Penicillium in pre-harvest corn from Valencia (Spain). I. Influence of different factors on the contamination

In the present study we attempt to determine the principal factors which influence the contamination by Penicillium of 116 samples of pre-harvest corn from five crop areas in Valencia (Spain).In the corn tested, Penicillium is the most abundant genus after Fusarium, with an incidence of 71.5% in infected samples, counts of about 642 cfu/g and kernel infection of 8.7%. The most frequently isolated species are Penicillium chrysogenum, P. steckii and P. purpurogenum.There is a high correlation between the contamination from this genus and the amout of kernels broken and infested by insects, as well as a correlation with crop areas.We have found no difference in the contamination of the two varieties of corn investigated.     

Effects of fire recurrence in Quercus coccifera L. shrublands of the Valencia Region (Spain): II. plant and soil nutrients

The consequences of fire recurrence (1, 2 and 3 fires in 16 years) on plant and soil C, N, P and K from Quercus coccifera garrigues were analysed in the Valencia Region (E Spain). Plant and forest floor (L horizon) nutrient concentrations either changed weakly or showed no change with fire recurrence. At the soil surface (0-2.5 cm), soil potential mineralisable nitrogen increased and available P decreased after an initial increase, whereas exchangeable K was not affected by successive fires. However, the significance of those observed trends for N and P was site-dependent. Despite the rapid formation of the L soil horizon, fire recurrence did not permit the development of the whole forest floor profile observed in the unburned garrigues. These organic layers contained a great proportion of the total nutrient pool, especially for N. Forest-floor and aboveground plant combustion by fire may produce significant losses of N and P compared with those available in mineral soil, whereas soil exchangeable K is large enough to replace these losses. Belowground nutrient reserves may account for the quick recovery of the Quercus coccifera aboveground biomass although successive fires could deplete these reserves and produce a loss of biomass and productivity in this species.     

Population dynamics and ecology of subdominant phytoplankton species in a shallow hypertrophic lake (Albufera of Valencia,Spain)

Long-term population dynamics and ecology of the abundant but non-dominant phytoplankton species of the shallow hypertrophic lake the Albufera of Valencia (Spain) are described for the period 1980–1988. The lake is used as a reservoir for the surrounding ricefield cultivation. It is continuously dominated by three filamentous blue-green algae, Planktothrix agardhii, Pseudanabaena galeata and Geitlerinema sp. Horizontal differences of the phytoplankton were less important than annual and seasonal variations. An annual increasing trend was observed for Planktolyngbya subtilis, Planktolyngbya contorta, Cylindrospermopsis raciborskii, Microcystis incerta, Nitzschia palea var. tenuirostris and Rhodomonas lacustris var. nannoplanctica, whereas Anabaenopsis elenkinii, Scenedesmus acuminatus, Scenedesmus quadricauda and Cyclotella meneghiniana showed an opposite trend. This pattern seems related to the increase of nitrogen and phosphorus loading in the lake and certain hydrological changes occurred in the latter years of the study. Seasonal pattern of the subdominant species showed the presence of Cyclotella meneghiniana, Scenedesmus species and Chlamydomonas spp. in spring, during moderate water renovation rates and phosphate availability. Periodicity shifted to blue-green algae and Nitzschia species in summer and early autumn, during reduced phosphate levels and initial low but later high water renewal. Autumn and winter species, such as Monoraphidium contortum, Nitzschia gracilis, Rhodomonas lacustris var. nannoplanctica and Cryptomonas erosa, were mainly related to light intensity and temperature. Although the lake has a typical hypertrophic phytoplankton assemblage, the general seasonal variation of the species is similar to that often described in temperate lakes. Diatom species composition differs to that cited in other shallow hypertrophic lakes of Europe.     

A new Aspleniutn hybrid from Valencia (Spain) related to A. majoricum Litard

PANGUA, E., PRADA, C, PAJARON, S. & SALVO, E., 1992. A new Aspleniutn hybrid from Valencia (Spain) related to A. majoricum Litard . A new diploid Asplenium hybrid, found in the Iberian Peninsula (Valencia, Benifairo de Valldigna), is described and the name Asplenium x protomajoricum proposed. The plants exhibit c. 72^I at meiosis. The cytology and morphology of the hybrid and its occurrence between the assumed parentals suggest that it originated from a cross between A. fontanum and A. petrarchae subsp. bivalens. The occurrence of A. petrarchae subsp. bivalens in eastern Spain is confirmed cytologically. The occurrence of A. majoricum on the mainland is also discussed.     

Characteristics of rice straw and sewage sludge as composting materials in Valencia (Spain)

This work supports the idea that composting can be useful for minimizing the rice straw and sewage sludge environmental impact. Several physical, chemical and microbiological properties of these raw materials were analyzed. The characteristics of the rice straw were complementary to those of the sewage sludge for the application of composting. The C/N ratios suitable for a rapid increased in microbial activity were the lowest (17-24). A temperature of 62 degrees C during 48 h removed pathogenic microorganisms from rice straw and sewage sludge mixture. The results obtained in the present work suggested that these materials could be use in the composting process.     

Monitoring butocarboxim resistance of the woolly whitefly (Homoptera: Aleyrodidae) in citrus from Valencia, Spain.

Glass vials coated internally with an insecticide were used as a resistance monitoring technique for testing field populations of the woolly whitefly, Aleurothrixus floccosus (Maskell), collected from citrus. The distribution of resistance to the insecticide butocarboxim in citrus orchards from Valencia (Spain) during 1993 and 1994 was determined by means of this technique. Adults resting on citrus shoots were captured with a portable vacuum cleaner and introduced into the vials. The technique provides control mortality of <25% when assessed 7 h after the insects are captured. In 21 populations tested, LC50s ranged from 1.8 to 42.3 mg/ml. This represents resistance ratios >20-fold among populations. Lower slopes of the concentration-mortality line were found in whitefly populations that exhibited a low level of the LC50. Resistance was widespread in the Valencia areabut spatially irregular, with nearby orchards occasionally showing wide differences in resistance levels. The levels of resistance to butocarboxim obtained with this technique closely matched the field efficacy of the insecticide. This residue bioassay provides a convenient and rapid method to monitor insecticide resistance in A. floccosus populations.     

Long-term phytoplankton changes in a shallow hypertrophic lake,Albufera of Valencia (Spain)

A long-term phytoplankton study was carried out in the Albufera of Valencia, a shallow hypertrophic lake (surface area 21 km², mean depth 1 m, total inorganic nitrogen load 155 g m^-2 y^-1, total inorganic phosphate load 15 g m^-2 y^-1) from 1980 to 1988. The lake functions as a reservoir for the surrounding rice cultivation. From 1940's to 1988, its phytoplankton assemblage has been altered from a mesotrophic to a hypertrophic character, as consequence of the increasing pollution. For 1980–88, annual variations in the phytoplankton were less pronounced than seasonal changes. The hypertrophic and morphometric features of the lake favoured the stability of the phytoplankton assemblage and chlorophyll a levels during the study period. Seasonal and horizontal distribution of the total phytoplankton abundance and biomass were highly influenced by the hydrological cycle of the lagoon. Compared with other shallow nutrient rich lakes, the Albufera of Valencia is similar to the shallow hypertrophic lakes of the Netherlands.     

A new species of Veronica L. (Scrophulariaceae) in the Cantabrian Range (Spain)

A new species of Veronica vadiniense in section Veronica is described from material from the Cantabrian Range, in the north-east of the province of León (north-west Spain). Several morphological characters related to stems, leaves, racemes, flowers and capsules are given, and also those related to the indumentum of different parts of the plant, especially calyx lobes and capsule. Indications about distribution and habitat with reference to bioclimatic, biogeographical and phytosociological aspects are provided. Diagnostic features are also given to enable comparison with the most similar species, Veronica officinalis and V. allionii , particularly in the indumentum and consistency of leaves, and in the indumentum and shape of the capsule.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 119–124.     

Changes in the House Sparrow Passer domesticus population in Valencia (Spain) from 1998 to 2008

Capsule The population of House Sparrow Passer domesticus has experienced a sharp decline in the municipality of Valencia.

Aims To investigate the population trends of House Sparrows.

Methods Between September 1998 and December 2008, House Sparrows were censused monthly in 22 urban parks covering a total of 118 ha. Additionally, birds in the wider urban landscape were censused in 24 plots of about 50 ha during the winter and spring of years 1998, 2003 and 2007.

Results The House Sparrow population experienced a significant decline of about 70% over 10 years in urban parks, with monthly peak values decreasing from about 2000 birds in 1998 to about 500 in 2008. Between 1998 and 2007, a significant decline was detected in the urban landscape mostly during the winter.

Conclusions Urban parks are a main feeding habitat for House Sparrows, and habitat structure of urban parks has remained similar throughout these years. Therefore, the decreasing number of sparrows recorded in parks probably reflects an overall population decline of the species in Valencia. This decline has coincided with high‐intensity urban development i.e. an increase in the building density and a reduction in the amount of wastelands and other feeding habitats. Thus, shortage of nest‐sites did not seem to be a limiting factor for the population, but a reduction of food availability may be partially responsible for the observed patterns.     

The Gravettian occipital bone from the site of Malladetes (Barx,Valencia, Spain)

The juvenile occipital bone from the site of Malladetes in Valencia (Spain) is described and compared with other European Pleistocene representatives of the genus Homo. This specimen derives from a Gravettian cultural context and has been AMS radiocarbon-dated to 25,120 +/- 240 years BP. As such, it provides evidence on early modern human anatomy from the Central Mediterranean region of the Iberian peninsula. The clear evidence for a late survival of Neandertals in southern Iberia, has led to considerable debate surrounding the biological and cultural interactions between these Pleistocene humans and their early modern human successors, and it is within this context that the Malladetes specimen represents an important contribution to the discussion. The recently discovered Upper Paleolithic infant from the site of Lagar Velho in Portugal is said to show a mosaic of Neandertal and early modern human characteristics throughout the skeleton and is argued to represent the strongest evidence yet recovered in favor of hybridization between these two Pleistocene populations. Our analysis of the Malladetes occipital, however, reveals no evidence of Neandertal genetic influence.     

Effects of fire recurrence in Quercus coccifera L. shrublands of the Valencia Region (Spain): I. plant composition and productivity

The purpose of this study was to determine whether fire recurrence modifies the regeneration capacity of Quercus coccifera garrigues in the Valencia region (eastern Spain). We studied several areas with different fire recurrences (1, 2 and 3 fires in 16 years), all of which had sustained a common last fire in 1994. Three-and-a-half years after the last fire, differences between the 3 fire recurrences were not detected with respect to total plant cover and Q. coccifera cover, with a mean value between 92 and 76%. On the most frequently burned sites, herbaceous and subshrub species cover showed a tendency to increase, while that of the obligate seeding shrub, Ulex parviflorus, decreased with both fire frequency and shorter last-fire interval. The most recurrently burned areas with the shortest last-fire intervals presented higher species richness, which mainly affected the herbaceous and subshrub species group, and of these, the hemichryptophytes. The major effect of fire recurrence was the significant decrease in stem and total biomass of Q. coccifera in the three studied sites. Three-and-a-half years after the fire, the mean total biomass values were around 1500, 1000 and 700 g. m⁻² in the garrigues with 1, 2 and 3 fires respectively. Stem production was more affected than leaf production. Leaf area index values showed the same pattern as leaf biomass. Recurrent fires also caused a decrease in net primary production measured the fourth year after fire. The results point to the fact that fire recurrence can cause depletion in garrigue productivity and recovery capacity in southern areas, in contrast with the high resilience observed in northern Mediterranean garrigues.     

Early post-fire regeneration dynamics of Brachypodium retusum Pers. (Beauv.) in old fields of the Valencia region (eastern Spain)

Extensive wildfires have affected the Valencia region in the last two decades. A large portion of the burnt areas has been localised in old fields. Although Mediterranean communities are usually resilient to fire and recover very quickly to the pre-fire state, burnt old fields with a low number of species could show poor recovery capacity. The response capacity of these systems to fire, and, especially, the role of the native herbaceous Brachypodium retusum were studied. Two years after fire, plant cover reached a value of 56 %. Resprouter species were more important in number and in specific cover. B. retusum represented the species with the highest contribution to total plant cover for all the study period. Total biomass in burnt plots was always lower than in unburnt plots. However, B. retusum green biomass showed a quick recovery to pre-disturbance levels, and below-ground biomass was similar in burnt and unburnt plots. Reproductive biomass greatly increased in burnt with respect to unburnt plots during the first post-fire year, with no stalk production in unburnt plots. B. retusum may be considered a promising species for the restoration of extremely degraded lands because of its high resilience to fire.     

Spatial and temporal variation of community composition and species cover following dune restoration in the Devesa de Albufera (Valencia,Spain).

Plant populations were reintroduced to the coastal dune bar of the Devesa de Albufera from 1988 to 2004; different coastline sections received different species composition and cover. With the aim to detect spatial and temporal variation of floristic diversity, we compared current species composition and cover across the length of the Devesa and across the dune bar with those imposed at the time of restoration. Non-metric multidimensional scaling (NMDS) detected significant differences both across the dune faces and across the coast sections. Differences across the dune faces reflect the sea-inland ecological gradient and resulted from a spatial rearrangement of plant populations: Calystegia soldanella, Achillea maritima and Polygonum maritimum prefer the windward face; Malcolmia littorea and Lagurus ovatus the leeward. Differences across coast sections are related to those at restoration time, with a slow trend towards the homogenization of plant communities. At the current level of anthropic pressure, the plant cover is likely to evolve following the trends pointed out in this research.     

Growth in species of the genus Ascobolus. II. (Pezizales-Ascomycota)

The kinetics of growth of six heterothallic species of the genus Ascobolus was studied in liquid culture media. The results obtained showed variation among the species in the duration of the different phases of the growth cycle. Four groups can be recognized considering the extension of the exponential phase of growth. The stationary phase, which differs in its length, is frequently very short, entering quickly in the phase of death, accompanied by the autolysis of the mycelium.     

Effects of environmental and temporal factors on Glomeromycotina spores in sand dunes along the Gulf of Valencia (Spain)

AMF symbiosis in sand dunes is the key for maintenance of stable vegetation. The main goal of this work was to determine the effects of environmental and temporal factors on AMF living in sand dunes (Gulf of Valencia, Spain). Soil samples were collected seasonally at 6 sites, during 2 yrs, from three habitats and four plant species and the frequency and relative abundance of AMF was examined. AMF were more frequent in mobile than in embryonic dunes, in spring and in sites with old vegetation. Ten AMF species were identified, their distribution depending mainly on the anthropogenic disturbance of the site. Gigasporaceae Cetraspora sp. and Dentiscutata sp. preferred undisturbed soil whereas Diversisporaceae, Glomeraceae and other Gigasporaceae were associated with recently restored soils. All AMF species were found in all plant species although Corymbiglomus corymbiforme was mainly associated with Echinophora spinosa. Our results might be of help for Mediterranean sand dune restoration.