Overview of Research on Sustainable Agriculture in Developing Countries. The Case of Mexico

One of the principal challenges faced by Mexican agriculture is the development of management models that are able to increase production while respecting the environment and generating wealth for society as a whole. In recent years, the number of studies analysing the sustainability of Mexican agriculture has grown significantly. The purpose of this study is to analyse the evolution of the research on the sustainability of agriculture in Mexico. For this purpose, a review and bibliometric analysis of a sample of 867 articles was carried out. The results reveal that the research has focused on the development of sustainable agricultural models in vulnerable rural areas, the sustainable exploitation of agroforestry systems, the development of energy crops for different uses, water resource management and land uses and their changes, conservation farming and climate change. Although research focused on sustainability is still in its early stages, it has become a priority field. A need to promote research from the economic and social disciplines may be observed, together with holistic projects that include the three pillars of sustainability (social, economic and environmental). This study could be useful to researchers in this field as it identifies the recent trends and principal agents that drive knowledge.

Spatial variation of human influences on grassland biomass on the Qinghai-Tibetan plateau

An improved understanding of increased human influence on ecosystems is needed for predicting ecosystem processes and sustainable ecosystem management. We studied spatial variation of human influence on grassland ecosystems at two scales across the Qinghai-Tibetan Plateau (QTP), where increased human activities may have led to ecosystem degradation. At the 10 km scale, we mapped human-influenced spatial patterns based on a hypothesis that spatial patterns of biomass that could not be attributed to environmental variables were likely correlated to human activities. In part this hypothesis could be supported via a positive correlation between biomass unexplained by environmental variables and livestock density. At the 500 m scale, using distance to settlements within a radius of 8 km as a proxy of human-influence intensity, we found both negatively human-influenced areas where biomass decreased closer to settlements (regions with higher livestock density) and positively human-influenced areas where biomass increased closer to settlements (regions with lower livestock density). These results suggest complex relationships between livestock grazing and biomass, varying between spatial scales and regions. Grazing may boost biomass production across the whole QTP at the 10 km scale. However, overgrazing may reduce it near settlements at the 500 m scale. Our approach of mapping and understanding human influence on ecosystems at different scales could guide pasture management to protect grassland in vulnerable regions on the QTP and beyond.

Anthropogenic transformation of the terrestrial biosphere

Human populations and their use of land have transformed most of the terrestrial biosphere into anthropogenic biomes (anthromes), causing a variety of novel ecological patterns and processes to emerge. To assess whether human populations and their use of land have directly altered the terrestrial biosphere sufficiently to indicate that the Earth system has entered a new geological epoch, spatially explicit global estimates of human populations and their use of land were analysed across the Holocene for their potential to induce irreversible novel transformation of the terrestrial biosphere. Human alteration of the terrestrial biosphere has been significant for more than 8000 years. However, only in the past century has the majority of the terrestrial biosphere been transformed into intensively used anthromes with predominantly novel anthropogenic ecological processes. At present, even were human populations to decline substantially or use of land become far more efficient, the current global extent, duration, type and intensity of human transformation of ecosystems have already irreversibly altered the terrestrial biosphere at levels sufficient to leave an unambiguous geological record differing substantially from that of the Holocene or any prior epoch. It remains to be seen whether the anthropogenic biosphere will be sustained and continue to evolve.