Hass A.L., Kormann U.G., Tscharntke T., Clough Y., Baillod A.B., Sirami C., Fahrig L., Martin J.-L., Baudry J., Bertrand C., Bosch J., Brotons L., Bure F., Georges R., Giralt D., Marcos-García M.Á., Ricarte A., Siriwardena G., Batáry P. (2018) Landscape configurational heterogeneity by small-scale agriculture, not crop diversity, maintains pollinators and plant reproduction in western Europe. Proceedings of the Royal Society B: Biological Sciences. 285: 0-0.LinkDoi: 10.1098/rspb.2017.2242
Agricultural intensification is one of the main causes for the current biodiversity crisis. While reversing habitat loss on agricultural land is challenging, increasing the farmland configurational heterogeneity (higher field border density) and farmland compositional heterogeneity (higher crop diversity) has been proposed to counteract some habitat loss. Here, we tested whether increased farmland configurational and compositional heterogeneity promote wild pollinators and plant reproduction in 229 landscapes located in four major western European agricultural regions. High-field border density consistently increased wild bee abundance and seed set of radish (Raphanus sativus), probably through enhanced connectivity. In particular, we demonstrate the importance of crop-crop borders for pollinator movement as an additional experiment showed higher transfer of a pollen analogue along crop-crop borders than across fields or along semi-natural crop borders. By contrast, high crop diversity reduced bee abundance, probably due to an increase of crop types with particularly intensive management. This highlights the importance of crop identity when higher crop diversity is promoted. Our results show that small-scale agricultural systems can boost pollinators and plant reproduction. Agri-environmental policies should therefore aim to halt and reverse the current trend of increasing field sizes and to reduce the amount of crop types with particularly intensive management. © 2018 The Author(s) Published by the Royal Society. All rights reserved.
Hermoso V., Morán-Ordóñez A., Brotons L. (2018) Assessing the role of Natura 2000 at maintaining dynamic landscapes in Europe over the last two decades: implications for conservation. Landscape Ecology. 33: 1447-1460.LinkDoi: 10.1007/s10980-018-0683-3
Context: The Natura 2000 aims to promote the persistence of biodiversity and traditional uses. European landscapes have, however, undergone large transformations in the past decades, mainly associated with the abandonment of less productive lands concentration of intensive agriculture. These changes could pose management challenges and new opportunities to the achievement of the network´s goals. Objective: Evaluate changes in land cover within Natura 2000 in the last two decades. Methods: We use different Corine Land Cover datasets to construct transition matrices of land uses for measuring changes for each Natura 2000 site. We also explore the role of different drivers in observed changes and assess the impacts of these changes in the structure of landscape. Results: Landscape has been highly dynamic within Natura 2000 in the last two decades with more than 20% undergoing land cover changes. The most systematic transitions involved both, succession processes towards naturalisation in older and more abrupt protected areas (PAs) and anthropization in less steep and more recently designated PAs. Changes across land cover categories had also significant effects on the landscape configuration towards a higher homogenisation. Conclusions: Two different strategies would be needed to enhance the role of Natura 2000, (i) tighter control to ensure anthropization, mainly intensive agriculture, does not compromise conservation goals within PAs and (ii) tackle more effectively the ecological and socio-economic effects of abandonment in less productive areas to halt loss of key habitats. On the other hand, changes in composition and structure of landscape open new conservation opportunities derived from enhanced connectivity. © 2018, Springer Nature B.V.
Hermoso V., Villero D., Clavero M., Brotons L. (2018) Spatial prioritisation of EU's LIFE-Nature programme to strengthen the conservation impact of Natura 2000. Journal of Applied Ecology. 55: 1575-1582.LinkDoi: 10.1111/1365-2664.13116
Despite advances in conservation efforts within Europe during recent decades, assessments highlight a need for adequate financing mechanisms to support the Natura 2000 network, the centrepiece of the EU's Biodiversity Strategy. Besides the need for greater investment (currently only covering a fifth of the estimated cost of the network), better planning for this investment could help better achieve conservation goals. We demonstrate a method that could be used to identify priority Natura 2000 sites, and species therein, that could guide investment in the future. We first used the lists of key species associated with each Natura 2000 site to map the distribution of all priority species covered by the Birds and Habitats Directives. We then used Marxan software to prioritise allocation of conservation funds among all Natura 2000 sites, while trying to mimic the observed conservation effort implemented under the LIFE programme, the main financial tool of the EU's Biodiversity Strategy, in the period 1992–2013. Some Natura 2000 sites show exceptional value, holding species that either do not, or only very rarely, occur elsewhere in the network. These priority sites were concentrated mainly on islands and in the south western, eastern and northern extremes of Europe's mainland, thus reflecting patterns in species richness and endemism. We found a poor relationship between the priorities identified here and the way funds had been distributed in previous LIFE-Nature programmes. Policy implications. We propose that prioritisation exercises like the one shown here could be used to inform a top-down EU regulation mechanism by providing lists of site and species priorities that better reflect European conservation needs. These recommendations, performed at continental scale, could then help guide LIFE project proposals from the Member States and fill the current gap in the coverage of priority species. This top-down control mechanism could be integrated in the current system of budget distribution, rather than replacing it completely, to enhance the efficiency of conservation investment in the EU and achievement of continental goals. © 2018 The Authors. Journal of Applied Ecology © 2018 British Ecological Society
Hinojo-Hinojo C., Castellanos A.E., Llano-Sotelo J., Peñuelas J., Vargas R., Romo-Leon J.R. (2018) High Vcmax, Jmax and photosynthetic rates of Sonoran Desert species: Using nitrogen and specific leaf area traits as predictors in biochemical models. Journal of Arid Environments. : 0-0.LinkDoi: 10.1016/j.jaridenv.2018.04.006
Dryland ecosystems largely control the inter-annual variability of the global carbon cycle. Unfortunately, there is a paucity of data on key biochemical parameters, such as maximum carboxylation velocity (Vcmax25) and electron transport rate (Jmax25), from species in these ecosystems which limits our capacity to model photosynthesis across ecological scales. We studied six dominant C3 shrub and tree species from the Sonoran Desert with different leaf traits and phenological strategies. We characterized Vcmax25 and Jmax25 for each species and assessed which traits or trait combinations were the best predictors of these parameters for biochemical models of photosynthesis. All species had high values of Vcmax25 and Jmax25, mostly explained by high leaf nitrogen content (Narea) and high nitrogen allocation to photosynthetic enzymes comparable to those reported for herbs and crop species but higher than those of shrubs and other functional types in world databases. We found that the high values of Vcmax25 and Jmax25, by increasing rates of photosynthetic reactions, enhance photosynthetic water and nitrogen-use efficiencies and may favor carbon gain under typical conditions in drylands. Our findings improve the parameterization of photosynthesis models, and provide novel implications to common findings of high Narea in dryland species. © 2018 Elsevier Ltd
Hong, S., Piao, S., Chen, A., Liu, Y., Liu, L., Peng, S., Sardans, J., Sun, Y., Peñuelas, J., Zeng, H. (2018) Afforestation neutralizes soil pH. Nature Communications. 9: 0-0.LinkDoi: 10.1038/s41467-018-02970-1
Hu M., Peñuelas J., Sardans J., Sun Z., Wilson B.J., Huang J., Zhu Q., Tong C. (2018) Stoichiometry patterns of plant organ N and P in coastal herbaceous wetlands along the East China Sea: implications for biogeochemical niche. Plant and Soil. : 0-0.LinkDoi: 10.1007/s11104-018-3759-6
Background and aims: Nitrogen (N) and phosphorus (P) are essential nutrients for plant growth, and their availability and stoichiometry play pivotal roles in trophic dynamics and community composition. The biogeochemical niche (BN) hypothesis claims that each species should have an optimal elemental composition and stoichiometry as a consequence of its optimal function in its specific ecological niche. Little attention, however, has been given to N and P stoichiometric patterns and test the BN hypothesis in coastal wetland communities from the perspective of organ and species-specific comparisons. Methods: We investigated factors responsible for changes in N and P stoichiometry patterns in different functional groups in coastal wetlands and tested the BN hypothesis by evaluating N and P composition in whole aboveground plants and organs. Results: Both plant N and P concentrations were high in coastal wetlands, indicating that N and P were not likely limiting, although the N:P ratio was slightly lower than the ratio reported in global and Chinese terrestrial flora. N and P concentrations and N:P ratios varied strongly between C3 and C4 species, among species, and among organs within species. N and P concentrations were not correlated with latitude, mean annual temperature and precipitation, although N:P ratio was weakly correlated with these factors. The differences in N and P concentrations and N:P ratios along the wetland gradients were mainly because of the species-specific community composition of each site. Conclusions: The results are consistent with the BN hypothesis. First, N and P composition is species-specific (homeostatic component of BN), each species tends to maintain its own composition even growing in different sites with different species composition. Second, different species, despite maintaining their own composition, have distinct degree of composition phenotypic flexibility (flexibility component of BN); this different size of “biogeochemical space” was observed when comparing different species living in the same community and the shifts in species BN space and size was observed when comparing populations of the same species living in different sites. © 2018, Springer Nature Switzerland AG.
Kagambèga A., Thibodeau A., Trinetta V., Soro D.K., Sama F.N., Bako É., Bouda C.S., Wereme N'Diaye A., Fravalo P., Barro N. (2018) Salmonella spp. and Campylobacter spp. in poultry feces and carcasses in Ouagadougou, Burkina Faso. Food Science and Nutrition. : 0-0.LinkDoi: 10.1002/fsn3.725
The importance of Salmonella and Campylobacter as foodborne pathogens is well recognized worldwide. Poultry and poultry products are commonly considered as the major vehicles of Salmonella and Campylobacter infection in humans. The aim of this study was to investigate the hygienic status of poultry facilities and determine the prevalence of Salmonella and Campylobacter in slaughtered poultry feces and carcasses in four different markets in Ouagadougou, capital city of Burkina Faso. A total of 103 poultry feces and 20 carcasses were analyzed using microbiological standard methods. Among the 103 fecal samples, 70 were positive for Campylobacter ssp (67.96%) and 54 for Salmonella ssp (52.42%). The hippurate hydrolysis test revealed that among the 70 Campylobacter strains isolated from feces, 49 were C. jejuni (70%) and 21 were C. coli (30%). From the 20 carcasses analyzed, 18 were contaminated with Salmonella (90%) and 10 with Campylobacter ssp (50%). Among the 10 Campylobacter ssp samples isolated from poultry carcasses, all were identified as C. jejuni using the API CAMPY system and the hippurate hydrolysis test. The assessment of markets hygienic practices for production, transportation, display, and vending of meat revealed unhygienic conditions. To complete the observation of unhygienic practices, we have sampled chicken-washing solution from the study sites and microbiological analysis of these samples revealed the presence of Salmonella spp in 100% of the samples. This study highlighted that poultry products on sale in Ouagadougou are highly contaminated with Salmonella and Campylobacter. To the best of our knowledge, this is the first report describing Campylobacter presence in the poultry industry of Burkina Faso. Our findings might help to better understand the epidemiology of Salmonella and Campylobacter. © 2018 Published by Wiley Periodicals, Inc.
Karavani, A., De Cáceres, M., Martínez de Aragón, J., Bonet, J.A., de-Miguel, S. (2018) Effect of climatic and soil moisture conditions on mushroom productivity and related ecosystem services in Mediterranean pine stands facing climate change. Agricultural and Forest Meteorology. 248: 432-440.LinkDoi: 10.1016/j.agrformet.2017.10.024
Karimoune L., Ba M.N., Baoua I.B., Muniappan R. (2018) The parasitoid Trichogrammatoidea armigera Nagaraja (Hymenoptera: Trichogrammatidae) is a potential candidate for biological control of the millet head miner Heliocheilus albipunctella (de Joannis) (Lepidoptera: Noctuidae) in the Sahel. Biological Control. 127: 9-16.LinkDoi: 10.1016/j.biocontrol.2018.08.003
[No abstract available]
Kováč D., Veselovská P., Klem K., Večeřová K., Ač A., Peñuelas J., Urban O. (2018) Potential of photochemical reflectance index for indicating photochemistry and light use efficiency in leaves of European beech and Norway spruce trees. Remote Sensing. 10: 0-0.LinkDoi: 10.3390/rs10081202
Hyperspectral reflectance is becoming more frequently used for measuring the functions and productivity of ecosystems. The purpose of this study was to re-evaluate the potential of the photochemical reflectance index (PRI) for evaluating physiological status of plants. This is needed because the reasons for variation in PRI and its relationships to physiological traits remain poorly understood. We examined the relationships between PRI and photosynthetic parameters in evergreen Norway spruce and deciduous European beech grown in controlled conditions during several consecutive periods of 10-12 days between which the irradiance and air temperature were changed stepwise. These regime changes induced significant changes in foliar biochemistry and physiology. The responses of PRI corresponded particularly to alterations in the actual quantum yield of photosystem II photochemistry (ΦPSII). Acclimation responses of both species led to loss of PRI sensitivity to light use efficiency (LUE). The procedure of measuring PRI at multiple irradiance-temperature conditions has been designed also for testing accuracy of ΔPRI in estimating LUE. A correction mechanism of subtracting daily measured PRI from early morning PRI has been performed to account for differences in photosynthetic pigments between irradiance-temperature regimes. Introducing ΔPRI, which provided a better estimate of non-photochemical quenching (NPQ) compared to PRI, also improved the accuracy of LUE estimation. Furthermore, ΔPRI was able to detect the effect of drought, which is poorly observable from PRI. © 2018 by the authors.
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