Greenhouse gas,upwelling‐favorable winds,and the future of coastal ocean upwelling ecosystems

Coastal ocean upwelling ecosystems generally represent the most productive large marine ecosystems of the world's oceans, in terms of both primary production rates and tonnages of exploitable fish produced. The Peruvian upwelling system, in particular, stands out as a major factor in world fish production. The Pacific trade winds have traditionally been considered to be the primary driving force for the upwelling system off Peru, but are projected to weaken as climate change proceeds. This leads to concern that the upwelling process in the Peru system, to which its productivity is linked, may likewise weaken. However, other mechanisms involving greenhouse‐associated intensification of thermal low‐pressure cells over the coastal landmasses of upwelling regions suggest general intensification of wind‐driven ocean upwelling in coastal upwelling regions of the world's oceans. But although certain empirical results have supported this expectation, it has not been consistently corroborated in climate model simulations, possibly because the scale of the coastal intensification may be small relative to the scales that are appropriately reflected in the standard models. Here we summarize available evidence for the intensification mechanism and present a proxy test that uses variations in water vapor, the dominant natural greenhouse gas, to offer multiple‐realization empirical evidence for action of the proposed mechanism in the real world situation. While many potential consequences to the future of marine ecosystems would codepend on climate change‐related changes in the thermocline and nutricline structures, an important subset, involving potential increased propensities for hypoxia, noxious gas eruptions, toxic red tide blooms, and/or jellyfish outbreaks, may depend more directly on changes in the upwelling‐favorable wind itself. A prospective role of fisheries in either mitigating or reinforcing this particular class of effects is suggested.     

Systematic revision of the Late Miocene sabre‐toothed felid Paramachaerodus in Spain

Abstract: A systematic revision of the sabre‐toothed cat genus Paramachaerodus  Pilgrim, 1913 is presented. Two species are recognized within Paramachaerodus, Pa. orientalis, and Pa. maximiliani, and the genus Promegantereon  Kretzoi, 1938 is retrieved to include Promegantereon ogygia. Material from the Turolian Spanish localities of Crevillente‐2 (MN 11, Alicante) and Las Casiones (MN 13, Teruel), which was previously assigned to Paramachaerodus, is now included in the tribe Metailurini. The exceptional discoveries at the Spanish Vallesian (MN 10, Madrid) fossil site of Batallones‐1 have made it possible to characterize the dentition and cranial anatomy of a previously very poorly known machairodontine cat, formerly included in Paramachaerodus as Pa. ogygia, which now can be distinguished from Pa. orientalis and Pa. maximiliani by the following features: canines without crenulations, P3 with a marked disto‐lingual expansion, P4 without ectostyle and with a well‐developed protocone, M1 bucco‐lingually elongated and double‐rooted, m1 with a larger talonid, and primitive mandible morphology. Thus, the population from Batallones‐1 constitutes a clearly different form from the genus Paramachaerodus, and we propose its inclusion in the genus Promegantereon  Kretzoi, 1938 , together with an upper canine from Crevillente‐2 (MN 11), very similar to those from Batallones‐1. In contrast, Pa. orientalis shows the following apomorphies: crenulated canines, P3 reduced in size and without disto‐lingual expansion, P4 with a clear ectostyle as well as a reduced, backwardly displaced protocone and with a rounded and single‐rooted M1. The species Pa. maximiliani is characterized by its slightly larger size, crenulated canines, very elongated P3 with a moderate disto‐lingual expansion and P4 and M1 similar to those of Pa. orientalis. Paramachaerodus orientalis is recorded at Puente Minero (MN 11, Teruel), Concud (MN 12, Teruel), Crevillente‐15, and Crevillente‐16 (both MN 12, Alicante), and Paramachaerodus maximiliani in Venta del Moro (MN 13, Valencia). The available data suggest that Pr. ogygia was present in the Iberian Late Vallesian and Early Turolian faunas (MN 10 and MN 11) but disappeared after that age. Paramachaerodus was present in the faunas throughout the Turolian, with the species Pa. orientalis and Pa. maximiliani, this latter being probably part of the same immigration event that occurred in the Late Turolian and involved other mammal taxa such as camelids and ursids.     

Polyphyly of Limoniastrum (Plumbaginaceae): evidence from DNA sequences of plastid rbcL, trnL intron and trnL-F intergene spacer

Phylogenetic relationships of Limoniastrum and other genera of subfamily Staticoideae (Plumb-aginaceae) were studied using parsimony analysis of the plastid gene rbc L, the intron of trn L and the intergene spacer of trnL-trn F. Our analysis showed that Limoniastrum was polyphyletic. Limoniastrum ifniense , in both rbc L and combined data analyses, is sister to Armeria and Psylliostachys , whereas in the trn L-F (intron and spacer combined) analysis it is sister to a clade composed of Acantholimon, Dictyolimon and the remaining species of Limoniastrum . In all analyses, the five remaining species of Limoniastrum (excluding Limoniatrum ifniense ) formed a clade with two groups of species: L. monopetalum+L. guyonianum and those sometimes considered as the segregate genus Bubania ( L.feei, L. weygandiorum and L. rechingeri ). Levels of sequence divergence among these three groups of Limoniatrum were greater than for other well supported genera in the family and, in combination with morphological differences and paucity of synapomorphies, led us to conclude that separate generic status for each of the three clades is warranted.     

Climate warming, dispersal inhibition and extinction risk

Global warming impels species to track their shifting habitats or adapt to new conditions. Both processes are critically influenced by individual dispersal. In many animals, dispersal behaviour is plastic, but how organisms with plastic dispersal respond to climate change is basically unknown. Here, we report the analysis of interannual dispersal change from 16 years of monitoring a wild population of the common lizard, and a 12-year manipulation of lizards' diet intended to disentangle the direct effect of temperature rise on dispersal from its effects on resource availability. We show that juvenile dispersal has declined dramatically over the last 16 years, paralleling the rise of spring temperatures during embryogenesis. A mesoscale model of metapopulation dynamics predicts that in general dispersal inhibition will elevate the extinction risk of metapopulations exposed to contrasting effects of climate warming.     

Effects of potassium and gibberellic acid on stem growth of whole sunflower plants

Abstract The effects of gibberellic acid (GA₃) on whole sunflower (Helianthus annuus L.) plants grown at three potassium (K) levels (0.0, 0.5 and 5.0 mM) were studied. A tenfold increase in the length of the first internode was observed when plants grown without K were treated with GA₃. The uneven K distribution along the plant (higher K content in the higher internodes) was enhanced by GA₃ treatment. Gibberellic acid increased the content of reducing sugars, especially in K-deficient plants. An increase in the K level in the nutrient solution resulted in a decrease of the osmotic potential of stem segments. Osmotic potential differences within the elongating first internode were increased by GA₃ treatment.     

Electrophoretic characterization of Amaranthus L. seed proteins and its systematic implications

The seed protein profiles of 11 Amaranthus taxa (Amaranthaceae) from Spain were studied. These profiles were evaluated as a chemical character to clarify the taxonomic complexity in the genus. Tricine-sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE) profiles of the Amaranthus seed proteins studied showed a range of peptides varying from 64 to 12 kDa, with a larger number of protein bands observed between 25.1 and 12 kDa. For the taxonomic study, 14 bands, some of them subdivided into several isoforms, were considered. The similarity analysis based on the SDS-PAGE profile is a useful character for the discrimination of species in Amaranthus , except for A. cruentus and A. hypochondriacus , for which a hybrid population was found. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 57–63.     

Concordance between ecotypes and macroinvertebrate assemblages in Mediterranean streams

1. According to the guidelines of the European Water Framework Directive, assessment of the ecological quality of streams and rivers should be based on ecotype-specific reference conditions. Here, we assess two approaches for establishing a typology for Mediterranean streams: a top-down approach using environmental variables and bottom-up approach using macroinvertebrate assemblages.
2. Classification of 162 sites using environmental variables resulted in five ecotypes: (i) temporary streams; (ii) evaporite calcareous streams at medium altitude; (iii) siliceous headwater streams at high altitude; (iv) calcareous headwater streams at medium to high altitude and (v) large watercourses.
3. Macroinvertebrate communities of minimally disturbed sites ( n  = 105), grouped using UPGMA (unweighted pair-group method using arithmetic averages) on Bray–Curtis similarities, were used to validate four of the five ecotypes obtained using environmental variables; ecotype 5, large watercourses, was not included as this group had no reference sites.
4. Analysis of similarities ( anosim ) showed that macroinvertebrate assemblage composition differed among three of the four ecotypes, resulting in differences between the bottom-up and top-down classification approaches. Siliceous streams were clearly different from the other three ecotypes, evaporite and calcareous ecotypes did not show large differences in macroinvertebrate assemblages and temporary streams formed a very heterogeneous group because of large variability in salinity and hydrology.
5. This study showed that stream classification schemes based on environmental variables need to be validated using biological variables. Furthermore, our findings indicate that special attention should be given to the classification of temporary streams.     

Relationships between the close congeners Anthoxanthum odoratum and A. alpinum (Poaceae, Pooideae) assessed by morphological and molecular methods

Anthoxanthum alpinum Löve & Löve has been described as a diploid perennial distributed in northern Eurasia and the high mountains of central and eastern Europe. Difficulties in finding reliable morphological differences between this taxon and the widespread tetraploid Anthoxanthum odoratum L. have resulted in taxonomists treating them as conspecific, despite the cytological differentiation. The purpose of this study was to use different approaches to assess the relationships between close congeners, such as the pair A. odoratum / A. alpinum . Macromorphological, micromorphological, and molecular data were gathered and analysed for 14 populations representing both taxa from Scandinavia and the Iberian Peninsula. Different cluster analyses were performed to study the relatedness between individuals and populations. Subsequently, a principal components analysis was computed on the basis of macromorphological quantitative traits, and principal coordinates analysis was used to analyse qualitative, micromorphological, and random amplification of polymorphic DNA (RAPD) data. An analysis of molecular variance was applied to the molecular data, and the genetic differentiation between samples was measured using the F _ST estimator. The results showed that the geographical origin was more important than the ploidy level in explaining the relatedness between specimens and populations. Moreover, a strong correlation was found between the micromorphological traits and environmental parameters. The results of the analyses do not support the assignment of a specific taxonomic rank to A. alpinum .  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 237–252.     

Are predatory birds effective secondary seed dispersers?

We have studied the unusual phenomenon of secondary seed dispersal of Lycium intricatum seeds on a small oceanic Atlantic island (Alegranza, Canarian Archipelago) in which a small frugivorous lizard ( Gallotia atlantica ) and two different predatory birds participate, a shrike ( Lanius excubitor ) and a kestrel ( Falco tinnunculus ). Endemic lizards that are common prey of both bird species consume Lycium fruits. Lizard remains were significantly matched with the presence of Lycium fruits in the regurgitation pellets of the two predatory birds. Seeds were found in 7.3% of the lizard droppings, 31.0% of kestrel pellets and 55.7% of shrike regurgitations. The mean number of seeds per dropping or pellet was 4.8 ±4 in lizard, 20.2 ±34.5 in shrike and 6.7 ±8.1 in kestrel. The percentage of viable seeds showed significant differences among all four treatments, decreasing in the following direction: seeds collected directly from plants (98.0%), shrikes (88.0%), lizards (72.3%), and kestrels (31.7%). Seeds from Lycium fresh fruits and shrike pellets showed significantly higher germination rates than those from lizard droppings and kestrel pellets. While lizards and shrikes are effective seed dispersers, kestrel gut treatment decreases seed viability. Seed viability is always higher than seed germination in each of the four treatments. In this island environment, Lycium seeds are under an important random influence during the seed dispersal process. Secondary seed dispersal seems to acquire a relevant dimension in small and remote insular environments or isolated continental systems where interactions among the different elements involved are intense, all of them are abundant native residents, and they have been coexisting for a long time. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 75 , 345–352.     

CHANGES IN SEROTONIN LEVEL AND TURNOVER IN DISCRETE HYPOTHALAMIC NUCLEI AFTER PINEALECTOMY AND MELATONIN ADMINISTRATION TO RATS

The influence of the pineal gland on the hypothalamic serotonergic function was examined by studying the effects of long-term pinealectomy (1 month) and melatonin replacement (500 μg/kg; 10 days) on serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) content as well as on the in vivo 5-HT synthesis rate in discrete hypothalamic nuclei. Pinealectomy was followed by a significant decrease of 5-HT content in the anterior hypothalamic nuclei (AHN) and the ventromedial hypothalamic nuclei (VMHN), and also in 5-HIAA content in lateral (LPON) and medial preoptic nuclei (MPON). The 5-HT synthesis rate, estimated from the accumulation of 5-hydroxytryptophan after blockade of the 1-amino acid decarboxylase activity, were also decreased in the AHN and the paraventricular hypothalamic nuclei (PVHN) of pinealectomized rats. In contrast, an enhanced 5-HT synthesis rate and basal 5-HIAA content were found in the suprachiasmatic nuclei (SCN) after pinealectomy. Daily treatment with melatonin for 10 days reversed most of the effects induced by pinealectomy. Thus, melatonin increased the levels of 5-HT in the AHN and VMHN, and slightly increased the 5-HIAA content in preoptic nuclei. In addition, melatonin increased the 5-HT synthesis rate in the AHN and VMHN, but also in the MPON, VMHN and dorsomedial hypothalamic nuclei (DMHN) where pinealectomy had no effect. By contrast, melatonin treatment did not affect SCN 5-HT synthesis rate, although it decreased 5-HIAA levels. The results demonstrate that melatonin is able to stimulate 5-HT metabolism in most of the hypothalamic areas, but inhibits SCN 5-HT function. Some of the effects of melatonin seems to be exerted by modulating the synthesis of the amine, although melatonin likely also interacts with other regulatory processes of 5-HT function (i.e. release/uptake). The well defined presence of melatonin receptors in the rat SCN, and its absence in other hypothalamic structures, suggest that this may be the mechanism mediating the differential response to endogenous melatonin. Moreover, the larger effect of exogenous melatonin in relation to pinealectomy suggests the presence of melatonin unespecific effects possibly owing to supraphysiological doses. The present findings may be relevant for the mode of action of melatonin and its implication in several endocrine and behavioral functions mediated by serotonergic neurons. Copyright © 1996 Elsevier Science Ltd