In the Netherlands the creation of sown field margins, known as ‘fauna margins’, is a common form of subsidised AES.
It is assumed that these margins provide habitat for animals in the broad sense, i.e., for birds, small mammals and invertebrates. Due to the manner in which the scheme is regulated, they are commonly installed for a period of 6 years only. As AES may not always be effective in promoting biodiversity (Kleijn et al. 2001, 2006; Kohler et al. 2007; Blomqvist et al. 2009) and often cost a considerable amount of money, it is of great importance to assess the contribution of these margins to biodiversity. Invertebrates, being a species-rich and diverse group of small animals, seem to be especially fit to use as focus group for studying the biodiversity of small landscape elements like fauna margins. The age of such margins might be expected to be a leading factor in invertebrate occurrence, with older margins selleckchem having a greater chance of invertebrate colonisation (Corbet 1995). However, only a limited number of papers have been published on the Cediranib order development of invertebrate communities
in field margins after initial establishment (more papers have been published on plant succession, e.g., Kleijn et al. 1998; Critchley et al. 2006; Manhoudt et al. 2007; Musters et al. 2009). Most of them found in increase with age of the margins (Denys and Tscharntke 2002; Olson and Wäckers 2007; Frank and Reichhart 2004; Woodcock et al. 2008; Musters et al. 2009), although Woodcock et al. (2008) found predatory beetles to peak in the second year after establishment Isotretinoin and to decrease in 2 year thereafter. However, none of these studies deal with a broad range of invertebrate groups and only Musters et al. (2009) and Denys and Tscharntke (2002) discuss patterns over a considerable period of time. To gain more insight into the development of invertebrate groups in field margins, and especially the patterns for distinct functional groups, we performed an inventory on their diversity and abundance in a large
number of these margins in the province of Zeeland, the Netherlands. We formulated two research objectives: (1) How does the number of invertebrate taxa in these strips relate to the age of the margin? (2) How is the abundance of three functional feeding groups—predators, herbivores and detritivores—related to the age of the margin? From the literature cited above, we expected that the field margins would become more species rich with age and that invertebrates would become more abundant. The second question is of major importance, as two of these functional groups may have a direct impact on farming practice: predators that function as enemies of pest organisms and herbivores that might be damaging to crops. It is however possible that the two groups affect each other, resulting in unexpected changes in abundance (Corbet 1995).