To see a World in a Grain of Sand And a Heaven in a Wild Flower,
Hold Infinity in the palm of your hand And Eternity in an hour. William Blake (1757-1827)
martes, 19 de junio de 2018
A global synthesis of the effects of diversified farming systems on arthropod diversity within fields and across agricultural landscapes
Lichtenberg et al., 2017.
Agricultural intensification is a leading cause of global biodiversity loss, which can reduce the provisioning of ecosystem services in managed ecosystems. Organic farming and plant diversification are farm management schemes that may mitigate potential ecological harm by increasing species richness and boosting related ecosystem services to agroecosystems. What remains unclear is the extent to which farm management schemes affect biodiversity components other than species rich- ness, and whether impacts differ across spatial scales and landscape contexts. Using a global metadataset, we quantified the effects of organic farming and plant diversi- fication on abundance, local diversity (communities within fields), and regional diver- sity (communities across fields) of arthropod pollinators, predators, herbivores, and detritivores. Both organic farming and higher in-field plant diversity enhanced arthropod abundance, particularly for rare taxa. This resulted in increased richness but decreased evenness. While these responses were stronger at local relative to regional scales, richness and abundance increased at both scales, and richness on farms embedded in complex relative to simple landscapes. Overall, both organic farming and in-field plant diversification exerted the strongest effects on pollinators and predators, suggesting these management schemes can facilitate ecosystem ser- vice providers without augmenting herbivore (pest) populations. Our results suggest that organic farming and plant diversification promote diverse arthropod metacom- munities that may provide temporal and spatial stability of ecosystem service provi- sioning. Conserving diverse plant and arthropod communities in farming systems therefore requires sustainable practices that operate both within fields and across landscapes.
Effects of farm management schemes on abundance (a, b) and richness (c, d) of common vs. rare taxa in simple and complex landscapes. Mean log- response ratios (SE) of (left column) adopting organic farming and (right column) promoting in-field plant diversity. A“*”below a pair of means indicates a significant difference between rare and common taxa within a landscape complexity category (determined via paired t-tests; a=0.1; Tables S19. .
"None of the human faculties should be excluded from scientific activity. The depths of intuition, a sure awareness of the present, mathematical profundity, physical exactitude, the heights of creative reason and sharpness of understanding, together with a versatile and ardent imagination and a loving delight in the world of the senses, they are all essential for a lively and productive apprehension of the moment." J. W. Goethe (1749 - 1832)
La orquídea de noche esconde en su perfume el blanco de su flor.
Yosa Buson (1716-1783)
Ecology has been eminently a descriptive science despite some pioneering work by theoreticians such as Lotka, Volterra, Nicholson, and others. Description is a first step toward understanding a system. However, such a first step needs to be accompanied by the development of a theoretical framework in order to achieve real insight and, whenever possible, predictive power.
Ricard V. Solé and Jordi Bascompte, 2006 (Self-Organization in Complex Ecosystems).
Animal Liberation Front
"Toda pregunta es siempre más que una pregunta, está probando una carencia, una ansiedad por llenar un hueco intelectual o psicológico, y hay muchas veces en que el hecho de encontrar una respuesta es menos importante que haber sido capaz de vivir a fondo la pregunta, de avanzar ansiosamente por las pistas que tiende a abrir en nosotros"
Julio Cortázar. Desafíos.
“If our means of investigation became more and more incisive, we would discover the simple under the complex, then the complex under the simple, then again the simple under the complex, and so on, without being able to predict which state would ultimately prevail” Jules Henri Poincaré (1854 –1912)