Journal articles on the topic 'Holm oak ecosystem'
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Mora-Sala, Beatriz, Mónica Berbegal, and Paloma Abad-Campos. "The Use of qPCR Reveals a High Frequency of Phytophthora quercina in Two Spanish Holm Oak Areas." Forests 9, no. 11 (November 10, 2018): 697. http://dx.doi.org/10.3390/f9110697.
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The struggling Spanish holm oak woodland situation associated with Phytophthora root rot has been studied for a long time. Phytophthora cinnamomi is considered the main, but not the only species responsible for the decline scenario. This study verifies the presence and/or detection of Phytophthora species in two holm oak areas of Spain (southwestern “dehesas” and northeastern woodland) using different isolation and detection approaches. Direct isolation and baiting methods in declining and non-declining holm oak trees revealed Phytophthora cambivora, Phytophthora cinnamomi, Phytophthora gonapodyides, Phytophthora megasperma, and Phytophthora pseudocryptogea in the dehesas, while in the northeastern woodland, no Phytophthora spp. were recovered. Statistical analyses indicated that there was not a significant relationship between the Phytophthora spp. isolation frequency and the disease expression of the holm oak stands in the dehesas. Phytophthora quercina and P. cinnamomi TaqMan real-time PCR probes showed that both P. cinnamomi and P. quercina are involved in the holm oak decline in Spain, but P. quercina was detected in a higher frequency than P. cinnamomi in both studied areas. Thus, this study demonstrates that molecular approaches complement direct isolation techniques in natural and seminatural ecosystem surveys to determine the presence and distribution of Phytophthora spp. This is the first report of P. pseudocryptogea in Europe and its role in the holm oak decline should be further studied.
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Ibañez, Mercedes, María José Leiva, Cristina Chocarro, Salvador Aljazairi, Àngela Ribas, and Maria-Teresa Sebastià. "Tree—Open Grassland Structure and Composition Drive Greenhouse Gas Exchange in Holm Oak Meadows of the Iberian Peninsula." Agronomy 11, no. 1 (December 28, 2020): 50. http://dx.doi.org/10.3390/agronomy11010050.
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Iberian holm oak meadows are savannah-like ecosystems that result from traditional silvo-pastoral practices. However, such traditional uses are declining, driving changes in the typical tree—open grassland structure of these systems. Yet, there are no studies integrating the whole ecosystem—including the arboreal and the herbaceous layer—as drivers of greenhouse gas (GHG: CO2, CH4 and N2O) dynamics. Here, we aimed at integrating the influence of tree canopies and interactions among plant functional types (PFT: grasses, forbs, and legumes) of the herbaceous layer as GHG exchange drivers. For that purpose, we performed chamber-based GHG surveys in plots dominated by representative canopy types of Iberian holm oak meadows, including Quercus species and Pinus pinea stands, the last a common tree plantation replacing traditional stands, and unraveled GHG drivers through a diversity-interaction model approach. Our results show the tree–open grassland structure, especially drove CO2 and N2O fluxes, with higher emissions under the canopy than in the open grassland. Emissions under P. pinea canopies are higher than those under Quercus species. In addition, the inclusion of diversity and compositional terms of the herbaceous layer improve the explained variability, with legumes enhancing CO2 uptake and N2O emissions. Changes in the tree cover and tree species composition, in combination with changes in the structure and composition of the herbaceous layer, will imply deep changes in the GHG exchange of Iberian holm oak meadows. These results may provide some guidelines to perform better management strategies of this vast but vulnerable ecosystem.
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Ogaya, Romà, and Josep Peñuelas. "Climate Change Effects in a Mediterranean Forest Following 21 Consecutive Years of Experimental Drought." Forests 12, no. 3 (March 6, 2021): 306. http://dx.doi.org/10.3390/f12030306.
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Research Highlights: A small, long-term decrease in the water availability in a Mediterranean holm oak forest elicited strong effects on tree stem growth, mortality, and species composition, which led to changes in the ecosystem function and service provision. Background and Objectives: Many forest ecosystems are increasingly challenged by stress conditions under climate change. These new environmental constraints may drive changes in species distribution and ecosystem function. Materials and Methods: An evergreen Mediterranean holm oak (Quercus ilex L.) forest was subjected to 21 consecutive years of experimental drought (performing 30% of rainfall exclusion resulted in a 15% decrease in soil moisture). The effects of the annual climatic conditions and the experimental drought on a tree and shrub basal area increment were studied, with a focus on the two most dominant species (Q. ilex and the tall shrub Phillyrea latifolia L.). Results: Stem growth decreased and tree mortality increased under the experimental drought conditions and in hot and dry years. These effects differed between the two dominant species: the basal area of Q. ilex (the current, supradominant species) was dependent on water availability and climatic conditions, whereas P. latifolia was more tolerant to drought and experienced increased growth rates in plots where Q. ilex decay rates were high. Conclusions: Our findings reveal that small changes in water availability drive changes in species growth, composition, and distribution, as demonstrated by the continuous and ongoing replacement of the current supradominant Q. ilex by the subdominant P. latifolia, which is better adapted to tolerate hot and dry environments. The consequences of these ecological transformations for ecosystem function and service provision to human society are discussed.
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Campos, Álvarez, Oviedo, Ovando, Mesa, and Caparrós. "Income and Ecosystem Service Comparisons of Refined National and Agroforestry Accounting Frameworks: Application to Holm Oak Open Woodlands in Andalusia, Spain." Forests 11, no. 2 (February 7, 2020): 185. http://dx.doi.org/10.3390/f11020185.
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There is growing consensus regarding the implementation of a new statistical framework for environmental-economic accounting to improve ecosystem related policies. As the standard System of National Accounts (SNA) fails to measure the economic contribution of ecosystems to the total income of individuals, governments recognize the need to expand the standard SNA through the ongoing System of Environmental Economic Accounting (SEEA). Based on the authors’ own data, this study focuses on linking 15 economic activities and 12 ecosystem services for a holm oak (Quercus ilex L.) open woodlands (HOW) ecosystem type in Andalusia, Spain. We emphasize that overcoming the challenges of multiple use is preferable to measuring single ecosystem products for improving habitat conservation policies. The objectives of this paper are to measure and compare the environmental assets, ecosystem services, and incomes at basic and social prices by applying a refined version of the standard System of National Accounts (rSNA) and the authors’ Agroforestry Accounting System (AAS), respectively, to HOW. Considering intermediate products and consumptions of HOW farmer and government activities, we find that the rSNA ecosystem services and environmental incomes at basic prices are 123.3 €/ha and −28.0 €/ha, respectively, while those of the AAS at social prices are 442.2 €/ha and 250.8 €/ha. Given advances in non-market valuation techniques, we show that an expanded definition of economic activities can be applied to measure the contribution to total income of managed natural areas taking into account the multiple uses of the ecosystem type. However, HOW sustainability continues to be a challenging issue that requires ecological threshold indicators to be identified, not only because of the economic implications but also because they provide vital information on which to base policy implementation.
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Fernández Ruiz, Abel, David Rodríguez de la Cruz, José Luis Vicente Villardón, Sergio Sánchez Durán, Prudencio García Jiménez, and José Sánchez Sánchez. "Considerations on Field Methodology for Macrofungi Studies in Fragmented Forests of Mediterranean Agricultural Landscapes." Agronomy 12, no. 2 (February 20, 2022): 528. http://dx.doi.org/10.3390/agronomy12020528.
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The methodology used for the determination of macrofungal diversity in Mediterranean areas differs in the time of sampling and the number of years displayed, making it difficult to compare results. Furthermore, the results could be refuted because the studies are being conducted over an insufficient number of years or without considering the variation of the meteorological conditions from one year to the next and its effects on fruiting time, which might not fit the sampling. In order to optimize field work on fungal fruiting in Mediterranean environments dominated by holm oak (Quercus ilex L.), a weekly field analysis of macrofungal diversity from February 2009 to June 2013 was carried out in a Mediterranean holm oak forest in the middle-west of the Iberian Peninsula. The results revealed that fruiting bodies appeared throughout the year and that there was a delay in autumn fruiting, overlapping with spring. All this seems to indicate that weekly collection throughout the year and for a period of two years could be sufficient to estimate the macrofungal biodiversity of this ecosystem.
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Campos, Pablo, Alejandro Álvarez, José L. Oviedo, Paola Ovando, Bruno Mesa, and Alejandro Caparrós. "Refined Systems of National Accounts and Experimental Ecosystem Accounting Versus the Simplified Agroforestry Accounting System: Testing in Andalusian Holm Oak Open Woodlands." Forests 11, no. 4 (April 2, 2020): 393. http://dx.doi.org/10.3390/f11040393.
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The scientific debate over how to make visible the connections between the standard System of National Accounts (SNA) and its ongoing satellite Environmental Economic Ecosystem Accounting–Experimental Ecosystem Accounting (SEEA–EEA) is a challenge that is still pending. The literature on environmental accounting of agroforestry and silvopastoral landscapes rarely values the multiple ecosystem services of an area, an economic unit (e.g., farm), or a vegetation type (e.g., holm oak—Quercus ilex L.—open woodland). Generally, the literature presents the market value of the products consumed directly or a correction of the latter that reduces their exchange values in order to approximate them to their resource rents. In our previous publications, we have applied and compared our Agroforestry Accounting System (AAS) with the System of National Accounts (SNA), and we refined the latter to avoid the lag between income generation and its accounting in the period in which the product is extracted. These previous publications did not develop experimental applications of the SEEA–EEA with comparisons to the SNA and it being integrated into the AAS. The main novelty of this article is that, for the first time, we present detailed applications and comparisons of our developments of the refined SEEA–EEA and refined SNA with a simplified version of the AAS. The accounting frameworks applied take the production and capital accounts in the process of being updated by the United Nations Statistics Division (UNSD) at the scale of the holm oak open woodlands of Andalusia into account. In this study, we compare three environmental accounting approaches for ecosystem services and environmental income measurements at basic and social prices: our slightly refined standard System of National Accounts (rSNA); our refined, updated and ongoing satellite System of Environmental Economic Accounting–Experimental Ecosystem Accounting (rSEEA–EEA); and our simplified Agroforestry Accounting System (sAAS). We tested them for 15 economic activities in 1408 thousand hectares of the predominantly mixed holm oak open woodland (HOW) land use tiles in the region of Andalusia, Spain. We considered the government institutional sector to be the collective owner of public economic activities, which we incorporated in the rSNA and the sAAS approaches. We discuss consistencies in environmental incomes identified from the results of the three ecosystem accounting frameworks applied to the HOW. The discrepancies in the measurement of ecosystem services of the government institutional sector between the rSEEA–EEA and the sAAS were due to the omission in the former of the government manufactured costs incurred in the supply of freely consumed public final products. The most notable finding of our comparison is that the ecosystem services and the environmental income results for individual market products offered the same values, whichever the ecosystem accounting framework applied. This was not the case with the ecosystem services of public products without market prices, due to the fact that the rSNA estimates these products at production cost and the rSEEA–EEA did not consider the government manufactured production costs and ordinary manufactured net operating margin of government final public product consumption. We also found that, according to modeling of the scheduled management of future biological resources of the HOW, the environmental income shows biological sustainability of the individual nature-based total product consumption.
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Reichstein, M., J. D. Tenhunen, O. Roupsard, J. M. Ourcival, S. Rambal, S. Dore, and R. Valentini. "Ecosystem respiration in two Mediterranean evergreen Holm Oak forests: drought effects and decomposition dynamics." Functional Ecology 16, no. 1 (February 2002): 27–39. http://dx.doi.org/10.1046/j.0269-8463.2001.00597.x.
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Sardans, Jordi, Ifigenia Urbina, Oriol Grau, Dolores Asensio, Romà Ogaya, and Josep Peñuelas. "Long-term drought decreases ecosystem C and nutrient storage in a Mediterranean holm oak forest." Environmental and Experimental Botany 177 (September 2020): 104135. http://dx.doi.org/10.1016/j.envexpbot.2020.104135.
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Naziha, Melouani, and Kadik Leila. "Ecosystem dynamics after forest fire. Blideen Atlas case." Territorium, no. 29(I) (December 17, 2021): 67–75. http://dx.doi.org/10.14195/1647-7723_29-1_6.
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Human disturbances affect the majority of terrestrial ecosystems. The radical changes in the behaviour of ecological systems, partial or total destruction of plant biomass, often with the death of fundamental entities. Of these disturbances, fires affect many terrestrial ecosystems, particularly forests, by changing their floristic composition, their structure and their functioning; the global average annual forest area burned is estimated at 65 million ha. The Mediterranean basin, a hotspot, annually loses between 0.5 and 1 million hectares of forest. In Algeria, the annual average of areas destroyed by fire is between 45,000 and 50,000 ha. Our work set out to study the changes in the plant coverage of the land one year after the passage of fire. We studied the effects at the floristic, ecological and dynamic level in a forest ecosystem located in the north of Algeria (Atlas Blideen). The phytoecological inventory of vegetation (74 surveys, 162 species) was carried out from subjective sampling. To highlight the different groupings in the study area, classical statistical treatments (factorial analysis of correspondences) were applied to the floristic and ecological data. The results of computer processing made it possible to individualize and classify four plant groups according to the degree of the fire. The qualitative and quantitative analysis of these groups shows a therophytization of the flora, due to the regression of the forest cover (disappearance of the phanerophytes) caused by the passage of fire, with a floral procession represented mainly by Asteraceae, Poaceae and Fabaceae and an index disturbance which greatly exceeds 50%. However, some tree and shrub taxa such as cork oak, holm oak and Pistacia lentiscus tree have the capacity to reappear by rejecting the calcined stumps.
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Adamo, Irene, Svetlana Dashevskaya, and Josu G. Alday. "Fungal Perspective of Pine and Oak Colonization in Mediterranean Degraded Ecosystems." Forests 13, no. 1 (January 8, 2022): 88. http://dx.doi.org/10.3390/f13010088.
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Forest restoration has become one of the most important challenges for restoration ecology in the recent years. In this regard, soil fungi are fundamental drivers of forest ecosystem processes, with significant implications for plant growth and survival. However, the post-disturbance recovery of belowground communities has been rarely assessed, especially in highly degraded systems such as mines. Our aim was to compare forests and mined systems for biomass and structure of fungal communities in soil during early stages of tree establishment after disturbance. We performed ergosterol analysis and PacBio and Illumina sequencing of internal transcribed spacer 2 amplicons across soil layers in P. sylvestris, Q. robur and Q. ilex (holm oak) forests and naturally revegetated mined sites. In pine forests, total fungal biomass was significantly higher in litter and humus compared to mineral layers, with dominance of the mycorrhizal genera Tomentella, Inocybe and Tricholoma. Conversely, in oak forests the most abundant mycorrhizal genera were Tomentella, Cortinarius and Sebacina, but the biomass of saprotrophic fungi was greater in the litter layer compared to mycorrhizal fungi, with the genus Preussia being the most abundant. In the revegetated mined sites, ectomycorrhizal fungi dominated in the humus and mineral layers, with the mycorrhizal genus Oidiodendron being dominant. In contrast, in holm oak forests saprotrophic fungi dominated both soil humus and mineral layers, with the genera of Alternaria, Bovista and Mycena dominating the soil humus forest layer, while the genus Cadophora dominated the mineral layer. The habitat-specific differences in soil fungal community composition and putative functions suggest that an understanding of soil–plant–microbial interactions for different tree species and use of specific soil/litter inoculum upon planting/seeding might help to increase the effectiveness of tree restoration strategies in Mediterranean degraded sites.
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Serrano, João, Shakib Shahidian, José Marques da Silva, Francisco Moral, Fernando Carvajal-Ramirez, Emanuel Carreira, Alfredo Pereira, and Mário de Carvalho. "Evaluation of the Effect of Dolomitic Lime Application on Pastures—Case Study in the Montado Mediterranean Ecosystem." Sustainability 12, no. 9 (May 6, 2020): 3758. http://dx.doi.org/10.3390/su12093758.
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The Montado ecosystem, predominant in the Mediterranean region, consists of poor soils, a sparse cover of cork and holm with an understory of natural biodiverse pastures, grazed by animals in extensive regime. The recommended procedure for increasing productivity of these pastures is based on the application of phosphate fertilizer. One of the main productivity-limiting factors is, however, associated with soil acidity. The objective of this work was to evaluate the simultaneous effect of the holm oak canopy and the application of dolomitic lime on the productivity and quality of a permanent biodiverse pasture, grazed by sheep, in an acid soil (pH = 5.4 ± 0.3). Pasture was monitored at the end of autumn 2018 and winter and spring 2019. The results show that amendment of soil acidity is a slow and gradual process that improves soil Mg/Mn ratio and has a positive impact on pasture productivity and quality. Pasture crude protein availability (CP, kg·ha−1), which is based on both pasture dry matter yield (kg·ha−1) and quality (CP, %), proved to be a very practical indicator of the contributions of tree canopy and soil acidity correction to the holistic management of the Montado ecosystem.
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Martinez-Sanchez, A., S. Rojo, and M. A. Marcos-Garcia. "Annual and spatial activity of dung flies and carrion in a Mediterranean holm-oak pasture ecosystem." Medical and Veterinary Entomology 14, no. 1 (March 2000): 56–63. http://dx.doi.org/10.1046/j.1365-2915.2000.00205.x.
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Vallicrosa, Helena, Jordi Sardans, Romà Ogaya, Pere Roc Fernández, and Josep Peñuelas. "Short-Term N-Fertilization Differently Affects the Leaf and Leaf Litter Chemistry of the Dominant Species in a Mediterranean Forest under Drought Conditions." Forests 12, no. 5 (May 12, 2021): 605. http://dx.doi.org/10.3390/f12050605.
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Nitrogen (N) deposition is a key driver of global change with significant effects on carbon (C) cycling, species fitness, and diversity; however, its effects on Mediterranean ecosystems are unclear. Here, we simulated N deposition in an N-fertilization experiment with 15N-labeled fertilizer in a montane evergreen Mediterranean holm oak forest, in central Catalonia, to quantify short-term impacts on leaf, leaf litter elemental composition, and resorption efficiency in three dominant species (Quercus ilex, Phillyrea latifolia, and Arbutus unedo). We found that even under drought conditions, 15N isotope analysis of leaf and leaf litter showed a rapid uptake of the added N, suggesting an N deficient ecosystem. Species responses to N fertilization varied, where A. unedo was unaffected and the responses in P. latifolia and Q. ilex were similar, albeit with contrasting magnitude. P. latifolia benefited the most from N fertilization under drought conditions of the experimental year. These differences in species response could indicate impacts on species fitness, competition, and abundance under increased N loads in Mediterranean forest ecosystems. Further research is needed to disentangle interactions between long-term N deposition and the drought predicted under future climate scenarios in Mediterranean ecosystems.
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Bastida, F., R. López-Mondéjar, P. Baldrian, M. Andrés-Abellán, N. Jehmlich, I. F. Torres, C. García, and F. R. López-Serrano. "When drought meets forest management: Effects on the soil microbial community of a Holm oak forest ecosystem." Science of The Total Environment 662 (April 2019): 276–86. http://dx.doi.org/10.1016/j.scitotenv.2019.01.233.
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Smit, Christian, Mario Díaz, and Patrick Jansen. "Establishment limitation of holm oak (Quercus ilex subsp. ballota (Desf.) Samp.) in a Mediterranean savanna — forest ecosystem." Annals of Forest Science 66, no. 5 (January 2009): 511. http://dx.doi.org/10.1051/forest/2009028.
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Campos, Pablo, Alejandro Álvarez, Bruno Mesa, José L. Oviedo, Paola Ovando, and Alejandro Caparrós. "Total income and ecosystem service sustainability index: Accounting applications to holm oak dehesa case study in Andalusia-Spain." Land Use Policy 97 (September 2020): 104692. http://dx.doi.org/10.1016/j.landusepol.2020.104692.
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Rodríguez, Alexandra, Jorge Curiel Yuste, Ana Rey, Jorge Durán, Raúl García-Camacho, Antonio Gallardo, and Fernando Valladares. "Holm oak decline triggers changes in plant succession and microbial communities, with implications for ecosystem C and N cycling." Plant and Soil 414, no. 1-2 (November 30, 2016): 247–63. http://dx.doi.org/10.1007/s11104-016-3118-4.
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Flores-Rentería, Dulce, Ana Rincón, Teresa Morán-López, Ana-Maria Hereş, Leticia Pérez-Izquierdo, Fernando Valladares, and Jorge Curiel Yuste. "Habitat fragmentation is linked to cascading effects on soil functioning and CO2emissions in Mediterranean holm-oak-forests." PeerJ 6 (October 30, 2018): e5857. http://dx.doi.org/10.7717/peerj.5857.
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We studied key mechanisms and drivers of soil functioning by analyzing soil respiration and enzymatic activity in Mediterranean holm oak forest fragments with different influence of the agricultural matrix. For this, structural equation models (SEM) were built including data on soil abiotic (moisture, temperature, organic matter, pH, nutrients), biotic (microbial biomass, bacterial and fungal richness), and tree-structure-related (basal area) as explanatory variables of soil enzymatic activity and respiration. Our results show that increased tree growth induced by forest fragmentation in scenarios of high agricultural matrix influence triggered a cascade of causal-effect relations, affecting soil functioning. On the one hand, soil enzymatic activity was strongly stimulated by the abiotic (changes in pH and microclimate) and biotic (microbial biomass) modifications of the soil environment arising from the increased tree size and subsequent soil organic matter accumulation. Soil CO2emissions (soil respiration), which integrate releases from all the biological activity occurring in soils (autotrophic and heterotrophic components), were mainly affected by the abiotic (moisture, temperature) modifications of the soil environment caused by trees. These results, therefore, suggest that the increasing fragmentation of forests may profoundly impact the functioning of the plant-soil-microbial system, with important effects over soil CO2emissions and nutrient cycling at the ecosystem level. Forest fragmentation is thus revealed as a key albeit neglected factor for accurate estimations of soil carbon dynamics under global change scenarios.
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González-Cascón, R., J. Pacheco-Labrador, and M. P. Martín. "Evolución del comportamiento espectral y la composición química en el dosel arbóreo de una dehesa." Revista de Teledetección, no. 46 (June 27, 2016): 31. http://dx.doi.org/10.4995/raet.2016.5688.
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<p>In the context of the BIOSPEC and FLUXPEC projects (http://www.lineas.cchs.csic.es/fluxpec/), spectral and biophysical variables measurements at leaf level have been conducted in the tree canopy of a holm oak dehesa (Quercus ilex) ecosystem during four vegetative periods. Measurements of bi-conical reflectance factor of intact leaf (ASD Fieldspec 3® spectroradiometer), specific leaf mass (SLM), leaf water content (LWC), nutrient (N, P, K, Ca, Mg, Mn, Fe, and Zn) and chlorophyll concentration were performed. The spectral measurements have been related with the biophysical variables by stepwise and partial least squares regression analyses. These analyses allowed to identify the spectral bands and regions that best explain the evolution of the biophysical variables and to estimate the nutrient contents during the leaf maturation process. Statistically significant estimates of the majority of the variables studied were obtained. Wavelengths that had the highest contributions explaining the chemical composition of the forest canopy were located in spectral regions of the red edge, the green visible region, and the shortwave infrared.</p>
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Schauman, Santiago, Aleixandre Verger, Iolanda Filella, and Josep Peñuelas. "Characterisation of Functional-Trait Dynamics at High Spatial Resolution in a Mediterranean Forest from Sentinel-2 and Ground-Truth Data." Remote Sensing 10, no. 12 (November 23, 2018): 1874. http://dx.doi.org/10.3390/rs10121874.
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The characterisation of functional-trait dynamics of vegetation from remotely sensed data complements the structural characterisation of ecosystems. In this study we characterised for the first time the spatial heterogeneity of the intra-annual dynamics of the fraction of absorbed photosynthetically active radiation (FAPAR) as a functional trait of the vegetation in Prades Mediterranean forest in Catalonia, Spain. FAPAR was derived from the Multispectral Instrument (MSI) on the Sentinel-2 satellite and validated by comparison with the ground measurements acquired in June 2017 at the annual peak of vegetation activity. The validation results showed that most of points were distributed along the 1:1 line, with no bias nor scattering: R2 = 0.93, p < 0.05; with a root mean square error of 0.03 FAPAR (4.3%). We classified the study area into nine vegetation groups with different dynamics of FAPAR using a methodology that is objective and repeatable over time. This functional classification based on the annual magnitude (FAPAR-M) and the seasonality (FAPAR-CV) from the data on one year (2016–2017) complements structural classifications. The internal heterogeneity of the FAPAR dynamics in each land-cover type is attributed to the environmental and to the specific species composition variability. A spatial autoregressive (SAR) model for the main type of land cover, evergreen holm oak forest (Quercus ilex), indicated that topographic aspect, slope, height, and the topographic aspect x slope interaction accounted for most of the spatial heterogeneity of the functional trait FAPAR-M, thus improving our understanding of the explanatory factors of the annual absorption of photosynthetically active radiation by the vegetation canopy for this ecosystem.
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Campos, Pablo, José L. Oviedo, Alejandro Álvarez, Paola Ovando, Bruno Mesa, and Alejandro Caparrós. "Measuring environmental incomes beyond standard national and ecosystem accounting frameworks: testing and comparing the agroforestry Accounting System in a holm oak dehesa case study in Andalusia-Spain." Land Use Policy 99 (December 2020): 104984. http://dx.doi.org/10.1016/j.landusepol.2020.104984.
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Ogaya, Romà, and Josep Peñuelas. "Wood vs. Canopy Allocation of Aboveground Net Primary Productivity in a Mediterranean Forest during 21 Years of Experimental Rainfall Exclusion." Forests 11, no. 10 (October 14, 2020): 1094. http://dx.doi.org/10.3390/f11101094.
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A Mediterranean holm oak forest was subjected to experimental partial rainfall exclusion during 21 consecutive years to study the effects of the expected decrease in water availability for Mediterranean vegetation in the coming decades. Allocation in woody structures and total aboveground allocation were correlated with annual rainfall, whereas canopy allocation and the ratio of wood/canopy allocation were not dependent on rainfall. Fruit productivity was also correlated with annual rainfall, but only in Quercus ilex. In the studied site, there were two types of forest structure: high canopy stand clearly dominated by Quercus ilex, and low canopy stand with more abundance of a tall shrub species, Phillyrea latifolia. In the tall canopy stand, the allocation to woody structures decreased in the experimental rainfall exclusion, but not the allocation to canopy. In the low canopy stand, wood allocation in Quercus ilex was very small in both control and plots with rainfall exclusion, but wood allocation in Phillyrea latifolia was even higher than that obtained in tall canopy plots, especially in the plots receiving the experimental rainfall exclusion. These results highlight likely future changes in the structure and functioning of this ecosystem induced by the decrease in water availability. A serious drop in the capacity to mitigate climate change for this Mediterranean forest can be expected, and the ability of Phillyrea latifolia to take advantage of the limited capacity to cope with drought conditions detected in Quercus ilex makes likely a forthcoming change in species dominance, especially in the low canopy stands.
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Maldonado-Alconada, Ana María, María Ángeles Castillejo, María-Dolores Rey, Mónica Labella-Ortega, Marta Tienda-Parrilla, Tamara Hernández-Lao, Irene Honrubia-Gómez, et al. "Multiomics Molecular Research into the Recalcitrant and Orphan Quercus ilex Tree Species: Why, What for and How." International Journal of Molecular Sciences 23, no. 17 (September 1, 2022): 9980. http://dx.doi.org/10.3390/ijms23179980.
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The holm oak (Quercus ilex L.) is the dominant tree species of the Mediterranean forest and the Spanish agrosilvopastoral ecosystem, “dehesa.” It has been, since the prehistoric period, an important part of the Iberian population from a social, cultural, and religious point of view, providing an ample variety of goods and services, and forming the basis of the economy in rural areas. Currently, there is renewed interest in its use for dietary diversification and sustainable food production. It is part of cultural richness, both economically (tangible) and environmentally (intangible), and must be preserved for future generations. However, a worrisome degradation of the species and associated ecosystems is occurring, observed in an increase in tree decline and mortality, which requires urgent action. Breeding programs based on the selection of elite genotypes by molecular markers is the only plausible biotechnological approach. To this end, the authors’ group started, in 2004, a research line aimed at characterizing the molecular biology of Q. ilex. It has been a challenging task due to its biological characteristics (long life cycle, allogamous, high phenotypic variability) and recalcitrant nature. The biology of this species has been characterized following the central dogma of molecular biology using the omics cascade. Molecular responses to biotic and abiotic stresses, as well as seed maturation and germination, are the two main objectives of our research. The contributions of the group to the knowledge of the species at the level of DNA-based markers, genomics, epigenomics, transcriptomics, proteomics, and metabolomics are discussed here. Moreover, data are compared with those reported for Quercus spp. All omics data generated, and the genome of Q. ilex available, will be integrated with morphological and physiological data in the systems biology direction. Thus, we will propose possible molecular markers related to resilient and productive genotypes to be used in reforestation programs. In addition, possible markers related to the nutritional value of acorn and derivate products, as well as bioactive compounds (peptides and phenolics) and allergens, will be suggested. Subsequently, the selected molecular markers will be validated by both genome-wide association and functional genomic analyses.
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Grote, R., T. Keenan, A. V. Lavoir, and M. Staudt. "Process-based simulation of seasonality and drought stress in monoterpene emission models." Biogeosciences Discussions 6, no. 5 (September 11, 2009): 8961–9004. http://dx.doi.org/10.5194/bgd-6-8961-2009.
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Abstract. Canopy emissions of volatile hydrocarbons such as isoprene and monoterpenes play an important role in air chemistry. They depend on various environmental conditions, are highly species-specific and are expected to be affected by global change. In order to estimate future emissions of these isoprenoids, differently complex models are available. However, seasonal dynamics driven by phenology, enzymatic activity, or drought stress strongly modify annual ecosystem emissions. Although these impacts depend themselves on environmental conditions, they have yet received little attention in mechanistic modelling. In this paper we propose the application of a mechanistic method for considering the seasonal dynamics of emission potential using the ''Seasonal Isoprenoid synthase Model'' (Lehning et al., 2001). We test this approach with three different models (GUENTHER, Guenther et al., 1993; NIINEMETS, Niinemets et al., 2002a; BIM2, Grote et al., 2006) that are developed for simulating light-dependent monoterpene emission. We also suggest specific drought stress representations for each model. Additionally, the proposed model developments are compared with the approach realized in the MEGAN (Guenther et al., 2006) emission model. Models are applied to a Mediterranean Holm oak (Quercus ilex) site with measured weather data. The simulation results demonstrate that the consideration of a dynamic emission potential has a strong effect on annual monoterpene emission estimates. The investigated models, however, show different sensitivities to the procedure for determining this seasonality impact. Considering a drought impact reduced the differences between the applied models and decreased emissions at the investigation site by approximately 33% on average over a 10 year period. Although this overall reduction was similar in all models, the sensitivity to weather conditions in specific years was different. We conclude that the proposed implementations of drought stress and internal seasonality strongly reduce estimated emissions and indicate measurements are needed to further evaluate the models.
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Grote, R., T. Keenan, A. V. Lavoir, and M. Staudt. "Process-based simulation of seasonality and drought stress in monoterpene emission models." Biogeosciences 7, no. 1 (January 20, 2010): 257–74. http://dx.doi.org/10.5194/bg-7-257-2010.
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Abstract. Canopy emissions of volatile hydrocarbons such as isoprene and monoterpenes play an important role in air chemistry. They depend on various environmental conditions, are highly species-specific and are expected to be affected by global change. In order to estimate future emissions of these isoprenoids, differently complex models are available. However, seasonal dynamics driven by phenology, enzymatic activity, or drought stress strongly modify annual ecosystem emissions. Although these impacts depend themselves on environmental conditions, they have yet received little attention in mechanistic modelling. In this paper we propose the application of a mechanistic method for considering the seasonal dynamics of emission potential using the "Seasonal Isoprenoid synthase Model" (Lehning et al., 2001). We test this approach with three different models (GUENTHER, Guenther et al., 1993; NIINEMETS, Niinemets et al., 2002a; BIM2, Grote et al., 2006) that are developed for simulating light-dependent monoterpene emission. We also suggest specific drought stress representations for each model. Additionally, the proposed model developments are compared with the approach realized in the MEGAN (Guenther et al., 2006) emission model. Models are applied to a Mediterranean Holm oak (Quercus ilex) site with measured weather data. The simulation results demonstrate that the consideration of a dynamic emission potential has a strong effect on annual monoterpene emission estimates. The investigated models, however, show different sensitivities to the procedure for determining this seasonality impact. Considering a drought impact reduced the differences between the applied models and decreased emissions at the investigation site by approximately 33% on average over a 10 year period. Although this overall reduction was similar in all models, the sensitivity to weather conditions in specific years was different. We conclude that the proposed implementations of drought stress and internal seasonality strongly reduce estimated emissions and indicate the measurements that are needed to further evaluate the models.
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Martínez, María Teresa, and Elena Corredoira. "Efficient Procedure for Induction Somatic Embryogenesis in Holm Oak: Roles of Explant Type, Auxin Type, and Exposure Duration to Auxin." Forests 14, no. 2 (February 19, 2023): 430. http://dx.doi.org/10.3390/f14020430.
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Holm oak is the dominant tree species in the Mediterranean climate. Currently, worrisome degradation of its ecosystems has been observed, produced, among other factors, by changes in land use, extreme weather events, forest fires, climate change, and especially the increasingly frequent episodes of high tree mortality caused by “oak decline”, which has brought with it a social concern that transcends the productive interest. Breeding and conservation programs for this species are necessary to ensure the prevalence of these ecosystems for future generations. Biotechnological tools such as somatic embryogenesis (SE) have great potential value for tree improvement and have been shown to be highly efficient in the propagation and conservation of woody species. One challenge to this approach is that SE induction in holm oak has not yet been optimized. Here, we present a new reproducible procedure to induce SE in holm oak; we evaluated the responsiveness of different initial explants exposed to different types, concentrations, and durations of auxin. SE rates were significantly improved (37%) by culturing nodal segments for two weeks in induction medium. In addition, a significant auxin–genotype interaction was observed.
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García Jiménez, Prudencio, Abel Fernández Ruiz, José Sánchez Sánchez, and David Rodríguez de la Cruz. "Mycological Indicators in Evaluating Conservation Status: The Case of Quercus spp. Dehesas in the Middle-West of the Iberian Peninsula (Spain)." Sustainability 12, no. 24 (December 14, 2020): 10442. http://dx.doi.org/10.3390/su122410442.
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The use of bioindicators to assess the conservation status of various ecosystems is becoming increasingly common, although fungi have not been widely used for this purpose. The aim was to use the analysis of the macromycetes fruiting bodies in the area of a natural reserve and the degree of preservation of its different zones combined with the use of geographical information systems (GIS). For this purpose, quantitative and qualitative fungal samples were carried out in plots of the middle-west of the Iberian Peninsula previously delimited and characterised thanks to GIS during the springs and autumns of the 2009–2012 period. In addition, the lifestyles of the fungal species were analysed as well as the influence of the main meteorological parameters on fungal fruiting. A total of 10,125 fruiting bodies belonging to 148 species were counted on 20 plots with four vegetation units (holm oak dehesas, mixed holm oaks and Pyrenean oak dehesas with different abundance and grasslands). The distribution of the different species, their lifestyles and the number of fruiting bodies in the different plots of the reserve indicated that the eastern part was best conserved, showing that the combination of fungal diversity studies and the use of GIS could be useful in the management of areas with environmental relevance.
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Martínez-Baroja, Loreto, José María Rey-Benayas, Lorenzo Pérez-Camacho, and Pedro Villar-Salvador. "Drivers of oak establishment in Mediterranean old fields from 25-year-old woodland islets planted to assist natural regeneration." European Journal of Forest Research 141, no. 1 (October 23, 2021): 17–30. http://dx.doi.org/10.1007/s10342-021-01423-7.
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AbstractPlanted woodland islets can provide seeds for restoring forest ecosystems in Mediterranean old fields lacking seed sources, but other factors than seed arrival can also hinder the establishment of woody species. We experimentally examined factors affecting the emergence, survival, growth and recruitment of holm oak (Quercus ilex) seedlings juveniles from 25-year-old 100-m2 oak woodland islets planted in a Mediterranean old field. Wet springs and summers increased seedling emergence and survival. Distance to the islets per se did not affect seedling performance. However, emergence and survival increased in microsites close to the islets in less sun-exposed orientations of the islets and far from the islets in more sun-exposed orientations. Damage by wild boar reduced emergence, and unsheltered seedlings had 26% lower survival than sheltered ones, reflecting herbivory. Herb community biomass and light reduction by herbs increased with distance from nearest islet; the sparse herb cover around islets was due to competition from woodland islets, not to herbivory. There was a mismatch between the pattern of seedling survival and how the abundance of naturally recruited oaks varied with distance from the nearest islet; this suggests that other drivers can counteract the spatial pattern of seedling survival. We conclude that natural regeneration of Q. ilex in old fields from planted woodland islets is slow (5.7 seedlings ha−1 yr−1) due to acorn and seedling predation, and drought during spring and summer. Despite their small size, planted islets affected survival of oak juveniles depending on the orientation and distance relative to the islets.
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Serrazina, Susana, Mª Teresa Martínez, Vanesa Cano, Rui Malhó, Rita Lourenço Costa, and Elena Corredoira. "Genetic Transformation of Quercus ilex Somatic Embryos with a Gnk2-like Protein That Reveals a Putative Anti-Oomycete Action." Plants 11, no. 3 (January 24, 2022): 304. http://dx.doi.org/10.3390/plants11030304.
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Holm oak is a key tree species in Mediterranean ecosystems, whose populations have been increasingly threatened by oak decline syndrome, a disease caused by the combined action of Phytophthora cinnamomi and abiotic stresses. The aim of the present study was to produce holm oak plants that overexpress the Ginkbilobin-2 homologous domain gene (Cast_Gnk2-like) that it is known to possess antifungal properties. Proembryogenic masses (PEMs) isolated from four embryogenic lines (Q8, E2, Q10-16 and E00) were used as target explants. PEMs were co-cultured for 5 days with Agrobacterium EHA105pGnk2 and then cultured on selective medium containing kanamycin (kan) and carbenicillin. After 14 weeks on selective medium, the transformation events were observed in somatic embryos of lines Q8 and E2 and a total of 4 transgenic lines were achieved. The presence of the Cast_Gnk2-like gene on transgenic embryos was verified by PCR, and the number of transgene copies and gene expression was estimated by qPCR. Transgenic plants were obtained from all transgenic lines after cold storage of the somatic embryos for 2 months and subsequent transfer to germination medium. In an in vitro tolerance assay with the pathogen P. cinnamomi, we observed that transgenic plants were able to survive longer than wild type.
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Garcia-Fayos, Patricio, Vicente J. Monleon, Tiscar Espigares, Jose M. Nicolau, and Esther Bochet. "Increasing aridity threatens the sexual regeneration of Quercus ilex(holm oak) in Mediterranean ecosystems." PLOS ONE 15, no. 10 (October 14, 2020): e0239755. http://dx.doi.org/10.1371/journal.pone.0239755.
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Leiva, María José, Juan Manuel Mancilla-Leyton, and Ángel Martín-Vicente. "Methods to improve the recruitment of holm-oak seedlings in grazed Mediterranean savanna-like ecosystems (dehesas)." Annals of Forest Science 70, no. 1 (August 1, 2012): 11–20. http://dx.doi.org/10.1007/s13595-012-0225-0.
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Jakovljević, Tamara, Aldo Marchetto, Lucija Lovreškov, Nenad Potočić, Ivan Seletković, Krunoslav Indir, Goran Jelić, et al. "Assessment of Atmospheric Deposition and Vitality Indicators in Mediterranean Forest Ecosystems." Sustainability 11, no. 23 (November 30, 2019): 6805. http://dx.doi.org/10.3390/su11236805.
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Considering the fragility of the Mediterranean environment, there is an increasing need to improve the knowledge of this forest environment. The aim of this study was to examine the effects of air pollution on the forest ecosystem’s condition by analyzing tree vitality. The study area was chosen to represent the most important and the most common species in Mediterranean forest ecosystems of the Eastern Adriatic coast. Quercus pubescens, Quercus ilex, Pinus halepensis, and Pinus nigra plots were equipped with rain collectors and dendrometer bands. Sampling, measurements, and analyses of atmospheric deposition, foliar nutrient, defoliation, and growth were all carried out. Results showed that actual N deposition loads were the lowest in Aleppo pine forest and the highest in holm oak forests. This, however, did not have an effect on the concentrations of N in foliage. Most elements’ concentrations were in the plausible range. No relevant differences in mean defoliation between the plots were observed. The plots with a lower percentage of basal area increment (BAI%) were found to have lower defoliation. The research was conducted to bridge the gap in the knowledge of air pollutants and vitality indicators in different forest types. These findings are a valuable contribution to the sustainable forest management of Mediterranean forest.
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Carbayo, J., J. Martín, and E. Civantos. "Habitat type influences parasite load in Algerian Psammodromus (Psammodromus algirus) lizards." Canadian Journal of Zoology 97, no. 2 (February 2019): 172–80. http://dx.doi.org/10.1139/cjz-2018-0145.
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Understanding how habitat type and deterioration may affect parasitism is important in assessing the effects of human-induced environmental change on host–parasite dynamics. In this study, we examined inter-population differences in parasite load in the Mediterranean lizard Psammodromus algirus (Linnaeus, 1758). We analyzed prevalence and intensity of infection by blood parasites and ectoparasites in two populations separated by a 400 m elevational gradient and with different habitat types that also differed in the degree of human alteration. We also compared data obtained from the same populations 10 years later to assess whether there have been temporary changes in parasite loads. Results showed that prevalence and intensity of blood parasites were higher in the deteriorated lowland holm oak forest population than in the well-preserved upland oak forest. In contrast, the prevalence and intensity of infection by Ixodes Latreille, 1795 ticks was higher in the upland oak forest population. Individuals from the lowland population were in poorer condition. Intensities of infection by blood parasites and ectoparasites have decreased significantly from 2005–2006 to 2016 in both populations. Our results suggest that inter-population differences in parasite load may be explained by differences in habitat characteristics. This study contributes to the identification of ecosystems and habitats that are most sensitive to prevalence and intensity of infection by parasites.
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Lovreškov, Lucija, Ivana Radojčić Redovniković, Ivan Limić, Nenad Potočić, Ivan Seletković, Mia Marušić, Ana Jurinjak Tušek, Tamara Jakovljević, and Lukrecija Butorac. "Are Foliar Nutrition Status and Indicators of Oxidative Stress Associated with Tree Defoliation of Four Mediterranean Forest Species?" Plants 11, no. 24 (December 13, 2022): 3484. http://dx.doi.org/10.3390/plants11243484.
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Mediterranean forest ecosystems in Croatia are of very high significance because of the ecological functions they provide. This region is highly sensitive to abiotic stresses such as air pollution, high sunlight, and high temperatures alongside dry periods; therefore, it is important to monitor the state of these forest ecosystems and how they respond to these stresses. This study was conducted on trees in situ and focused on the four most important forest species in the Mediterranean region in Croatia: pubescent oak (Quercus pubescens Willd.), holm oak (Quercus ilex L.), Aleppo pine (Pinus halepensis Mill.) and black pine (Pinus nigra J. F. Arnold.). Trees were selected and divided into two groups: trees with defoliation of >25% (defoliated) and trees with defoliation of ≤25% (undefoliated). Leaves and needles were collected from selected trees. Differences in chlorophyll content, hydrogen peroxide content, lipid peroxidation and enzyme activity (superoxide dismutase, catalase, ascorbate peroxidase, non-specific peroxidase), and nutrient content between the defoliated and undefoliated trees of the examined species were determined. The results showed that there were significant differences for all species between the defoliated and undefoliated trees for at least one of the examined parameters. A principal component analysis showed that the enzyme ascorbate peroxidase can be an indicator of oxidative stress caused by ozone. By using oxidative stress indicators, it is possible to determine whether the trees are under stress even before visual damage occurs.
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Fernández-Bravo, María, Inmaculada Garrido-Jurado, Pablo Valverde-García, Jürg Enkerli, and Enrique Quesada-Moraga. "Responses to abiotic environmental stresses among phylloplane and soil isolates of Beauveria bassiana from two holm oak ecosystems." Journal of Invertebrate Pathology 141 (November 2016): 6–17. http://dx.doi.org/10.1016/j.jip.2016.09.007.
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Ruiz-Gómez, Francisco J., and Cristina Miguel-Rojas. "Antagonistic Potential of Native Trichoderma spp. against Phytophthora cinnamomi in the Control of Holm Oak Decline in Dehesas Ecosystems." Forests 12, no. 7 (July 17, 2021): 945. http://dx.doi.org/10.3390/f12070945.
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Phytophthora root rot caused by the pathogen Phytophthora cinnamomi is one of the main causes of oak mortality in Mediterranean open woodlands, the so-called dehesas. Disease control is challenging; therefore, new alternative measures are needed. This study focused on searching for natural biocontrol agents with the aim of developing integrated pest management (IPM) strategies in dehesas as a part of adaptive forest management (AFM) strategies. Native Trichoderma spp. were selectively isolated from healthy trees growing in damaged areas by P. cinnamomi root rot, using Rose Bengal selective medium. All Trichoderma (n = 95) isolates were evaluated against P. cinnamomi by mycelial growth inhibition (MGI). Forty-three isolates presented an MGI higher than 60%. Twenty-one isolates belonging to the highest categories of MGI were molecularly identified as T. gamsii, T. viridarium, T. hamatum, T. olivascens, T. virens, T. paraviridescens, T. linzhiense, T. hirsutum, T. samuelsii, and T. harzianum. Amongst the identified strains, 10 outstanding Trichoderma isolates were tested for mycoparasitism, showing values on a scale ranging from 3 to 4. As far as we know, this is the first report referring to the antagonistic activity of native Trichoderma spp. over P. cinnamomi strains cohabiting in the same infected dehesas. The analysis of the tree health status and MGI suggest that the presence of Trichoderma spp. might diminish or even avoid the development of P. cinnamomi, protecting trees from the worst effects of P. cinnamomi root rot.
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Leiva, María José, Juan Manuel Mancilla-Leyton, and Ángel MartínVicente. "Differences in the facilitative ability of two Mediterranean shrubs on holm-oak seedling recruitment in Mediterranean savanna-forest ecosystems." Ecological Engineering 82 (September 2015): 349–54. http://dx.doi.org/10.1016/j.ecoleng.2015.05.019.
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Browne, Luke, Jessica W. Wright, Sorel Fitz-Gibbon, Paul F. Gugger, and Victoria L. Sork. "Adaptational lag to temperature in valley oak (Quercus lobata) can be mitigated by genome-informed assisted gene flow." Proceedings of the National Academy of Sciences 116, no. 50 (November 25, 2019): 25179–85. http://dx.doi.org/10.1073/pnas.1908771116.
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Climate change over the next century is predicted to cause widespread maladaptation in natural systems. This prediction, as well as many sustainable management and conservation practices, assumes that species are adapted to their current climate. However, this assumption is rarely tested. Using a large-scale common garden experiment combined with genome-wide sequencing, we found that valley oak (Quercus lobata), a foundational tree species in California ecosystems, showed a signature of adaptational lag to temperature, with fastest growth rates occurring at cooler temperatures than populations are currently experiencing. Future warming under realistic emissions scenarios was predicted to lead to further maladaptation to temperature and reduction in growth rates for valley oak. We then identified genotypes predicted to grow relatively fast under warmer temperatures and demonstrated that selecting seed sources based on their genotype has the potential to mitigate predicted negative consequences of future climate warming on growth rates in valley oak. These results illustrate that the belief of local adaptation underlying many management and conservation practices, such as using local seed sources for restoration, may not hold for some species. If contemporary adaptational lag is commonplace, we will need new approaches to help alleviate predicted negative consequences of climate warming on natural systems. We present one such approach, “genome-informed assisted gene flow,” which optimally matches individuals to future climates based on genotype–phenotype–environment associations.
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Serrano, João, Luís Roma, Shakib Shahidian, Anabela D. F. Belo, Emanuel Carreira, Luís L. Paniagua, Francisco Moral, Luís Paixão, and José Marques da Silva. "A Technological Approach to Support Extensive Livestock Management in the Portuguese Montado Ecosystem." Agronomy 12, no. 5 (May 18, 2022): 1212. http://dx.doi.org/10.3390/agronomy12051212.
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Extensive livestock production systems based on improved pastures under Montado of Holm oaks represent an approach in line with the challenges of sustainability and biodiversity. The increasing incorporation of technologies in the monitoring of this ecosystem allows for a better knowledge of the spatial and temporal variability and, consequently, a more economically profitable management. In this study, between July 2020 and June 2021, soil and pastures were monitored in a 20 ha Montado area located in Alentejo (Southern Portugal) and used for extensive grazing of cattle. The survey of soil apparent electrical conductivity (ECa), the application of algorithms for definition of homogeneous management zones (HMZ), the use of indices obtained from satellite imagery time series to characterize the evolution of pasture quality and the soil and pasture sampling, including the identification of bio-indicator botanical species, were the basis of this exploratory study, allowing a holistic approach to this complex soil-pasture-trees and animals ecosystem. In the near future, this knowledge could represent an important milestone in providing decision-making support systems to farm managers in terms of smart sampling, differential application of fertilizers, amendments or seeds, choosing the best spacing and density of trees in this ecosystem, promoting dynamic grazing, or identifying the animal feed supplementation needs in the critical periods of the year.
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Rota, Emilia, Nicola Bianchi, and Roberto Bargagli. "Metal Availability and Transfer along Food Chains in Siena, a Small Medieval Town in Italy." Journal of Chemistry 2018 (October 9, 2018): 1–8. http://dx.doi.org/10.1155/2018/3035091.
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Heavy metals originating from vehicular emissions and other anthropogenic sources pose one of the main environmental health risks in urban areas. The assessment of metal bioaccumulation in selected species of synanthropic organisms allows evaluating their bioavailability and the transfer along food chains in urban ecosystems. An overall view of the results achieved in Siena on urban ecosystems shows that the mean Cd, Cu, Pb, and Zn concentrations in biological crusts covering urban walls (0.66, 34, 65, and 184 μg·g−1 d.w.) are higher than the respective concentrations in tree leaf litter (0.19, 9.5, 9.2, and 38 μg·g−1 d.w.) and topsoil (0.40, 44, 34.2, and 102 μg·g−1 d.w.). Furthermore, the epilithic moss Tortula muralis accumulated much higher levels of Cd, Cu, Pb, and Zn (0.34, 65, 17.6, and 106 μg·g−1 d.w.) than epiphytic lichens (0.22, 11.6, 2.1, and 47.3 μg·g−1 d.w.) or the holm oak live foliage (0.15, 14, 1.51, and 26.5 μg·g−1 d.w.), respectively. However, analyses of the soft tissues of Papillifera papillaris, a snail dwelling on stone walls, show that metals deposited on urban walls are scarcely bioavailable. Papillifera accumulates (and transfers to the next trophic level) amounts of Cd, Cu, Pb, and Zn (1.7, 171, 1.1, and 71 μg·g−1 d.w., respectively) that are comparable or inferior to those found in a ground-dwelling snail (3.3, 88, 2.0, and 880 μg·g−1 d.w.) and two earthworm species (2.0–4.4, 18–23, 1.4–2.2, and 356–594 μg·g−1 d.w.) from the same urban green area.
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Stevenson, Anthony C., Jamie Skinner, G. Edward Hollis, and Michael Smart. "The El Kala National Park and Environs, Algeria: An Ecological Evaluation." Environmental Conservation 15, no. 4 (1988): 335–48. http://dx.doi.org/10.1017/s0376892900029830.
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The structure of the El Kala National Park, its aims, zonation scheme for conservation and development, and boundaries, are described. Those ecobiomes and ecosystems which merit the highest classification and protection within the National Park are described and evaluated along with the numerous sites of similar importance outside the Park. A summary evaluation table (Table III) of the habitats, the species, and the resources for sustainable utilization, is presented.Three wetlands within the Park—Lake Oubeïra (perennial freshwater lake: a Ramsar Convention site important for wintering waterfowl), Lake Tonga (semi-perennial freshwater lake with surrounding marsh and earn a Ramsar Convention site with significant numbers of breeding waterbirds), and the Bou Redim marsh (freshwater carr with open water and a breeding colony of herons) are placed in the highest category of protection for the National Park. Four wetlands outside the National Park—the Mkhada marsh (8,900 ha of seasonally-flooded freshwater marsh), Lake Fetzara (15,000 ha freshwater lake now refilled with water in winter), Lac des Oiseaux (40 ha perennial freshwater lake), and the Cheffia Reservoir (3,000 ha)—are considered as important and consequently deserving of legislative protection. A marine section of the Park needs further study.The highest level of protection is recommended for the coastal dunes, including alder carrs, within and outside the Park; for the pristine low-montane Cork Oak woodlands, including the last remnants of Pinus pinaster ssp. renoui in Algeria; for the rare Lusitanian Oak forests including the small and declining Algerian population of Barbary Deer (Cervus elephas barbarus); and for some of the last remaining riverine woodland in North Africa. In addition, the healthy and diverse population of raptors is noted. The megalithic and later archaeological remains are extensive, valuable, and little-known.MEcological improvements to Lakes Tonga and Fetzara, which were drained in the 1930s, have recently developed from the operation of the old sluices to hold water back in the lakes, although at Lake Tonga some of the marginal vegetation and alder forest appears to be suffering from the prolonged inundation. The construction of the large Mexanna Dam within the National Park will desiccate the Mkhada Marsh, and Lake Oubeïra may have its ecological character changed if it is used for regulatory storage. The dune ecosystems are being affected by agriculture, groundwater pumping, industrial forestry (including perhaps a pulp mill), and the new road which is being driven into the heart of the dunes. Fishing and aquaculture may further reduce the suitability of Lakes Oubeïra and Melah for wintering waterfowl, and deliberate fires continue to ravage the Cork Oak forests.
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Tejeda-Corvillo, Álvaro, Jesús Barrena-González, Joaquín Francisco Lavado-Contador, Alberto Alfonso-Torreño, Álvaro Gómez-Gutiérrez, and Manuel Pulido-Fernández. "Spatial Models Predictive of “Seca” Risk in Extremadura. Applications at Regional and Local Scale in Protected Natural Areas." Proceedings 30, no. 1 (May 19, 2020): 58. http://dx.doi.org/10.3390/proceedings2019030058.
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Rangeland (known as Dehesas or Montados) is a characteristic ecosystem of the southwestern part of the Iberian Peninsula that occupies approximately 3.5 million ha, representing the most important agrosilvopastoral system in Europe. Nowadays, this situation is changing, being under circumstances of threat due to different aspects that are causing degradation of holm oaks and cork oaks throughout the Iberian Peninsula. These problems are of various kinds, accentuating the disease or syndrome of seca, tree death caused by Phytophthora cinnamomi. For the development of death susceptibility models, maximum entropy algorithms (MAXENT) were used, often widely used in ecological niche models. In the development of models, a wide range of variables (dependents and predictive), both climatic or bioclimatic, geological or soil, vegetation and economic and geographical characteristics were used. The study was carried out at two scales, the Autonomous Community of Extremadura in its entirety, and another more specific work scale, such as seca focus in protected natural areas within the Natura 2000 Network. The regional model showed a total of 1,179,639 ha prone to be affected by this condition, among which, 383,339 ha showed a high potential risk level of seca presence. These models, carried out at local scale in 4 polygons selected within the Natura 2000 Network, showed more than 70% of the land surface studied as areas with risk of suffering seca.
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Rosavec, Roman, Damir Barčić, Željko Španjol, Milan Oršanić, Tomislav Dubravac, and Alan Antonović. "Flammability and Combustibility of Two Mediterranean Species in Relation to Forest Fires in Croatia." Forests 13, no. 8 (August 10, 2022): 1266. http://dx.doi.org/10.3390/f13081266.
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Climatic conditions are extremely important for the start and spread of forest fires. Flammability and the spread of fire are sensitive to the interactions of variables within ecosystems, such as weather, fuel, and topography. Certain variables are highly significant for forest fires and are applied in various models, particularly the moisture content of potential fuel, and its flammability or combustibility. However, such these models cannot determine the true values of the required variables, unlike actual empirical research. Areas with the highest number of fires show significant variability and differences in air temperature, humidity, and precipitation. These factors have a strong influence on flammability, combustibility, and moisture content of Mediterranean species. This study analyses the flammability and combustibility of two Mediterranean species important for the Adriatic area in Croatia: climazonal holm oak (Quercus ilex L.) and Aleppo pine (Pinus halepensis Mill.) as an important conifer for afforestation and reforestation. The results of linear correlation coefficients of flammability of these species at the studied localities show a statistically significant and very strong correlation between flammability and the moisture content of the tested sample, with the exception of Aleppo pine on the island of Rab. The analysis of variance of combustibility showed that there were no statistically significant differences between nearly all variables tested. The results indicate the significant effect of live fuel moisture content on the flammability and combustibility of natural fuels.
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Vacca, Andrea, Gianluca Serra, and Riccardo Scalenghe. "Vegetation, soils, and humus forms of Sardinian holm oak forests and approximated cross-harmonization of vegetation types, WRB Soil Groups and humus forms in selected Mediterranean ecosystems." Applied Soil Ecology 123 (February 2018): 659–63. http://dx.doi.org/10.1016/j.apsoil.2017.06.024.
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Sciarretta, A., L. Marziali, M. Squarcini, L. Marianelli, D. Benassai, F. Logli, and P. F. Roversi. "Adaptive management of invasive pests in natural protected areas: the case of Matsucoccus feytaudi in Central Italy." Bulletin of Entomological Research 106, no. 1 (November 2, 2015): 9–18. http://dx.doi.org/10.1017/s0007485315000851.
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AbstractInvasive species are a significant threat to affected ecosystems, having serious environmental, economic and social impacts. The maritime pine bast scale, Matsucoccus feytaudi Ducasse (Hemiptera: Matsucoccidae), causes serious damage to Pinus pinaster forests in SE France, Corsica and Italy where it has been introduced. This study illustrates the adaptive management plan implemented in the Migliarino, San Rossore, Massaciuccoli Regional Natural Park in Tuscany, Italy, where M. feytaudi arrived in 2004, leading to the decay of local P. pinaster stands. The management programme, aimed at slowing the establishment and growth of M. feytaudi, was carried out in the main sector of the park, Tenuta di San Rossore, to retard the destruction of the P. pinaster coastal strip protecting the more internal woodland from sea salt and to allow replacement of P. pinaster trees with a more stable broad-leaved wood. The combined use of mass trapping and silvicultural interventions, applied in a targeted manner according to distribution maps of pest captures and damage, helped to delay forest destruction compared with a nearby unmanaged area of the park Tenuta di Tombolo. Although M. feytaudi continued to spread during the management period, the populations remained at low levels for 6 years, showing a marked increase in 2012. During this period, the P. pinaster stands were reduced from 320 to 249 ha. The final result of this ongoing gradual conversion process will be transformation of the P. pinaster forest into Holm oak woods and Mediterranean shrub land, while P. pinaster will survive as clusters or blocks of trees.
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Langford, Ben, James Cash, W. Joe F. Acton, Amy C. Valach, C. Nicholas Hewitt, Silvano Fares, Ignacio Goded, et al. "Isoprene emission potentials from European oak forests derived from canopy flux measurements: an assessment of uncertainties and inter-algorithm variability." Biogeosciences 14, no. 23 (December 8, 2017): 5571–94. http://dx.doi.org/10.5194/bg-14-5571-2017.
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Abstract. Biogenic emission algorithms predict that oak forests account for ∼ 70 % of the total European isoprene budget. Yet the isoprene emission potentials (IEPs) that underpin these model estimates are calculated from a very limited number of leaf-level observations and hence are highly uncertain. Increasingly, micrometeorological techniques such as eddy covariance are used to measure whole-canopy fluxes directly, from which isoprene emission potentials can be calculated. Here, we review five observational datasets of isoprene fluxes from a range of oak forests in the UK, Italy and France. We outline procedures to correct the measured net fluxes for losses from deposition and chemical flux divergence, which were found to be on the order of 5–8 and 4–5 %, respectively. The corrected observational data were used to derive isoprene emission potentials at each site in a two-step process. Firstly, six commonly used emission algorithms were inverted to back out time series of isoprene emission potential, and then an average isoprene emission potential was calculated for each site with an associated uncertainty. We used these data to assess how the derived emission potentials change depending upon the specific emission algorithm used and, importantly, on the particular approach adopted to derive an average site-specific emission potential. Our results show that isoprene emission potentials can vary by up to a factor of 4 depending on the specific algorithm used and whether or not it is used in a big-leaf or canopy environment (CE) model format. When using the same algorithm, the calculated average isoprene emission potential was found to vary by as much as 34 % depending on how the average was derived. Using a consistent approach with version 2.1 of the Model for Emissions of Gases and Aerosols from Nature (MEGAN), we derive new ecosystem-scale isoprene emission potentials for the five measurement sites: Alice Holt, UK (10 500 ± 2500 µg m−2 h−1); Bosco Fontana, Italy (1610 ± 420 µg m−2 h−1); Castelporziano, Italy (121 ± 15 µg m−2 h−1); Ispra, Italy (7590 ± 1070 µg m−2 h−1); and the Observatoire de Haute Provence, France (7990 ± 1010 µg m−2 h−1). Ecosystem-scale isoprene emission potentials were then extrapolated to the leaf-level and compared to previous leaf-level measurements for Quercus robur and Quercus pubescens, two species thought to account for 50 % of the total European isoprene budget. The literature values agreed closely with emission potentials calculated using the G93 algorithm, which were 85 ± 75 and 78 ± 25 µg g−1 h−1 for Q. robur and Q. pubescens, respectively. By contrast, emission potentials calculated using the G06 algorithm, the same algorithm used in a previous study to derive the European budget, were significantly lower, which we attribute to the influence of past light and temperature conditions. Adopting these new G06 specific emission potentials for Q. robur (55 ± 24 µg g−1 h−1) and Q. pubescens (47 ± 16 µg g−1 h−1) reduced the projected European budget by ∼ 17 %. Our findings demonstrate that calculated isoprene emission potentials vary considerably depending upon the specific approach used in their calculation. Therefore, it is our recommendation that the community now adopt a standardised approach to the way in which micrometeorological flux measurements are corrected and used to derive isoprene, and other biogenic volatile organic compounds, emission potentials.
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Sánchez-Martín, Blas-Morato, and Rengifo-Gallego. "The Dehesas of Extremadura, Spain: A Potential for Socio-economic Development Based on Agritourism Activities." Forests 10, no. 8 (July 25, 2019): 620. http://dx.doi.org/10.3390/f10080620.
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Dehesas form an agroforestry system which is highly developed in Extremadura as they occupy over 1,000,000 hectares. This is an extensive production system based on exploitation by stockbreeding with certain complements of agricultural and extractive products. It is however underexploited for activities other than agrolivestock production. As a result this research starts from the hypothesis that greater socio-economic development is possible in areas near this type of ecosystem if we consider that it is extremely attractive to tourism, at least in some of its forms. Complementing agrolivestock exploitation with tourist exploitation means that it is necessary to be familiar with the situation of the current availability of accommodation. In order to do so we analyse the main parameters characterising rural accommodation in Extremadura, Spain, the results of which reflect low occupancy for a large part of the year and consequently seasonal variation is high. This fact contrasts with the huge potential of dehesas for agritourism. In order to carry out this study we resort to the use of spatial statistics, in particular the grouping analysis. In its configuration we consider the location of the rural accommodation and its proximity to areas of dehesas made up of holm oaks (Quercus ilex) and cork oaks (Quecus suber) together with protected natural spaces, basing ourselves also on proximity to livestock trails and natural swimming pools. The results lead to the creation of 5 homogeneous groups of which 3 correspond to accommodation establishments capable of setting up agritourism and agriecotourism initiatives; this affects 45% of the establishments. However, no current initiatives of this type exist despite the fact that the National Reference Centre for Agritourism is located in Extremadura. From this can be inferred the need for implementing tourist policies to encourage the generating of tourist products specifically intended to exploit the potential of the dehesa as a complement to the current availability of rural accommodation.
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Hortelano Mínguez, Luís Alfonso, Eduardo Azofra Agustín, María Isabel Martín Jiménez, and José Ignacio Izquierdo Misiego. "Patrimonio cultural y turismo en torno al cerdo ibérico en Salamanca." Cuadernos de Turismo, no. 44 (November 28, 2019): 193–218. http://dx.doi.org/10.6018/turismo.44.404811.
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Se analizan los vínculos del territorio con el Patrimonio Cultural generados a partir de la cría del cerdo ibérico, en un sistema agroecológico adaptado a las condiciones del medio natural conocido como monte hueco o dehesa, y de la elaboración de embutidos (en concreto el chorizo ibérico) a partir de la sabiduría popular. Este proceso, asentado en un largo devenir histórico de construcción de un paisaje agrosilvopastoril adecuado para una gestión sostenible del territorio, donde el cerdo ibérico juega un papel preponderante, y en las claves culturales transmitidas de generación en generación del modo de hacer embutidos derivados del cochino ibérico. Este modo de vida ha sido plasmado en pinturas, fotografías, folklore y textos literarios que demuestran las estrechas relaciones de las gentes salmantinas con su territorio, paisaje y costumbres y su valoración como recurso turístico-gastronómico. Based on the breeding of Iberian hog in the Province of Salamanca, the relations between the territory and cultural heritage are analysed. Breeding conditions are well-adapted to the local ecosystem of pastureland with holm oaks, known as monte hueco or dehesa. Meat processing, for example the production of Iberian chorizo, is based on folk knowledge. The long historical past of pig rearing is embedded in a sustainable agro-sylvo-pastoral landscape and in a local culture related to the production of ham and sausages. This way of life is reflected in paintings, photographs, folklore and literary texts, which show the intense relationship of the people of Salamanca with their territory, landscape and traditions, as well as its asset as a touristic -gastronomic resource.
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Balci, Y., S. Balci, J. Eggers, W. L. MacDonald, J. Juzwik, R. Long, and K. W. Gottschalk. "First Report of Phytophthora europaea in Oak Forests in the Eastern and North-Central United States." Plant Disease 90, no. 6 (June 2006): 827. http://dx.doi.org/10.1094/pd-90-0827b.
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In 2003 and 2004, soils in oak forest ecosystems in nine central and eastern states of the United States were surveyed for Phytophthora spp. Soil samples were collected around healthy and symptomatic trees. Symptoms included dieback of branches, gaps in lateral branch systems, yellowing of foliage, wilting and clustering of leaves, and the presence of epicormic shoots. Soil subsamples were collected in each of the four cardinal directions and at a distance of 1 to 2 m from the base of a tree. The four subsamples were bulked to produce a sample of approximately 2,000 ml. In the laboratory, each sample was mixed thoroughly and a single 250-g subsample was flooded with 500 ml of distilled water and baited with Quercus robur leaflets for 3 to 5 days at 17 to 20°C. Discolored leaflets were examined microscopically (×200) and those with sporangia typical of Phytophthora spp. were plated on PARPNH selective medium (1). Phytophthora europaea was recovered from soil samples collected from Q. alba in West Virginia, Q. rubra in Minnesota, West Virginia, and Wisconsin, Q. phellos in Ohio, and Q. velutina in Pennsylvania. Cultures were identified as P. europaea by their morphological, physiological, and molecular characteristics (4). Average dimensions of nine isolates were determined. Oogonia were 40 ± 3.9 μm in diameter and often had few bullet protuberances and tapered bases; oospores mostly filled the oogonia and averaged 36 ± 3.7 μm; sporangia dimensions averaged 42 ± 6.1 × 30 ± 4.1 μm with a length/width ratio of 1:4. Isolates produced larger oogonia and oospores but had similar sporangia length/width ratios comparable to the species description (4). Growth optimum (5.8 to 6.9 mm day-1) on V8 juice agar (V8A) occurred at 25°C. On potato dextrose agar, colonies produced dense, felt-like mycelia, often with a central mound of aerial hyphae. DNA also was extracted from eight representative isolates and the internal transcribed spacer (ITS) region of rDNA from each isolate was amplified and sequenced. ITS sequences were identical to those of P. europaea in the NCBI GenBank database (Accession No. DQ313222). Pathogenicity of six isolates (one from each site) was confirmed by wounding stems of 2-year-old Q. alba, Q. rubra, and Q. velutina seedlings and inoculating wounds with V8A plugs (6 mm) containing mycelia; V8A plugs without mycelia were used for controls. Two months after inoculation, P. europaea was reisolated on PARPNH medium from advancing lesions on all inoculated seedlings but was not isolated from control plants. Mean lesion lengths on seedlings inoculated with P. europaea were significantly greater (P < 0.05) than those on control plants; lesions averaged 0.46 cm on Q. alba, 1.38 cm on Q. rubra, and 1.01 cm on Q. velutina. Previously, P. europaea only was reported from oak trees and soil in forests of Austria, France, and Germany (1–4). These findings extend the current distribution of P. europaea and raise questions about its origin and role in the health of oak forests in eastern and north-central United States. Q. alba, Q. phellos, Q. rubra, and Q. velutina are new host associations for P. europaea. References: (1) Y. Balci and E. Halmschlager. For. Pathol. 33:157, 2003. (2) E. Hansen and C. Delatour. Ann. Sci. For. 56:539, 1999. (3) G. Hartmann and R. Blank. Forst Holz. 57:539, 2002. (4) T. Jung et al. Mycol. Res. 106:397, 2002.
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Carrière, Simon Damien, Nicolas K. Martin-StPaul, Claude Doussan, François Courbet, Hendrik Davi, and Guillaume Simioni. "Electromagnetic Induction Is a Fast and Non-Destructive Approach to Estimate the Influence of Subsurface Heterogeneity on Forest Canopy Structure." Water 13, no. 22 (November 13, 2021): 3218. http://dx.doi.org/10.3390/w13223218.
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The spatial forest structure that drives the functioning of these ecosystems and their response to global change is closely linked to edaphic conditions. However, the latter properties are particularly difficult to characterize in forest areas developed on karst, where soil is highly rocky and heterogeneous. In this work, we investigated whether geophysics, and more specifically electromagnetic induction (EMI), can provide a better understanding of forest structure. We use EMI (EM31, Geonics Limited, Ontario, Canada) to study the spatial variability of ground properties in two different Mediterranean forests. A naturally post-fire regenerated forest composed of Aleppo pines and Holm oaks and a monospecific plantation of Altlas cedar. To better interpret EMI results, we used electrical resistivity tomography (ERT), soil depth surveys, and field observations. Vegetation was also characterized using hemispherical photographs that allowed to calculate plant area index (PAI). Our results show that the variability of ground properties contribute to explaining the variability in the vegetation cover development (plant area index). Vegetation density is higher in areas where the soil is deeper. We showed a significant correlation between edaphic conditions and tree development in the naturally regenerated forest, but this relationship is clearly weaker in the cedar plantation. We hypothesized that regular planting after subsoiling, as well as sylvicultural practices (thinning and pruning) influenced the expected relationship between vegetation structure and soil conditions measured by EMI. This work opens up new research avenues to better understand the interplay between soil and subsoil variability and forest response to climate change.