.”

Coniferous trees are most efficient in removing PM10 from the polluted air. “This is because of the pointed structure of the needles. Deciduous trees can also be used especially if their leaf surfaces are rough, sticky and hairy.” Deciduous trees with flat and broad leaves are most efficient in absorbing ammonia. “For instance poplars or willows are quite effective. Coniferous trees are less suited because they are relatively sensitive to ammonia exposure. Thus, a mix of deciduous trees can best be planted to remove both PM10 and ammonia from polluted air around intensively managed livestock.”

Tonneijck says “landscape elements are worth much more than one thinks. The investment in landscape elements is particularly valuable since we gain a lot of profits.”