| Knowledge gap target groupOrganizations for landscape management Research ObjectivesInsight in potential contribution of different types of green landscape elements and the role of element structure in control of pollution with small dust particles and ammonia in rural areas. Results and productsTrees can catch and hold dust. Interception capacity varies between species, depending on their crown structure and leaf characteristics. The capacity of conifers exceeds that of broadleaved trees species. Within broadleaved species, which are the most important in Dutch landscape elements, species with a high Leaf Area Index and with rough and hairy leaves like Acer pseudoplatanus, Sorbus aucuparia, Prunus padus and Betulus pubescens have presumably greater capacity than others. Also shrub species like Lonicera xylosteum and Rubus idaeus look to be efficient species. Landscape elements of trees can also catch ammoniac from the air. Research on efficiency is restricted. Leaves of broadleaved trees species are expected to be more suitable than needles of conifers. Needles of conifers are more easily damaged by ammonia. Catch capacity of landscape elements is determined by tree and shrub species, but also by the dimensions and structure. For optimal results the landscape element should be porous. Deposition takes place in 3 ways: vertically, horizontally at the edge of the element and inside of the element. The amount of dust and ammonia from different sources in a pilot area was estimated. The present green landscape elements, which cover 3 % of the pilot area, catch about 10 % of the dust emission and 8 % of the ammonia emission. With new elements established on the right place and in the right way, this contribution can be improved. |
