Eating up the world’s food web and the human trophic level

Abstract

Trophic levels are critical for synthesizing species' diets, depicting energy pathways, understanding food web dynamics and ecosystem functioning, and monitoring ecosystem health. Specifically, trophic levels describe the position of species in a food web, from primary producers to apex predators (range, 1-5). Small differences in trophic level can reflect large differences in diet. Although trophic levels are among the most basic information collected for animals in ecosystems, a human trophic level (HTL) has never been defined. Here, we find a global HTL of 2.21, i.e., the trophic level of anchoveta. This value has increased with time, consistent with the global trend toward diets higher in meat. National HTLs ranging between 2.04 and 2.57 reflect a broad diversity of diet, although cluster analysis of countries with similar dietary trends reveals only five major groups. We find significant links between socio-economic and environmental indicators and global dietary trends. We demonstrate that the HTL is a synthetic index to monitor human diets and provides a baseline to compare diets between countries.human ecology | nutrition transition | trophic ecology

Adaptive rewiring aggravates the effects of species loss in ecosystems

“…To conclude, forming of new feeding links by consumers adapting to the loss of prey does not rescue food webs from cascading extinction. These results have possible bearings on human exploitation of natural populations where large-scale rewiring has been documented [28][29][30] .…”

“…Thus, rewiring is a two-edged sword; it might be advantageous for individual consumer species in the short term, yet harmful for long-term network persistence. This finding has a bearing on the interaction of human harvesters with natural populations in that human harvesters are examples of especially flexible and efficient consumers [28][29][30]55 . Our study indicates that under such circumstances rewiring can potentially trigger extensive extinction cascades causing large changes in the structure and dynamics of ecosystems.…”

The World Flora Online, Target 1 of the Global Strategy for Plant Conservation, and the Species Plantarum Programme: Flora of the World: Compatible Concepts or Mutually Exclusive Mandates?

“…In 1989, only 10% of the average Chinese diet was comprised of animal products. This grew to 20% in 2009 and is on trajectory to reach 30% by 2030 (Bonhommeau et al, 2013). China's per capita consumption of meat, milk and eggs increased four-, four-and eight-fold, respectively, between 1978(Liu and Diamond, 2005.…”

“…centered diet of the modern western nations is spreading among developing cultures around the world. The proportions animal products in modern human diets ranges from about 45% in the United States and France to as low as 5% in some African countries (Bonhommeau et al, 2013). Average global per capita animal product consumption is increasing, with increases primarily occurring in developing countries.…”

O paradigma agroecológico e as crises da sociedade contemporânea: contribuições socioantropológicas na perspectiva da teoria mimética

“…Assim, quando o individualismo (no sentido utilizado anteriormente) se desenvolve em um país, ele substitui o modo de vida comunitário ou tradicional, aumentando a demanda em energia e commodities para atender às "necessidades" (ou seja, aos desejos) de cada pessoa. Por exemplo, o consumo de carne que se desenvolve por meio da imitação (à escala das sociedades) do modo de vida estadunidense, o American way of life (Bonhommeau et al, 2013).…”