Diversifying crop rotations with temporary grasslands - Université de ...

INDEX OF FIGURES
Fig. 1: Population trends of common bird species in Europe. ............................................................................... 7
Fig. 2: Relation between weed seed density and skylark (Alauda arvensis) density in winter (Norfolk, UK). ..... 8
Fig. 3: Published estimations of superficial weed seed densities in arable soils during the 20th century. ............ 9
Fig. 4: Characterisation of common weed species according to their biodiversity value and potential crop
yield loss. ............................................................................................................................................... 13
Fig. 5: Comparison of strategies for combining agricultural production and biodiversity conservation. ............ 17
Fig. 6: Simplified illustration of the trade-off between farming (crop yield), environmental protection and
biodiversity conservation. ...................................................................................................................... 20
Fig. 7: Illustration of the modified cropping system (upper part) and hypothetical population dynamics of
different weed species (lower part). ....................................................................................................... 32
Fig. 8: Structure of the research project showing 4 empirical approaches. ......................................................... 36
Fig. 9: A) Geographic position of the study region in western France, B) map of crops grown at the study site
in 2008, C) the ‘star’ configuration of the 32 vegetation relevés in each field centre, D) temporal
development of the principal crops on the study region from 1995 to 2008. ......................................... 40
Fig. 10: A) Spatial set up of the 36 experimental plots (9 crop treatments * 4 repetitions) on an experimental
field with 6*9=54 plots. B) Localisation of plant density and biomass measurements on the 6 microplots
of each plot. ................................................................................................................................... 77
Fig. 11: Spatial heterogeneities of organic carbon and total nitrogen concentrations in the soil of the
experimental field in October 2006 and November 2008. ..................................................................... 78
Fig. 12: Development of emerged weed densities (plants per m 2 ) (A), emerged weed species richnesses (B),
and richness/abundance ratios (C) in nine crop treatments. ................................................................... 81
Fig. 13: Temporal development of emerged weed densities (plants per m 2 ) in six perennial crop treatments
(T2-T8, upper part) and three successions of annual crops (T9-T11, lower part, plotted with two
scales). ................................................................................................................................................... 85
Fig. 14: Temporal development of emerged plant densities of 19 major weed species in nine crop treatments. 86
Fig. 15: Relation between weed sowing density and field emergence densities of 17 weed species. .................. 89
Fig. 16: Effect of weed seed addition on plant density of 16 weed species during the 2-years experiment. ....... 90
Fig. 17: Cumulated crop and weed biomass production in 2007 and 2008 in different crop treatments. ............ 92
Fig. 18: Temporal development of crop and weed biomass in perennial and annual crop treatments. ................ 93
Fig. 19: Relation between crop and weed biomass at five observation dates in 2007 (A) and 2008 (B). ............ 94
Fig. 20: Life cycle of annual and perennial weeds. ............................................................................................. 99
Fig. 21: Comparison of relative weed species frequencies in annual and perennial crops in the large-scale
weed surveys (Chizé) and the field experiment (Epoisses). ................................................................. 158
Fig. 22: Comparison of weed seed predation rates of the 2007 and 2008 experiments (cf. Article 6 and 8). .... 166
Fig. 23: Possible relations between the plant age and the plant’s regrowth ability after cutting determined by
the ‘quantity of carbohydrate resources that can be remobilized for regrowth’ (B) [g d°day -1 ]. ......... 172
Fig. 24: Daily aboveground biomass increase (ΔBMj) before and after a partial destruction of the
photosynthetically active plant organs (cutting). ................................................................................. 174
Fig. 25: Overview of factors determining post-dispersal weed seed predation. ................................................ 177
Fig. 26: Weed species frequency distribution in the large-scale weed surveys (Chizé). ................................... 209
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