Quercus Research Papers - Academia.edu (original) (raw)

Dichotomous Key to Oaks of Southern California

Symbiosis is a major theme in the history of life and can be an important force driving evolution. However, across symbioses, it is difficult to tease apart the mechanisms that structure the interactions among potential partners. We used... more

Symbiosis is a major theme in the history of life and can be an important force driving evolution. However, across symbioses, it is difficult to tease apart the mechanisms that structure the interactions among potential partners. We used genetic similarity and frequency-based methods to qualitatively and quantitatively examine the patterns of association among several co-occurring Cladonia lichen fungi and their algal photobionts in six disjunct Florida scrub sites. The patterns of association were described by the degree of specificity, i.e. the phylogenetic range of associated partners, and of selectivity, i.e. the frequency of association among partners. Six fungal species associated with only one algal internal transcribed spacer clade, with the remaining two fungi being associated with two algal clades. In all cases, the fungi associated in unequal frequencies with the observed algal photobiont genotypes within those clades — suggesting that both specificity and selectivity were higher than expected. Fungal species can be grouped into three significantly different specificity classes: photobiont specialists, intermediates and generalists. In contrast to the pronounced specificity for photobionts among fungal species, the different Florida scrub sites do not harbour distinct photobiont pools, and differential photobiont availability cannot explain the patterning of lichen associations at this spatial scale. Therefore, we conclude that fungal specificity and selectivity for algal photobionts are major factors in determining the local composition of symbiotic partnerships.

Cork powder and granules are the major subproducts of the cork industry, one of the leading economic activities in Portugal and other Mediterranean countries. Many applications have been envisaged for this product, from cork stoppers... more

Cork powder and granules are the major subproducts of the cork industry, one of the leading economic activities in Portugal and other Mediterranean countries. Many applications have been envisaged for this product, from cork stoppers passing through the incorporation in agglomerates and briquettes to the use as an adsorbent in the treatment of gaseous emissions, waters and wastewaters. This paper aims at reviewing the state of the art on the properties of cork and cork powder and their application in adsorption technologies. Cork biomass has been used on its original form as biosorbent for heavy metals and oils, and is also a precursor of activated carbons for the removal of emerging organic pollutants in water and VOCs in the gas phase. Through this literature review, different potential lines of research not yet explored can be more easily identified.

Polyphenolics, which are ubiquitous in plants, currently are among the most studied phytochemicals because of their perceptible chemical properties and antioxidant activity. Oak barrels and their alternatives, which are widely used in... more

Polyphenolics, which are ubiquitous in plants, currently are among the most studied phytochemicals because of their perceptible chemical properties and antioxidant activity. Oak barrels and their alternatives, which are widely used in winemaking nowadays, contribute polyphenolics to wines and are thought to play crucial roles in the development of wines during aging. This study summarizes the detailed information of polyphenolics in oak woods and their products by examining their structures and discussing their chemical reactions during wine aging. This paper evaluates the most recent developments in polyphenolic chemistry by summarizing their extraction, separation, and their identification by the use of chromatographic and spectral techniques. In addition, this paper also introduces polyphenol bioactive ingredients in other plant foods.

In September 2016, a survey conducted in the Circeo National Park revealed an outbreak and serious damage caused by the black twig borer (Xylosandrus compactus) and its associated fungi in the Mediterranean maquis. Among the affected... more

In September 2016, a survey conducted in the Circeo National Park revealed an outbreak and serious damage caused by the black twig borer (Xylosandrus compactus) and its associated fungi in the Mediterranean maquis. Among the affected hosts, Quercus ilex, Viburnum tinus, Ruscus aculeatus, Pistacia lentiscus, Laurus nobilis and Ceratonia siliqua, showed
flagging and wilting of branches and, in younger individuals, the death of the whole plant occurred. In total, 18 different fungal taxa were found associated with the insect. These included Ambrosiella xylebori, Geosmithia pallida, Fusarium spp., Epicoccum nigrum and Bionectria sp. This is the first report in Europe of X. compactus and associated ambrosia
fungi in a natural environment

Abstact Forensic botany can provide significant supporting evidence during criminal investigations. However, it is still an underutilized field of investigation with its most common application limited to identifying specific as well as... more

Abstact Forensic botany can provide significant supporting evidence during criminal investigations. However, it is still an underutilized field of investigation with its most common application limited to identifying specific as well as suspected illegal plants. The ubiquitous presence of plant species can be useful in forensics, but the absence of an accurate identification system remains the major obstacle to the present

Epiphytic lichen and bryophyte distribution and frequency were investigated on the trunks of 145 young oak trees throughout London and surrounding counties, and compared with pollution levels and bark pH. Sixty-four lichen and four... more

Epiphytic lichen and bryophyte distribution and frequency were investigated on the trunks of 145 young oak trees throughout London and surrounding counties, and compared with pollution levels and bark pH. Sixty-four lichen and four bryophyte species were recorded. Three major zones were identified: (i) two central regions with a few lichens, bryophytes absent; (ii) a surrounding region with a more diverse flora including a high cover of nitrophyte lichens; and (iii) an outer region, characterised by species absent from central London, including acidophytes. Nineteen species were correlated with nitrogen oxides and 16 with bark pH, suggesting that transport-related pollution and bark acidity influence lichen and bryophyte distribution in London today. Lichens and bryophytes are responding to factors that influence human and environmental health in London. Biomonitoring therefore has a practical role to assess the effects of measures to improve London's air quality.

The potential nutritive values of acorns of Quercus suber, Quercus branti, Quercus coccifera, Quercus cerris and Quercus infectoria were estimated by chemical composition and in vitro gas production technique. Acorns collected at least 10... more

The potential nutritive values of acorns of Quercus suber, Quercus branti, Quercus coccifera, Quercus cerris and Quercus infectoria were estimated by chemical composition and in vitro gas production technique. Acorns collected at least 10 different trees in three experimental plots. There were significant (P<0.001) differences in the chemical composition among acorns obtained from different oak species. Crude protein (CP) contents of acorns ranged from 25.48 to 61.94 g/kg dry matter (DM). Neutral detergent fiber (NDF) contents ranged from 231.4 to 326.3 g/kg DM. Acid detergent fiber (ADF) contents ranged from 155.9 to 215.4 g/kg DM. Condensed tannin (CT) contents ranged from 7.2 to 26.7 g/kg DM. Starch contents ranged from 600.0 to 681.5 g/kg DM. Polyethylene glycol (PEG) addition significantly (P<0.001) increased the gas production and some estimated parameters of oak acorns. Although there is no significant (P>0.5) differences in the potential gas production of acorn among oak species when incubated in the absence of PEG, there is significant (P<0.001) differences in the potential gas production of acorn among oak species when incubated in the presence of PEG. Although the estimated organic matter (OMD) and metabolisable (ME) contents of acorn for Q. suber and Q. infectoria were significantly (P<0.001) higher than those for Q. branti, Q. coccifera and Q. cerris when incubated in the absence of PEG, the estimated OMD and ME contents of acorn for Quercus cerris and Q. infectoria were significantly lower than those for Q. suber, Q. branti and Q. coccifera when incubated in the presence of PEG. The improvement in gas production, OMD and ME in the presence of PEG emphasizes the negative effect of tannins on digestibility. As a conclusion, oak acorns have potential nutritive values for ruminant animals such as sheep and goat since acorns have high starch, OMD and ME but low level of CT contents. However these results obtained in the current study should be supported by in vivo feeding experiments.

Sardinia is a large island (24.100 km 2 , the 48 th largest in the world) placed in the middle of the Mediterranean basin. Home to extensive sclerophyllous forests and a range of other vegetation types, the island hosts thousands of... more

Sardinia is a large island (24.100 km 2 , the 48 th largest in the world) placed in the middle of the Mediterranean basin. Home to extensive sclerophyllous forests and a range of other vegetation types, the island hosts thousands of macrofungi, many of which are linked through ectomycorrhizal (ECM) symbiosis to trees, shrubs and herbs. Despite this rich diversity, however, our knowledge of Sardinian mycota is still superficial, as relatively few studies have been devoted to this topic. One of the reasons behind this lack of interest is probably the traditional mycophoby of Sardinian people, who until recently did collect and consume only a handful of wild edible mushrooms, and used a few more as medical remedies and for other purposes. This article provides a precise account of the current status of knowledge of Sardinia macrofungi, with a special focus on ECM species. We also report on the recent change of attitude of Sardinians towards mushrooms, with their sharp rise in popularity as food, but also as crucial ecological actors, and discuss relevant consequences.

The early Burdigalian (MN3) plant assemblage of the Güvem area (northwestern Central Anatolia) is preserved in lacustrine sediments of the Dereköy pyroclastics. Its age is well constrained by radiometric dates of basaltic rocks bracketing... more

The early Burdigalian (MN3) plant assemblage of the Güvem area (northwestern Central Anatolia) is preserved in lacustrine sediments of the Dereköy pyroclastics. Its age is well constrained by radiometric dates of basaltic rocks bracketing the pyroclastics, making the Güvem flora one of the extremely few precisely dated early Miocene floras in the Mediterranean region. The rich assemblage of impression fossils comprises ferns and fern allies (2 species), gymnosperms (12 spp.) and angiosperms (129 spp.). Ilex miodipyrena sp. nov. is described as a new fossil-species. The most diverse families in the assemblage are the Fagaceae with 12 taxa and the Fabaceae with 12 leaf morphotypes and one fruit taxon. Aquatic plants are represented by seven taxa, riparian (including palms) and swamp forest elements by >35 taxa, and lianas by three taxa (Smilax spp., Chaneya). The relatively large number of aquatic and riparian/swamp elements is congruent with the rich fish, amphibian and reptile record of the Güvem area. Another characteristic feature of the plant assemblage is the presence of various lobed leaves which show similarities with modern species of different families (e.g. Alangium, various Malvales). Trees and shrubs growing on well-drained soils and forming closed-canopy and open-canopy forests are the most diversified group (>70 taxa). In terms of number of specimens in the collection and based on field observations, by far the most abundant leaf fossils belong to evergreen oaks of Quercus drymeja and Q. mediter-ranea and to various types of foliage that cannot be assigned to a particular extant or extinct genus of Fagaceae. These sclerophyllous trees must have covered vast areas surrounding the wetlands that developed during the early Miocene in the Güvem Basin. Based on a recent reassessment of the ecology and taxonomic affinity of these trees, they are considered to reflect humid temperate climatic conditions but with a brief drier season during the winter months. These forests are more similar to the laurel forests of the southeastern United States and those stretching in a narrow belt south of the Himalayas to eastern central China. The large number of Fabaceae may indicate the presence of warm subtropical environments but this is difficult to assess, as they are known for having wide ecological ranges today and in the past. All in all, a larger part of the plant taxa point to forested vegetation. This is in agreement with previous palynological studies which detected only small amounts of her-baceous and grass pollen. Open patches of vegetation may have been restricted to river banks and to rocky areas in a volcanic landscape. The biogeographic patterns detected for the early Miocene of the Güvem assemblage are manifold; most taxa are widespread Northern Hemispheric elements. A substantial part of the species migrated from Asia into Europe during the (late) Paleogene and reached Anatolia during the early Miocene (Fagus, Paliu-rus, Chaneya, Ailanthus, Quercus kubinyii, Davallia haidingeri, Acer angustilobum, A. palaeosaccharinum). Fewer taxa may have been in Anatolia before they migrated to Europe (e.g. Nerium, Smilax miohavanensis, Quercus sosnowskyi). Finally, very few taxa are Anatolian endemics (e.g. Ilex miodipyrena).