Improvements in the Finnish Agri-Environment Scheme are Needed in Order to Support Rich Farmland Avifauna

Abstract

This tutorial demostrates the use of ordination methods in R package vegan. The tutorial assumes familiarity both with R and with community ordination. Package vegan supports all basic ordination methods, including non-metric multidimensional scaling. The constrained ordination methods include constrained analysis of proximities, redundancy analysis and constrained correspondence analysis. Package vegan also has support functions for fitting environmental variables and for ordination graphics.

Landscape, cropping and field boundary influences on bird abundance

“…Previous research has indicated that specialist, conservation priority farmland birds respond differently to variation in landscape variables to more generalist species in the same assemblages (Concepción and Díaz 2010, Filippi‐Codaccioni et al 2010, but see Vepsäläinen et al 2010). It is noteworthy, however, that the subset of specialists considered here did not show clear differences from the results for the full set of species.…”

“…Instead of a national causal relationship, this could reflect avoidance of the more marginal, mixed farming areas where spring cereals are more common by birds found typically on predominantly arable farmland, where spring cereals are rare (Siriwardena et al 2000). Conversely, farmland heterogeneity tended to have positive effects (Table 5c): heterogeneity in cropping is also often a positive influence on farmland bird presence or abundance (Schläpfer 1988, Benton et al 2003, Sheldon et al 2004, Vepsäläinen et al 2010), and will usually be increased, in practice, by adding (spring) break crops to simple cereal‐based crop rotations.…”

“…There are also no data on some aspects of habitat, such as boundaries, at larger scales. Nevertheless, it is clear that relationships between agricultural land‐use and bird presence and abundance are detectable at scales both smaller (Whittingham et al 2005, Vepsäläinen et al 2010) and larger (Chamberlain et al 2000, Siriwardena et al 2000) than the 1 km square, and that the nature of the relationships can change with scale (Filippi‐Codaccioni et al 2010, Pickett and Siriwardena in press). An important caveat in comparing relationships like this across scales, however, is that habitat variables can change in meaning between studies conducted at different scales: for example, ‘arable’ would include both fields and hedgerows at the 1 km square scale or larger, but would probably just describe cropped field areas in studies at the scale of bird territories.…”

“…Such relationships can, however, be complicated by effects of landscape context: in complex landscapes, variation in local habitat heterogeneity has a reduced effect on habitat quality (Tscharntke et al 2005, Concepcíon et al 2008). Thus, both field‐ and landscape‐scale habitat factors tend to work together to determine bird community composition (Concepcíon and Díaz 2010) and the effects of factors such as local habitat heterogeneity can be positive or negative depending on the landscape context (Filippi‐Codaccioni et al 2010, Vepsäläinen et al 2010).…”

“…The latter can be divided into cropped areas (feeding and, for some species, nesting habitat) and peripheral, semi‐natural habitats that are intrinsic parts of the farmed landscape but not specifically farmed (e.g. hedgerows that frequently provide food, nest sites and cover) (Vepsäläinen et al 2010). Of these habitat components, cropping is especially important in practice because it can change rapidly in response to economic change and changes in agricultural subsidy structures, or to the development of new markets, such as for biofuel crops (Haughton et al 2009).…”