Weak isolation by distance and geographic diversity gradients persist in scottish relict pine forest

González-Díaz P., Cavers S., Iason G.R., Booth A., Russell J., Jump A.S. (2018) Weak isolation by distance and geographic diversity gradients persist in scottish relict pine forest. IForest. 11: 449-458.
Enlace
Doi: 10.3832/ifor2454-011

Resumen:

Gene flow is one of the main factors shaping genetic diversity within and among tree populations, and occurs through pollen and seed dispersal. Recent findings of pollen-release asynchronies in distant populations of Scots pine (Pi-nus sylvestris L.) within Scotland suggest that gene dispersal among more distant populations might be less effective than previously thought. Limited gene dispersal is one of the major factors causing genetic structure for neutral markers, and pollen-release asynchrony could have driven isolation by distance (IBD) among Scottish populations. Previous studies of neutral markers found little differentiation among Scottish populations of Scots pine, however they did not consider IBD over the full Scottish range. We analysed data from 6 nuclear simple sequence repeats (SSR) and 5 chloroplast SSR loci in a total of 540 individuals of Scots pine from 18 populations across Scotland. Our aim was to assess contemporary levels and distribution of genetic variation and to test if the distribution of genetic diversity was consistent with IBD. We also analysed patterns of gene flow that could have contributed to the observed patterns of variation. Levels of genetic diversity were high, for both nuclear and chloroplast markers within populations, and there was no significant differentiation among populations. A weak signal of IBD was present. We found an increase in nuclear diversity towards the East along with greater gene flow in a West-East direction commensurate with the prevailing winds. Our findings suggest that this wind-driven gene flow is dominant over genetic drift and prevents differentiation among the Scottish populations. It may also counteract any pollen-release asynchronies among populations. © SISEF.

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Reproduction, energy storage and metabolic requirements in a mesophotic population of the gorgonian Paramuricea macrospina

Grinyó J., Viladrich N., Díaz D., Muñoz A., Mallol S., Salazar J., Castillo R., Gili J.-M., Gori A. (2018) Reproduction, energy storage and metabolic requirements in a mesophotic population of the gorgonian Paramuricea macrospina. PLoS ONE. 13: 0-0.
Enlace
Doi: 10.1371/journal.pone.0203308

Resumen:

This study examined the sexual reproductive cycle, energy storage and metabolic requirements of a Mediterranean gorgonian in a mesophotic ecosystem (~70 m depth). Paramuricea macrospina resulted to be a gonochoric internal brooding species with a 1:1 population sex ratio. Oogenesis lasted ~12–14 months, whereas spermatogenesis was significantly shorter, only lasting 6 months. Fertilization occurred during late summer (August) and larval release occurred during autumn (September–October). The organic matter and total lipid content showed a slight seasonal variability. Stable isotopic composition remained constant throughout the year, reflecting a general stability in gorgonian food sources. Conversely, the free fatty acid composition varied seasonally, reflecting changes in P. macrospina energetic demands probably related to gametogenesis and larval brooding. The reproductive ecology and biochemical composition of P. macrospina significantly differ from shallow coastal gorgonian species, reflecting the higher environmental stability of deeper environments. © 2018 Grinyó et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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Do asynchronies in extinction debt affect the structure of trophic networks? A case study of antagonistic butterfly larvae–plant networks

Guardiola M., Stefanescu C., Rod F., Pino J. (2018) Do asynchronies in extinction debt affect the structure of trophic networks? A case study of antagonistic butterfly larvae–plant networks. Oikos. 127: 803-813.
Enlace
Doi: 10.1111/oik.04536

Resumen:

Habitat loss and fragmentation affect species richness in fragmented habitats and can lead to immediate or time-delayed species extinctions. Asynchronies in extinction and extinction debt between interacting species may have severe effects on ecological networks. However, these effects remain largely unknown. We evaluated the effects of habitat patch and landscape changes on antagonistic butterfly larvae–plant trophic networks in Mediterranean grasslands in which previous studies had shown the existence of extinction debt in plants but not in butterflies. We sampled current species richness of habitat-specialist and generalist butterflies and vascular plants in 26 grasslands. We assessed the direct effects of historical and current patch and landscape characteristics on species richness and on butterfly larvae–plant trophic network metrics and robustness. Although positive species- and interactions–area relationships were found in all networks, structure and robustness was only affected by patch and landscape changes in networks involving the subset of butterfly specialists. Larger patches had more species (butterflies and host plants) and interactions but also more compartments, which decreased network connectance but increased network stability. Moreover, most likely due to the rescue effect, patch connectivity increased host-plant species (but not butterfly) richness and total links, and network robustness in specialist networks. On the other hand, patch area loss decreased robustness in specialist butterfly larvae–plant networks and made them more prone to collapse against host plant extinctions. Finally, in all butterfly larvae–plant networks we also detected a past patch and landscape effect on network asymmetry, which indicates that there were different extinction rates and extinction debts for butterflies and host plants. We conclude that asynchronies in extinction and extinction debt in butterfly–plant networks provoked by patch and landscape changes caused changes in species richness and network links in all networks, as well as changes in network structure and robustness in specialist networks. © 2017 The Authors

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Phylogeny of the ant genus Aphaenogaster (Hymenoptera: Formicidae) in the Iberian Peninsula, with the description of a new species

Gómez K., Martínez D., Espadaler X. (2018) Phylogeny of the ant genus Aphaenogaster (Hymenoptera: Formicidae) in the Iberian Peninsula, with the description of a new species. Sociobiology. 65: 215-224.
Enlace
Doi: 10.13102/sociobiology.v65i2.2099

Resumen:

A phylogenetic tree of the Iberian Aphaenogaster species - except for A. splendida (Roger) - and a key to the worker caste of all Iberian Aphaenogaster species are proposed. The position of A. striativentris Forel and A. cardenai Espadaler is discussed, stating the possibility that this second species may belong to a new, undescribed genus. Aphaenogaster ulibeli n. sp. is described from the Iberian Peninsula. Its closest relatives are A. gibbosa (Latreille) and A. striativentris. Its habitat seems to be restricted to caducifolia forests in the Western Central Massif. © 2018 Universidade Estadual de Feira de Santana. All rights reserved.

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Earwigs and woolly apple aphids in integrated and organic apple orchards: responses of a generalist predator and a pest prey to local and landscape factors

Happe A.-K., Roquer-Beni L., Bosch J., Alins G., Mody K. (2018) Earwigs and woolly apple aphids in integrated and organic apple orchards: responses of a generalist predator and a pest prey to local and landscape factors. Agriculture, Ecosystems and Environment. 268: 44-51.
Enlace
Doi: 10.1016/j.agee.2018.09.004

Resumen:

Organic management, connective woody habitats, and landscape complexity are supposed to enhance beneficial arthropods and biological pest control in agro-ecosystems. We studied earwigs (Dermaptera: Forficulidae) as generalist predators and aphids (Hemiptera: Aphididae) as key pests serving as earwig prey in a total of 58 commercial apple orchards differing in management (integrated production (IP) versus organic) in Germany and Spain. We focused on the effects of local agri-environmental structures, orchard management, and composition of the surrounding landscape on earwig populations and on tree infestation by the woolly apple aphid (WAA), Eriosoma lanigerum. Surprisingly, the common earwig, Forficula auricularia, did not benefit from organic management in either country, and we found even slightly higher earwig abundances in IP than in organic orchards in Germany. In Spain, we found a negative impact of IP compared to organic management on abundance of the earwig Forficula pubescens, whereas orchard management did not affect the abundance of F. auricularia. The presence of woody habitats adjacent to the orchard reduced the abundance of F. auricularia in IP but not in organic orchards in Germany. We did not study the effects of woody habitats in Spain, where these structures were very scarce. There was no effect of high plant species richness at the orchard boundary or compositional landscape heterogeneity on earwig abundance in either country. In Germany, WAA infestation was very low and driven by landscape characteristics rather than orchard management. In Spain, WAA infestation differed strongly between management types (higher in organic orchards). There were no strong, consistent correlations between earwig abundance and WAA infestation in either country. Our study shows that adjacent woody structures and orchard management may affect earwigs in perennial cropping systems. The consequences of orchard management, however, seem to strongly depend on earwig species. Our study suggests that woody elements may serve as sink habitats – potentially attracting earwigs by providing alternative prey and shelter – in IP (but not in organic) orchards. © 2018 Elsevier B.V.

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Research frontiers for improving our understanding of drought-induced tree and forest mortality

Hartmann, H., Moura, C.F., Anderegg, W.R.L., Ruehr, N.K., Salmon, Y., Allen, C.D., Arndt, S.K., Breshears, D.D., Davi, H., Galbraith, D., Ruthrof, K.X., Wunder, J., Adams, H.D., Bloemen, J., Cailleret, M., Cobb, R., Gessler, A., Grams, T.E.E., Jansen, S., Kautz, M., Lloret, F., O'Brien, M. (2018) Research frontiers for improving our understanding of drought-induced tree and forest mortality. New Phytologist. 218: 15-28.
Enlace
Doi: 10.1111/nph.15048

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Landscape configurational heterogeneity by small-scale agriculture, not crop diversity, maintains pollinators and plant reproduction in western Europe

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.
Enlace
Doi: 10.1098/rspb.2017.2242

Resumen:

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.

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Assessing the role of Natura 2000 at maintaining dynamic landscapes in Europe over the last two decades: implications for conservation

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.
Enlace
Doi: 10.1007/s10980-018-0683-3

Resumen:

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.

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Spatial prioritisation of EU's LIFE-Nature programme to strengthen the conservation impact of Natura 2000

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.
Enlace
Doi: 10.1111/1365-2664.13116

Resumen:

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

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High Vcmax, Jmax and photosynthetic rates of Sonoran Desert species: Using nitrogen and specific leaf area traits as predictors in biochemical models

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.
Enlace
Doi: 10.1016/j.jaridenv.2018.04.006

Resumen:

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

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