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36 result(s) for "Sirami, Clélia"
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A greener path for the EU common agricultural policy
It's time for sustainable, environmental performance The Common Agricultural Policy (CAP) of the European Union (EU) is one of the world's largest agricultural policies and the EU's longest-prevailing one. Originally focused mostly on supporting production and farm income, the CAP has progressively integrated instruments to support the environment. Nonetheless, there is considerable agreement among EU citizens that the CAP still does not do enough to address ongoing environmental degradation and climate change (92% of nonfarmers, 64% of farmers) ( 1 ). In May and June 2018, the European Commission (EC) published the financial plan and legislative proposal for the CAP post-2020 ( 2 ), prompting numerous proposed amendments that the newly elected European Parliament (EP) will now have to consider. With an eye toward the next and final reform stages, including budget discussions and “trilogue” negotiations between the EC, the Council, and the EP to begin in autumn 2019, we examine whether the proposed post-2020 CAP can address key sustainability issues and meet societal demands for higher environmental performance.
Increasing crop heterogeneity enhances multitrophic diversity across agricultural regions
Agricultural landscape homogenization has detrimental effects on biodiversity and key ecosystem services. Increasing agricultural landscape heterogeneity by increasing seminatural cover can help to mitigate biodiversity loss. However, the amount of seminatural cover is generally low and difficult to increase in many intensively managed agricultural landscapes. We hypothesized that increasing the heterogeneity of the crop mosaic itself (hereafter “crop heterogeneity”) can also have positive effects on biodiversity. In 8 contrasting regions of Europe and North America, we selected 435 landscapes along independent gradients of crop diversity and mean field size. Within each landscape, we selected 3 sampling sites in 1, 2, or 3 crop types. We sampled 7 taxa (plants, bees, butterflies, hoverflies, carabids, spiders, and birds) and calculated a synthetic index of multitrophic diversity at the landscape level. Increasing crop heterogeneity was more beneficial for multitrophic diversity than increasing seminatural cover. For instance, the effect of decreasing mean field size from 5 to 2.8 ha was as strong as the effect of increasing seminatural cover from 0.5 to 11%. Decreasing mean field size benefited multitrophic diversity even in the absence of seminatural vegetation between fields. Increasing the number of crop types sampled had a positive effect on landscape-level multitrophic diversity. However, the effect of increasing crop diversity in the landscape surrounding fields sampled depended on the amount of seminatural cover. Our study provides large-scale, multitrophic, cross-regional evidence that increasing crop heterogeneity can be an effective way to increase biodiversity in agricultural landscapes without taking land out of agricultural production.
impact of shrub encroachment on savanna bird diversity from local to regional scale
Evidence is accumulating of a general increase in woody cover of many savanna regions of the world. Little is known about the consequences of this widespread and fundamental ecosystem structural shift on biodiversity. South Africa. We assessed the potential response of bird species to shrub encroachment in a South African savanna by censusing bird species in five habitats along a gradient of increasing shrub cover, from grassland/open woodland to shrubland dominated by various shrub species. We also explored historical bird species population trends across southern Africa during the second half of the 20th century to determine if any quantifiable shifts had occurred that support an ongoing impact of shrub encroachment at the regional scale. At the local scale, species richness peaked at intermediate levels of shrub cover. Bird species composition showed high turnover along the gradient, suggesting that widespread shrub encroachment is likely to lead to the loss of certain species with a concomitant decline in bird species richness at the landscape scale. Finally, savanna bird species responded to changes in vegetation structure rather than vegetation species composition: bird assemblages were very similar in shrublands dominated by Acacia mellifera and those dominated by Tarchonanthus camphoratus. Shrub encroachment might have a bigger impact on bird diversity in grassland than in open woodland, regardless of the shrub species. Species recorded in our study area were associated with historical population changes at the scale of southern Africa suggesting that shrub encroachment could be one of the main drivers of bird population dynamics in southern African savannas. If current trends continue, the persistence of several southern African bird species associated with open savanna might be jeopardized regionally.
Ecosystem services, social interdependencies, and collective action: a conceptual framework
The governance of ecosystem services (ES) has been predominantly thought of in terms of market or state-based instruments. Comparatively, collective action mechanisms have rarely been considered. This paper addresses this gap by proposing a conceptual framework that brings together ES, social interdependencies, and collective action thinking. We use an ES conceptual lens to highlight social interdependencies among people so as to reflect on existing or potential collective actions among them. This framework can also contribute to increasing people’s awareness of their mutual interdependencies and thereby fostering, framing, or enriching collective action, in ways that take into account the diversity and complexity of ecological processes underlying human activities. Our approach can contribute in particular to agroecological transitions that require landscape level innovations and coordination mechanisms among land users and managers. The framework distinguishes three types of social interdependencies: (i) between ES beneficiaries and ES providers, (ii) among beneficiaries, and (iii) among providers. These social interdependencies are in turn analyzed according to four main dimensions that are critical for collective action: (i) cognitive framing of interdependencies, (ii) levels of organization, (iii) formal and informal institutions, and (iv) power relations. Finally, we propose a strategy to turn this framework into action in contexts of participatory action research, a strategy grounded on a number of methodological principles and tools that convey complexity and increase people’s awareness of interdependencies in agrarian social-ecological systems.
Nutrient enrichment of ecosystems by fungus-growing versus non-fungus-growing termites
Fungus-growing termites (Macrotermitinae) collect water to air-condition their fungi and have been recorded tunnelling deeper than 80 m for groundwater. This collection of water ultimately results in solute accumulation and nutrient enrichment of their termitaria. We consequently hypothesized that nutrient enrichment of termitaria constructed by fungus-growing termites would be greater than by non-fungus-growing termites. To test this, we compared nutrient enrichment of termitaria of fungus-growing Macrotermes spp. in Namibia and termitaria of two non-fungus-growing termites – Trinervitermes trinervoides in South Africa and Nasutitermes triodiae in Australia. Compared with adjacent topsoils, Macrotermes termitaria were significantly enriched in 18 elements whereas T. trinervoides and N. triodiae termitaria were enriched in only one and five elements, respectively. Nutrients particularly enriched in Macrotermites termitaria included Ca (an enrichment factor of 12), Mg (2.9), Co (2.8), Fe (2.4), Mn (2.3), Se (2.2) and Cu (2.0). We suggest that fungus-growing termites that collect water for air-conditioning their fungi have the potential to inadvertently boost – to a far greater degree than non-fungus-growing termites – the availability of nutrients to local plants and herbivores.
Vegetation and songbird response to land abandonment: from landscape to census plot
While intensification of human activities and its ecological effects in many natural areas have recently received much attention, land abandonment in marginal areas is still the largely ignored side of a process rooted in the same socioeconomic context. Decreasing human impact in marginal rural areas often triggers a recovery of seminatural vegetation. Over a period of 25 years, we studied the changes in landscape and vegetation structure that followed land abandonment in a traditional Mediterranean mosaic of crops, grasslands, shrublands and woodlands, and assessed their effects on songbird occurrence and distribution. We combined an analysis of vegetation changes based on aerial photo interpretation with an analysis of bird censuses from 1978, 1992 and 2003 at two spatial scales: landscape and census plot (respectively 2800 and 3 ha). The perceived temporal changes in the vegetation were scale dependent. At the landscape scale, open habitats tended to disappear and woodlands matured. The contrasts in vegetation structure that defined habitat patches at the onset of the study tended to disappear. There was an overall shift of the bird community in favour of woodland species. At the scale of the census plot, however, the colonization by woody vegetation of patches formerly characterized by a homogeneous grass cover increased the local diversity of the vegetation, at least temporarily. Of seven species dependent on open habitats, the occurrence rate of five species significantly decreased, whereas it increased for two species: woodlark (Lulula arborea) and melodious warbler (Hippolais polyglotta). This increase was linked to the transitional increase in local vegetation diversity. In patches originally dominated by woodlands, local vegetation diversity decreased as woody vegetation expanded into clearings. The occurrence rate significantly increased for seven species relying on closed woodlands, while it decreased for two woodland species. As most species of high conservation profile in the Mediterranean are tied to open or to heterogeneous transitional habitats, these trends raise questions concerning their persistence in the future.
Landscape configurational heterogeneity by small-scale agriculture, not crop diversity, maintains pollinators and plant reproduction in western Europe
This research was funded by the ERA-Net BiodivERsA, with the national funders French National Research Agency (ANR-11-EBID-0004), German Ministry of Research and Education (FKZ:01LC1104A) and Spanish Ministry of Economy and Competitiveness, part of the 2011 BiodivERsA call for research proposals. The contribution from the UK was funded by the UK Government Department of the Environment, Food and Rural Affairs (Defra), as project WC1034.
Impacts of global change on species distributions: obstacles and solutions to integrate climate and land use
Aim: The impact of multiple stressors on biodiversity is one of the most pressing questions in ecology and biodiversity conservation. Here we critically assess how often and efficiently two main drivers of global change have been simultaneously integrated into research, with the aim of providing practical solutions for better integration in the future. We focus on the integration of climate change (CC) and land‐use change (LUC) when studying changes in species distributions. Location: Global. Methods: We analysed the peer‐reviewed literature on the effects of CC and LUC on observed changes in species distributions, i.e. including species range and abundance, between 2000 and 2014. Results: Studies integrating CC and LUC remain extremely scarce, which hampers our ability to develop appropriate conservation strategies. The lack of CC–LUC integration is likely to be a result of insufficient recognition of the co‐occurrence of CC and LUC at all scales, covariation and interactions between CC and LUC, as well as correlations between species thermal and habitat requirements. Practical guidelines for the study of these interactive effects include considering multiple drivers and processes when designing studies, using available long‐term datasets on multiple drivers, revisiting single‐driver studies with additional drivers or conducting comparative studies and meta‐analyses. Combining various methodological approaches, including time lags and adaptation processes, represent further avenues to improve global change science. Main conclusions: Despite repeated claims for a better integration of multiple drivers, the effects of CC and LUC on species distributions and abundances have been mostly studied in isolation, which calls for a shift of standards towards more integrative global change science. The guidelines proposed here will encourage study designs that account for multiple drivers and improve our understanding of synergies or antagonisms among drivers.
Effects of fire frequency on savanna butterfly diversity and composition: A preliminary study
Fire plays a major role in many biomes, is widely used as a management tool and is likely to be affected by climate change. For effective conservation management, it is essential to understand how fire regimes affect different taxa, yet responses of invertebrates are particularly poorly documented. We tested how different fire frequencies influence savanna butterfly diversity and composition by using a long-term savanna fire experiment initiated in 1954 in the Kruger National Park (South Africa). We compared butterfly abundance, species richness and community composition across three fire frequencies: high (burnt annually), medium (burnt triennially) and low (burnt twice in 60 years). Plots with high fire frequency hosted higher abundance than medium- or low-frequency plots. Fire frequencies did not affect species richness, but they led to distinct communities of butterflies. Our findings suggest that, in view of the three fire frequencies tested, a spatial diversity of fire frequencies may increase butterfly diversity at the landscape level in wet savannas. Managers may need to promote a greater diversity of fire frequencies by increasing fire frequency in some areas to provide habitat for species requiring high fire frequency, and by decreasing fire frequency in a large proportion of the landscape to provide fire refuges. This study provides new insights for butterfly conservation in savannas and highlights several knowledge gaps, which further studies should address for insect responses to be given adequate consideration in fire management strategies.Conservation implications: A spatial diversity of fire frequencies may increase butterfly diversity. Managers may need to promote a greater diversity of fire frequencies by increasing fire frequency in some areas to provide habitat for species requiring high fire frequency, and by decreasing fire frequency in other areas to provide fire refuges.
Ways of farming and ways of thinking
The efficiency of the European Union’s Common Agricultural Policy in mitigating the negative effects of agricultural intensification on the landscape and biodiversity is increasingly being questioned. Enhancing a reciprocal understanding of various stakeholders’ mental models of agro-social-ecosystems has been proposed to trigger changes in both policy design and farmers’ behaviors. However, the relationship between farmers’ mental models and practices is rarely considered. Here, we explore the relationship between farmers’ individual mental models (IMMs) of the agricultural landscape and their land management practices. To do so, we developed a theoretical and methodological framework grounded in cognitive psychology and farming system research for eliciting and comparing IMMs and land management practices. We applied this framework in the Coteaux de Gascogne territory, a hilly crop-livestock region in southern France. We identified groups of farmers according to their cropland and semi-natural habitat management practices. The results of our quantitative and qualitative comparisons of mental models between farmer groups showed that the way of farming partly relates to farmers’ ways of thinking about the landscape and highlighted the heterogeneity of IMMs between and within farmer groups. We found evidence that path-dependent factors that constrain farmers’ practices can modify their mental models, e.g., the role of agricultural machinery. Our study illustrates how an interdisciplinary framework coupling mental models and farming systems approaches provides an opportunity to enhance our understanding of the relationships between farmers’ world views and their practices. Moreover, our results challenge current ways of thinking and designing biodiversity conservation policies in farmed landscapes.