The identification of a universal law that can predict the spatiotemporal structure of any entity at any scale has long been pursued. Thermodynamics have targeted this goal, and the concept of entropy has been widely applied for various disciplines and purposes, including landscape ecology. Within this discipline, however, the uses of the entropy concept and its underlying assumptions are various and are seldom described explicitly. In addition, the link between this concept and thermodynamics is unclear. The aim of this paper is to review the various interpretations and applications of entropy in landscape ecology and to sort them into clearly defined categories. First, a retrospective study of the concept genesis from thermodynamics to landscape ecology was conducted. Then, 50 landscape ecology papers that use or discuss entropy were surveyed and classified by keywords, variables and metrics identified as related to entropy. In particular, the thermodynamic component of entropy in landscape ecology and its various interpretations related to landscape structure and dynamics were considered. From the survey results, three major definitions (i.e., spatial heterogeneity, the unpredictability of pattern dynamics and pattern scale dependence) associated with the entropy concept in landscape ecology were identified. The thermodynamic interpretations of these definitions are based on different theories. The thermodynamic interpretation of spatial heterogeneity is not considered relevant. The thermodynamic interpretation related to scale dependence is also questioned by complexity theory. Only unpredictability can be thermodynamically relevant if appropriate measurements are used to test it.

This article discusses the economic dimensions of agroecological farming systems in Europe. It firstly theoretically elaborates the reasons why, and under what conditions, agroecological farming systems have the potential to produce higher incomes than farms that follow the conventional logic. This theoretical exposition is then followed by a presentation of empirical material from a wide range of European countries that shows the extent to which this potential is being realized. The empirical data draw upon different styles of farming that can be described as 'proto-agroecological': approaches to farming that are agroecological by nature, but which may not necessarily explicitly define themselves as agroecological. The empirical material that we present shows the huge potential and radical opportunities that Europe's, often silent, 'agroecological turn' offers to farmers that could (and should) be the basis for the future transformation of European agricultural policies, since agroecology not only allows for more sustainable production of healthier food but also considerably improves farmers' incomes. It equally carries the promise of re-enlarging productive agricultural (and related) employment and increasing the total income generated by the agricultural sector, at both regional and national levels. While we recognise that agroecology is a worldwide and multidimensional phenomenon we have chosen to limit this analysis to Europe and the economic dimension. This choice is made in order to refute current discourses that represent agroecology as unproductive and unprofitable and an option that would require massive subsidies.

BackgroundIn Thailand, pig production intensified significantly during the last decade, with many economic, epidemiological and environmental implications. Strategies toward more sustainable future developments are currently investigated, and these could be informed by a detailed assessment of the main trends in the pig sector, and on how different production systems are geographically distributed. This study had two main objectives. First, we aimed to describe the main trends and geographic patterns of pig production systems in Thailand in terms of pig type (native, breeding, and fattening pigs), farm scales (smallholder and large-scale farming systems) and type of farming systems (farrow-to-finish, nursery, and finishing systems) based on a very detailed 2010 census. Second, we aimed to study the statistical spatial association between these different types of pig farming distribution and a set of spatial variables describing access to feed and markets.ResultsOver the last decades, pig population gradually increased, with a continuously increasing number of pigs per holder, suggesting a continuing intensification of the sector. The different pig-production systems showed very contrasted geographical distributions. The spatial distribution of large-scale pig farms corresponds with that of commercial pig breeds, and spatial analysis conducted using Random Forest distribution models indicated that these were concentrated in lowland urban or peri-urban areas, close to means of transportation, facilitating supply to major markets such as provincial capitals and the Bangkok Metropolitan region. Conversely the smallholders were distributed throughout the country, with higher densities located in highland, remote, and rural areas, where they supply local rural markets. A limitation of the study was that pig farming systems were defined from the number of animals per farm, resulting in their possible misclassification, but this should have a limited impact on the main patterns revealed by the analysis.ConclusionsThe very contrasted distribution of different pig production systems present opportunities for future regionalization of pig production. More specifically, the detailed geographical analysis of the different production systems will be used to spatially-inform planning decisions for pig farming accounting for the specific health, environment and economical implications of the different pig production systems.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-016-0849-7) contains supplementary material, which is available to authorized users.

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Située à proximité de Kinshasa, la province du Bas-Congo (R.D. Congo) est l'une des principales pourvoyeuses en produits vivriers de cette ville. Par conséquent, l'augmentation de la pression sur les ressources naturelles s'accentue. L'analyse diachronique du paysage peut servir à montrer l'effet des actions anthropiques sur l'occupation du sol de cette province. La présente étude a pour but la quantification de la dynamique paysagère dans une zone test de cette province entre 1960 et 2005. Elle a permis, grâce à la matrice de transition appuyée par le calcul d'indices de structure spatiale, de montrer que l'occupation du sol a profondément changé. La matrice du paysage, initialement constituée par les forêts secondaires (49,95% du paysage), s'est dégradée au profit des savanes (qui ont conquis 14,23% des forêts secondaires) et des jachères et champs (qui ont conquis 27,23% des forêts secondaires). L'étude a ainsi révélé trois processus de transformation du paysage: la savanisation, la fragmentation de l'écosystème forestier et enfin une la formation de forêt dense (succession). Ces changements-excepté la succession-sont principalement dus à des perturbations anthropiques. La pression démographique et les pratiques agricoles non durables ont orienté la modification de l'occupation du sol. Les écosystèmes forestiers ont été substitués par des écosystèmes anthropisés menaçant alors la biodiversité de cette zone.

This study evaluates the feasibility of using the grass species Rendlia altera, Monocymbium ceresiiforme, Cynodon dactylon, and amendments (compost and lime) for the phytostabilisation of soils contaminated by Cu in the province of Katanga (Democratic Republic of Congo). Species were grown on control and Cu-contaminated plots (artificially contaminated with 2,500 mg kg(-1) Cu) unamended (NA), amended with 4.5 kg compost m(-2) or 0.2 kg lime m(-2). R. altera was also grown on contaminated plots amended with 22.5 kg compost m(-2) or 1 kg lime m(-2). Plant survival, growth, and reproduction were monitored for two years. Cu-concentration in leaves of R. altera and M. ceresiiforme were analysed. pH and extractable Cu (0.01 M CaCl2) in soil were analysed in April 2007 and 2008. Results showed that R. altera seems to be the best candidate because of its highest survival on NA, followed by M. ceresiiforme, while liming was necessary to ensure survival of C. dactylon. Lime increased plant reproduction and reduced Cu accumulation in leaves compared to compost. However, higher survival and number of spikes of R. altera obtained in experiment 2 with 22.5 kg compost m(-2) suggest that lime x compost interactions should be investigated in further studies.

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