Impacts of field margin relevant herbicide and fertilizer deposition on appearance, flower generation and reproduction of different non-target plants

Karoline Schäfer, Diploma thesis

Study Description

Since many decades a decline in biodiversity could be watched in the cultivated landscape. The floral diversity is the source of the faunistic diversity. Plants as primary producers are the first an initial step of the food chain and therefore they are a fundamental part of terrestrial ecosystems. Field margins are not only habitat and food resource for many animal- and plant species they are also a refugee for species who could not survive in the adjacent cultivated landscape. Field margins are also important to connect different biotopes by creating near-natural habitats.

Plants which grow in field margins are affected by the input of pesticides and fertilizer due to the fact that they are in direct contact to the farmland. In the first meters of field margins herbicide expositions could be expected which causes lethal as well as sub-lethal effects on plants. Sub-lethal effects are expressed through a lower fitness, flower intensity and reproduction of the affected plants.

In the present risk assessment these sub-lethal effects which also can cause a change in the plant community are not considered. To preserve the biodiversity sub-lethal effects on plants should be examined more closely at the risk assessment. In addition to pesticides field margins are also affected by fertilizer. Nitrophilous plant species benefit from nutrient addition. They are aided in growth and consequently they are much more competitive compared to fewer nitrophilous species. The species diversity decreases over several vegetation periods and also the composition of the plant community could be changed sustainably by fertilization. To quantify the impacts of agrochemicals on plants and plant communities a collaborative consideration is wise and necessary.