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Zusammenfassung Der Wandel zu einer „bio-basierten“ Wirtschaft, wie er in nationalen und internationalen Biookonomie-Strategien propagiert wird, kann nur mit tiefgreifenden Veranderungen landwirtschaftlicher Systeme zur Steigerung der Agrarproduktion einhergehen. Besonders in Landern des Globalen Sudens gingen solche Prozesse jedoch meist mit unbeabsichtigten – oder in Kauf genommenen – negativen Konsequenzen wie Umweltdegradation oder die Verscharfung gesellschaftlicher Ungleichheiten einher. Dennoch finden die Kenntnisse uber die Risiken bisheriger landwirtschaftlicher Interventionen kaum in politischen Biookonomie-Strategien Berucksichtigung, die auf wirtschaftlich-technische Losungen einer „nachhaltigen“ Intensivierung durch agrartechnologische Innovationen auf der einen, und eine Ausweitung von Produktionsflachen auf der anderen Seite setzen. Wie diese Produktionssteigerungen okologisch und sozial nachhaltig gestaltet werden sollen, bleibt unklar, und bisherige Erfahrungen mit derartigen Interventionen lassen eher das Gegenteil befurchten. Anhand von zwei historischen Beispielen – der Grunen Revolution im Punjab Pakistans und der Neulandkampagne in Kasachstan – skizziert der Beitrag die vielschichtigen sozialen und okologischen Folgen bisheriger, grosangelegter landwirtschaftlicher Interventionen zur Produktionssteigerung und geht der Frage nach, inwiefern diese Erfahrungen (besser) in Biookonomie-Strategien Berucksichtigung finden (konnen). Kritische Reflektion sollte dabei vor allem die Rolle institutioneller Pfadabhangigkeiten in der Gestaltung aktueller und zukunftiger Entwicklungen erfahren. Wie bisherige Erfahrungen im Landwirtschaftssektor deutlich machen, mussen Biookonomie-Strategien ihren geforderten systemischen Ansatz ernst nehmen – was impliziert, dass technologie- und produktivitatsorientierte Ziele stets sozialen und okologischen Zielen untergeordnet werden mussen. Schlagworter: Landwirtschaft, Biookonomie-Strategien, Produktionssteigerung, Grune Revolution, Neulandkampagne, Pakistan, Kasachstan ----- Overcoming Path Dependencies in the Bioeconomy? Agricultural Intensification Processes from a Social-Ecological Perspective Abstract The “transformation” to a bio-based economy as propagated in international and national bioeconomy strategies implies profound changes in agricultural systems to increase production. In countries of the Global South, however, such processes have usually been accompanied by unintended – or deliberately accepted – negative consequences, such as environmental degradation or a widening of social inequalities. Yet, existing knowledge about the risks of agricultural interventions is hardly considered in bioeconomy strategies, which, on the one hand, focus on economic and technical approaches to “sustainable” intensification through agro-technological innovations, and, on the other hand, an expansion of production areas. These strategies lack any plausible ideas on how production increases can be made ecologically and socially sustainable, and previous experience with agrarian interventions give reasons for concern. Using two historical examples – the Green Revolution in the Punjab of Pakistan and the Virgin Lands Campaign in Kazakhstan – this article outlines the complex social and ecological consequences of large-scale agricultural interventions to increase production and examines the extent to which these experiences can (and should) be taken into account in bioeconomy strategies. In this context, the role of institutional path-dependencies in shaping present and future developments should be critically reflected on. As past experience in the agricultural sector has shown, bioeconomy strategies must take their claimed “systemic” approach seriously, which implies that technology and productivity-oriented goals must always be subordinated to social and ecological goals. Keywords: agriculture, bioeconomy strategies, intensification, extensification, green revolution, virgin lands campaign, Pakistan, Kazakhstan ----- Bibliographie: Alff, Henryk/Spies, Michael: Pfadabhangigkeiten in der Biookonomie uberwinden? Landwirtschaftliche Intensivierungsprozesse aus sozial-okologischer Perspektive, PERIPHERIE – Politik • Okonomie • Kultur, 3+4-2020, S. 334-359. https://doi.org/10.3224/peripherie.v40i3-4.06

We investigated the role of labour in explaining the yield gap of cereals at both crop and farm levels on smallholder farms in Southern Ethiopia. A household survey containing detailed information of labour use at crop and farm level of ca. 100 farms in a maize-based system around Hawassa and ca. 100 farms in a wheat-based system around Asella was used for this purpose. Stochastic frontier analysis was combined with the principles of production ecology to decompose maize and wheat yield gaps. Actual maize and wheat yields were on average 1.6 and 2.6 t ha−1, respectively, which correspond to 23 and 26% of the water-limited yield (Yw) of each crop. For both crops, nearly half of the yield gap was attributed to the technology yield gap, indicating sub-optimal crop management to achieve Yw even for the farmers with the highest yields. The efficiency yield gap was ca. 20% of Yw for both crops; it was negatively associated with sowing date and with the proportion of women's labour used for sowing in the case of maize but with the proportion of hired labour used for sowing and weed control in the case of wheat. The resource yield gap was less than 10% of Yw for both crops due to small differences in input use between highest- and lowest-yielding farms. The contribution of capital and farm power availability to crop yields, input use and labour use was analysed at the farm level. Labour calendars showed that crops cultivated in Hawassa were complementary, with peak labour occurring at different times of the year. By contrast, crops cultivated in Asella competed strongly for labour during sowing, hand-weeding and harvesting months, resulting in potential trade-offs at farm level. Oxen ownership was associated with capital availability, but not farm power in Hawassa and with both capital availability and farm power in Asella. Farmers with more oxen applied more nitrogen (N) to maize in Hawassa and cultivated more land in Asella, which is indicative of an intensification pathway in the former and an extensification pathway in the latter. Differences in land:labour ratio and in the types of crops cultivated explained the different strategies used in the two sites. In both sites, although gross margin per unit area increased linearly with increasing crop yield and farm N productivity, gross margin per labour unit increased up to an optimal level of crop yield and farm N productivity after which no further response was observed. This suggests that narrowing the yield gap may not be economically rational in terms of labour productivity. We conclude that labour (and farm power) is not a major determinant of maize yield gaps in Hawassa, but is a major determinant of wheat yield gaps in Asella.

Highlights • Extensification of dairy sheep systems provides an environmental benefit when soil C sequestration is considered. • Extensification of dairy sheep systems determines lower environmental impact per hectare of utilized agricultural area. • Enteric methane emissions are the main source of GHG emissions of the sheep milk life cycle. • Carbon sequestration in permanent grasslands can considerably contribute to climate change mitigation. Abstract A life cycle assessment (LCA) study of a transition from semi-intensive to semi-extensive Mediterranean dairy sheep farm suggests that the latter has a strong potential for offsetting greenhouse gas (GHG) emissions through the soil C sequestration (Cseq) in permanent grasslands. The extensification process shows clear environmental advantage when emission intensity is referred to the area-based functional unit (FU). Several LCA studies reported that extensive livestock systems have greater GHG emissions per mass of product than intensive one, due to their lower productivity. However, these studies did not account for soil Cseq of temporary and permanent grasslands, that have a strong potential to partly mitigate the GHG balance of ruminant production systems. Our LCA study was carried out considering the transition from a semi-intensive (SI) towards a semi-extensive (SE) production system, adopted in a dairy sheep farm located in North-Western Sardinia (Italy). Impact scope included enteric methane emissions, feed production, on-farm energy use and transportation, infrastructures as well as the potential C sink arising from soil Cseqwith respect to the emission intensity. In order to provide a more comprehensive analysis, we used the following FUs: 1 kg of fat and protein corrected milk (FPCM) and 1 ha of utilised agricultural area (UAA). We observed that the extensification of production system determined contrasting environmental effects when using different FUs accounting for soil Cseq. When soil Cseq in emission intensity estimate was included, we observed slightly lower values of GHG emissions per kg of FPCM in the SI production system (from 3.37 to 3.12 kg CO2 equivalents – CO2-eq), whereas a greater variation we observed in the SE one (from 3.54 to 2.90 kg CO2-eq). Considering 1 ha of UAA as FU and including the soil Cseq, the emission intensity in SI moved from 6,257 to 5,793 kg CO2-eq, whereas values varied from 4,020 to 3,299 kg CO2-eq in SE. These results indicated that the emission intensity from semi-extensive Mediterranean dairy sheep farms can be considerably reduced through the soil Cseq, although its measurement is influenced by the models used in the estimation.

Recent studies assessing agricultural policies, including the EU's Agri-Environment Scheme, have shown that these have been successful in attaining some environmental goals. In Finland, however, the economic situation of farms has dramatically fallen and hence, the actions do not result in social acceptability. Sustainable intensification is a means to combine the three dimensions of sustainability: environmental, economic and social. Here we introduce a novel land use optimization and planning tool for the sustainable intensification of high-latitude agricultural systems. The main rationale for the development of the tool was to achieve a systematic and comprehensive conception for land allocation across Finland, where field parcels vary substantially in their conditions. The developed tool has a three-step scoring system based on seven physical characteristics (parcel size, shape, slope, distance to the farm center and waterways, soil type and logistic advantages) and the productivity of field parcels. The productivity estimates are based on vegetation indices derived from optical satellite data. The tool allocates virtually all >1 million field parcels in Finland either to sustainable intensification, extensification or afforestation. The tool is dynamic in the sense that its boundary values for land allocation can be fixed according to changes in social targets and supporting policies. Additionally, it can be applied year after year by acknowledging new available data, e.g., on vegetation indices and field parcel rearrangements between farms. Furthermore, it can be applied to all farm types and across Finland. It is a tool for land use planning, implementation and monitoring, but its thorough implementation calls for further development of policy instruments, which are currently more supportive towards land sharing than land sparing activities.

In traditional agricultural areas, where traditional crops (TCs) are cultivated, small farms are still highly represented. Located prevalently in marginal and sensitive areas, agricultural areas have undergone deep transformation. Smallholders have maintained the traditional asset of cultivation (extensive and low input requirement management) only to some extent. In some cases they have adapted traditional orchards into more intensive planting systems. Frequently, they have abandoned agriculture. The land use and management influence soil functions, i.e., the capability of a specific soil to provide key functions in terrestrial ecosystems. In order to assess whether small farms are environmentally sustainable, we used a set of soil quality indicators in three traditional tree crops in the Latium region (central Italy), like hazelnut, grapevine, and Citrus. The soil parameters, chemical, biological, and biochemical, were quantified under three different management models: extensive cultivation, intensive cultivation, and abandonment. The selected set of indicators proved to be able to discriminate adequately between the management models and to be suitable for the soil health assessment. Results proved that hazelnut orchards stored more organic C, independently from farming management, while vineyard showed the lower total organic carbon (TOC). The microbial carbon vs. organic carbon ratio (Cmic-to Corg ratio) was higher for vineyards and Citrus groves, denoting a more active degradation of soil organic matter. Soil enzymes (ESs) involved in C cycle were variable along the different treatments and mainly influenced by the C inputs to soil and soil cover, whereas those involved in N, P, and S cycles were higher in abandoned and extensive TCs. Overall, extensive cultivation performed better in terms of soil quality than intensive or abandonment. This study suggests that a transition to an agriculture based on agroecological principles and toward extensification would provide significant soil-based environmental benefits in marginal sensitive areas.

In recent decades the intensification of agricultural production in many European countries has been one of the key components of land-use change. The impact of agricultural intensification varies according to national and local contexts and a greater understanding of the drivers of intensification will help to mitigate against its negative impacts and harness potential benefits. This paper analyses changes in land use intensity in six case studies in Europe. A total of 437 landowners were interviewed and their responses were analysed in relation to changes in land use intensity and agricultural production between 2001 and 2011. In the case studies in Western and Eastern Europe we observed stabilisation during the last decade, and no clear tendency of increase or decrease of land use intensity. The use of fertilizers and pesticides seems to have decreased in our cases in Western Europe, which is contrary to trends in Eastern Europe. Agricultural production remained stable in almost all cases, except for an increase in Austria and Romania which may indicate that the farming efficiency has increased. A statistical analysis showed a division between study areas in Romania and Austria (increasing land use intensity) versus those in the Netherlands, Denmark and Greece (decreasing). In the Mediterranean cases we observe a process where agriculture is becoming increasingly marginalised, at the same time as changes in function with regard to urbanisation and recreational land uses have taken place. Logistic regression highlighted the importance of farm size and farmer type in understanding changes in land use intensity. The dominant pattern of stabilisation which has occurred over the past 10 years may also partly be a result of effective EU and national environmental and agricultural policies, which are increasingly concerned with improving environmental conditions in rural areas.

EU-member states are obliged to designate Natura2000 sites for habitat protection. Natura2000 sites comprise approximately 18 percent of the terrestrial area of the EU. On average, around 22 percent of Natura2000 sites are covered by agricultural land use, such as intensive cropland and more extensively managed land. Particularly in regions with high proportions of agricultural land use in Natura2000 sites, habitat protection is closely linked with the intensity of agricultural land use. Thus, it is important to understand dynamics between intensive and extensive land use. Denmark, where Natura2000 sites comprise approximately 8 percent of the terrestrial area, is the EU member state with the highest proportion of agricultural land use in Natura2000 sites. The Habitat Directive (HD) was implemented in Denmark in 2003. This implied increased focus from authorities on extensification of agricultural land use in Natura2000 sites. We applied data from agricultural registers to test if the implementation of the HD had a significant effect on extensification of agricultural land use within Natura2000 sites compared to areas outside Natura2000. We assessed area of extensive land use in 2013 and change in area of extensive land use for two periods: From 2000 to 2003, before the implementation of the HD and from 2003 to 2013, after its implementation. In order to control for the influences of biophysical constraints on agricultural intensity, we included information on slopes and peat soil. Results from a regression analysis indicate that even if influences of peat soils and slopes are taken into account, Natura2000 sites are positively related to the extent of extensive land use in 2013 and to the magnitude of extensification. Furthermore, this relation is more significant in the period after 2003, indicating that the implementation of the HD had an extensifying effect on agricultural land use within Nautra2000 sites.

Future biorefineries will prefer crops with high biomass yields, thus may precipitate fundamental changes to the agricultural landscape and the biomass production systems. Understanding the fate of nitrogen (N) in novel agricultural land uses is vital for product optimisation and environmental protection. This work reports and investigates the first multi-annual N balances for novel cropping systems optimised for high biomass production compared to traditional systems under North European climate and soil conditions. In a three-year study, two types of novel systems, i) a rotation of annual crops optimised for maximum biomass production (maize, beet, hemp/oat, triticale as main crops, and winter rye and winter oilseed rape as “second” - cover crops), and ii) perennial grasses (intensively fertilised (festulolium, reed canary grass, tall fescue and cocksfoot), low-fertilised (miscanthus) and unfertilised (grass-legume mixtures)), were compared with iii) traditional systems (continuous maize or triticale, and a cereal crop rotation) at two sites in Denmark varying in temperature, rainfall and soil type (sandy loam and coarse sand). Harvested biomass N and soil nitrate dynamics, as well as model-supported nitrate leaching and field surface N balance (input minus output) of the systems were compared. At each study site, the fertilised perennial grasses outperformed all other systems by doubling biomass N and reducing nitrate leaching by 70–80% compared to the traditional systems. Compared to continuous maize monoculture, the optimised rotation supplied 70% more biomass N and 40% less nitrate leaching on coarse sandy soil, whereas on sandy loam soil it yielded about 10% less biomass N with 50% less nitrate leaching. Field surface N balances were overall neutral/positive, except for festulolium and continuous maize monoculture that slightly mined the soil for N. When N losses by leaching, denitrification and volatilisation were included, soil total N stocks were estimated to decline for the majority of the systems at both sites.

Crop residues are important for livestock feed and nutrient cycling among many other functions on smallholder farming systems of sub-Saharan Africa. The objective of this study was to assess differences in resource endowment, crop productivity and crop residue management in selected sites in southern Africa. Three sites were selected along a gradient of intensification of crop production; Murehwa, Zimbabwe and Ruaca and Gorongosa, central Mozambique. Murehwa and Ruaca have mixed crop-livestock systems with more intensive crop production in Murehwa. Gorongosa is predominantly crop based with small livestock that do not impact on crop production. A combination of land size and cattle ownership was the major attribute that defined wealth status among farmers in mixed crop-livestock systems whereas land size and labor availability were important under crop-based extensification systems. Farm systems were more diverse where livestock was more important. The wealthiest farmers (resource group-RG1) in Murehwa produced an average of 2.2 t ha-1 maize crop residues, and productivity decreased with decrease in resource ownership with the poorest (RG4) achieving only 0.8 t ha-1. In Ruaca 1.3 and 0.5 t ha-1 was produced by RG1 and RG4 respectively, whereas in Gorongosa 0.4 and 0.2 t ha-1 was produced by RG1 and RG4. These crop residues are insufficient to achieve the minimum threshold of soil cover (30%) required for the practice of conservation agriculture. However, they can provide sufficient feed to sustain livestock of RG1 farmers in Murehwa for 63 days and 54 days for RG2 farmers. In Ruaca, they can feed cattle for 37 days for RG1 and 17 days for RG2 farmers. The product of livestock × population density determined the extent and manner in which crop residues are used. The population density limited the extent of the grazing area, increased grazing frequency and reduced the grazing quality leading to the need to supplement animal feed with crop residues. Farmers preferentially allocate crop residues to livestock where labor is available. The crop residues fed to animals allow farmers to increase manure quantity and quality which explains the major differences in crop productivity between the different resource groups. In the absence of cattle, crop residues are burned before the cropping season to facilitate land clearance. In conclusion, land size, cattle ownership and labor availability largely define the intensity of crop production and the fate of crop residues on smallholder farms in southern Africa.

Metadata only record Two agricultural intensification policies currently have a foothold in Southern Africa: intensification by plough-based, animal integrated practices and intensification by conservation agricultural practices including natural resource management. The former ideology originated from colonialism while the latter is currently promoted by nongovernmental organizations and development agencies. However, analysis on farmer knowledge relating to both of these practices reveals a predisposition towards extensification, or the farming on more land and using more resources to increase yields, instead of intensification. Other factors include limited cash, elevated risks, fluctuations in labor availability, and high input prices. Interestingly, the authors cite reliance on purely technical fixes, the disregarding of local or placed-based knowledge, and ultimately the lack of innovation on the side of researchers, development agencies, and policy-makers as the true reasons why Africa farmers are "failing to yield."

This work aims to provide a comprehensive, wall-to-wall analysis of land use/cover changes in the continental areas of Portugal and Spain between 1990 and 2012. This overall objective is developed into two main research questions: (1) Whether differences between the extent and prevalence of changes exist between both countries and (2) which are the hotspots of change (areas where a given land use/cover transition dominates the landscape) in each country. We used Corine Land Cover in three different points in time (1990, 2000, 2012) to explore eight characteristic land cover transitions and carried out a cluster analysis at LAU2 level (municipalities in Spain, parishes in Portugal) that allowed to identify the areas in which each transition was dominant. The main findings include the decline of agricultural area and the increase of urbanized and artificial covers in both countries, but different trends followed by forest cover, with an increase in Spain and a decrease in Portugal. At the same time, the spatial analysis provided an overview of the main gradients of change related to tensions between agricultural intensification–extensification, on the one hand, and deforestation–afforestation, on the other.

International audience; Question: How do functional types respond to contrasting levels of herbage use in temperate and fertile grasslands? Location: Central France (3 degrees 1' E, 45 degrees 43' N), 870 m a.s.l. Methods: Community structure and the traits of dominant plant species were evaluated after 12 years of contrasted grazing and mowing regimes in a grazing trial, comparing three levels of herbage use (high, medium and low). Results and Conclusions: Of 22 measured traits (including leaf traits, shoot morphology and composition, phenology), seven were significantly affected by the herbage use treatment. A decline in herbage use reduced individual leaf mass, specific leaf area and shoot digestibility, but increased leaf C and dry matter contents. Plants were taller, produced larger seeds and flowered later under low than high herbage use. Nine plant functional response types were identified by multivariate optimization analysis; they were based on four optimal traits: leaf dry matter content, individual leaf area, mature plant height and time of flowering. In the high-use plots, two short and early flowering types were co-dominant, one competitive. grazing-tolerant and moderately grazing-avoiding, and one grazing-avoiding but not -tolerant. Low-use plots were dominated by one type, neither hardly grazing-avoiding C 0 nor grazing-tolerant, but strongly competitive for light.

Many farmers in central Mozambique intercrop maize with grain legumes as a means to improve food security and income. The objective of this study was to understand the farming system, and to evaluate the suitability of maize–legume intercropping to alleviate the biophysical and socio-economic constraints faced by smallholder farmers in Ruaca and Vunduzi villages, central Mozambique. To achieve this we characterised the farming systems and measured grain yields, rainfall infiltration, economic returns and acceptability of maize–legume intercrops under different N and P application rates. Two intercropping strategies were tested: (a) an additive design of within-row intercropping in which legume was intercropped with alternating hills of maize within the same row; maize plant population was the same as sole crop maize, and (b) a substitutive design with distinct alternating rows of maize and legume (local practice). Fertiliser treatments imposed on all treatments were: (i) no fertiliser, (ii) 20 kg P ha −1 , (iii) 20 kg P ha −1 + 30 kg N ha −1 , and (iv) 20 kg P ha −1 + 60 kg N ha −1 . Intercrops were relatively more productive than the corresponding sole crops; land equivalent ratios (LER) for within-row intercropping ranged between 1.1 and 2.4, and between 1.0 and 1.9 for distinct-row intercropping. Average maize yield penalty for intercropping maize and pigeonpea in the within-row was small (8%) compared with 50% in the distinct-row design; average (season × fertiliser) sole maize yield was 3.2 t ha −1 . Intercropping maize and cowpea in within-row led to maize yield loss of only 6%, whereas distinct-row intercropping reduced maize yield by 25% from 2.1 t ha −1 of sole maize (season × fertiliser). Cowpea yield was less affected by intercropping: sole cowpea had an average yield of 0.9 t ha −1 , distinct-row intercropping (0.8 t ha −1 ) and the within-row intercropping yielded 0.9 t ha −1 . Legumes were comparatively less affected by the long dry spells which were prevalent during the study period. Response to N and P fertiliser was weak due to poor rainfall distribution. In the third season, maize in rotation with pigeonpea and without N fertiliser application yielded 5.6 t ha −1 , eight times more than continuous maize which was severely infested by striga ( Striga asiatica ) and yielded only 0.7 t ha −1 . Rainfall infiltration increased from 6 mm h −1 to 22 mm h −1 with long-term maize–legume intercropping due to a combination of good quality biomass production which provided mulch combined with no tillage. Intercropping maize and pigeonpea was profitable with a rate of return of at least 343% over sole maize cropping. Farmers preferred the within-row maize–legume intercropping with an acceptability score of 84% because of good yields for both maize and legume. Intercropping increased the labour required for weeding by 36% compared with the sole crops. Farmers in Ruaca faced labour constraints due to extensification thus maize–pigeonpea intercropping may improve productivity and help reduce the area cultivated. In Vunduzi, land limitation was a major problem and intensification through legumes is amongst the few feasible options to increase both production and productivity. The late maturity of pigeonpea means that free-grazing of cattle has to be delayed, which allows farmers to retain crop residues in the fields as mulch if they choose to; this allows the use of no-tillage practises. We conclude that maize–legume intercropping has potential to: (a) reduce the risk of crop failure, (b) improve productivity and income, and (c) increase food security in vulnerable production systems, and is a feasible entry point to ecological intensification.

http://www.sciencedirect.com/science/article/pii/S0143622811001603; International audience; The Amazonian state of Mato Grosso is the main production area for soybeans in Brazil and contains 31.3% of the national production as of 2009.The rapid evolution of the agricultural systems in this area shows that the region is experiencing a rapid agricultural transition. In this paper, we broke down this transition process into three steps: crop expansion, agricultural intensification and ecological intensification. We used remote sensing products to develop and compute satellite-derived indices describing the main agricultural dynamics during the cropping years from 2000-2001 to 2006-2007. Our results indicated that Mato Grosso is continuing to expand its agricultural sector, with a 43% increase in the net cropped area during the study period. Although this expansion mainly occurred in the cerrado ecoregion until the early 2000s, the forest ecoregion is experiencing expansion at this time. We observed that65% of the crop expansion in Mato Grosso from 2000 to 2006 occurred in this ecoregion. However, we did not identify this crop expansion as the major driver of deforestation in Mato Grosso because only12.6% of the cleared areas were directly converted into croplands. Agricultural intensification also evolved rapidly, as the proportion of the net cropped area cultivated with double cropping systems harvesting two successive commercial crops (i.e., soybean and corn or soybean and cotton) increased from 6% to 30% during the study period. Finally, we found that ecological intensification occurred because the region's farmers planted a non-commercial crop (i.e., millet or sorghum) after the soybean harvest to prevent soil erosion, improve soil quality, break pest cycles, maintain soil moisture and set the conditions for high-quality no-tillage operations. In 2006-2007, 62% of the net cropped area was permanently covered by crops during the entire rainy season. This practice allowed the farmers to diversify their production, as shown by the positive evolution of the Area Diversity Index. Future scholars can use the method proposed in this paper to improve their understanding of the forces driving the agricultural dynamics in Mato Grosso.

International audience; 1. Many studies have identified relationships between plant reproductive behaviour and environmental conditions. However, they have all been based on cross-species analysis and take no account of the relative abundance of species with vegetation. 2. Using two reproductive traits - seed mass and dispersal vector - as examples, a range of previously identified relationships were tested using both unweighted and weighted-by-abundance data collected from land-use transitions at 12 sites across Europe. 3. Seed mass was correlated positively with most measures of temperature (stronger relationships for unweighted data) and declined against measures of disturbance (stronger relationships with weighted data). It was not related consistently to measures of water availability. 4. There was some evidence that endozoochory was associated with damper environments, hoarding with drier ones and exozoochory with more fertile habitats. 5. Weighting reduced the slope of relationships between seed mass and environmental variables, possibly indicating that dominance within vegetation is determined by land use after the operation of a climatic filter. Fewer significant relationships were detected for weighted dispersal mechanisms compared to unweighted ones, indicating less difference of the dominants from other species with regard to this trait. 6. Synthesis. This analysis shows that weighting by abundance in the vegetation (compared to unweighted analysis) has a significant impact on the relationships between key species traits and a range of environmental parameters related to climate and land use, and that this impact was not consistent in its effects.

17 páginas, 12 figuras, 4 tablas.-- El documento se encuentra en su versión post-print., A vegetation cover increase has been identified at global scales using satellite images and vegetation indices. This fact is usually explained by global climatic change processes such as CO2 and temperature increases. Nevertheless, although these causes can be important, the role of socioeconomic transformations must be considered in some places, since in several areas of Northern Hemisphere an important change in management practices has been detected. Rural depopulation and land abandonment have reactivated the natural vegetation regeneration processes. This work analyses the vegetation evolution in the central Spanish Pyrenees from 1982 to 2000. The analysis has been done by using calibrated-NDVI temporal series from NOAA-AVHRR images. A positive and significant trend in NDVI data has been identified from 1982 to 2000 coinciding with a temperature increase in the study area. However, the spatial differences in magnitude and the sign of NDVI trends are significant. The role of land management changes in the 20th century is considered as a hypothesis to explain the spatial differences in NDVI trends. The role of land-cover and human land-uses on this process has been analyzed. The highest increment of NDVI is detected in lands affected by abandonment and human extensification. The importance of management changes in vegetation growth is discussed, and we indicate that although climate has great importance in vegetal evolution, land-management changes can not be neglected in our study area., The authors wish to acknowledge financial support from the following projects: La recuperación del espacio agrícola como estrategia de gestión integrada del territorio en área de montaña: El ejemplo de los Altos Valles del Aragón y del Gállego (P049/2000), financed by the DGA; Caracterización espacio-temporal de las sequías en el valle medio del Ebro e identificación de sus impactos (BSO2002-02743); La identificación de fuentes de sedimento y áreas generadoras de escorrentía en relación con los cambios de uso del suelo (REN/2000-1709- C04/01/GLO), and Efectos erosivos del fuego a lo largo de un gradiente climático. Aportaciones para la gestión de áreas quemadas (REN/2002-00133), financed by the CICYT.

Because of an human massive emigration, the corsican breeding system evolved to an extensive logic, characterized by an important decrease of the number of animals and a near stagnation of the physical yields. To day, this extensive logic is showing all its limits., Du fait d'une émigration humaine massive, l'élevage pastoral corse a évolué selon une logique extensive, caractérisée par une forte régression des effectifs et une quasi stagnation des rendements physiques. Aujourd'hui cette logique extensive révèle toutes ses limites., Vercherand Jean. La question du développement de l'élevage en Corse ... In: Économie rurale. N°198, 1990. p. 20.