Retrospective assessment as a tool for the management of sustainability in diversified farms
Pedro Alcázar,Ileana Espejel,Marisa Reyes-Orta &María Concepción Arredondo-García
This study develops a proposal of retrospectively assessing sustainability. We selected the diversified farm El Mogor – in Guadalupe Valley, Mexico – with available record-books since 1954. The farm owner provided documentation of 60 years of productive diversification. We analyzed the farm record-books and the data obtained from structured interviews with the MESMIS, Green Rural Enterprises, and Emergy techniques. The farm’s retrospective sustainability was described, evaluated, and represented in instructive diagrams showing the progress and adaptability to external economic, ecological, and social changes through time. The results provide a guideline to continue future evaluations and to recommend its use to other farms.
International Journal of Agricultural Sustainability
Variations in ecosystem services in response to paddy expansion in the Sanjiang Plain, Northeast China
Fengqin Yan,Shuwen Zhang &Fenzhen Su
The ecosystem of the Sanjiang Plain in China has dramatically changed in the past four decades. This study investigated the history of paddy field expansion in the Sanjiang Plain and discovered the ecosystem service variations in response to paddy expansion. Integrating a series of Landsat images, we obtained the paddy expansion history from 1976 to 2015. Then, we calculated ecosystem service values (ESVs) to estimate the ecosystem service variations caused by paddy expansion in the Sanjiang Plain. The results indicate that the paddy area increased from 404,789–2,598,449 ha during 1976–2015, leading to a decline in the total ecosystem service values by 11288.04 million dollars. The largest decline in ESVs in response to paddy expansion was caused by wetland reclamation (9998.54 million dollars). Apart from agricultural products and gas regulation functions, the ESVs provided by other functions all showed a declining trend. Paddy expansion in the Sanjiang Plain increased agricultural product function at the expense of the decline of other functions. In future management practices, the rational allocation of water resources and paddy distribution are necessary in order to achieve sustainable development of both water resources and agricultural production. Some suggestions including coculture systems, restoring habitats for aquatic species, farm management that fosters biodiversity in paddy fields are provided for future sustainability.
Identifying the tree species compositions that maximize ecosystem functioning in European forests
Lander Baeten et al.
- Forest ecosystem functioning generally benefits from higher tree species richness, but variation within richness levels is typically large. This is mostly due to the contrasting performances of communities with different compositions. Evidence‐based understanding of composition effects on forest productivity, as well as on multiple other functions will enable forest managers to focus on the selection of species that maximize functioning, rather than on diversity per se.
- We used a dataset of 30 ecosystem functions measured in stands with different species richness and composition in six European forest types. First, we quantified whether the compositions that maximize annual above‐ground wood production (productivity) generally also fulfil the multiple other ecosystem functions (multifunctionality). Then, we quantified the species identity effects and strength of interspecific interactions to identify the “best” and “worst” species composition for multifunctionality. Finally, we evaluated the real‐world frequency of occurrence of best and worst mixtures, using harmonized data from multiple national forest inventories.
- The most productive tree species combinations also tended to express relatively high multifunctionality, although we found a relatively wide range of compositions with high‐ or low‐average multifunctionality for the same level of productivity. Monocultures were distributed among the highest as well as the lowest performing compositions. The variation in functioning between compositions was generally driven by differences in the performance of the component species and, to a lesser extent, by particular interspecific interactions. Finally, we found that the most frequent species compositions in inventory data were monospecific stands and that the most common compositions showed below‐average multifunctionality and productivity.
- Synthesis and applications. Species identity and composition effects are essential to the development of high‐performing production systems, for instance in forestry and agriculture. They therefore deserve great attention in the analysis and design of functional biodiversity studies if the aim is to inform ecosystem management. A management focus on tree productivity does not necessarily trade‐off against other ecosystem functions; high productivity and multifunctionality can be combined with an informed selection of tree species and species combinations.
Integrating evolutionary patterns in biodiversity science and conservation
https://doi.org/10.1016/j.sajb.2017.01.016Get rights and content
Ever since the revolutionary ideas put forward by Darwin, evolutionary studies have played a fundamental role in our understanding of life and the mechanisms that led to its current diversity. Until relatively recently however, evolutionary biology and associated sub-disciplines had a relatively modest involvement in tackling conservation issues. This state of affairs has however shifted considerably in recent years, with numerous approaches being proposed to integrated evolutionary history and phylogenetic information in biodiversity science. I will present a few examples of studies integrating evolutionary information in biodiversity science that exemplifies how such information can be crucial in conservation planning and decision making. In a first study, we investigated the evolutionary patterns in the flora of the Cape region of South Africa, one of the five Mediterranean-type ecosystems of the world and a centre of high species diversity and endemism. Previous research using a genus-level phylogenetic tree of the region’s flora showed that phylogenetic diversity is more clustered in the western part of the region, while it is more over-dispersed in the eastern part. These patterns were attributed to the fact that the western part acted as a refugium with high rates of speciation and low extinction, while the eastern part was the scene of more exchanges with neighbouring biomes. We examined phylogenetic diversity patterns in the region using modelled species distributions and phylogenetic trees from 21 “Cape floral clades”, groups of plants that have mostly diversified in the Cape, representing more than 2,500 of the ca. 9,300 species found in the Cape. These new analyses provide a more refined account of the phylogenetic patterns uncovered in the genus-level study and identified new ones. In a second study, I will discuss the combinations of extinction risk data, obtained from conservation assessments made using the IUCN Red List categorisation, and phylogenetic information to rank species according to how evolutionary distinct and globally endangered they are: the EDGE approach. I will present results from the first major group of plants that have been assessed using this approach, the gymnosperms.
Grey leaf spot disease of maize and food security research
https://doi.org/10.1016/j.sajb.2017.01.028Get rights and content
Maize is an important staple food in South Africa cultivated on large commercial farms and small-holder farms. Grey leaf spot (GLS) disease of maize is characterized by leaf lesions which, in severe cases, can coalesce to form blighted leaves, resulting in grain yield losses. The GLS-maize research programme at the University of Pretoria focuses on the molecular biology of the pathosystem. Field trials of a maize mapping population were conducted over three seasons in several environments in KwaZulu-Natal province, where the disease is rife. Quantitative loci for disease resistance were identified. Transcriptome analysis identified gene regulatory networks associated with susceptibility and resistance. Population genetic analysis of the fungus Cercospora zeina that causes GLS indicated that diverse isolates are scattered throughout the region. This implies that maize breeders should deploy different maize resistance in South Africa to ensure food security.
The Lancet Planetary Health, volume 3 issue2
More than a diet
In an Editorial published in The Lancet on Jan 16, 2019 was declared to be the year of nutrition. And indeed, this announcement was set to coincide with the launch of two Commissions investigating the links between food systems, human health, and the environment. The first, the EAT-Lancet Commission on healthy diets from sustainable food systems focused on identifying the challenges inherent to maintaining food systems that are both environmentally sustainable and beneficial for human health, whereas the second report, The Global Syndemic of Obesity, Undernutrition and Climate Change, was centred around human systems and their role in the interplay between climate, nutrition, and health. Both Commissions make planetary health central to their messages, with the so-called planetary health diet arising from the EAT-Lancet Commission bringing the concept to a broad new audience. With debates around this diet reverberating in canteens and kitchens across the world, planetary health has rarely been discussed more.
However, the purpose of the Commissions was not to tell people what they can and cannot eat and nor did they set out to propose the one diet that would save the world. Instead, they aimed to illustrate the ways that food production and consumption, perhaps more so than any other human activities, inextricably link the earth’s natural systems and human health, and that this relationship does not have to boil down to a choice between health or the environment. Furthermore, the development of sustainable food systems should not be represented purely as a matter of personal responsibility and consumer choice. In the EAT-LancetCommission, for example, diet is only one aspect of the future projections of environmental impacts, with important roles reserved for productivity and waste. Even if entirely vegan diets were adopted worldwide, the authors estimate that, without improvements to productivity and reductions in waste, food production would still be pushing cropland use, nitrogen and phosphorus application, and biodiversity loss beyond their sustainable environmental boundaries. This is not to attack the importance of dietary choices. Both Commissions show that something is clearly going wrong. In the EAT-Lancet report, no combination of improved productivity and reduced waste was sufficient to bring greenhouse gas emissions within the proposed boundary under the “business as usual” dietary scenario, whereas the Global Syndemic report contains the alarming statistic that, globally, 3% of children with stunting are also obese—a figure that should be closer to 0%.