Mudanças climáticas previstas para o final do século afetam o desempenho e o desenvolvimento esquelético de larvas de tambaqui (Colossoma macropomum)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Investigating South American biogeographic history using patterns of skull shape variation on Cerdocyon thous (Mammalia: Canidae)

Patterns of geographic variation of the canid Cerdocyon thous have historically been obscured by its remarkable intraspecific morphological variability. The observed distribution is highly associated with phytophysiognomy, a feature considered highly dynamic along geological time. In the present study, we tested whether vegetation distribution during the Holocene Glacial Maximum of South America (HGM) explains the patterns of morphological variation within Cerdocyon thous. The species was divided in groups according to paleohabitats that could support their presence during the HGM, and then tested for differences in skull morphometrics. The results obtained demonstrate that the climatic changes during the HGM influenced the population structure of this species, resulting in the establishment of geographical groups with different degrees of morphological cohesion. Higher morphological cohesion found in the Northern group might be explained by the marked discontinuity between its geographical range and the rest of the species`distribution. The Eastern and Southern morphological divergence is less striking and, although this could be related to past vegetation distribution, the disappearance of those barriers leads to a population structure that could be slowly breaking down. (C) 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 77-84.

Carbon and nitrogen stock and fluxes in coastal Atlantic Forest of southeast Brazil: potential impacts of climate change on biogeochemical functioning

The Atlantic Forest is one of the most important biomes of Brazil. Originally covering approximately 1.5 million of km(2), today this area has been reduced to 12% of its original size. Climate changes may alter the structure and the functioning of this tropical forest. Here we explore how increases in temperature and changes in precipitation distribution could affect dynamics of carbon and nitrogen in coastal Atlantic Forest of the southeast region of Brazil The main conclusion of this article is that the coastal Atlantic Forest has high stocks of carbon and nitrogen above ground, and especially, below ground. An increase in temperature may transform these forests from important carbon sinks to carbon sources by increasing loss of carbon and nitrogen to the atmosphere. However, this conclusion should be viewed with caution because it is based on limited information. Therefore, more studies are urgently needed to enable us to make more accurate predictions.

GEOGRAPHICAL GENETIC STRUCTURING AND PHENOTYPIC VARIATION IN THE VELLOZIA HIRSUTA (VELLOZIACEAE) OCHLOSPECIES COMPLEX

Premise of the study: Vellozia hirsuta forms a complex presenting wide morphological and anatomical variation, resulting in five specific names and 14 morpho-anatomical patterns occurring in disjunct populations. We carried out a phylogeographical study to investigate the existence of correlation among the genetic and morphological patterns within this complex, and to determine whether it is composed of various species or should be treated as an ochlospecies, a species having widely polymorphic and weakly polytypic complex variation, with morphological characteristics varying independently. Methods: We carried out phylogeographical analyses using cpDNA rpl32F-trnL intergenic region. Key results: We found 20 haplotypes in 23 populations sampled. The populations are genetically structured (Phi(ST) = 0.818) into four phylogeographical groups demonstrating geographical structuring but with no correlation with morpho-anatomical patterns. Our analyses do not support recognizing any of the species now synonymized under Vellozia hirsuta. The northern populations were the most genetically differentiated and could be considered a distinct taxon, as they are also morphologically different. Conclusions: It is recommended that Vellozia hirsuta be considered a single enormously variable species. The patterns of variation within V. hirsuta probably are related to climatic changes that occurred during the Pleistocene Epoch in tropical Brazil when reductions in forest cover favored the expansion of V. hirsuta populations into extensive lowland areas. The expansion of forest cover at the end of the glaciations would have again restricted the occurrence of campos rupestres vegetation to high elevations, which constitute the current centers of diversity of this species.

Can climate shape flight activity patterns of Plebeia remota (Hymenoptera, Apidae)?

Flight activity of foragers of four colonies of Plebeia remota (Holmberg, 1903) was registered from December 1998 to December 1999, using an automated system (photocells and PLC system). The colonies originated from two different regions: Cunha, state of Sao Paulo, and Prudentopolis, state of Parana, Brazil. Flight activity was influenced by different climatic factors in each season. In the summer, the intensity of the correlations between flight activity and climatic factors was smaller than in the other seasons. During the autumn and winter, solar radiation was the factor that most influenced flight activity, while in the spring, this activity was influenced mainly by temperature. Except in the summer, the various climatic factors similarly influenced flight activity of all of the colonies. Flight activity was not affected by geographic origin of the colonies. Information concerning seasonal differences in flight activity of P. remota will be useful for prediction of geographic distribution scenarios under climatic changes.

Activity, movement and secretive behavior of a threatened arboreal folivore, the thin-spined porcupine, in the Atlantic forest of southern Bahia, Brazil

Activity and behavior patterns are important components of a given species ecological strategy, as they have profound implications for its survival and reproduction. Here, we studied the activities, movements and secretive behavior of the thin-spined porcupine Chaetomys subspinosus (Rodentia: Erethizontidae), a threatened arboreal folivore in the Brazilian Atlantic rainforest. We aimed to ascertain the behavioral strategies used by this species as well as its responses to seasonal and daily climatic changes. Four radio-collared individuals were followed continuously for 72-h in the summer and winter, as well as during 146 half-night sessions conducted from April 2005 to September 2006 in forest remnants in southern Bahia. The thin-spined porcupines were nocturnally active (17:30-05:40 h), with peaks in activity and movement from 19:00 to 20:00 h and 03:00 to 04:00 h. Animals followed a circadian rhythm of activity during both the summer and winter. During the diel cycle, porcupines spent 74% of their time resting, 14% feeding, 11% traveling and 2% performing other activities. Distance traveled during the diel cycle averaged 277.5 +/- 117.9 m sd. The mean movement rate during the night was 21.6 +/- 30.1 m/h sd. No significant changes in activity budget or daily distance traveled were observed between seasons, most likely in response to the low fluctuations in climatic conditions and food availability throughout the year in the study region. However, rainfall reduced the time that the animals spent on feeding activities and explained day-to-day differences in activity budgets. We also provide details about intraspecific interactions and defecation behavior. Our observations confirmed that thin-spined porcupines, similar to other folivorous species, present low activity levels and short daily movements, and have adopted various cryptic habits, such as nocturnality, a solitary lifestyle, the tendency to leave offspring alone most of the time and defecation in concealed latrines.

Can climate shape flight activity patterns of Plebeia remota Hymenoptera, Apidae)?

Flight activity of foragers of four colonies of Plebeia remota (Holmberg, 1903) was registered from December 1998 to December 1999, using an automated system (photocells and PLC system). The colonies originated from two different regions: Cunha, state of São Paulo, and Prudentópolis, state of Paraná, Brazil. Flight activity was influenced by different climatic factors in each season. In the summer, the intensity of the correlations between flight activity and climatic factors was smaller than in the other seasons. During the autumn and winter, solar radiation was the factor that most influenced flight activity, while in the spring, this activity was influenced mainly by temperature. Except in the summer, the various climatic factors similarly influenced flight activity of all of the colonies. Flight activity was not affected by geographic origin of the colonies. Information concerning seasonal differences in flight activity of P. remota will be useful for prediction of geographic distribution scenarios under climatic changes.

Mesoscale dynamics and boundary-layer structure in topographically forced low-level jets

Two types of mesoscale wind-speed jet and their effects on boundary-layer structure were studied. The first is a coastal jet off the northern California coast, and the second is a katabatic jet over Vatnajökull, Iceland. Coastal regions are highly populated, and studies of coastal meteorology are of general interest for environmental protection, fishing industry, and for air and sea transportation. Not so many people live in direct contact with glaciers but properties of katabatic flows are important for understanding glacier response to climatic changes. Hence, the two jets can potentially influence a vast number of people. Flow response to terrain forcing, transient behavior in time and space, and adherence to simplified theoretical models were examined. The turbulence structure in these stably stratified boundary layers was also investigated. Numerical modeling is the main tool in this thesis; observations are used primarily to ensure a realistic model behavior. Simple shallow-water theory provides a useful framework for analyzing high-velocity flows along mountainous coastlines, but for an unexpected reason. Waves are trapped in the inversion by the curvature of the wind-speed profile, rather than by an infinite stability in the inversion separating two neutral layers, as assumed in the theory. In the absence of blocking terrain, observations of steady-state supercritical flows are not likely, due to the diurnal variation of flow criticality. In many simplified models, non-local processes are neglected. In the flows studied here, we showed that this is not always a valid approximation. Discrepancies between simulated katabatic flow and that predicted by an analytical model are hypothesized to be due to non-local effects, such as surface inhomogeneity and slope geometry, neglected in the theory. On a different scale, a reason for variations in the shape of local similarity scaling functions between studies is suggested to be differences in non-local contributions to the velocity variance budgets.

Evoluzione Morfotettonica delle Aree Alpine "Sempione" e "Brennero" attraverso Studi Termocronologici di bassa temperatura

E’ mostrata l’analisi e la modellazione di dati termocronologici di bassa temperatura da due regioni Alpine: il Sempione ed il Brennero. Le faglie distensive presenti bordano settori crostali profondi appartenenti al dominio penninico: il duomo metamorfico Lepontino al Sempione e la finestra dei Tauri al Brennero. I dati utilizzati sono FT e (U-Th)/He su apatite. Per il Sempione i dati provengono dalla bibliografia; per il Brennero si è provveduto ad un nuovo campionamento, sia in superficie che in sotterraneo. Gli attuali lavori per la galleria di base del Brennero (BBT), hanno consentito, per la prima volta, di raccogliere dati di FT e (U-Th)/He in apatite in sottosuolo per la finestra dei Tauri occidentale. Le analisi sono state effettuate tramite un codice a elementi finiti, Pecube, risolvente l’equazione di diffusione del calore per una topografia evolvente nel tempo. Il codice è stato modificato per tener conto dei dati sotterranei. L’inversione dei dati è stata effettuata usando il Neighbourhood Algorithm (NA), per ottenere il più plausibile scenario di evoluzione morfotettonico. I risultati ottenuti per il Sempione mostrano: ipotetica evoluzione dello stile tettonico della faglia del Sempione da rolling hinge a low angle detachment a 6.5 Ma e la cessazione dell’attività a 3 Ma; costruzione del rilievo fino a 5.5 Ma, smantellamento da 5.5 Ma ad oggi, in coincidenza dei cambiamenti climatici Messiniani e relativi all’inizio delle maggiori glaciazioni; incremento dell’esumazione da 0–0.6 mm/anno a 0.6–1.2 mm/anno a 2.4 Ma nell’emisfero settentrionale. I risultati al Brennero mostrano: maggiore attività tettonica della faglia del Brennero (1.3 mm/anno), maggiore attività esumativa (1–2 mm/anno) prima dei 10 Ma; crollo dell’attività della faglia del Brennero fra 10 Ma e oggi (0.1 mm/anno) e dell’attività esumativa nello stesso periodo (0.1–0.3 mm/anno); nessun aumento del tasso esumativo o variazioni topografiche negli ultimi 5 Ma.

Patogeni e zecche vettrici: studio epidemiologico in parchi pubblici dell'Emilia Romagna

Le malattie trasmesse da zecche sono un importante problema sia per la salute animale che per quella umana e negli ultimi decenni hanno aumentato notevolmente la loro diffusione, in seguito ai cambiamenti climatici, che hanno permesso la distribuzione delle zecche in aree prima non interessate. Per tale motivo si è deciso di effettuare un’indagine sulla diffusione delle zecche e sui patogeni da loro trasmessi, mediante campionamenti sia a livello ambientale, sia su animali e umani infestati in quattro siti di tre parchi dell’Emilia Romagna, dove non risultavano precedenti segnalazioni, nelle province di Bologna e Ravenna, da Aprile a Ottobre 2010. In totale sono state raccolte 8212 zecche. Dall’ambiente sono state campionate 6734 larve, 1344 ninfe, 61 adulti; dagli animali e da persone sono stati raccolti 68 adulti e 5 ninfe appartenenti a diverse specie di Ixodidae. Sono state condotte analisi sull’abbondanza delle zecche nelle diverse aree di raccolta, in funzione del periodo di campionamento, della temperatura e dell’umidità relativa misurata a 5 cm dal suolo al momento del campionamento e della vegetazione. Su tutti gli individui adulti e su pool di ninfe e di larve, per un totale di 393 campioni, sono state condotte analisi di tipo molecolare per la ricerca di piroplasmi, Anaplasma phagocytophilum e Borrelia burgdorferi s.l. Attraverso la PCR e il sequenziamento, è emerso che il 7,6% dei campioni era positivo per piroplasmi, tra i quali è stata riscontrata anche la presenza delle specie zoonosiche Babesia EU1 e B. divergens. La real-time PCR eseguita solo sui campioni costituiti da ninfe e adulti ha evidenziato una prevalenza del 9,2% per A. phagocytophilum e del 21,6% per B. burgdorferi s.l. Su questi patogeni sono state quindi condotte analisi di tipo filogenetico. In alcuni campioni sono state riscontrate coinfezioni con combinazioni di due patogeni contemporaneamente.

Reciproche influenze tra geomorfologia e popolamento antico presso le piane di foce dei fiumi tirrenici. Il caso del Fiume Garigliano

La Piana di foce del Garigliano (al confine tra Lazio e Campania) è caratterizzata, fino ad epoche recenti, dalla presenza di aree palustri e umide. Lo studio in corso cerca di ricostruire l’evoluzione dell’ambiente costiero mettendolo in relazione alla presenza dell’uomo, alla gestione del territorio, alle vicende storiche e alle variazioni climatiche utilizzando molteplici metodologie tipiche della geoarcheologia. Si tratta di un approccio multidisciplinare che cerca di mettere insieme analisi tipiche dell’archeologia, della topografia antica, della geomorfologia, della geologia e della paleobotanica. Fino all’età del Ferro l’unica traccia di popolamento viene da Monte d’Argento, uno sperone roccioso isolato lungo la costa, posto al limite occidentale di un ambiente sottostante che sembra una palude chiusa e isolata da apporti sedimentari esterni. Con il passaggio all’età del ferro si verifica un mutamento ambientale con la fine della grande palude e la formazione di una piccola laguna parzialmente comunicante con il mare. L’arrivo dei romani alla fine del III secolo a.C. segna la scomparsa dei grandi centri degli Aurunci e la deduzione di tre colonie (Sessa Aurunca, Sinuessa, Minturno). Le attività di sistemazione territoriale non riguardarono però le aree umide costiere, che non vennero bonificate o utilizzate per scopi agricoli, ma mantennero la loro natura di piccoli laghi costieri. Quest’epoca è dunque caratterizzata da una diffusione capillare di insediamenti, basati su piccole fattorie o installazioni legate allo sfruttamento agricolo. Poche sono le aree archeologiche che hanno restituito materiali successivi al II-III secolo d.C. La città resta comunque abitata fino al VI-VII secolo, quando l’instabilità politica e l’impaludamento dovettero rendere la zona non troppo sicura favorendo uno spostamento verso le zone collinari. Un insediamento medievale è attestato solo a Monte d’Argento e una frequentazione saracena dell’inizio del IX secolo è riportata dalle fonti letterarie, ma non vi è ancora nessuna documentazione archeologica.

Mineral dust mobilisation, transport, and deposition in different climate epochs

Mineral dust is an important component of the Earth's climate system and provides essential nutrientsrnto oceans and rain forests. During atmospheric transport, dust particles directly and indirectly influencernweather and climate. The strength of dust sources and characteristics of the transport, in turn, mightrnbe subject to climatic changes. Earth system models help for a better understanding of these complexrnmechanisms.rnrnThis thesis applies the global climate model ECHAM5/MESSy Atmospheric Chemistry (EMAC) for simulationsrnof the mineral dust cycle under different climatic conditions. The prerequisite for suitable modelrnresults is the determination of the model setup reproducing the most realistic dust cycle in the recentrnclimate. Simulations with this setup are used to gain new insights into properties of the transatlanticrndust transport from Africa to the Americas and adaptations of the model's climate forcing factors allowrnfor investigations of the impact of climatic changes on the dust cycle.rnrnIn the first part, the most appropriate model setup is determined through a number of sensitivity experiments.rnIt uses the dust emission parametrisation from Tegen et al. 2002 and a spectral resolutionrnof T85, corresponding to a horizontal grid spacing of about 155 km. Coarser resolutions are not able tornaccurately reproduce emissions from important source regions such as the Bodele Depression in Chad orrnthe Taklamakan Desert in Central Asia. Furthermore, the representation of ageing and wet deposition ofrndust particles in the model requires a basic sulphur chemical mechanism. This setup is recommended forrnfuture simulations with EMAC focusing on mineral dust.rnrnOne major branch of the global dust cycle is the long-range transport from the world's largest dustrnsource, the Sahara, across the Atlantic Ocean. Seasonal variations of the main transport pathways to thernAmazon Basin in boreal winter and to the Caribbean during summer are well known and understood,rnand corroborated in this thesis. Both Eulerian and Lagrangian methods give estimates on the typicalrntransport times from the source regions to the deposition on the order of nine to ten days. Previously, arnhuge proportion of the dust transported across the Atlantic Ocean has been attributed to emissions fromrnthe Bodele Depression. However, the contribution of this hot spot to the total transport is very low inrnthe present results, although the overall emissions from this region are comparable. Both model resultsrnand data sets analysed earlier, such as satellite products, involve uncertainties and this controversy aboutrndust transport from the Bodele Depression calls for future investigations and clarification.rnrnAforementioned characteristics of the transatlantic dust transport just slightly change in simulationsrnrepresenting climatic conditions of the Little Ice Age in the middle of the last millennium with meanrnnear-surface cooling of 0.5 to 1 K. However, intensification of the West African summer monsoon duringrnthe Little Ice Age is associated with higher dust emissions from North African source regions and wetterrnconditions in the Sahel. Furthermore, the Indian Monsoon and dust emissions from the Arabian Peninsula,rnwhich are affected by this circulation, are intensified during the Little Ice Age, whereas the annual globalrndust budget is similar in both climate epochs. Simulated dust emission fluxes are particularly influencedrnby the surface parameters. Modifications of the model do not affect those in this thesis, to be able tornascribe all differences in the results to changed forcing factors, such as greenhouse gas concentrations.rnDue to meagre comparison data sets, the verification of results presented here is problematic. Deeperrnknowledge about the dust cycle during the Little Ice Age can be obtained by future simulations, based onrnthis work, and additionally using improved reconstructions of surface parameters. Better evaluation ofrnsuch simulations would be possible by refining the temporal resolution of reconstructed dust depositionrnfluxes from existing ice and marine sediment cores.

The Mountain Research Initiative Reaches Outward and Clombs Upward

Mountain regions provide a multitude of goods and services for much of humanity (Price and Butt 2000; Becker and Bugmann 2001), especially in the realms of water supply, biodiversity, and other ecosystem services (Schimel et al 2002; Körner et al 2005; Viviroli et al 2007; Viviroli et al 2011). However, the future ability of mountain regions to provide goods and services to both highland and lowland residents is seriously threatened by climatic changes, environmental pollution, unsustainable management of natural resources, and serious gaps in understanding of mountain systems (Huber et al 2005). Disciplinary, interdisciplinary, and transdisciplinary research is required to maintain these goods and services in the face of these forces. The global mountain research community, however, has historically operated at a suboptimal level because of insufficient communication across geographic and linguistic barriers, less than desirable coordination of research frameworks, and a lack of funding.

Causes and consequences of past and projected Scandinavian summer temperatures, 500-2100 AD

Tree rings dominate millennium-long temperature reconstructions and many records originate from Scandinavia, an area for which the relative roles of external forcing and internal variation on climatic changes are, however, not yet fully understood. Here we compile 1,179 series of maximum latewood density measurements from 25 conifer sites in northern Scandinavia, establish a suite of 36 subset chronologies, and analyse their climate signal. A new reconstruction for the 1483–2006 period correlates at 0.80 with June–August temperatures back to 1860. Summer cooling during the early 17th century and peak warming in the 1930s translate into a decadal amplitude of 2.9°C, which agrees with existing Scandinavian tree-ring proxies. Climate model simulations reveal similar amounts of mid to low frequency variability, suggesting that internal ocean-atmosphere feedbacks likely influenced Scandinavian temperatures more than external forcing. Projected 21st century warming under the SRES A2 scenario would, however, exceed the reconstructed temperature envelope of the past 1,500 years.

A Comparative Chronology of the History of Eastern Europe and the Climate

Two main areas were examined in this project: * The detailed climatic history of the second part of the Holocene (approximately the last 5500 calendar years) for the Zapadnodvinskaya lowland, making it possible to reconstruct general climatic changes in eastern Europe (taking other palynological, dendrochronological, historical and instrumental data into account). * The most important historical events for the period of the 9th-17th centuries that had an impact on Russian history. The comparative chronology of the main climatic changes and events of Russian social history showed that as local climatic conditions became worse (i.e. falling average annual temperature or precipitation rate) the density of significant events in society rose. This suggests that climatic deterioration is both a stimulus and an outstanding factor in social development.