Late Holocene Vegetation History of Grevena Province, Northwestern Greece

<p>Palynological investigations aimed at reconstructing the vegetation history of the Grevena Province, northwestern Greece were conducted in association with an archaeological research project. Fossil pollen, spores, microscopic charcoal particles, and sediment stratigraphies of radiocarbon-dated sediment cores from three sites in pine, beech, and oak woodland zones provide evidence of climatic changes, land use, and erosion during the last 3500 years. Identification of pollen and spores was aided by an extensive reference collection of local species and construction of a pollen key modelled on that of Faegri & Iversen (1989). Extant vegetation units are characterized by their contemporary pollen assemblages. Surface samples collected along an elevational transect show that a fairly direct relationship exists between the major vegetation zones and pollen deposition: pine, beech, and oak pollen predominate in their respective zones. Over-representation of pine pollen is notable. The sequence from Gomara site in the pine wood-pasture zone at 1750 m asl covers the time span c. 1340 BC to 700 AD. A local open pine wood was gradually replaced by beech after c. 890 BC, perhaps through reduced disturbance and/or increased precipitation. A herbaceous pollen spike at c. 80 BC resulted from deposition of volcanic ash. Pine wood replaced beech at c. 330 AD. Two periods of accelerated erosion coincide with the pine wood phases and with anthropogenic burning and grazing. These periods are separated by a period of abandonment when the climate was probably wetter. The sequence from Anelia site in the beech wood zone at 1440 m asl spans c. 1560-1989 AD. The site was surrounded by beech wood for the duration of the sequence. Regional and local burning of vegetation is indicated by an abundance of microscopic charcoal particles from c. 1560 until c. 1730 AD, when it ceased. Periods of erosion occurred during this period. After c. 1730 AD a homogeneous peat formed on the wetland, suggesting a period of greater landscape stability. From pollen evidence, a variety of land-use practices such as cereal cultivation, grazing, coppicing, and lumbering were carried out in the vicinity of the site especially before c. 1730 AD, but these diminished after 1920 AD. The lower part of the sequence from Kellia site in the oak wood-steppe zone at 580 m asl is insecurely dated, but the upper part spans c. 1230-1989 AD. The lowlands were covered with deciduous/semi-evergreen oak woods for the duration of the sequence. Since c. 1230 AD land close to the site was intensively cultivated with a variety of cereals. Burning occurred frequently throughout the period. The ratio of deciduous to semi-evergreen oak pollen is correlated with temperature and indicates a decline from c. 1230-1680 AD, after which temperature increased, a pattern similar to that of the Little Ice Age. Frontispiece The cultural landscape of Grevena Province looking NE towards the Vourinos Mountains on the eastern border of Grevena, from a prominent hill about 1 1/4 km NW of the modern village of Itea. In the foreground is the stubble of a wheat field. Beyond is an 18th century church dedicated to Aghia Panaghia. The middle ground is the steppe oak wood pasture of Grevena plains. Recent erosion on the sides of gullies can be seen here, even though they appear to be well vegetated. Frescoes in the church are shown in the enlargement. It stands on a registered archaeological site, Grevena Project 108 (21 degrees 36.18' E, 40 degrees 04.29' N, 640 m asl) that covers more than 10,000 m2. Archaeological evidence dating to Early Iron Age, Archaic, Classical, Hellenistic, Roman, Early Medieval and Ottoman periods has been recorded.</p>

Late Holocene Vegetation History of Grevena Province, Northwestern Greece

<p>Palynological investigations aimed at reconstructing the vegetation history of the Grevena Province, northwestern Greece were conducted in association with an archaeological research project. Fossil pollen, spores, microscopic charcoal particles, and sediment stratigraphies of radiocarbon-dated sediment cores from three sites in pine, beech, and oak woodland zones provide evidence of climatic changes, land use, and erosion during the last 3500 years. Identification of pollen and spores was aided by an extensive reference collection of local species and construction of a pollen key modelled on that of Faegri & Iversen (1989). Extant vegetation units are characterized by their contemporary pollen assemblages. Surface samples collected along an elevational transect show that a fairly direct relationship exists between the major vegetation zones and pollen deposition: pine, beech, and oak pollen predominate in their respective zones. Over-representation of pine pollen is notable. The sequence from Gomara site in the pine wood-pasture zone at 1750 m asl covers the time span c. 1340 BC to 700 AD. A local open pine wood was gradually replaced by beech after c. 890 BC, perhaps through reduced disturbance and/or increased precipitation. A herbaceous pollen spike at c. 80 BC resulted from deposition of volcanic ash. Pine wood replaced beech at c. 330 AD. Two periods of accelerated erosion coincide with the pine wood phases and with anthropogenic burning and grazing. These periods are separated by a period of abandonment when the climate was probably wetter. The sequence from Anelia site in the beech wood zone at 1440 m asl spans c. 1560-1989 AD. The site was surrounded by beech wood for the duration of the sequence. Regional and local burning of vegetation is indicated by an abundance of microscopic charcoal particles from c. 1560 until c. 1730 AD, when it ceased. Periods of erosion occurred during this period. After c. 1730 AD a homogeneous peat formed on the wetland, suggesting a period of greater landscape stability. From pollen evidence, a variety of land-use practices such as cereal cultivation, grazing, coppicing, and lumbering were carried out in the vicinity of the site especially before c. 1730 AD, but these diminished after 1920 AD. The lower part of the sequence from Kellia site in the oak wood-steppe zone at 580 m asl is insecurely dated, but the upper part spans c. 1230-1989 AD. The lowlands were covered with deciduous/semi-evergreen oak woods for the duration of the sequence. Since c. 1230 AD land close to the site was intensively cultivated with a variety of cereals. Burning occurred frequently throughout the period. The ratio of deciduous to semi-evergreen oak pollen is correlated with temperature and indicates a decline from c. 1230-1680 AD, after which temperature increased, a pattern similar to that of the Little Ice Age. Frontispiece The cultural landscape of Grevena Province looking NE towards the Vourinos Mountains on the eastern border of Grevena, from a prominent hill about 1 1/4 km NW of the modern village of Itea. In the foreground is the stubble of a wheat field. Beyond is an 18th century church dedicated to Aghia Panaghia. The middle ground is the steppe oak wood pasture of Grevena plains. Recent erosion on the sides of gullies can be seen here, even though they appear to be well vegetated. Frescoes in the church are shown in the enlargement. It stands on a registered archaeological site, Grevena Project 108 (21 degrees 36.18' E, 40 degrees 04.29' N, 640 m asl) that covers more than 10,000 m2. Archaeological evidence dating to Early Iron Age, Archaic, Classical, Hellenistic, Roman, Early Medieval and Ottoman periods has been recorded.</p>

The Wooden Roof Framing Elements, Furniture and Furnishing of the Etruscan Domus of the Dolia of Vetulonia (Southern Tuscany, Italy)

The Etruscan Domus of the Dolia remained hidden until 2009, when archaeological excavations began in the Etruscan–Roman district of Vetulonia (Southern Tuscany). Based on the classification of the archaeological materials recovered, the destruction of the Domus and the Etruscan city of Vetulonia was traced back to the 1st century BC. The highly various and precious materials recovered inside the Domus revealed the richness of the building and its inhabitants. With this study, we present the anthracological analyses from the Domus of the Dolia. Wood charcoals were recovered from different house rooms, which had different functions based on the archaeological evidence. The tree species employed for the construction of the roof of the building were deciduous and semi-deciduous oak wood (Quercus sect. robur, Quercus sect. cerris) and silver fir wood (Abies cf. alba). Evergreen oak wood (Quercus sect. suber), boxwood (Buxus sempervirens), beech wood (Fagus cf. sylvatica), maple wood (Acer sp.) and cherry wood (Prunus cf. avium) were adopted for the furniture and furnishings of the house. Moreover, wood charcoal fragments of fruit trees belonging to the family of Rosaceae were identified, documenting a possible garden inside the court of the house. The study shows the use of the local tree species primarily. The silver fir wood and beech wood were likely sourced from the nearby (roughly 60 km) Mount Amiata.

8,000 years of climate, vegetation, fire and land-use dynamics in the thermo-mediterranean vegetation belt of northern Sardinia (Italy)

Knowledge about the vegetation history of Sardinia, the second largest island of the Mediterranean, is scanty. Here, we present a new sedimentary record covering the past ~ 8,000 years from Lago di Baratz, north-west Sardinia. Vegetation and fire history are reconstructed by pollen, spores, macrofossils and charcoal analyses and environmental dynamics by high-resolution element geochemistry together with pigment analyses. During the period 8,100–7,500 cal bp, when seasonality was high and fire and erosion were frequent, Erica arborea and E. scoparia woodlands dominated the coastal landscape. Subsequently, between 7,500 and 5,500 cal bp, seasonality gradually declined and thermo-mediterranean woodlands with Pistacia and Quercus ilex partially replaced Erica communities under diminished incidence of fire. After 5,500 cal bp, evergreen oak forests expanded markedly, erosion declined and lake levels increased, likely in response to increasing (summer) moisture availability. Increased anthropogenic fire disturbance triggered shrubland expansions (e.g. Tamarix and Pistacia) around 5,000–4,500 cal bp. Subsequently around 4,000–3,500 cal bp evergreen oak-olive forests expanded massively when fire activity declined and lake productivity and anoxia reached Holocene maxima. Land-use activities during the past 4,000 years (since the Bronze Age) gradually disrupted coastal forests, but relict stands persisted under rather stable environmental conditions until ca. 200 cal bp, when agricultural activities intensified and Pinus and Eucalyptus were planted to stabilize the sand dunes. Pervasive prehistoric land-use activities since at least the Bronze Age Nuraghi period included the cultivation of Prunus, Olea europaea and Juglans regia after 3,500–3,300 cal bp, and Quercus suber after 2,500 cal bp. We conclude that restoring less flammable native Q. ilex and O. europaea forest communities would markedly reduce fire risk and erodibility compared to recent forest plantations with flammable non-native trees (e.g. Pinus, Eucalyptus) and xerophytic shrubland (e.g. Cistus, Erica).

Remote Sensing Analysis to Quantify Change in Woodland Canopy Cover on the San Carlos Apache Reservation, Arizona, USA (1935 vs. 2017)

Since the late 1800s, pinyon–juniper woodland across the western U.S. has increased in density and areal extent and encroached into former grassland areas. The San Carlos Apache Tribe wants to gain qualitative and quantitative information on the historical conditions of their tribal woodlands to use as a baseline for restoration efforts. At the San Carlos Apache Reservation, in east-central Arizona, large swaths of woodlands containing varying mixtures of juniper (Juniperus spp.), pinyon (Pinus spp.) and evergreen oak (Quercus spp.) are culturally important to the Tribe and are a focus for restoration. To determine changes in canopy cover, we developed image analysis techniques to monitor tree and large shrub cover using 1935 and 2017 aerial imagery and compared results over the 82-year interval. Results showed a substantial increase in the canopy cover of the former savannas, and encroachment (mostly juniper) into the former grasslands of Big Prairie. The Tribe is currently engaged in converting juniper woodland back into an open savanna, more characteristic of assumed pre-reservation conditions for that area. Our analysis shows areas on Bee Flat that, under the Tribe’s active restoration efforts, have returned woodland canopy cover to levels roughly analogous to that measured in 1935.

Compound-specific δ2H using analytical pyrolysis (Py-CSIA) for assessing source and processes of soil organic matter driven by climatic changes within a Mediterranean evergreen oak forest (dehesas)

&lt;p&gt;Soil organic matter (SOM) is composed of multiple components from the living material, such as phenolic compounds, organic acids, lipids, peptides, polyesters, etc. A relevant part of these compounds forms part of supramolecular structures or mineral associations. Non-exchangeable hydrogen in SOM compounds is worth of study as an approach to estimate dynamic processes such as stabilization, mineralization, or biodegradation. The determination of H isotopes in SOMs faces analytical challenges related with e.g., the strength of the H bond, its exchangeability with ambient H from water or the instability of the isotopic analysis [1]. Nonetheless, along with the study of C isotopes, the study of H isotopes may certainly result in a complementary to give some light in this complex system, estimate the fate of organic compounds, and to better understand the link between hydrogen and carbon cycles in SOM [2].&lt;/p&gt;&lt;p&gt;In this communication, we describe and validate a methodology based on analytical pyrolysis for the direct measure of compound-specific H isotope composition (&amp;#948;&lt;sup&gt;2&lt;/sup&gt;H) in soil samples. The technique combines Py-GC with a high-temperature conversion reactor and a continuous flow isotope ratio mass spectrometer (IRMS) (Py-GC-HTC-IRMS).&lt;/p&gt;&lt;p&gt;Composite &lt;em&gt;dehesa&lt;/em&gt; surface (0-10 cm) soil samples (Pozoblanco, C&amp;#243;rdoba, Spain) were taken from four forced climatic treatment plots representing warming (W), drought (D), its combination (W+D), and control (D), installed in two different habitats: under evergreen oak canopy and in the open pasture. The samples were analysed in triplicate by conventional analytical pyrolysis (Py-GC/MS) and in parallel for &amp;#948;&lt;sup&gt;2&lt;/sup&gt;H Py-CSIA using the same chromatographic conditions and separation column type.&lt;/p&gt;&lt;p&gt;Up to 32 compounds were identified by Py-GC/MS, which H isotope composition corresponded presumably to non-exchangeable H, and with origin mainly from lignin (G- and S- units) and lipids. The H isotope composition showed an estimated average of -55 &amp;#8240; &amp;#177; 7.09 for G-lignin units, -64 &amp;#8240; &amp;#177; 8.64 S-lignin units and lighter -112 &amp;#8240; &amp;#177; 4.32 for fatty acids (-109 &amp;#8240; &amp;#177; 3.65) and the n-alkane series (C-19 to C-31). Significant differences are reportedly driven by the differences in habitat: more depleted &amp;#948;&lt;sup&gt;2&lt;/sup&gt;H values were found in SOM produced in the open pasture than under the tree canopy. In addition, a &amp;#948;&lt;sup&gt;2&lt;/sup&gt;H enrichment is observed for lignin-derived compounds in SOM under the W+D treatment.&lt;/p&gt;&lt;p&gt;The technique used and tested is expected to bring novelty results in relation to the processes affecting the isotopic composition of non-exchangeable hydrogen exerted by climatic treatments on diverse SOM specific compounds. Besides presenting the analytical challenges that are faced, we will discuss the effects of canopy and climatic treatments to tackle potential harsh climatic conditions as predicted, especially in Mediterranean areas.&amp;#160;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Acknowledgement:&lt;/strong&gt; INTERCARBON project (CGL2016-78937-R), DECAFUN (CGL2015-70123-R). MICIU for funding FPI research grants (BES-2017-07968). Mrs Desir&amp;#233; Monis, Mrs Alba M. Carmona &amp; Mr Eduardo Guti&amp;#233;rrez Gonz&amp;#225;lez are acknowledged for technical assistance.&lt;/p&gt;&lt;p&gt;[1] Paul, A. et al (2016). &lt;em&gt;Biogeosciences, 13&lt;/em&gt;, 6587&amp;#8211;6598.&lt;/p&gt;&lt;p&gt;[2] Seki, O. et al (2010). &lt;em&gt;Geochimica et Cosmochimica Acta,&amp;#160;74&lt;/em&gt;(2), 599-613.&lt;/p&gt;

Evergreen Oak Biomass Residues for Firewood

This chapter presents the assessment of the availability for residential heating of residual biomass from cork and holm oaks in a 12,188 ha agroforest area in Portugal. First, the above-ground biomass of evergreen oaks using very high spatial resolution satellite images was determined, followed by the definition of different scenarios for residues removal from the stands. The useful energy potential of the firewood that can be collected from the study area under the various silviculture scenarios was determined considering different energy conversion technologies: open fireplaces (still popular in Portugal) and more efficient closed burning appliances. Additionally, emissions of airborne pollutants from combusting all the available residual biomass in the study area were determined. Depending on the percentage of residues collected when the trees are pruned and on the conversion technologies used, the energy potential of evergreen oak firewood ranged from 5.0 × 106 MJ year−1 to 7.5 × 107 MJ year−1. Heavier pruning combined with the use of open fireplaces generates less useful heat and much higher emissions of pollutants per unit useful energy produced than lighter pruning combined with a more efficient technology. This case study illustrates the need to promote the transition from inefficient to more efficient and cleaner technologies.

Effect of elicitors on holm oak somatic embryo development and efficacy inducing tolerance to Phytophthora cinnamomi

Holm oak trees (Quercus ilex L.) mortality is increasing worryingly in the Mediterranean area in the last years. To a large degree this mortality is caused by the oomycete Phytophthora spp., which is responsible for forest decline and dieback in evergreen oak forest areas of the southwestern Iberian Peninsula. This study is based on the possibility of applying chemical elicitors or filtered oomycete extracts to holm oak somatic embryos (SE) in order to induce epigenetic memory, priming, that may increase tolerance to the pathogen in future infections. To this end, we first examined the effect of priming treatments on SE development and its oxidative stress state, to avoid elicitors that may cause damage to embryogenic tissues. Both, the sterile oomycete extracts and the chemical elicitor methyl jasmonate (MeJA) did not produce any detrimental effect on SE growth and development, unlike the elicitors benzothiadiazole (BTH) and p-aminobenzoic acid (PABA) that reduced the relative weight gain and resulted in necrotic and deformed SE when were applied at high concentrations (25 µM BTH or 50 µM PABA) in accordance with their high malondialdehyde content. No significant differences among elicitation treatments were found in dual culture bioassays, although those SEs elicited with 50 µM MeJA increased H2O2 production after challenged against active oomycete indicating the activation of stress response. Since this elicitation treatment did not produce any adverse effect in the embryogenic process we suggest that could be used in further priming experiments to produce holm oak plants adapted to biotic stress.