L'économie de la Grèce a connu une croissance de près de 2 % pendant les trois années qui ont précédé la crise provoquée par le COVID-19. Les réformes structurelles, le niveau élevé des excédents ...budgétaires primaires et les mesures d'allègement de la dette avaient alimenté la reprise de l'économie grecque et contribué au rétablissement de la confiance.
Soil extracellular enzyme stoichiometry (EES), the ratio of extracellular enzyme activities (EEAs) related to the acquisition of nutrients such as carbon (C), nitrogen (N) and phosphorus (P), ...reflects the demand for resources by microorganisms. However, how grassland restoration shifts microbial nutrient limitation as indicated by soil EES remains unclear. Here, we evaluated microbial nutrient limitation by studying soil EES across a chronosequence of grassland restoration sites. The ratio of the natural logarithm of C-, N-, and P-acquiring enzymes in our studied system ranged from 1:1.47:1.05 to 1:0.82:1.38, and the average was 1:1.08:1.28, deviating from the global ratio of 1:1:1 and indicating that microorganisms were co-limited by N and P. Enzyme N:P ratio increased and vector angles decreased with time since restoration, suggesting that the restored grassland shifted from P-limitation (angles>45°) to N-limitation (angles<45°), and N limitation gradually exacerbated over time. Strong relationships between microbial biomass C:N:P ratios and soil EES suggest that soil EES was dependent on microbial resource availability. We also found that the variation in soil EES was better explained by biotic than by abiotic factors, and the total variation explained increased with time since restoration, indicating that biotic control over soil EES increased over time as the environmental conditions such as soil moisture availability and nutrients improved for microorganisms. Overall, this study highlights the utility of the ecoenzymatic stoichiometry approach in assessing relationships in microbial resource ecology, and such insights provide guidance in developing restoration strategies such as the need for nutrient management in grassland ecosystems.
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•Soil C-, N-, P-acquiring enzymes gradually increased with grassland restoration.•The natural logarithm of soil C-, N-, P-acquiring enzyme ratio was 1:1.08:1.28.•Soil microorganisms shift from P- to N-limitation with grassland restoration.•The variation in soil EES was better accounted by biotic factors than by abiotic factors.
•The Atlantic Forest is the biome with the highest number of papers on ecological restoration.•Pantanal, Pampa and Caatinga are the least studied in terms of ecological restoration.•In all biomes, ...most of the studies are related to monitoring.•The number of species used in restored areas is limited.•It is necessary to include different life forms, restoration techniques and studies using reference areas to measure success.
The Bonn challenge aims at the restoration of 350 million hectares of degraded ladscapes by 2030. In Brazil, the restoration goal for 2030 is 12 million hectares. Despite the great demand for ecological restoration across the whole of Brazil, there have been no analyses of the studies carried out in different biomes. In addition, conservation efforts must cover all biomes, so that different regions can take advantage of the many benefits of restoration. Our aim was to identify advances and gaps in current restoration knowledge in order to guide future efforts in Brazil. Our bibliometric survey in the Web of Science using 23 keywords related to restoration generated a total of 530 papers, of which 291 were included in the analysis. The papers were published in 121 scientific journals between 1988 and 2018, with the largest number of papers in 2016. The Atlantic Forest was the biome with the highest number of studies, as it is one of the most threatened tropical forest regions in the world and maintains the largest number of research institutions and receives the highest level of funding support in the country. Regarding the types of studies, temporal monitoring was more frequent in the Amazon, Cerrado, Caatinga, and Pampa, while the monitoring at one point in time was more frequent in the Atlantic Forest. From the studies examined, 31% used a reference area for comparing restoration success. The most studied organisms were plants (81%), and among them, trees were the most frequent, followed by fungi, birds, invertebrates, mammals, and reptiles. The pre-restoration degradation differed among biomes, with deforestation for logging the most cited in the Amazon, agriculture, and livestock in the Atlantic Forest and Cerrado, logging and cattle ranching in Caatinga, and livestock in the Pampa and Pantanal. In general, active/assisted natural succession was the most frequent restoration process: planting seedlings more readily occurred in the Amazon, Atlantic Forest, and Caatinga, whereas natural regeneration in the Cerrado and Pantanal and sowing in Pampa. The studies varied among the age of restoration (>1 to 67 years for active restoration and >1 to 120 years for passive/unassisted natural succession), and the number of species planted (1 to 121 species). We identified an important regional knowledge gap for the Pantanal, Caatinga, and Pampa, as well as the need to include reference areas, evaluate different restoration techniques (besides planting seedlings), and the inclusion of other taxa and life forms in biodiversity studies apart from trees. We also identified the need to expand research to assess landscape metrics, prioritization, legislation, and public policies.
Linking plant phenology to conservation biology Morellato, Leonor Patrícia Cerdeira; Alberton, Bruna; Alvarado, Swanni T. ...
Biological conservation,
March 2016, 2016-03-00, 20160301, 2016-03, Volume:
195
Journal Article
Peer reviewed
Open access
Phenology has achieved a prominent position in current scenarios of global change research given its role in monitoring and predicting the timing of recurrent life cycle events. However, the ...implications of phenology to environmental conservation and management remain poorly explored. Here, we present the first explicit appraisal of how phenology — a multidisciplinary science encompassing biometeorology, ecology, and evolutionary biology — can make a key contribution to contemporary conservation biology. We focus on shifts in plant phenology induced by global change, their impacts on species diversity and plant–animal interactions in the tropics, and how conservation efforts could be enhanced in relation to plant resource organization. We identify the effects of phenological changes and mismatches in the maintenance and conservation of mutualistic interactions, and examine how phenological research can contribute to evaluate, manage and mitigate the consequences of land-use change and other natural and anthropogenic disturbances, such as fire, exotic and invasive species. We also identify cutting-edge tools that can improve the spatial and temporal coverage of phenological monitoring, from satellites to drones and digital cameras. We highlight the role of historical information in recovering long-term phenological time series, and track climate-related shifts in tropical systems. Finally, we propose a set of measures to boost the contribution of phenology to conservation science. We advocate the inclusion of phenology into predictive models integrating evolutionary history to identify species groups that are either resilient or sensitive to future climate-change scenarios, and understand how phenological mismatches can affect community dynamics, ecosystem services, and conservation over time.
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•We establish phenology as key research endeavour in applied ecology and conservation.•We show that climate-change phenological mismatches affect conservation of mutualisms.•Phenology supports managing impacts such as fire, invasive species or fragmentation.•New technologies improve spatial and temporal coverage of phenology monitoring.•The relevance of phenology as a tool for conservation education and citizen science
In the face of rapid environmental and cultural change, orthodox concepts in restoration ecology such as historical fidelity are being challenged. Here we re-examine the diverse roles played by ...historical knowledge in restoration, and argue that these roles remain vitally important. As such, historical knowledge will be critical in shaping restoration ecology in the future. Perhaps the most crucial role in shifting from the present version of restoration ecology ("v1.0") to a newer formulation ("v2.0") is the value of historical knowledge in guiding scientific interpretation, recognizing key ecological legacies, and influencing the choices available to practitioners of ecosystem intervention under conditions of open-ended and rapid change.
A primary goal of ecological restoration is to increase biodiversity in degraded ecosystems. However, the success of restoration ecology is often assessed by measuring the response of a single ...functional group or trophic level to restoration, without considering how restoration affects multitrophic interactions that shape biodiversity. An ecosystem-wide approach to restoration is therefore necessary to understand whether animal responses to restoration, such as changes in biodiversity, are facilitated by changes in plant communities (plant-driven effects) or disturbance and succession resulting from restoration activities (management-driven effects). Furthermore, most restoration ecology studies focus on how restoration alters taxonomic diversity, while less attention is paid to the response of functional and phylogenetic diversity in restored ecosystems. Here, we compared the strength of plant-driven and management-driven effects of restoration on four animal communities (ground beetles, dung beetles, snakes, and small mammals) in a chronosequence of restored tallgrass prairie, where sites varied in management history (prescribed fire and bison reintroduction). Our analyses indicate that management-driven effects on animal communities were six-times stronger than effects mediated through changes in plant biodiversity. Additionally, we demonstrate that restoration can simultaneously have positive and negative effects on biodiversity through different pathways, which may help reconcile variation in restoration outcomes. Furthermore, animal taxonomic and phylogenetic diversity responded differently to restoration, suggesting that restoration plans might benefit from considering multiple dimensions of animal biodiversity. We conclude that metrics of plant diversity alone may not be adequate to assess the success of restoration in reassembling functional ecosystems.
Analyses of functional traits have become fundamental tools for understanding patterns and processes in plant community ecology. In this context, regenerative seed traits play an important, yet ...overlooked, role because they largely determine the ability of plants to disperse and re-establish. A survey of recent publications in community ecology suggests that seed germination traits in particular are neglected at the expense of other relevant but overused traits based only on seed morphology. As a response to this bias, we discuss the functional significance of seed germination traits in comparison with morphological and biophysical seed traits, and advocate their use in vegetation science. We also demonstrate how research in community assembly, climate change and restoration ecology can benefit from the inclusion of germination traits, encompassing functions that cannot be explained solely by adult plant traits. Seed germination experiments conducted in the laboratory or field to quantify these traits provide ecologically meaningful and relatively easy-to-obtain information about the functional properties of plant communities. We argue that bridging the gap between seed physiologists and community ecologists will improve the prediction of plant assemblages, and propose further perspectives for including seed traits into the research agenda of functional community ecologists.
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•Soil was the largest carbon pool in all the restoration methods evaluated.•Stocks differ among carbon pools, but not among restoration methods.•Active and assisted restoration ...resulted in greater carbon stocks in the tree pool.•Isotope analysis showed that the source of carbon changed with restoration method.•Carbon content (%) differed between the pools and restoration methods.
Restoring degraded areas is an effective strategy to reestablish the environmental services provided by the forests including global warming mitigation by carbon sequestration. Restoring lands is especially important in the Atlantic Forest, a global hotspot in Brazil threatened by deforestation. To successfully restore degraded lands, it is necessary to apply the most suitable method for each situation. However, studies comparing restoration techniques are scarce. This lack of information hampers the Atlantic Forest restoration and, given the original complexity of its ecological dynamics, restoration success is even more challenging in this ecosystem. This study aimed to assess carbon stocks (above and belowground), carbon content (%), and carbon isotope at 5-year old sites implemented by different restoration methods in southeastern Brazil. The restoration methods tested were active restoration (AR), assisted restoration (AsR), and passive restoration in an abandoned pasture (AP), which were compared to a nearby pasture (P) and a remaining forest fragment (RF). The assessed pools were: tree, coarse roots, fine roots, herbaceous, litter, standing dead wood, fallen dead wood, and soil (0–1 cm, 5–10 cm, 10–20 cm layers). Total carbon stock was higher on RF (152.304 Mg C ha−1), followed by the P (84.378 Mg C ha−1), AR (66.414 Mg C ha−1), AsR (65.73 Mg C ha−1) and AP (65.581 Mg C ha−1). The restoration areas sites are still too young to show significant differences in total carbon stock as a result of different restoration methods. However, carbon stock and carbon content (%) differed among the pools according to the method and, in all cases, the largest carbon pool was soil, which shows the importance of sampling every pool for carbon stock and carbon content (%) estimation. Isotope analysis showed that carbon inputs in the soil had different sources, C3 or C4 plants, depending on the method. We concluded that these young secondary areas are already sequestering carbon, which helps mitigate global warming, and that monitoring every pool is important for a complete assessment, not only to restore secondary forests and understand growth but also for other land-uses such as pastures. Besides, the results obtained can be generalized to other tropical forest ecosystems with similar conditions (local and landscape), constituting a relevant contribution to forest restoration and carbon-sequestration related sciences.
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