Long-term global trends in crop yield and production reveal no current pollination shortage but increasing pollinator dependency

Fil: Aizen, Marcelo A. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio Ecotono; Argentina.Fil: Garibaldi, Lucas Alejandro. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio Ecotono; Argentina. Universidad de Buenos Aires (UBA). Facultad de Agronomía; Argentina.Fil: Cunningham, Saul A. CSIRO Entomology; Australia.Fil: Klein, Alexandra M. University of California; USA.Fil: Klein, Alexandra M. University of Goettingen; Alemania.Fil: Aizen, Marcelo A. Instituto de Investigaciones en Biodiversidad y Medioambiente (INIBIOMA); Argentina.Fil: Aizen, Marcelo A. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Fil: Garibaldi, Lucas Alejandro. Universidad de Buenos Aires (UBA). Facultad de Agronomía; Argentina.There is evidence that pollinators are declining as a result of local and global environmental degradation 1, 2, 3, 4. Because a sizable proportion of the human diet depends directly or indirectly on animal pollination [5], the issue of how decreases in pollinator stocks could affect global crop production is of paramount importance 6, 7, 8. Using the extensive FAO data set [9], we compared 45 year series (1961–2006) in yield, and total production and cultivated area of pollinator-dependent and nondependent crops [5]. We investigated temporal trends separately for the developed and developing world because differences in agricultural intensification, and socioeconomic and environmental conditions might affect yield and pollinators 10, 11, 12, 13. Since 1961, crop yield (Mt/ha) has increased consistently at average annual growth rates of ∼1.5%. Temporal trends were similar between pollinator-dependent and nondependent crops in both the developed and developing world, thus not supporting the view that pollinator shortages are affecting crop yield at the global scale. We further report, however, that agriculture has become more pollinator dependent because of a disproportionate increase in the area cultivated with pollinator-dependent crops. If the trend toward favoring cultivation of pollinator-dependent crops continues, the need for the service provided by declining pollinators will greatly increase in the near future

Local Weather Have Direct and Indirect Influence on Apple Quality

In a changing climate, altered temperature and precipitation patterns can affect the production and quality of various crops, such as fruits. However, crop production could also be modified indirectly by weather changes through modifying ecological communities and in turn ecosystem functions. These ecosystem functions, including biomass decomposition, biological control of pests and pollination, can influence food production and crop quality. Therefore, fruit and seed set can be affected, both directly through temperature- induced effects on crops, and indirectly, through e.g. changes in pollination success. Apple is a pollination dependent crop sensitive to low temperatures. We evaluated effects of local weather on pollinator visits and pollination success of apples. This was done by observing flower visiting insects and temperature logging in apple orchards in Sweden and Argentina. We found both direct and indirect effects of local temperatures on apple quality. For example, pollination success increased with temperature at flowering, which was correlated with higher sugar content in ripe fruit. Furthermore, fruits at harvest were heavier had they developed in higher temperature. We conclude that temperature variations may have several effects on apple production and quality. Both direct effects of temperatures and responses mediated through changes in pollinator behaviour are of importance. This is important to consider in management decisions related to apple production in a changing climate.Trabajo publicado en Acta Bioquímica Clínica Latinoamericana; no. 52, supl. 2, parte II, diciembre de 2018.Universidad Nacional de La Plat

Neotyphodium endophyte transmission to Lolium multiflorum seeds depends on the host plant fitness

Fil: Gundel, Pedro E. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas vinculadas a la Agricultura (IFEVA)-CONICET; Argentina.Fil: Garibaldi, Lucas Alejandro. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. INIBIOMA-CONICET. Laboratorio Ecotono; Argentina.Fil: Martínez Ghersa, María A. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas vinculadas a la Agricultura (IFEVA)-CONICET; Argentina.Fil: Ghersa, Claudio M. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas vinculadas a la Agricultura (IFEVA)-CONICET; Argentina.Fil: Garibaldi, Lucas Alejandro. Universidad de Buenos Aires (UBA). Facultad de Agronomía; Argentina.Frequency and distribution of symbiosis in nature depend both on the direct symbiont effect on the host fitness and on its efficiency to spread within host populations (transmission). For vertically transmitted Neotyphodium fungi, the attention has been centered on the endophyte effect on host grass plants but little is known about the controls of transmission. Environmental and genetic factors have been suggested as important controls of transmission efficiency. We studied the effect of these two factors on the transmission efficiency of the Neotyphodium endophyte in Lolium multiflorum plants. Plant genotype of a host population naturally endophyte-infected (95%) was manipulated by conducting controlled crosses with genetically distant plant populations. The resulting progeny was subjected to two types of factors, resource shortage and oxidative stress induced by an herbicide. Irrespective of plant genotype, high resource level increased seed yield per plant by 26-fold, spike-to-seed transmission by 12%, and plant-to-seed transmission by 10% (not significant). Although herbicide effects could be mediated indirectly by changes in plant density or directly by oxidative stress, neither plant fitness nor transmission efficiency was affected. An interesting pattern between transmission efficiency and seed yield per plant was revealed when plants (from both experiments) were plotted together. Low yielding plants, that is plants that grew under low resource level at high plant density, showed high transmission failures whereas high yielding plants, that is plants growing at low density with and without herbicide treatment, showed high transmission rates. Transmission failures may be a consequence of the endophyte cost for host plants growing under restrictive conditions, suggesting that lower transmission efficiency may partially explain previous evidence showing lower endophyte infection frequency for grasses under stressful conditions. Host plants could be penalizing the endophyte through a competition-like mechanism, instead of depressing their own fitness

Soybean expansion and agriculture diversity in Argentina

Se ha propuesto que el incremento en el cultivo de soja (Glycine max) que ha ocurrido en la Argentina durante las últimas dos décadas está asociado a un empobrecimiento de la diversidad de la agricultura. En este trabajo evaluamos esta hipótesis a través de estimar los cambios en la superficie cultivada, en la identidad y magnitud de la dominancia en términos de la proporción del área sembrada con el cultivo principal, y en la diversidad de cultivos a lo largo del período 1961-2006. La superficie total cultivada de nuestro país se ha incrementado aproximadamente 45% desde 1990 hasta 2006, en coincidencia con la gran expansión del cultivo de soja, que ha reemplazado al trigo (Triticum spp.) como cultivo dominante. En 2006, la soja representó alrededor de 50% de la superficie cultivada en la Argentina. Ningún otro cultivo alcanzó en las últimas cinco décadas semejante dominancia. Distintos estimadores indican que, asociado a este incremento de la dominancia de la soja, la diversidad de cultivos del campo argentino ha decrecido >20% durante el período 1990-2006. Además de la expansión de la frontera agrícola y de la pérdida de biodiversidad por destrucción de ecosistemas naturales, nuestros resultados ponen en evidencia una tendencia hacia la homogeneización del paisaje agrícola. De continuarse un aumento en la dominancia del cultivo de soja es probable que se profundicen los múltiples costos ambientales, sociales y económicos asociados a una menor diversidad de cultivos en nuestro país.The environmental and socio-economic consequences of the great expansion of soybean (Glycine max) cultivation in Argentina during the last two decades are strongly debated in our society. Soybean and its derivatives constitute presently most important Argentina's export and cash source. Here, we tested whether soybean´s expansion has caused a detectable decrease in crop diversity. We specifically assessed changes in total cultivated area, identity and degree of dominance of the most important crop (i.e., the one accounting for the largest proportion of the total cultivated area), and crop diversity over the period 1961-2006. Argentina's total cultivated area increased by about 45% from 1990 to 2006 and it was associated with a replacement of wheat by soybean as the dominant crop. In 2006 soybean accounted for ~50% of the total cultivated area in our country, the largest dominance reached by any crop during the last five decades. Different diversity indicators, including Shannon-Wiener´s H´, Pielou´s J and Hurlbert´s PIE indexes agreed that crop diversity has decreased >20% during the period of soybean dominance. In addition to the direct loss of biodiversity caused by deforestation for agriculture expansion, our results evidence a trend towards homogenization of Argentina's agriculture landscape with likely consequences for remnant biodiversity, degradation of different ecosystem services, and a more vulnerable production structure

Viability of Neotyphodium endophytic fungus and endophyte-infected and noninfected Lolium multiflorum seeds

Fil: Gundel, Pedro E. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas vinculadas a la Agricultura; Argentina.Fil: Martínez Ghersa, María A. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas vinculadas a la Agricultura; Argentina.Fil: Garibaldi, Lucas Alejandro. Universidad de Buenos Aires. Facultad de Agronomía; Argentina.Fil: Ghersa, Claudio M. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas vinculadas a la Agricultura; Argentina.Fil: Gundel, Pedro E. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Fil: Martínez-Ghersa, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Fil: Garibaldi, Lucas Alejandro. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio Ecotono; Argentina.Fil: Ghersa, Claudio M. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Neotyphodium endophyte fungi are vertically transmitted symbionts of cool-season grasses. The seed phase of the grass’ life cycle appears to be critical for the persistence of the fungus. Endophyte viability decreases faster than seed viability, but little is known of the effects of this endophyte on seed viability. The endophyte could affect seed viability through changes in water content. Here, we assessed the effects of the endophyte on seed viability, the differential survival of endophyte and seed, and the effects of infection on seed water content. Viability of endophyte-infected and noninfected seeds and endophyte were evaluated over a period of 729 d under 12 controlled environmental conditions. Seed viability was reduced by the infection at high temperature and high relative humidity, but not under other conditions. Moreover, endophyte viability decreased faster than seed viability only under high humidity or high temperature. Seed water content was not affected by endophyte presence. The proportion of viable infected seeds was mainly affected by the loss in endophyte viability and secondly by the differential survival of infected and noninfected seeds. Knowledge on the relative importance of these processes is critical to understand the factors affecting the efficiency of endophyte vertical transmission and the frequency of endophyte-infected plants

Agroecology in large scale farming:A research agenda

Agroecology promises a third way between common global agriculture tradeoffs such as food production and nature conservation, environmental sustainability and ecosystem services. However, most successful examples of mainstreaming agroecology come from smallholder, family agriculture, that represents only about 30% of the world agricultural area. Mainstreaming agroecology among large scale farmers is urgently needed, but it requires addressing specific questions in research, technology and policy development to support sustainable transitions. Here we take stock of the existing knowledge on some key aspects necessary to support agroecological transitions in large scale farming, considering two contrasting starting points: highly subsidized and heavily taxed agricultural contexts, represented here by the examples of Western Europe and temperate South America. We summarize existing knowledge and gaps around service crops, arthropod-mediated functions, landscape and watershed regulation, graze-based livestock, nature-inclusive landscapes, and policy mechanisms to support transitions. We propose a research agenda for agroecology in large scale farming organized in five domains: (i) Breeding for diversity, (ii) Scalable complexity, (iii) Managing cycles beyond fields and farms, (iv) Sharing the cultivated landscape, and (v) Co-innovation with farmers, value chains and policy makers. Agroecology may result in a renewed impetus in large scale farming, to attract the youth, foster clean technological innovation, and to promote a new generation of large-scale farmers that take pride in contributing to feeding the world while serving the planet and its people

Implications of landscape configuration on understory forage productivity: a remote sensing assessment of native forests openings

Sound management of native forests used for cattle grazing requires understanding the dynamics of forage productivity in the openings. Despite their importance, forage productivity drivers in highly heterogeneous forested landscapes, or their variability over the year, are still unclear. The aim of this work is to find predictors of Normalized Difference Vegetation Index (NDVI) variation in the openings of native temperate forests and to evaluate how these predictors change within the growing season. We used high spatial resolution remote sensing imagery from NW Patagonia to separate forest openings from tree dense canopy. We obtained data of each opening related with herbaceous and shrub forage productivity and calculated landscape metrics. We estimated a multiple linear regression model for predicting NDVI in each season. Beyond known variables related with forage productivity (altitude, precipitation, etc.), the shape of forest’ openings appeared as relevant in predicting NDVI. Higher values of forest opening perimeters were related with a decrease in NDVI in spring when soil water content is not limiting and conversely with an increase in NDVI in summer when water is limiting growth. These results suggest that environmental drivers such as temperature and soil moisture inside the opening, and competition or facilitation process between trees and grasses are mediated by the shape of the opening. Management of heterogeneous native forests for cattle raising requires considering the shape of the openings to maximize forage productivity.Fil: Trinco, Fabio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. - Universidad Nacional de Rio Negro. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural; ArgentinaFil: Rusch, Verónica E.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Howison, Ruth A.. University of Groningen; Países BajosFil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. - Universidad Nacional de Rio Negro. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural; ArgentinaFil: Tittonell, Pablo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentin

Pollinator dependence of Argentinean agriculture: current status and temporal analysis.

Fil: Chacoff, Natacha P. Instituto Argentino de Investigaciones de las Zonas Áridas (IADIZA)-CONICET; Argentina.Fil: Morales, Carolina L. Universidad Nacional del Comahue. INIBIOMA-CONICET. Laboratorio Ecotono; Argentina.Fil: Garibaldi, Lucas Alejandro. Universidad Nacional del Comahue. INIBIOMA-CONICET. Laboratorio Ecotono; Argentina.Fil: Ashworth, Lorena. Universidad Nacional de Córdoba. Instituto Multidisciplinario de Biología Vegetal (IMBIV)-CONICET; Argentina.Fil: Aizen, Marcelo A. Universidad Nacional del Comahue. INIBIOMA-CONICET. Laboratorio Ecotono; Argentina.Fil: Garibaldi, Lucas Alejandro. Universidad de Buenos Aires (UBA). Facultad de Agronomía; Argentina.A sizable proportion of agricultural production depends directly or indirectly on animal pollination but estimation of the size of this dependence is missing for most countries, even for some of the most important food producers. Here, we evaluate the current status and temporal trends (1961-2007) in pollinator dependency of Argentinean agriculture. We classified crops in categories according to their pollinator dependence, and estimated their harvested area, production, economic and nutritional values. We also estimated the expected production deficit in the absence of pollinators, the extra area needed to cope with this deficit, and trends in honeybee stocks. From a total of 68 crops, animal pollination increased directly production in 37 and indirectly in 13. More than half of the harvested area and total agricultural production corresponded to pollinator dependent crops, a trend highly influenced by the inclusion of soybean as a modestly dependent crop. Highly pollinator-dependent crops produced 2-4 times more income per hectare than any other crop, and modestly dependent crops bear on average the highest protein and fat content. During the study period the production deficit increased three-fold, reaching 12% in 2007, whereas the area needed to compensate for these deficiencies attained 24%. Regarding pollination services, indicators are mixed; whereas Argentinean honey-bee stock triplicates from 1961 to 2007, native forest area, a source of pollinator diversity, shrank to more than half since 1940’s. Experiments testing the degree of pollinator dependency on the quality and quantity of crop production for soybean varieties cultivated in Argentina are urgently needed. Our estimations depict an agriculture that is becoming more dependent on pollinators, but native forests and other native terrestrial habitats, which host most of the country’s pollinator diversity, are decreasing at an alarming rate

Multidimensional Performance of Farming Approaches

Fil: Garibaldi, Lucas Alejandro. Universidad Nacional de Río Negro. Sede Andina; Argentina.Fil: Gemmill Herren, Barbara. World Agroforestry Centre; Kenya.Fil: D’Annolfo, Raffaele. Università Cattolica del Sacro Cuore; Italia.Fil: Graeub, Benjamin E. Biovision Foundation for Ecological Development y Ricolab; Suiza.Fil: Cunningham, Saul A. Australian National University; Australia.Fil: Breeze, Thomas D. University of Reading; UK.Fil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.The letter by Mehrabi et al. [1] provides interesting insights regarding the scientific framework and attitudes needed to support farming approaches for greater biodiversity, livelihoods, and food security. In general, we do not see a dichotomy between our point of view [2] and that put forward by Mehrabi et al. [1]. We share their view that the different farming systems we have described do not form distinct, non-overlapping categories. We do not seek to promote a binary choice between conventional and alternative farming