Role of seed size, phenology, oogenesis and host distribution in the specificity and genetic structure of seed weevils (Curculio spp.) in mixed forests

Arias-Leclaire H., Bonal R., GarcÍa-LÓpez D., Espelta J.M. (2018) Role of seed size, phenology, oogenesis and host distribution in the specificity and genetic structure of seed weevils (Curculio spp.) in mixed forests. Integrative Zoology. 13: 267-279.
Link
Doi: 10.1111/1749-4877.12293

Abstract:

Synchrony between seed growth and oogenesis is suggested to largely shape trophic breadth of seed-feeding insects and ultimately to contribute to their co-existence by means of resource partitioning or in the time when infestation occurs. Here we investigated: (i) the role of seed phenology and sexual maturation of females in the host specificity of seed-feeding weevils (Curculio spp.) predating in hazel and oak mixed forests; and (ii) the consequences that trophic breadth and host distribution have in the genetic structure of the weevil populations. DNA analyses were used to establish unequivocally host specificity and to determine the population genetic structure. We identified 4 species with different specificity, namely Curculio nucum females matured earlier and infested a unique host (hazelnuts, Corylus avellana) while 3 species (Curculio venosus, Curculio glandium and Curculio elephas) predated upon the acorns of the 2 oaks (Quercus ilex and Quercus pubescens). The high specificity of C. nucum coupled with a more discontinuous distribution of hazel trees resulted in a significant genetic structure among sites. In addition, the presence of an excess of local rare haplotypes indicated that C. nucum populations went through genetic expansion after recent bottlenecks. Conversely, these effects were not observed in the more generalist Curculio glandium predating upon oaks. Ultimately, co-existence of weevil species in this multi-host-parasite system is influenced by both resource and time partitioning. To what extent the restriction in gene flow among C. nucum populations may have negative consequences for their persistence in a time of increasing disturbances (e.g. drought in Mediterranean areas) deserves further research. © 2017 The Authors. Integrative Zoology published by International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd

Read more

Increased anthropogenic disturbance and aridity reduce phylogenetic and functional diversity of ant communities in Caatinga dry forest

Arnan X., Arcoverde G.B., Pie M.R., Ribeiro-Neto J.D., Leal I.R. (2018) Increased anthropogenic disturbance and aridity reduce phylogenetic and functional diversity of ant communities in Caatinga dry forest. Science of the Total Environment. 631-632: 429-438.
Link
Doi: 10.1016/j.scitotenv.2018.03.037

Abstract:

Anthropogenic disturbance and climate change are major threats to biodiversity. The Brazilian Caatinga is the world's largest and most diverse type of seasonally dry tropical forest. It is also one of the most threatened, but remains poorly studied. Here, we analyzed the individual and combined effects of anthropogenic disturbance (three types: livestock grazing, wood extraction, and miscellaneous use of forest resources) and increasing aridity on taxonomic, phylogenetic and functional ant diversity in the Caatinga. We found no aridity and disturbance effects on taxonomic diversity. In spite of this, functional diversity, and to a lesser extent phylogenetic diversity, decreased with increased levels of disturbance and aridity. These effects depended on disturbance type: livestock grazing and miscellaneous resource use, but not wood extraction, deterministically filtered both components of diversity. Interestingly, disturbance and aridity interacted to shape biodiversity responses. While aridity sometimes intensified the negative effects of disturbance, the greatest declines in biodiversity were in the wettest areas. Our results imply that anthropogenic disturbance and aridity interact in complex ways to endanger biodiversity in seasonally dry tropical forests. Given global climate change, neotropical semi-arid areas are habitats of concern, and our findings suggest Caatinga conservation policies must prioritize protection of the wettest areas, where biodiversity loss stands to be the greatest. Given the major ecological relevance of ants, declines in both ant phylogenetic and functional diversity might have downstream effects on ecosystem processes, insect populations, and plant populations. © 2018 Elsevier B.V.

Read more

A framework for deriving measures of chronic anthropogenic disturbance: Surrogate, direct, single and multi-metric indices in Brazilian Caatinga

Arnan X., Leal I.R., Tabarelli M., Andrade J.F., Barros M.F., Câmara T., Jamelli D., Knoechelmann C.M., Menezes T.G.C., Menezes A.G.S., Oliveira F.M.P., de Paula A.S., Pereira S.C., Rito K.F., Sfair J.C., Siqueira F.F.S., Souza D.G., Specht M.J., Vieira L.A., Arcoverde G.B., Andersen A.N. (2018) A framework for deriving measures of chronic anthropogenic disturbance: Surrogate, direct, single and multi-metric indices in Brazilian Caatinga. Ecological Indicators. 94: 274-282.
Link
Doi: 10.1016/j.ecolind.2018.07.001

Abstract:

The development of multi-metric indices of chronic anthropogenic disturbance (CAD) from disparate disturbance indicators represents a major challenge for understanding the impacts of CAD on biodiversity, especially in tropical dry areas where livelihoods of local populations are highly dependent on natural resources. We present a conceptual framework for deriving variably integrated, multi-metric measures of CAD from disparate disturbance indicators. Our framework has three steps: (1) identifying the main sources of CAD in the target region, and quantifying them using data of varying levels of spatial and intensity precision; (2) classifying the sources of disturbance into general disturbance pressures, and deriving an index for each; and (3) combining the individual disturbance pressure indices into a fully integrated index that characterizes the overall level of CAD. We apply this framework to Catimbau National Park in the Brazilian Caatinga, using 12 primary data sources to derive disturbance pressure indices relating to livestock, wood extraction and people pressure. The meaningfulness of pressure and overall CAD indices were validated by reference to variation in ant communities. Our analysis revealed notable findings. First, indirect measures from the geographic and socio-ecological context were poorly correlated with direct, field-based measurements, and were therefore of questionable reliability. Second, the three main disturbance pressures were largely independent of each other, which points to complex patterns of resource use by local communities. Third, different weightings of component disturbance pressure indices had little influence on the Global index, making our Global CAD index somewhat insensitive to assessments of the relative importance of different disturbance pressures. Finally, our results caution against a reliance on multivariate ordination to derive integrated indices of disturbance from disparate data sources. Our multi-scale integration of disturbance data can facilitate the analysis of the resource use effects on biodiversity, contributing to effective conservation management and sustainable livelihood development. © 2018 Elsevier Ltd

Read more

Xylem hydraulic safety and construction costs determine tropical tree growth

B. Eller, C., de V. Barros, F., R.L. Bittencourt, P., Rowland, L., Mencuccini, M., S. Oliveira, R. (2018) Xylem hydraulic safety and construction costs determine tropical tree growth. Plant Cell and Environment. 41: 548-562.
Link
Doi: 10.1111/pce.13106

Abstract:

Assessing ecosystem isoprene emissions by hyperspectral remote sensing

Balzarolo M., Peñuelas J., Filella I., Portillo-Estrada M., Ceulemans R. (2018) Assessing ecosystem isoprene emissions by hyperspectral remote sensing. Remote Sensing. 10: 0-0.
Link
Doi: 10.3390/rs10071086

Abstract:

This study examined the relationship between foliar isoprene emissions, light use efficiency and photochemical reflectance index (PRI) throughout the canopy profile and explored the contribution of xanthophyll cycle pigments versus other carotenoid pigments to the isoprene/PRI relationship. Foliar isoprene emissions within the canopy profile were measured in a high-density poplar plantation in Flanders (Belgium) during the 2016 growing season. The results confirmed that PRI was a promising estimator of isoprene emissions at canopy level. Interestingly, xanthophyll cycle pigments contributed more to isoprene biosynthesis than chlorophyll and drove the isoprene/PRI relationship. The simple independent pigment index and novel defined indices, such as the hyperspectral isoprene index and simple hyperspectral isoprene index, showed promising results and could be suitable estimators of isoprene emissions due to their strong relationship with the xanthophyll pool. © 2018 by the authors.

Read more

Multi-temporal influence of vegetation on soil respiration in a droughtaffected forest

Barba, J., Lloret, F., Poyatos, R., Molowny-Horas, R., Yuste, J.C. (2018) Multi-temporal influence of vegetation on soil respiration in a droughtaffected forest. IForest. 11: 189-198.
Link
Doi: 10.3832/ifor2448-011

Abstract:

Loss of pollinators: evidences, causes and consequences [Pérdida de polinizadores: Evidencias, causas y consecuencias]

Bartomeus I., Bosch J. (2018) Loss of pollinators: evidences, causes and consequences [Pérdida de polinizadores: Evidencias, causas y consecuencias]. Ecosistemas. 27: 1-2.
Link
Doi: 10.7818/ECOS.1542

Abstract:

[No abstract available]

Read more

Trophic transfer from aquatic to terrestrial ecosystems: a test of the biogeochemical niche hypothesis

Bartrons M., Sardans J., Hoekman D., Peñuelas J. (2018) Trophic transfer from aquatic to terrestrial ecosystems: a test of the biogeochemical niche hypothesis. Ecosphere. 9: 0-0.
Link
Doi: 10.1002/ecs2.2338

Abstract:

Matter and energy flow across ecosystem boundaries. Transfers from terrestrial to aquatic ecosystems are frequent and have been widely studied, but the flow of matter from aquatic to terrestrial ecosystems is less known. Large numbers of midges emerge from some lakes in northern Iceland and fly to land. These lakes differ in their levels of eutrophication due to different intensities of geothermal warming and nutrient inputs. In the context of this material transfer from an aquatic to a terrestrial ecosystem, we investigated the relationships between the deposition of midges and the elemental composition and stoichiometry of organisms in low-productivity terrestrial ecosystems. We analyzed several terrestrial food webs in northeastern Iceland with similar food web compositions of terrestrial arthropods but different inputs of midges and analyzed the stoichiometric composition of the different trophic groups. Elemental composition differed among trophic groups and taxa much more than within each trophic group or taxa across the midge deposition gradient. Specifically, the change in N concentration was significant in plants (up to 70% increase in the site with maximum input) but not in predators, which had a more homeostatic elemental composition. These results thus show (1) a significant movement of matter and nutrients from an aquatic to a terrestrial habitat via the emergence of aquatic insects and the deposition of insect carcasses, (2) a larger impact on the elemental composition of plants than arthropods, and (3) support for the biogeochemical niche hypothesis, which predicts that different species should have a specific elemental composition, stoichiometry, and allocation as a consequence of their particular metabolism, physiology, and structure. © 2018 The Authors.

Read more

Citizen Science: A Gateway for Innovation in Disease-Carrying Mosquito Management?

Bartumeus F., Oltra A., Palmer J.R.B. (2018) Citizen Science: A Gateway for Innovation in Disease-Carrying Mosquito Management?. Trends in Parasitology. : 0-0.
Link
Doi: 10.1016/j.pt.2018.04.010

Abstract:

Traditional methods for tracking disease-carrying mosquitoes are hitting budget constraints as the scales over which they must be implemented grow exponentially. Citizen science offers a novel solution to this problem but requires new models of innovation in the public health sector. © 2018 Elsevier Ltd

Read more

All in One: Encoding spatio-temporal big data in XML, JSON, and RDF without information loss

Baumann P., Hirschorn E., Maso J., Merticariu V., Misev D. (2018) All in One: Encoding spatio-temporal big data in XML, JSON, and RDF without information loss. Proceedings - 2017 IEEE International Conference on Big Data, Big Data 2017. 2018-January: 1-10.
Link
Doi: 10.1109/BigData.2017.8258326

Abstract:

With the unprecedented availability of continuously observed and generated data there is a likewise unprecedented potential for new and timely insights; yet, benefits are not fully leveraged as of today. The plethora of formats in combination with heterogeneous services remains is an obstacle-e.g., image services prefer binary formats, SPARQL endpoints like to think in RDF triples, and browsers integrate JSON data smoothly. We propose a model-based multi-encoding approach for overcoming the limitations of individual formats while still supporting their use. Concretely, this approach is being followed by the OGC Coverage Implementation Schema (CIS) standard which establishes a concrete, interoperable data model unifying n-D spatiotemporal regular and irregular grids, point clouds, and meshes. We describe how independence from data formats is achieved, in particular for three practically relevant formats-XML, JSON, and RDF-, thereby fostering integration of hitherto rather separate application domains. © 2017 IEEE.

Read more

Pages