The Structure and Dynamics of Agricultural Landscapes as Drivers of Biodiversity - Landscape Ecology for Sustainable Environment and Culture - page 289

15% of interfaces between
complementary crops

84% of interfaces between
complementary crops

(a)

Crop types: Wheat Barley

(b)

1.2

0.8

0.4

0.0

15% 84%
Proportion of interfaces between complementary
crops (maize-wheat, wheat-barley, maize-barley)

Fig. 14.6 Scenarios of spatial organization of the crop mosaic (15 and 84 % of interfaces
between complementary crops: maize-wheat, wheat-barley and maize-barley) (a) and predicted
growth rate of carabid populations (mean ± 95 % CI) after 30 years of simulation (10 cycles of
rotation) for the two scenarios (b). (Details of the ANGORA model given in Vasseur 2012 )

populations could be strongly affected by the extent of habitat destruction and of
direct disturbances caused by mowing.
Complementation of resources by species is not only dependent on the avail-
ability of alternative suitable resource patches each year but also on their acces-
sibility (Dunning et al. 1992 ). Thus, the spatial organization of asynchronous,
complementary cropped habitats each year might be crucial for long-term popu-
lation persistence as well. We used a spatio-temporally explicit model to simulate
the dynamics of carabid populations (P. melanarius) in a cropping system mosaic
characterized by a rotation of three annual crops (maize-wheat-barley) differing
mainly by their period of sowing and harvest (''ANGORA'' model, Vasseur 2012 ).
Simulations were run on virtual landscapes (grids of 45 9 45 fields) with similar
compositions each year (33 % of each crop type) but contrasted spatial organi-
zations of the crop mosaic (i.e. 15 vs. 84 % of total interfaces between comple-
mentary crops) (Fig. 14.6 a). The results show that, in crops mosaics with similar
compositions, the population growth rate over 30 years is higher in mosaics where
adjacency between complementary crops, i.e. with asynchronous cover states