EAGESTADINRAThe DISCO-WEED project : disentangling the role of anthropic DISturbances and eCOlogi... more EAGESTADINRAThe DISCO-WEED project : disentangling the role of anthropic DISturbances and eCOlogical processes on WEED community assembly. Sfécologie-2016, International Conference of Ecological Science
La agricultura ofrece situaciones interesantes para estudiar la sucesión ecológica en comunidades... more La agricultura ofrece situaciones interesantes para estudiar la sucesión ecológica en comunidades de malezas. Existe evidencia empírica que indica que la composición florística de las comunidades de malezas se modifica ante cambios ambientales y tecnológicos, lo que ha sido interpretado en el marco de la teoría de sucesión. A su vez, las reglas de ensamblaje proveen un marco conceptual útil para describir y predecir los patrones de cambio en comunidades de malezas. El objetivo de este artículo es presentar la aplicación de un enfoque basado en las reglas de ensamblaje de comunidades para estudiar los cambios florísticos en comunidades de malezas. Las reglas de ensamblaje se asocian con factores específicos que explican los patrones observados a nivel de comunidad. Estas reglas operan a modo de filtros que restringen el número de especies del conjunto regional que forman las comunidades locales. El conjunto de especies es definido aquí en tres dominios espaciales: el geográfico, el p...
Biodiversity ecosystem services in agroecosystems are negatively affected by farmland homogenisat... more Biodiversity ecosystem services in agroecosystems are negatively affected by farmland homogenisation due to intensive agriculture. The Pampas, an important worldwide region producing commodity crops, have been greatly homogenised with the expansion no-tillage and herbicide-tolerant transgenic soybeans since the 1990s. Here, we tested the hypothesis of that dietary changes in barn owls will be associated with the loss of semi-natural habitats derived from farming intensification. We characterised the dietary habits of western barn owls by analysing their pellets between two sampling periods (2004–2005 and 2010–2012). We also assessed the habitat loss due to cropping intensification through fencerow removal and pasture conversion to annual crops during the same period. We observed that barn owls shifted from eating mostly rodents in the first sampling period to eating a higher proportion of anurans in the second sampling period. Between sampling, rodent proportion in pellets decreased from 80% to 61.6%, while anuran proportion increased from 20% to 37.7%. A rapid farming intensification occurred on the farm between both sampling periods. Pastures were ploughed to grow annual crops. Thus, the annually cropped area increased by 60% from 2004 to 2012, while the area with pastures was reduced in about 80%. During the same period, nearly two-thirds of fences on the farm were removed to enlarge the cropped area. Our findings suggest that dietary habits of barn owls may shift to consume more anurans when rodent availability declines in association with the loss of semi-natural habitats, which resulted from rapid farming intensification on the studied farm. We suggest monitoring the population size and diet of barn owls for evaluating environmental changes produced in agroecosystems by farming intensification, as well as the adaptive responses of different rodent and anuran species to such changes.
Abstract Many complex, natural landscapes have been transformed into simpler agroecosystems by co... more Abstract Many complex, natural landscapes have been transformed into simpler agroecosystems by continuous cropping and the application of glyphosate and fertilizers. The current mosaic with different land cover types can harbor different soil microbial communities. Here, we investigated how the microbial community and ryegrass plants responded to glyphosate and nitrogen application to soils from four different cover types (soybean monocropping; wheat/soybean-field pea rotation, herbaceous- and woody- uncropped margins). We predict that soils from different land cover types will display different responses of their detritivore microbial communities and plant growth to herbicide and fertilizer application. All the studied variables differed among land cover types. Woody margins tripled the soil carbon content and the microbial respiration of herbaceous margins, although the later had more diverse soil microbial communities. Soils from soybean monoculture had higher respiration rates (37%) than those from crop rotation, where ryegrass accumulated lower biomass (12% lower). Despite these differences between land cover types, neither glyphosate nor nitrogen fertilization significantly influenced these properties. Only ryegrass plants growing on glyphosate-treated soils accumulated more biomass than the rest whereas they did not respond to nitrogen. These results suggest that glyphosate and nitrogen at recommended doses did not have a significant impact on the soil performance of the different types of cover.
Figure 1. Location of the study sites across the sunflower cropping area in eastern Argentina, th... more Figure 1. Location of the study sites across the sunflower cropping area in eastern Argentina, the limits of which are indicated by the shaded area. Acronyms correspond to the localities where fields were located (see Table 1 for details).
Figure 5. Functional composition of the non-Lasioglossum (Dialictus) bee assemblage: proportion o... more Figure 5. Functional composition of the non-Lasioglossum (Dialictus) bee assemblage: proportion of the taxa for each life-history trait category.
Figure 2. Semi-natural area of the study site: (a) semi-natural grassland; (b) the stream 'Ar... more Figure 2. Semi-natural area of the study site: (a) semi-natural grassland; (b) the stream 'Arroyo Dulce' and its banks (Photos: Violette Le Féon).
Figure 6. Mean number of (a) bee individuals, (b) non-Lasioglossum (Dialictus) bee individuals an... more Figure 6. Mean number of (a) bee individuals, (b) non-Lasioglossum (Dialictus) bee individuals and (c) bee taxa per point, in cropped area (n = 28 points) and semi-natural area (n = 11 points). ns indicates a non-significant result. Asterisks indicate that means are significantly different (Wilcoxon rank sum test, *** = P <0.001). Bars show SEs.
Figure 1. Location of (a) the Argentinean Pampas in South America, (b) the study site (Estancia &... more Figure 1. Location of (a) the Argentinean Pampas in South America, (b) the study site (Estancia 'Las Polvaredas', partido de Rojas, provincia de Buenos Aires; black square) in the Rolling Pampa and (c) the 39 sampling points in the study site. The map shows the land use of the year when bee sampling occurred (2010–2011 growing season). Black dots represent points located in the cropped area (n = 28), and white dots represent points located in the semi-natural area (n = 11). On each point, bees were collected with pan traps (one blue, one white and one yellow) during three 48- hour sessions.
A dataset of 3,250,404 measurements, collated from 26,114 sampling locations in 94 countries and ... more A dataset of 3,250,404 measurements, collated from 26,114 sampling locations in 94 countries and representing 47,044 species. The data were collated from 480 existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database was assembled as part of the PREDICTS project - Projecting Responses of Ecological Diversity In Changing Terrestrial Systems; [www.predicts.org.uk](http://www.predicts.org.uk).\r\n\r\nThe taxonomic identifications provided in the original data sets are those determined at the time of the original research, and so will not reflect subsequent taxonomic changes.\r\n\r\nThis dataset is described in [10.1002/ece3.2579](http://dx.doi.org/10.1002/ece3.2579). A description of the way that this dataset was assembled is given in [10.1002/ece3.1303](http://dx.doi.org/10.1002/ece3.1303).\r\n\r\n* `columns.csv`: Description of data extract columns\r\n* `database...
Abstract Landscape fragmentation and farming can affect the diversity of plants and pollinators h... more Abstract Landscape fragmentation and farming can affect the diversity of plants and pollinators harbored by linear landscape elements (LLE) in agroecosystems. To assess the role of these habitats in sustaining plant-pollinator communities, twenty portions of LLE (road verges) were studied during two consecutive field seasons in the Argentine Pampas. A hierarchical approach was taken, describing three features of road verges in different scales of observation: width of the road verge (local scale), the land use of the neighboring fields (adjacent land use scale), and landscape heterogeneity (landscape scale). The influence of these features on the composition and abundance of entomophilous flowering plants and their visitors were examined with GLMMs. Plant and flower visitor communities in road verges were dominated by alien species. The local scale feature was the most influential, as the widest road verges had higher plant richness and higher flower visitor abundance. Contrary to our expectations, richness and abundance of both plants and flower visitors were not related to adjacent land use or landscape heterogeneity. These results suggest that the conservation and management of wider road verges should be a priority to sustain high species diversity in intensely managed agroecosystems.
In weed science and management, models are important and can be used to better understand what ha... more In weed science and management, models are important and can be used to better understand what has occurred in management scenarios, to predict what will happen and to evaluate the outcomes of control methods. To-date, perspectives on and the understanding of weed models have been disjointed, especially in terms of how they have been applied to advance weed science and management. This paper presents a general overview of the nature and application of a full range of simulation models on the ecology, biology, and management of arable weeds, and how they have been used to provide insights and directions for decision making when long-term weed population trajectories are impractical to be determined using field experimentation. While research on weed biology and ecology has gained momentum over the past four decades, especially for species with high risk for herbicide resistance evolution, knowledge gaps still exist for several life cycle parameters for many agriculturally important w...
The semiarid Espinal in central Argentina, being recently transformed from natural semiarid grass... more The semiarid Espinal in central Argentina, being recently transformed from natural semiarid grasslands into agriculture, represents an interesting scenario to understand the early stages of weed community assembly and its relationship with crop identity and management. Our aim was to characterize the weed communities in corn (Zea maysL.) and soybean [Glycine max(L.) Merr.], the main crops of the Espinal region, under the dominant rainfed conditions. Weed surveys were carried out in 53 fields, and farmers were interviewed to collect information about crop management. Floristic composition was compared within and between crops by calculating the additive partition of the abundance-based Bray-Curtis dissimilarity. We compared the frequency and mean cover of functional groups between crops through generalized linear models. Finally, canonical correspondence analysis was carried out to analyze the associations between floristic composition and agronomic variables. Mean alpha and gamma di...
EAGESTADINRAThe DISCO-WEED project : disentangling the role of anthropic DISturbances and eCOlogi... more EAGESTADINRAThe DISCO-WEED project : disentangling the role of anthropic DISturbances and eCOlogical processes on WEED community assembly. Sfécologie-2016, International Conference of Ecological Science
La agricultura ofrece situaciones interesantes para estudiar la sucesión ecológica en comunidades... more La agricultura ofrece situaciones interesantes para estudiar la sucesión ecológica en comunidades de malezas. Existe evidencia empírica que indica que la composición florística de las comunidades de malezas se modifica ante cambios ambientales y tecnológicos, lo que ha sido interpretado en el marco de la teoría de sucesión. A su vez, las reglas de ensamblaje proveen un marco conceptual útil para describir y predecir los patrones de cambio en comunidades de malezas. El objetivo de este artículo es presentar la aplicación de un enfoque basado en las reglas de ensamblaje de comunidades para estudiar los cambios florísticos en comunidades de malezas. Las reglas de ensamblaje se asocian con factores específicos que explican los patrones observados a nivel de comunidad. Estas reglas operan a modo de filtros que restringen el número de especies del conjunto regional que forman las comunidades locales. El conjunto de especies es definido aquí en tres dominios espaciales: el geográfico, el p...
Biodiversity ecosystem services in agroecosystems are negatively affected by farmland homogenisat... more Biodiversity ecosystem services in agroecosystems are negatively affected by farmland homogenisation due to intensive agriculture. The Pampas, an important worldwide region producing commodity crops, have been greatly homogenised with the expansion no-tillage and herbicide-tolerant transgenic soybeans since the 1990s. Here, we tested the hypothesis of that dietary changes in barn owls will be associated with the loss of semi-natural habitats derived from farming intensification. We characterised the dietary habits of western barn owls by analysing their pellets between two sampling periods (2004–2005 and 2010–2012). We also assessed the habitat loss due to cropping intensification through fencerow removal and pasture conversion to annual crops during the same period. We observed that barn owls shifted from eating mostly rodents in the first sampling period to eating a higher proportion of anurans in the second sampling period. Between sampling, rodent proportion in pellets decreased from 80% to 61.6%, while anuran proportion increased from 20% to 37.7%. A rapid farming intensification occurred on the farm between both sampling periods. Pastures were ploughed to grow annual crops. Thus, the annually cropped area increased by 60% from 2004 to 2012, while the area with pastures was reduced in about 80%. During the same period, nearly two-thirds of fences on the farm were removed to enlarge the cropped area. Our findings suggest that dietary habits of barn owls may shift to consume more anurans when rodent availability declines in association with the loss of semi-natural habitats, which resulted from rapid farming intensification on the studied farm. We suggest monitoring the population size and diet of barn owls for evaluating environmental changes produced in agroecosystems by farming intensification, as well as the adaptive responses of different rodent and anuran species to such changes.
Abstract Many complex, natural landscapes have been transformed into simpler agroecosystems by co... more Abstract Many complex, natural landscapes have been transformed into simpler agroecosystems by continuous cropping and the application of glyphosate and fertilizers. The current mosaic with different land cover types can harbor different soil microbial communities. Here, we investigated how the microbial community and ryegrass plants responded to glyphosate and nitrogen application to soils from four different cover types (soybean monocropping; wheat/soybean-field pea rotation, herbaceous- and woody- uncropped margins). We predict that soils from different land cover types will display different responses of their detritivore microbial communities and plant growth to herbicide and fertilizer application. All the studied variables differed among land cover types. Woody margins tripled the soil carbon content and the microbial respiration of herbaceous margins, although the later had more diverse soil microbial communities. Soils from soybean monoculture had higher respiration rates (37%) than those from crop rotation, where ryegrass accumulated lower biomass (12% lower). Despite these differences between land cover types, neither glyphosate nor nitrogen fertilization significantly influenced these properties. Only ryegrass plants growing on glyphosate-treated soils accumulated more biomass than the rest whereas they did not respond to nitrogen. These results suggest that glyphosate and nitrogen at recommended doses did not have a significant impact on the soil performance of the different types of cover.
Figure 1. Location of the study sites across the sunflower cropping area in eastern Argentina, th... more Figure 1. Location of the study sites across the sunflower cropping area in eastern Argentina, the limits of which are indicated by the shaded area. Acronyms correspond to the localities where fields were located (see Table 1 for details).
Figure 5. Functional composition of the non-Lasioglossum (Dialictus) bee assemblage: proportion o... more Figure 5. Functional composition of the non-Lasioglossum (Dialictus) bee assemblage: proportion of the taxa for each life-history trait category.
Figure 2. Semi-natural area of the study site: (a) semi-natural grassland; (b) the stream 'Ar... more Figure 2. Semi-natural area of the study site: (a) semi-natural grassland; (b) the stream 'Arroyo Dulce' and its banks (Photos: Violette Le Féon).
Figure 6. Mean number of (a) bee individuals, (b) non-Lasioglossum (Dialictus) bee individuals an... more Figure 6. Mean number of (a) bee individuals, (b) non-Lasioglossum (Dialictus) bee individuals and (c) bee taxa per point, in cropped area (n = 28 points) and semi-natural area (n = 11 points). ns indicates a non-significant result. Asterisks indicate that means are significantly different (Wilcoxon rank sum test, *** = P <0.001). Bars show SEs.
Figure 1. Location of (a) the Argentinean Pampas in South America, (b) the study site (Estancia &... more Figure 1. Location of (a) the Argentinean Pampas in South America, (b) the study site (Estancia 'Las Polvaredas', partido de Rojas, provincia de Buenos Aires; black square) in the Rolling Pampa and (c) the 39 sampling points in the study site. The map shows the land use of the year when bee sampling occurred (2010–2011 growing season). Black dots represent points located in the cropped area (n = 28), and white dots represent points located in the semi-natural area (n = 11). On each point, bees were collected with pan traps (one blue, one white and one yellow) during three 48- hour sessions.
A dataset of 3,250,404 measurements, collated from 26,114 sampling locations in 94 countries and ... more A dataset of 3,250,404 measurements, collated from 26,114 sampling locations in 94 countries and representing 47,044 species. The data were collated from 480 existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database was assembled as part of the PREDICTS project - Projecting Responses of Ecological Diversity In Changing Terrestrial Systems; [www.predicts.org.uk](http://www.predicts.org.uk).\r\n\r\nThe taxonomic identifications provided in the original data sets are those determined at the time of the original research, and so will not reflect subsequent taxonomic changes.\r\n\r\nThis dataset is described in [10.1002/ece3.2579](http://dx.doi.org/10.1002/ece3.2579). A description of the way that this dataset was assembled is given in [10.1002/ece3.1303](http://dx.doi.org/10.1002/ece3.1303).\r\n\r\n* `columns.csv`: Description of data extract columns\r\n* `database...
Abstract Landscape fragmentation and farming can affect the diversity of plants and pollinators h... more Abstract Landscape fragmentation and farming can affect the diversity of plants and pollinators harbored by linear landscape elements (LLE) in agroecosystems. To assess the role of these habitats in sustaining plant-pollinator communities, twenty portions of LLE (road verges) were studied during two consecutive field seasons in the Argentine Pampas. A hierarchical approach was taken, describing three features of road verges in different scales of observation: width of the road verge (local scale), the land use of the neighboring fields (adjacent land use scale), and landscape heterogeneity (landscape scale). The influence of these features on the composition and abundance of entomophilous flowering plants and their visitors were examined with GLMMs. Plant and flower visitor communities in road verges were dominated by alien species. The local scale feature was the most influential, as the widest road verges had higher plant richness and higher flower visitor abundance. Contrary to our expectations, richness and abundance of both plants and flower visitors were not related to adjacent land use or landscape heterogeneity. These results suggest that the conservation and management of wider road verges should be a priority to sustain high species diversity in intensely managed agroecosystems.
In weed science and management, models are important and can be used to better understand what ha... more In weed science and management, models are important and can be used to better understand what has occurred in management scenarios, to predict what will happen and to evaluate the outcomes of control methods. To-date, perspectives on and the understanding of weed models have been disjointed, especially in terms of how they have been applied to advance weed science and management. This paper presents a general overview of the nature and application of a full range of simulation models on the ecology, biology, and management of arable weeds, and how they have been used to provide insights and directions for decision making when long-term weed population trajectories are impractical to be determined using field experimentation. While research on weed biology and ecology has gained momentum over the past four decades, especially for species with high risk for herbicide resistance evolution, knowledge gaps still exist for several life cycle parameters for many agriculturally important w...
The semiarid Espinal in central Argentina, being recently transformed from natural semiarid grass... more The semiarid Espinal in central Argentina, being recently transformed from natural semiarid grasslands into agriculture, represents an interesting scenario to understand the early stages of weed community assembly and its relationship with crop identity and management. Our aim was to characterize the weed communities in corn (Zea maysL.) and soybean [Glycine max(L.) Merr.], the main crops of the Espinal region, under the dominant rainfed conditions. Weed surveys were carried out in 53 fields, and farmers were interviewed to collect information about crop management. Floristic composition was compared within and between crops by calculating the additive partition of the abundance-based Bray-Curtis dissimilarity. We compared the frequency and mean cover of functional groups between crops through generalized linear models. Finally, canonical correspondence analysis was carried out to analyze the associations between floristic composition and agronomic variables. Mean alpha and gamma di...
Uploads