Climate change is affecting altitudinal migrants and hibernating species

Calendar date of the beginning of the growing season at high altitude in the Colorado Rocky Mountains is variable but has not changed significantly over the past 25 years. This result differs from growing evidence from low altitudes that climate change is resulting in a longer growing season, earlier migrations, and earlier reproduction in a variety of taxa. At our study site, the beginning of the growing season is controlled by melting of the previous winter's snowpack. Despite a trend for warmer spring temperatures the average date of snowmelt has not changed, perhaps because of the trend for increased winter precipitation. This disjunction between phenology at low and high altitudes may create problems for species, such as many birds, that migrate over altitudinal gradients. We present data indicating that this already may be true for American robins, which are arriving 14 days earlier than they did in 1981; the interval between arrival date and the first date of bare ground has grown by 18 days. We also report evidence for an effect of climate change on hibernation behavior; yellow-bellied marmots are emerging 38 days earlier than 23 years ago, apparently in response to warmer spring air temperatures. Migrants and hibernators may experience problems as a consequence of these changes in phenology, which may be exacerbated if climate models are correct in their predictions of increased winter snowfall in our study area. The trends we report for earlier formation of permanent snowpack and for a longer period of snow cover also have implications for hibernating species.

Seaward limit of significant sand transport by waves : an annual zonation for seasonal profiles /

"January 1981."

Altitudinal variation in behavioural thermoregulation: Local adaptation vs. plasticity in California grasshoppers

We investigated the adaptive significance of behavioural thermoregulation in univoltine populations of the grasshopper Melanoplus sanguinipes along an altitudinal gradient in California using laboratory tests of animals raised under different temperatures. Trials consisted of continuous body temperature measurements with semi-implanted microprobes in a test arena, and observation and simultaneous recording of behavioural responses. These responses included mobility, basking and orientation of the body axes (aspect angle) towards a radiation source. Mobility and basking are determined by the altitudinal origin of the parental generation and not by the temperature treatments. With increasing altitude, individuals tend increasingly to raise body temperatures via mobility and increased basking. In contrast, body orientation towards the radiation source is influenced by the temperature treatments but not by the altitude of origin. Individuals experiencing higher temperatures during rearing show a lower tendency to lateral flanking. We conclude that body orientation responses are not adapted locally. In contrast other components of the behavioural syndrome that increase body temperature, such as mobility and basking, are adaptive in response to local selection pressure. The thermoregulatory syndrome of these grasshoppers is an important contribution to life-history adaptations that appropriately match season lengths.

Vegetación arbórea del Cerro Verde: distribución altitudinal, dispersión y dominancia

Se hace un análisis del transecto discontinuo realizado en la ladera suroeste del Cerro Verde, localizado en el departamento de Santa Ana, determinando la dominancia de las especies, a diferentes alturas de transecto, el cual va desde 1,580 hasta 2,000 m.s.n.m. Se consideran todos los arboles con una circunferencia a la altura del pecho(C.A.P. de 30 cas. O más), se determina el índice de valor de importancia, para cada especie; las especies dominantes resultaron ser: Montanoa Guatemalensis a 1,580 m.s.n.m., Lonchocarpus minimiflorus a 1,600 m.s.n.m., Oreopanax xalapensis a 1,750 m.s.n.m., Styrax argentus a 1,750 m.s.n. m.a 1,800 m.s.n.m. Eugenia sp. a 2,000 m.s.n.m., Quercus sp. a 2,000 m.s.n.m. A cada especie se le aplica el modelo de Poisson para determinar el grado de dispersión de la vegetación; Roupala Borealis resulto distribuida al azar; las demás ya mencionadas aparecen como agregadas.

Species-specific kinetics and zonation of hepatic DNA synthesis induced by ligands of PPARα

PPARα ligands evoke a profound mitogenic response in rodent liver, and the aim of this study was to characterise the kinetics of induction of DNA synthesis. The CAR ligand, 1,4-bis[2-(3,5- dichoropyridyloxy)]benzene, caused induction of hepatocyte DNA synthesis within 48 hours in 129S4/SvJae mice, but the potent PPARα ligand, ciprofibrate, induced hepatocyte DNA synthesis only after 3 or 4 days dosing; higher or lower doses did not hasten the DNA synthesis response. This contrasted with the rapid induction (24 hours) reported by Styles et al. (Carcinogenesis 9:1647-1655). C57BL/6 and DBA/2J mice showed significant induction of DNA synthesis after 4, but not 2, days ciprofibrate treatment. Alderley Park and 129S4/SvJae mice dosed with methylclofenapate induced hepatocyte DNA synthesis at 4, but not 2, days after dosing, and proved that inconsistency with prior work was not due to a difference in mouse strain or PPARα ligand. Ciprofibrate-induced liver DNA synthesis and growth was absent in PPARα- null mice, and are PPARα-dependent. In the Fisher344 rat, hepatocyte DNA synthesis was induced at 24 hours after dosing, with a second peak at 48 hours. Lobular localisation of hepatocyte DNA synthesis showed preferential periportal induction of DNA synthesis in rat, but panlobular zonation of hepatocyte DNA synthesis in mouse. These results characterise a markedly later hepatic induction of panlobular DNA synthesis by PPARα ligands in mouse, compared to rapid induction of periportal DNA synthesis in rat.

Species richness and composition of butterfly assemblages (Lepidoptera:Rhopalocera) along the altitudinal gradient of Serra da Estrela

Os gradientes altitudinais são importantes modelos em ecologia pois permitem, numa escala reduzida, estudar a influência da variação de diversas variáveis ambientais nos padrões de biodiversidade existentes. Estes padrões são influenciados por diversos factores, desde variáveis climáticas às relacionadas com a perturbação humana. Nesta tese é estudada a variação na composição das comunidades de borboletas ao longo do gradiente altitudinal na Serra da Estrela e são testadas duas hipóteses sobre os padrões de riqueza específica ao longo do gradiente altitudinal: a regra de Rapoport e o “Mid Domain Effect” (MDE). Foram assinaladas 70 espécies de borboletas neste estudo e constatou-se que a variação na riqueza de espécies de borboletas apresenta um padrão “mid peak” apoiando o MDE. Verificou-se também que as comunidades de borboletas do mesmo nível altitudinal são mais semelhantes entre si independentemente da vertente em que se encontram e são também mais semelhantes com as comunidades dos níveis altitudinais adjacentes. Finalmente, a análise da distribuição de algumas espécies ameaçadas de borboletas torna evidente a necessidade de realização de mais estudos sobre a biologia da conservação deste grupo de animais em Portugal; Abstract: Altitudinal gradients are important ecological models because they allow us to study the influence of diverse environmental variables in the existing biodiversity patterns. These patterns are influenced by various factors, from climatic variables to variables related to human disturbance. In this thesis we studied the variations in the composition of the butterfly assemblages along the altitudinal gradient of Serra da Estrela and we tested two hypotheses regarding the species richness patterns along the altitudinal gradient: Rapoport’s rule and the Mid Domain Effect (MDE). In this study 70 butterfly species were marked recorded and it was observed that the butterfly species richness presents a mid-peak pattern supporting the MDE. It was also noted that the butterfly assemblages in the same altitudinal level show more similarity within themselves regardless of the slope they are found in, and are also more similar to the assemblages present in the adjacent altitudinal levels. Finally, the distribution of some threatened butterfly species was analyzed and it became evident the need to do more studies regarding the conservation biology of this animal group in Portugal.

Analysis of mangrove forest succession, using sediment cores: a case study in the Cananéia -Iguape coastal system, São Paulo Brazil

Sediment cores are an essential tool for the analysis of the dynamics of mangrove succession. Coring was used to correlate changes in depositional environments and lateral sedimentary facies with discrete stages of forest succession at the Cananéia-Iguape Coastal System in southeastern Brazil. A local level successional pattern was examined based on four core series T1) a sediment bank; T2) a smooth cordgrass Spartina alterniflora bank; T3) an active mangrove progradation fringe dominated by Laguncularia racemosa, and; T4) a mature mangrove forest dominated by Avicennia schaueriana. Cores were macroscopically described in terms of color, texture, sedimentary structure and organic components. The base of all cores exhibited a similar pattern suggesting common vertical progressive changes in depositional conditions and subsequent successional colonization pattern throughout the forest. The progradation zone is an exposed bank, colonized by S. alterniflora. L. racemosa, replaces S. alterniflora as progradation takes place. As the substrate consolidates A. schaueriana replaces L. racemosa and attains the greatest structural development in the mature forest. Cores collected within the A. schaueriana dominated stand contained S. alterniflora fragments near the base, confirming that a smooth cordgrass habitat characterized the establishment and early seral stages. Cores provide a reliable approach to describe local-level successional sequences in dynamic settings subject to drivers operating on multiple temporal and spatial scales where spatial heterogeneity can lead to multiple equilibria and where similar successional end-points may be reached through convergent paths.

The ichthyofauna of upper rio Capivari: defining conservation strategies based on the composition and distribution of fish species

Although the rio Capivari basin is recognized as an area of great importance for the ichthyofauna, it lacks virtually every basic requirement for the definition of appropriate conservation strategies, since not even its species composition is known. The objective of this work is to determine the composition and distribution of fish species in the upper rio Capivari basin, relating them to the local physical features, and to evaluate the effectiveness of proposed conservations units, delimited based on areas of native vegetation remains, on the conservation of local ichthyofauna. During 2007, 50 different watercourses were sampled with gillnets, cast nets and kick nets. A total of 1308 individuals belonging to 41 species were captured. Degree of conservation, altitude and width were the parameters that best explained fish species richness. Considering the recently proposed boundaries for potential conservation units in the region only 15 or 20 out of 41 species would be found in the State Park and Environmental Protection Area respectively. In practice, the proposed conservation units would not be effective tools for fish conservation, since it would be located in mountainous areas of high altitude, of headwaters streams and where few species are found. In such context, the conservation of specific stretches of larger rivers is critical.

Herpetofauna do Parque Estadual Carlos Botelho, São Paulo, Brasil

O presente trabalho consiste em um inventário da herpetofauna do Parque Estadual Carlos Botelho (PECB), localizado na região da Serra de Paranapiacaba, Estado de São Paulo. Os dados foram obtidos por meio de coletas em seis áreas dentro do PECB durante um período de 76 dias distribuídos em um ano, e também por meio de consulta a coleções científicas para obtenção de dados secundários. São apresentados resultados sobre a biologia e ocorrência das espécies no PECB e no Brasil, além de fotografias das diferentes espécies que compõem a herpetofauna do PECB. A herpetofauna do PECB pode ser considerada uma das mais diversificadas de São Paulo, com 65 espécies de anfíbios confirmadas e 59 espécies de répteis registrados neste trabalho. Das 65 espécies de anfíbios, 84% (55 spp.) são endêmicas das formações florestais da Mata Atlântica. Devido às características do relevo do PECB, foram encontrados diferentes padrões altitudinais para os anfíbios: 46% das espécies foram registradas apenas em altitudes acima de 500 m, enquanto que 9% são exclusivas das regiões abaixo de 400 m e 45% ocorrem em todas as áreas amostradas do Parque. Das 59 espécies de répteis do PECB, foram registradas 10 espécies de lagartos, 48 de serpentes e um quelônio. Dentre as serpentes coletadas no PECB, a jararaca Bothrops jararaca foi a mais frequente, com 26,9% (N = 14) do total registrado. Espécies de difícil amostragem, como Echinanthera cephalostriata (13,5%; N = 7) e Taeniophallus affinis (7,7%; N = 4), também foram numerosas no PECB. Dentre os lagartos, Enyalius iheringii foi a espécie mais abundante, com 50% (N = 16) de registros. Uma análise de agrupamento entre 25 taxocenoses de anfíbios brasileiras, incluindo o PECB, resultou na formação de quatro agrupamentos principais. A anurofauna do PECB é mais relacionada com as taxocenoses do Parque Estadual Jacupiranga (0,68) e do Parque Estadual Intervales (0,66). Estes Parques se encontram geograficamente próximos e constituem um dos maiores fragmentos preservados de Mata Atlântica no Brasil. Este trabalho é o primeiro a apresentar a lista de répteis do PECB, alem de complementar o conhecimento em relação a fauna de anfíbios do PECB.

A New Genus of Microteiid Lizard from the Caparao Mountains, Southeastern Brazil, with a Discussion of Relationships among Gymnophthalminae (Squamata)

A new genus and species of microteiid lizard is described based on a series of specimens obtained at Parque Nacional do Caparao (20 degrees 28'S, 41 degrees 49'W), southeastern Brazil, along the division line between the States of Minas Gerais and Espirito Santo. The new lizard occurs in isolated high-altitude, open, rocky habitats above the altitudinal lit-nits of the Atlantic forest. It is characterized by the presence of prefrontals, frontoparietals, parietals, interparietal, and occipital scales; ear opening and eyelid distinct; three pairs of genials; absence of collar; lanceolate and mucronate dorsal scales; six regular transverse and longitudinal series of smooth ventrals that are longer than wide, with the lateral ones narrower. Maximum parsimony (MP) and partitioned Bayesian (PBA) phylogenetic analyses based on morphological and molecular characters with all known genera of Gymnophthalminae (except for Scriptosaura) Plus Rhachisaurus recovered this new lizard in a clade having Colobodactylus and Heterodactylus as its closest relatives. Both analyses recovered the monophyly of Gymnophthalminae and Gymnophthalmini. The monophyly of the Heterodactylini received moderate support in MP analyses but was not recovered in PBA. To eliminate classification controversy between these results, the present concept of Heterodactylini is restricted to accommodate the new genus, Colobodactylus and Heterodactylus, and a new tribe Iphisiini is proposed to allocate Alexandresaurus, Iphisa, Colobosaura, Acratosaura, and Stenolepis. Current phylogenetic knowledge of Gymnophthalminae suggests that fossoriality and increase of body elongation arose as adaptive responses to avoid extreme surface temperatures, either cold or hot, depending on circumstances.

Bacterial communities and biogeochemical transformations of iron and sulfur in a high saltmarsh soil profile

Microbial community structure in saltmarsh soils is stratified by depth and availability of electron acceptors for respiration. However, the majority of the microbial species that are involved in the biogeochemical transformations of iron (Fe) and sulfur (S) in such environments are not known. Here we examined the structure of bacterial communities in a high saltmarsh soil profile and discuss their potential relationship with the geochemistry of Fe and S. Our data showed that the soil horizons Ag (oxic-suboxic), Bg (suboxic), Cri (anoxic with low concentration of pyrite Fe) and Cr-2 (anoxic with high concentrations of pyrite Fe) have distinct geochemical and microbiological characteristics. In general, total S concentration increased with depth and was correlated with the presence of pyrite Fe. Soluble + exchangable-Fe, pyrite Fe and acid volatile sulfide Fe concentrations also increased with depth, whereas ascorbate extractable-Fe concentrations decreased. The occurrence of reduced forms of Fe in the horizon Ag and oxidized Fe in horizon Cr-2 suggests that the typical redox zonation, common to several marine sediments, does not occur in the saltmarsh soil profile studied. Overall, the bacterial community structure in the horizon Ag and Cr-2 shared low levels of similarity, as compared to their adjacent horizons, Bg and Cr-1, respectively. The phylogenetic analyses of bacterial 16S rRNA gene sequences from clone libraries showed that the predominant phylotypes in horizon Ag were related to Alphaproteobacteria and Bacteroidetes. In contrast, the most abundant phylotypes in horizon Cr-2 were related to Deltaproteo-bacteria, Chloroflexi, Deferribacteres and Nitrospira. The high frequency of sequences with low levels of similarity to known bacterial species in horizons Ag and Cr-2 indicates that the bacterial communities in both horizons are dominated by novel bacterial species. (c) 2008 Elsevier Ltd. All rights reserved.

Factors influencing biodiversity and distributional gradients in mangroves

Numerous factors affect the distribution of mangrove plants. Most mangrove species are typically dispersed by water-buoyant propagules, allowing them to lake advantage of estuarine, coastal and ocean currents both to replenish existing stands and to establish new ones. The direction they travel depends on sea currents and land barriers, but the dispersal distance depends on the time that propagules remain buoyant and viable. This is expected to differ for each species. Similarly, each species will also differ in establishment success and growth development rate, and each has tolerance limits and growth responses which are apparently unique. Such attributes are presumably responsible for the characteristic distributional ranges of each species, as each responds to the environmental, physical and biotic settings they might occupy. In practice, species are often ordered by the interplay of different factors along environmental gradients, and these may conveniently be considered at four geographic scales-global, regional, estuarine and intertidal. We believe these influencing factors act similarly around the world, and to demonstrate this point, we present examples of distributional gradients from the two global biogeographic regions, the Atlantic East Pacific and the Indo-West Pacific.

Community structure of Quaternary coral reefs compared with Recent life and death assemblages

This paper assesses the reliability with which fossil reefs record the diversity and community structure of adjacent Recent reefs. The diversity and taxonomic composition of Holocene raised fossil reefs was compared with those of modern reef coral life and death assemblages in adjacent moderate and low-energy shallow reef habitats Of Madang Lagoon, Papua New Guinea. Species richness per sample area and Shannon-Wiener diversity (H') were highest in the fossil reefs, intermediate in the life assemblages, and lowest in the death assemblages. The taxonomic composition of the fossil reefs was most similar to the combination of the life and death assemblages from the modern reefs adjacent to the two fossil reefs. Depth zonation was recorded accurately in the fossil reefs. The Madang fossil reefs represent time-averaged composites of the combined life and death assemblages as they existed at the time the reef was uplifted. Because fossil reefs include overlapping cohorts from the life and death assemblages, lagoonal facies of fossil reefs are dominated by the dominant sediment-producing taxa, which are not necessarily the most abundant in the life assemblage. Rare or slow-growing taxa accumulate more slowly than the encasing sediments and are underrepresented in fossil reef lagoons. Time-averaging dilutes the contribution of rare taxa, rather than concentrating their contribution. Consequently, fidelity indices developed for mollusks in sediments yield low values in coral reef death and fossil assemblages. Branching corals dominate lagoonal facies of fossil reefs because they are abundant, they grow and produce sediment rapidly, and most of the sediment they produce is not exported. Fossil reefs distinguished kilometer-scale variations in community structure more clearly than did the modern life assemblages. This difference implies that fossil,reefs may provide a better long-term record of community structure than modern reefs. This difference also suggests that modern kilometer-scale variation in coral reef community structure may have been reduced by anthropogenic degradation, even in the relatively unimpacted reefs of Madang Lagoon. Holocene and Pleistocene fossil reefs provide a time-integrated historical record of community composition and may be used as long-term benchmarks for comparison with modern, degraded, nearshore reefs. Comparisons between fossil reefs and degraded modern reefs display gross changes in community structure more effectively than they demonstrate local extinction of rare taxa.