Limited acclimation in leaf anatomy to experimental drought in tropical rainforest trees

Binks, O., Meir, P., Rowland, L., Da Costa, A.C.L., Vasconcelos, S.S., De Oliveira, A.A.R., Ferreira, L., Mencuccini, M. (2016) Limited acclimation in leaf anatomy to experimental drought in tropical rainforest trees. Tree Physiology. 36: 1550-1561.
Link
Doi: 10.1093/treephys/tpw078

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Diversity in insect seed parasite guilds at large geographical scale: The roles of host specificity and spatial distance

Bonal R., Espelta J.M., Muñoz A., Ortego J., Aparicio J.M., Gaddis K., Sork V.L. (2016) Diversity in insect seed parasite guilds at large geographical scale: The roles of host specificity and spatial distance. Journal of Biogeography. : 0-0.
Link
Doi: 10.1111/jbi.12733

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Aim: Host specificity within plant-feeding insects constitutes a fascinating example of natural selection that promotes inter-specific niche segregation. If specificity is strong, composition of local plant parasitic insect guilds is largely dependent on the presence and prevalence of the preferred hosts. Alternatively, if it is weak or absent, historic and stochastic demographic processes may drive the structuring of insect communities. We assessed whether the species composition of acorn feeding insects (Curculio spp. guilds) and their genetic variation change geographically according to the local host community. Location: An 800 km transect across California, USA. Methods: We used DNA taxonomy to detect potential Curculio cryptic speciation and assessed intra-specific genetic structure among sampling sites. We monitored larval performance on different hosts, by measuring the weight of each larva upon emerging from the acorn. Our phylogenetic and spatial analyses disentangled host specificity and geographical effects on Curculio community composition and genetic structure. Results: DNA taxonomy revealed no specialized cryptic species. Californian Curculio spp. were sister taxa that did not segregate among Quercus species or, at a deeper taxonomic level, between red and white oaks. Curculio species turnover and intra-specific genetic differentiation increased with geographical distance among localities irrespective of local oak species composition. Moreover, larval performance did not differ among oak species or acorn sizes when controlling for the effect of the locality. Main conclusions: Historical processes have contributed to the structuring of acorn weevil communities across California. Trophic niche overlapped among species, indicating that ecologically similar species can co-exist. Acorn crop inter-annual variability and unpredictability in mixed oak forests may have selected against narrow specialization, and facilitated co-existence by means of an inter-specific time partitioning of the resources. Wide-scale geographical records of parasitic insects and their host plants are necessary to understand the processes underlying species diversity. © 2016 John Wiley & Sons Ltd.

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Woody plant cover estimation in drylands from Earth Observation based seasonal metrics

Brandt M., Hiernaux P., Tagesson T., Verger A., Rasmussen K., Diouf A.A., Mbow C., Mougin E., Fensholt R. (2016) Woody plant cover estimation in drylands from Earth Observation based seasonal metrics. Remote Sensing of Environment. 172: 28-38.
Link
Doi: 10.1016/j.rse.2015.10.036

Abstract:

From in situ measured woody cover we develop a phenology driven model to estimate the canopy cover of woody species in the Sahelian drylands at 1km scale. The model estimates the total canopy cover of all woody phanerophytes and the concept is based on the significant difference in phenophases of dryland trees, shrubs and bushes as compared to that of the herbaceous plants. Whereas annual herbaceous plants are only green during the rainy season and senescence occurs shortly after flowering towards the last rains, most woody plants remain photosynthetically active over large parts of the year. We use Moderate Resolution Imaging Spectroradiometer (MODIS) and Satellite pour l'Observation de la Terre (SPOT) - VEGETATION (VGT) Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) time series and test 10 metrics representing the annual FAPAR dynamics for their ability to reproduce in situ woody cover at 43 sites (163 observations between 1993 and 2013) in the Sahel. Both multi-year field data and satellite metrics are averaged to produce a steady map. Multiple regression models using the integral of FAPAR from the onset of the dry season to the onset of the rainy season, the start date of the growing season and the rate of decrease of the FAPAR curve achieve a cross validated r2/RMSE (in % woody cover) of 0.73/3.0 (MODIS) and 0.70/3.2 (VGT). The extrapolation to Sahel scale shows agreement between VGT and MODIS at an almost nine times higher woody cover than in the global tree cover product MOD44B which only captures trees of a certain minimum size. The derived woody cover map of the Sahel is made publicly available and represents an improvement of existing products and a contribution for future studies of drylands quantifying carbon stocks, climate change assessment, as well as parametrization of vegetation dynamic models. © 2015 Elsevier Inc.

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Factors influencing the perception of ecosystem services in Ecuadorian tropical dry forests [Factores que influyen en la percepción de servicios de los ecosistemas de los bosques secos del sur del Ecuador]

Briceño, J., Iñiguez-Gallardo, V., Ravera, F. (2016) Factors influencing the perception of ecosystem services in Ecuadorian tropical dry forests [Factores que influyen en la percepción de servicios de los ecosistemas de los bosques secos del sur del Ecuador]. Ecosistemas. 25: 46-58.
Link
Doi: 10.7818/ECOS.2016.25-2.06

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Self-thinning in four pine species: an evaluation of potential climate impacts

Brunet-Navarro, P., Sterck, F.J., Vayreda, J., Martinez-Vilalta, J., Mohren, G.M.J. (2016) Self-thinning in four pine species: an evaluation of potential climate impacts. Annals of Forest Science. 73: 1025-1034.
Link
Doi: 10.1007/s13595-016-0585-y

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Towards a common methodology for developing logistic tree mortality models based on ring-width data

Cailleret, M., Igler, C.I.B., Mann, H.B., Camarero, J.J., Cufar, K., Davi, H., Mészáros, I., Inunno, F.M., Peltoniemi, M., Robert, E.M.R., Suarez, M.L., Tognett, R.I., Martínez-Vilalta, J. (2016) Towards a common methodology for developing logistic tree mortality models based on ring-width data. Ecological Applications. 26: 1827-1841.
Link
Doi: 10.1890/15-1402.1

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A synthesis of radial growth patterns preceding tree mortality

Cailleret, M., Jansen, S., Robert, E.M.R., Desoto, L., Aakala, T., Antos, J.A., Beikircher, B., Bigler, C., Bugmann, H., Caccianiga, M., Čada, V., Camarero, J.J., Cherubini, P., Cochard, H., Coyea, M.R., Čufar, K., Das, A.J., Davi, H., Delzon, S., Dorman, M., Gea-Izquierdo, G., Gillner, S., Haavik, L.J., Hartmann, H., Hereş, A.-M., Hultine, K.R., Janda, P., Kane, J.M., Kharuk, V.I., Kitzberger, T., Klein, T., Kramer, K., Lens, F., Levanic, T., Linares Calderon, J.C., Lloret, F., Lobo-Do-Vale, R., Lombardi, F., López Rodríguez, R., Mäkinen, H., Mayr, S., Mészáros, I., Metsaranta, J.M., Minunno, F., Oberhuber, W., Papadopoulos, A., Peltoniemi, M., Petritan, A.M., Rohner, B., Sangüesa-Barreda, G., Sarris, D., Smith, J.M., Stan, A.B., Sterck, F., Stojanović, D.B., Suarez, M.L., Svoboda, M., Tognetti, R., Torres-Ruiz, J.M., Trotsiuk, V., Villalba, R., Vodde, F., Westwood, A.R., Wyckoff, P.H., Zafirov, N., Martínez-Vilalta, J. (2016) A synthesis of radial growth patterns preceding tree mortality. Global Change Biology. : 0-0.
Link
Doi: 10.1111/gcb.13535

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Beyond the rand flora pattern: Phylogeny and biogeographical history of Volutaria (compositae)

Calleja J.A., Garcia-Jacas N., Roquet C., Susanna A. (2016) Beyond the rand flora pattern: Phylogeny and biogeographical history of Volutaria (compositae). Taxon. 65: 315-332.
Link
Doi: 10.12705/652.8

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The Rand Flora describes the disjunct phytogeographical pattern of a wide range of taxa distributed at the periphery of Africa and adjacent islands, as well as the Arabian Peninsula. We focused on Volutaria (Compositae: Cardueae: Centaurineae), a genus of ca. 18 species that conforms to the Rand Flora pattern; yet its phylogeny, interspecific relationships, and biogeographical history remain poorly known. We aim to construct a robust phylogeny that will allow us to interpret the biogeography and the diversification of this genus, together with its present distribution pattern, and to ascertain whether the latter arose by single or multiple gradual expansion processes, vicariance, or long-distance dispersal events. We sampled all extant Volutaria species, covering its entire geographical range, and generated sequences of nuclear-ribosomal DNA and three plastid regions, which were analyzed by Bayesian inference and maximum parsimony. Samples yielding more than one sequence in direct sequencing were cloned. Historical biogeographical analysis was performed using BioGeoBEARS based on a phylogeny dated using a relaxed molecular clock calibrated with a previous dating undertaken for the tribe Cardueae. Volutaria is a monophyletic taxon, having an Asian ancestor, and its present diversity is represented by four main clades that emerged in the Miocene. The earliest taxa of Volutaria to diverge are preserved in North Africa, whereas clades that diverged more recently have done so on both sides of the Sahara. This process involved both ancient and recent interspecific introgression and hybridization events, as indicated by incongruities between plastid and nuclear results, and by cloning of the ITS region. The distribution of Volutaria around two diversity poles conforms to the Rand Flora pattern, but this did not arise by a single event or process. Instead, the historical biogeography of Volutaria involves at least one migration wave from east to west, followed by the extinction of ancestral taxa and subsequent expansion and retraction events, together with speciation processes on both sides of the Sahara. The intense tectonic and climatic changes that occurred in North Africa and western Asia throughout the Neogene and Pleistocene periods might explain the present diversity and distribution pattern of the genus. © International Association for Plant Taxonomy (IAPT) 2016.

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Epiphytic bryophyte communities of Prunus lusitanica Iberian forests: Biogeographic islands shaped by regional climates

Calleja J.A., Mingorance L., Lara F. (2016) Epiphytic bryophyte communities of Prunus lusitanica Iberian forests: Biogeographic islands shaped by regional climates. Cryptogamie, Bryologie. 37: 53-85.
Link
Doi: 10.7872/cryb/v37.iss1.2016.53

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Epiphytic communities of Iberian forests remain partly unknown and most studies have focused on the dominant oak forests. We provide a comprehensive analysis and interpretation of the epiphytic bryophyte communities of forests dominated by the Tertiary relict evergreen cherry Prunus lusitanica. This type of forest, scattered in the western and northern half of the Iberian Peninsula, harbours a noticeable richness of epiphytic bryophytes, including an outstanding number of liverwort species. Their floristic composition varies markedly across the Peninsula yet is driven by the main climate patterns prevailing in the area. Multivariate analyses (TWINSPAN, CCA) render two main groups of epiphytic communities with their respective indicator species. Both groups share a high proportion of non-Mediterranean species, a circumstance that is most remarkable in the forests that fall within the Mediterranean Region, which could be considered as ecological refuges or biogeographic islands. © 2016 Adac. Tous droits réservés.

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Back to the Future: The Responses of Alpine Treelines to Climate Warming are Constrained by the Current Ecotone Structure

Camarero, J.J., Linares, J.C., García-Cervigón, A.I., Batllori, E., Martínez, I., Gutiérrez, E. (2016) Back to the Future: The Responses of Alpine Treelines to Climate Warming are Constrained by the Current Ecotone Structure. Ecosystems. : 1-18.
Link
Doi: 10.1007/s10021-016-0046-3

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