Brian Machovina

Biodiversity Conservation: The Key Is Reducing Meat Consumption

The consumption of animal-sourced food products by humans is one of the most powerful negative forces affecting the conservation of terrestrial ecosystems and biological diversity. Livestock production is the single largest driver of habitat loss, and both livestock and feedstock production are increasing in developing tropical countries where the majority of biological diversity resides. Bushmeat consumption in Africa and southeastern Asia, as well as the high growth-rate of per capita livestock consumption in China are of special concern. The projected land base required by 2050 to support livestock production in several megadiverse countries exceeds 30-50% of their current agricultural areas. Livestock production is also a leading cause of climate change, soil loss, water and nutrient pollution, and decreases of apex predators and wild herbivores, compounding pressures on ecosystems and biodiversity. It is possible to greatly reduce the impacts of animal product consumption by humans on natural ecosystems and biodiversity while meeting nutritional needs of people, including the projected 2-3 billion people to be added to human population. We suggest that impacts can be remediated through several solutions: (1) reducing demand for animal-based food products and increasing proportions of plant-based foods in diets, the latter ideally to a global average of 90% of food consumed; (2) replacing ecologically-inefficient ruminants (e.g. cattle, goats, sheep) and bushmeat with monogastrics (e.g. poultry, pigs), integrated aquaculture, and other more-efficient protein sources; and (3) reintegrating livestock production away from single-product, intensive, fossil-fuel based systems into diverse, coupled systems designed more closely around the structure and functions of ecosystems that conserve energy and nutrients. Such efforts would also impart positive impacts on human health through reduction of diseases of nutritional extravagance.

Bushmeat hunting and extinction risk to the world’s mammals

Terrestrial mammals are experiencing a massive collapse in their population sizes and geographical ranges around the world, but many of the drivers, patterns and consequences of this decline remain poorly understood. Here we provide an analysis showing that bushmeat hunting for mostly food and medicinal products is driving a global crisis whereby 301 terrestrial mammal species are threatened with extinction. Nearly all of these threatened species occur in developing countries where major coexisting threats include deforestation, agricultural expansion, human encroachment and competition with livestock. The unrelenting decline of mammals suggests many vital ecological and socio-economic services that these species provide will be lost, potentially changing ecosystems irrevocably. We discuss options and current obstacles to achieving effective conservation, alongside consequences of failure to stem such anthropogenic mammalian extirpation. We propose a multi-pronged conservation strategy to help save threatened mammals from immediate extinction and avoid a collapse of food security for hundreds of millions of people.

Taking a bite out of biodiversity.

In the Review “Status and ecological effects of the worlds largest carnivores” (10 January, DOI: 10.1126/science.1241484), W. J. Ripple et al. claim that meat consumption by humans is one of many threats to carnivores and biodiversity. We argue that human carnivory is in fact the single

Meat consumption as a key impact on tropical nature: a response to Laurance et al.

Laurance et al.’s recent review in TREE entitled ‘Agricultural expansion and its impacts on tropical nature’ [1] provides a valuable summary of how agricultural is affecting the diversity of tropical terrestrial and aquatic ecosystems. However, we believe that a major factor driving the loss of tropical ecosystems and biodiversity was not given sufficient attention and deserves further discussion. Of the eight points discussed by Laurance et al. as ‘key challenges ahead’, no mention was made of the challenges posed by increasing per capita meat consumption.

Increasing preference for beef magnifies human impact on world’s food web

Bonhommeau et al.’s report, “Eating up the world’s food web and the human trophic level” (1), provides a valuable perspective on the role of human food consumption within the global ecosystem. However, the ranking of human beings at a similar trophic level as other animals downplays the effects that humans have on the Earth in comparison with other species. The sheer volume of food consumed by humans and our growing preference for inefficient food sources cause us to have increasingly disproportionate impacts on the global ecosystem in relation to other species, even of the same trophic level.

Restoring low-input high-diversity grasslands as a potential global resource for biofuels

Reducing meat consumption by humans and shifting to more efficient plant and animal protein sources could potentially free up large areas of pasture and feedcrop agricultural land for restoration or conversion to low-input high-diversity (LIHD) grasslands. LIHD grasslands improve biodiversity, carbon sequestration, erosion control, water storage, while also providing opportunities to produce biofuels. We examined the potential of converting pastures globally, and animal feedstock agricultural lands in the USA and Brazil, to LIHD biomass sources and the capacity of these systems to meet national energy demands via (1) cellulosic ethanol and (2) integrated gasification and combined cycle technology with Fischer-Tropsch hydrocarbon synthesis (IGCC-FT) processing. Our analyses, which we argue are conservative, indicate that large amounts of energy, far in excess of many countrys current demands, can potentially be produced from IGCC-FT processing of grassland biomass grown on converted pastures, especially in tropical developing countries. Over 40 countries could meet ≥100% of their domestic demands for electricity, gasoline, and diesel. If energy products were shared between countries, the 95 countries with positive energy production yields could meet 46%, 28%, and 39% of their combined electricity, gasoline, and diesel demands, respectively. While it is clearly unrealistic to propose a 100% conversion of pasture lands to biofuel production, these analyses highlight the potential gains in ecosystem services and energy production that could theoretically be achieved on already-managed lands.

UAV remote sensing of spatial variation in banana production

Abstract. Remote sensing through Unmanned Aerial Vehicles (UAV) can potentially be used to identify the factors influencing agricultural yield and thereby increase production efficiency. The use of UAV remains largely underutilised in tropical agricultural systems. In this study we tested a fixed-wing UAV system equipped with a sensor system for mapping spatial patterns of photosynthetic activity in banana plantations in Costa Rica. Spatial patterns derived from the Normalised Difference Vegetation Index (NDVI) were compared with spatial patterns of physical soil quality and banana fruit production data. We found spatial patterns of NDVI were significantly positively correlated with spatial patterns of several metrics of fruit yield and quality: bunch weight, number of hands per bunch, length of largest finger, and yield. NDVI was significantly negatively correlated with banana loss (discarded due to low quality). Spatial patterns of NDVI were not correlated with spatial patterns of physical soil quality. These results indicate that UAV systems can be used in banana plantations to help map patterns of fruit quality and yield, potentially aiding investigations of spatial patterns of underlying factors affecting production and thereby helping to increase agricultural efficiency.