Conservation Evidence strives to be as useful to conservationists as possible. Please take our survey to help the team improve our resource.

Providing evidence to improve practice

Individual study: Do field margins contribute to enhancement of species diversity in a cleared arable landscape? Investigations on the insect community of mugwort (Artemisia vulgaris L).

Published source details

Denys C. (1997) Do field margins contribute to enhancement of species diversity in a cleared arable landscape? Investigations on the insect community of mugwort (Artemisia vulgaris L). Mitteilungen Der Deutschen Gesellschaft Fuer Allgemeine Und Angewandte Entomologie, Mitteilungen Der Deutschen Gesellschaft Fur Allgemeine Und Agewandte Entomologie, Band 11, Heft 1-6,, 69-72.


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Create uncultivated margins around intensive arable or pasture fields Farmland Conservation

A replicated, controlled study in summer 1995 in an intensively farmed landscape near Göttingen, Germany (Denys 1997) found higher arthropod species richness on potted mugwort Artemisia vulgaris plants placed in uncultivated margins (one and six years old) compared to a cereal field, but not compared to other margin types. The predator-prey ratio was significantly higher in the 6-year-old margin than in all other margin types and the control. The effect of uncultivated margins on individual arthropod numbers was species-dependent but slightly more individuals were found in the 1-year-old than in the 6-year-old uncultivated margins. Investigated margin types besides the two types of uncultivated margin were wildflower strips (wildflower seed mixture or Phacelia spp. only) and cereal strips/headlands. Potted mugwort plants (four pots) were placed in all margin types and the control (one winter wheat field). All herbivores and their predators on the plants were recorded during six visits in June and July. In September, all mugwort plants were dissected in the lab to assess numbers of arthropods feeding inside the plants. Results from the same study are also presented in (Denys et al. 1997, Denys & Tscharntke 2002).

Leave headlands in fields unsprayed (conservation headlands) Farmland Conservation

A replicated, controlled study in summer 1995 in five different field margin types and one control (winter wheat field) in an intensively farmed, homogenous landscape near Göttingen, Germany (Denys 1997) (same study as (Denys et al. 1997, Denys & Tscharntke 2002)) found higher arthropod species richness on potted mugwort Artemisia vulgaris plants placed in unsprayed cereal strips (headlands) compared to the cereal field, but not compared to other margin types. The predator-prey-ratio in the headland did not differ from the control but was significantly lower than in a six-year-old uncultivated field margin. The effect of unsprayed headlands on individual arthropod numbers was species-dependent with some species (e.g. the aphid Macrosiphoniella oblonga and the fly Oxyna parietina), but not all, being found in higher individual numbers in the headlands than in the control. Investigated margin types apart from the unsprayed cereal headlands were wildflower strips (wildflower seed mixture or Phacelia spp. only) and uncultivated margins (one and six-years-old). There were four replicates of each margin type. Potted mugwort plants were placed in all margin types and the control. All herbivores feeding on the plant and their predators were recorded during six visits in June and July. In September, all mugwort plants were dissected in the lab to assess numbers of arthropods feeding within the plants.

 

Plant nectar flower mixture/wildflower strips Farmland Conservation

A replicated, controlled study in summer 1995 near Göttingen, Germany (Denys 1997) found higher arthropod species richness on potted mugwort Artemisia vulgaris plants placed in sown wildflower strips compared to the cereal field, but not compared to other margin types. The predator-prey ratio in wildflower strips did not differ from the control winter wheat field but was significantly lower than in a 6-year-old uncultivated field margin. The effect of wildflower strips on numbers of individual arthropod species varied between species, with some species (e.g. the aphid Macrosiphoniella oblonga and the fruit fly Oxyna parietina), but not all found in higher numbers in wildflower strips than in the control. Two types of wildflower strip were sown with either a wildflower seed mixture or a phacelia Phacelia tanacetifolia mix. Other margin types were one-year-old and six-year-old uncultivated margins and cereal strips. There were four replicates of each margin type. Potted mugwort plants (four pots) were placed in all margin types and the control. All herbivores and their predators on the plants were recorded during six visits in June and July. In September, all mugwort plants were dissected to assess numbers of arthropods feeding inside the plants. Results from the same study are also presented in Denys et al. 1997, Denys & Tscharntke 2002.