Energy and the food system.

Modern agriculture is heavily dependent on fossil resources. Both direct energy use for crop management and indirect energy use for fertilizers, pesticides and machinery production have contributed to the major increases in food production seen since the 1960s. However, the relationship between energy inputs and yields is not linear.

Temperature dependence of respiration in roots colonized by arbuscular mycorrhizal fungi.

* The arbuscular mycorrhizal (AM) symbiosis is ubiquitous, and the fungus represents a major pathway for carbon movement in the soil-plant system. Here, we investigated the impacts of AM colonization of Plantago lanceolata and temperature on the regulation of root respiration (R). * Warm-grown AM plants exhibited higher rates of R than did nonAM plants, irrespective of root mass.

Mycorrhizal respiration: implications for global scaling relationships.

Most plant species form mycorrhizas, yet these are neglected by plant physiologists. One consequence of this neglect is reduced ability to predict plant respiration, because respiration rate (R) in mycorrhizal roots might be higher than in non-mycorrhizal roots owing to increased substrate availability associated with enhanced nutrient uptake, coupled with increased respiratory product demand. Other predictions include that mycorrhizal colonization will affect scaling of R with tissue nitrogen concentrations; that mycorrhizal and non-mycorrhizal root R differ in their response to nutrient supply; and that the impact of colonization on R is related to fungal biomass.

Investigating early hominin dispersal patterns: developing a framework for climate data integration.

An investigation using the Stepping Out model of early hominin dispersal out of Africa is presented here. The late arrival of early hominins into Europe, as deduced from the fossil record, is shown to be consistent with poor ability of these hominins to survive in the Eurasian landscape. The present study also extends the understanding of modelling results from the original study by Mithen and Reed (2002.

Theropithecus and 'Out of Africa' dispersal in the Plio-Pleistocene.

Theropithecus oswaldi was one of the most widely distributed Plio-Pleistocene primates, found in southern, East, and North Africa, as well as in Spain, India, and possibly Italy. Such a large geographic range for a single primate species is highly unusual. Here, the nature and timing of its dispersal is examined using the Stepping Out cellular automata model.