Local Factors Rather than the Landscape Context Explain Species Richness and Functional Trait Diversity and Responses of Plant Assemblages of Mediterranean Cereal Field Margins

Abstract

Arable field margins are valuable habitats providing a wide range of ecosystem services in rural landscapes. Agricultural intensification in recent decades has been a major cause of decline in plant diversity in these habitats. However, the concomitant effects on plant functional diversity are less documented, particularly in Mediterranean areas. In this paper, we analyzed the effect of margin width and surrounding landscape (cover and diversity of land use and field size), used as proxies for management intensity at local and landscape scales, on plant species richness, functional diversity and functional trait values in margins of winter cereal fields in southern Spain. Five functional traits were selected: life form, growth form, seed mass, seed dispersal mode and pollination type. RLQ and fourth-corner analyses were used to link functional traits and landscape variables. A total of 306 plant species were recorded. Species richness and functional diversity were positively related to margin width but showed no response to landscape variables. Functional trait values were affected neither by the local nor landscape variables. Our results suggest that increasing the margin width of conventionally managed cereal fields would enhance both taxonomic and functional diversity of margin plant assemblages, and thus the services they provide to the agro-ecosystem.

Landscape Is the Main Driver of Weed Assemblages in Field Margins but Is Outperformed by Crop Competition in Field Cores

“…The diversity of crop types [12] and the amount of seminatural habitats [29,30] in the landscape also benefit infield weed species richness. However, the effect of landscape varies with field position (i.e., field core versus field margin [12,13,31]) revealing the complex interplay between spatial dispersion and local processes. These differences can indeed be attributed to the variation in farming practices (crop density, fertilization and weed control) as well as to their distances to source habitats.…”

Identification of sentinel plant species for evaluating phytotoxicity of veterinary antibiotics in mediterranean europe

“…Arable eld margins provide a wide range of ecosystem services in rural landscapes and limit the negative effects of competitive and dominant species on crop productivity [98]. Plant diversity in these habitats has declined in recent decades due to agricultural intensi cation [97,[99][100][101][102]. Thus, one of the main challenges of agriculture worldwide is to balance crop productivity and biodiversity maintenance.…”

“…While all the above mentioned species have been listed in Annex 3 of the OECD 208 method, there are other weed species at the margins of arable elds and on pasture lands that could be useful in assessments of risk from veterinary antibiotics but are not listed in Annex 3. These species may include those identi ed as the most frequent in surveys of eld boundaries [99,100,102] and pasture lands (San Miguel et al, 2016) and that support biodiversity or food security. For example, Sonchus oleraceus is one of the most frequent weed species at eld boundaries in Spain [99], and it is important for biodiversity [101].…”

“…This similarity in most abundant species between our mapped scenarios and previous eldwork suggests that our analysis based on the GBIF data is reliable.In addition, our results indicate the relevance of Hypericum perforatum L., the fourth most frequent wild species in Spain among those in Annex 3 (Table5). This species was not inventoried byPallavicini et al (2020) orCirujeda et al (2011), which may indicate that this moisture-loving species does not prefer the hot, dry conditions in the Ebro and Guadalquivir river basins.…”

“…Pallavicini et al (2020) identi ed 306 weed species, of which only 10 are catalogued in the OECD Annex 3. Among these catalogued species, the four most abundant were also among the ve most frequent in our agriculture scenario: Lysimachia arvensis, Galium aparine, Papaver rhoeas L. and Chenopodium album L. Similarly, in cereal elds of the Ebro basin in northeastern Spain,Cirujeda et al (2011) identi ed 175 weed species.…”