Cambium production pattern in Q. ilex growing at a dry site in Southern Italy

2020 ◽  
Author(s):  
Veronica De Micco ◽  
Katarina Cufar ◽  
Angela Balzano
Keyword(s):  
Southern Italy ◽  
Climatic Factors ◽  
High Hardness ◽  
Cambial Activity ◽  
Climatic Conditions ◽  
Density Fluctuations ◽  
Arid Environments ◽  
Growth Responses ◽  
Mediterranean Species ◽  
Thin Sections

<p>Survival of forest tree species in semi-arid environments such as the Mediterranean area is threatened by the increase in harsh drought conditions. Therefore, better knowledge of the eco-physiology of Mediterranean species and their growth responses to climatic factors is needed to develop strategies for sustainable management.</p><p>The studies of cambial activity and wood formation can provide information on tree growth and physiological responses to variations in intra-annual climatic parameters, helping to answer questions related to tree performance and plasticity under changing environmental conditions.</p><p>Our aim was to investigate cambium production in holm oak (Quercus ilex L.) as one of the most widespread evergreen oaks in Southern Italy. We studied the response of cambium activity throughout the particularly dry year 2017. We collected tissues from tree stems every two weeks by sampling microcores containing phloem, cambium and xylem. For the analyses, thin cross sections of the microcores were analysed under a light microscope to identify the timing of cambial production, xylogenesis and phloem formation. We detected the period in which the cambium was active, as well as the period in which the cambium was not productive. We interpreted the cambial response to climatic conditions at the site during the period of observation.</p><p>The observed pattern of xylogenesis differed from the expected bi-modal pattern typical for Mediterranean species which usually results in Intra-annual Density Fluctuations (IADFs) in tree-rings. In Q. ilex we observed only one peak of cambial activity, likely due to the low water availability during the year 2017.</p><p>The obtained results provide useful information supporting the forecasting of the wood-growth responses to expected climate change. Moreover, we gained technical experience on optimal preparation of thin sections of problematic tissues, which is especially challenging in Q.ilex due to high hardness of the peculiar wood structure making the investigations of xylogenesis very challenging in this species.</p>

INTRA-ANNUAL DENSITY FLUCTUATIONS IN TREE RINGS: HOW, WHEN, WHERE, AND WHY?

IAWA Journal ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 232-259 ◽  
Author(s):  
V. De Micco ◽  
F. Campelo ◽  
M. De Luis ◽  
A. Bräuning ◽  
M. Grabner ◽  
...  
Keyword(s):  
Tree Rings ◽  
Environmental Changes ◽  
Cambial Activity ◽  
Climatic Conditions ◽  
Density Fluctuations ◽  
Rooting Depth ◽  
Mediterranean Species ◽  
Abiotic Constraints ◽  
Trees And Shrubs

Intra-annual density fluctuations (IADFs) in tree rings are generally considered structural anomalies caused by deviations from the “normal course” of xylogenesis during the growing season. This definition is based on the bias that, under “normal conditions”, cambial activity stops once a year. Each tree ring can thus be dated to one calendar year, which is one of the principles of dendrochronology. The formation of IADFs can be triggered directly by environmental changes, especially in precipitation and temperature, that affect cambial activity and cell differentiation. It can also be the result of limited photosynthesis, due to defoliation induced by biotic or abiotic constraints.Often indicated with alternative terms, IADFs were first described in the 1930s, and recently reported for many trees and shrubs from different ecosystems throughout the world, particularly for Mediterranean species. Different types of IADFs have been detected; their formation and structural properties depend on many factors including tree genotype, age, size, rooting depth, habitat, soil, climate, photosynthetic activity, and allocation strategies. Whether IADFs affect the adaptive capability of plants remains, however, unclear.We provide an overview of the main anatomical features of IADFs and their occurrence in tree rings from various environments and climatic regimes. We propose a simplified way of classifying them and discuss the hypotheses about their functional role and the factors triggering their formation. To understand the ecological role of IADFs better, we recommend a multidisciplinary approach, involving wood anatomy, dendroecology, and stable isotopes, which has already been applied for Mediterranean species. We conclude by considering that IADFs appear to be the “rule” rather than “anomalies” in some ecosystems where they help plants cope with fluctuating environmental conditions. Moreover, their anatomical structure represents a valuable proxy of past climatic conditions at a sub-seasonal resolution and may be relevant to adapt hydraulic functioning of living trees to changing climatic conditions.

scholarly journals Radial Growth Response of European Larch Provenances to Interannual Climate Variation in Poland

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 334
Author(s):  
Norbert Szymański ◽  
Sławomir Wilczyński
Keyword(s):  
Radial Growth ◽  
Climatic Factors ◽  
Principal Component ◽  
Climatic Conditions ◽  
Growth Responses ◽  
European Larch ◽  
Temperature And Precipitation ◽  
Provenance Trials ◽  
High Precipitation ◽  
Climatic Elements

The present study identified the similarities and differences in the radial growth responses of 20 provenances of 51-year-old European larch (Larix decidua Mill.) trees from Poland to the climatic conditions at three provenance trials situated in the Polish lowlands (Siemianice), uplands (Bliżyn) and mountains (Krynica). A chronology of radial growth indices was developed for each of 60 European larch populations, which highlighted the interannual variations in the climate-mediated radial growth of their trees. With the aid of principal component, correlation and multiple regression analysis, supra-regional climatic elements were identified to which all the larch provenances reacted similarly at all three provenance trials. They increased the radial growth in years with a short, warm and precipitation-rich winter; a cool and humid summer and when high precipitation in late autumn of the previous year was noted. Moreover, other climatic elements were identified to which two groups of the larch provenances reacted differently at each provenance trial. In the lowland climate, the provenances reacted differently to temperature in November to December of the previous year and July and to precipitation in September. In the upland climate, the provenances differed in growth sensitivity to precipitation in October of the previous year and June–September. In the mountain climate, the provenances responded differently to temperature and precipitation in September of the previous year and to precipitation in February, June and September of the year of tree ring formation. The results imply that both climatic factors and origin (genotype), i.e., the genetic factor, mediate the climate–growth relationships of larch provenances.

scholarly journals Xylem and Phloem Formation Dynamics in Quercus ilex L. at a Dry Site in Southern Italy

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 188
Author(s):  
Angela Balzano ◽  
Katarina Čufar ◽  
Veronica De Micco
Keyword(s):  
Quercus Ilex ◽  
Southern Italy ◽  
Cambial Activity ◽  
Growth Conditions ◽  
Density Fluctuations ◽  
Tissue Preparation ◽  
Outer Bark ◽  
Technical Problems ◽  
Formation Dynamics ◽  
Cambial Cells

Quercus ilex L. dieback has been recently reported at numerous Mediterranean sites. Wood and phloem formation dynamics and tree-ring series of anatomical traits can be used to evaluate growth conditions of trees. We monitored cambial activity in Q. ilex trees growing at a site in southern Italy in order to assess how xylem and phloem production are affected by harsh seasonal climatic variation during a dry year. We followed xylogenesis by counting the number of cambial cells and detecting the occurrence of post-cambial cells throughout the year. As phloem did not show clear growth rings and boundaries between them, we followed the development of phloem fibres—their morphological traits during development and the distance from the cambium served as a reference point to evaluate the phloem production during the year. We detected a multimodal pattern in cambial activity, with wood production in three periods of the year and consequent formation of intra-annual density fluctuations (IADFs). The lowest production of xylem cells was observed in the dry late spring and summer period (likely due to the low water availability), while the highest occurred in autumn (the wettest period). Although we could not differentiate between early and late phloem, the analysis of phloem traits was useful to follow the dynamics of phloem production, which is generally difficult in Mediterranean tree species. We found cambial production of phloem throughout the year, even in the periods without xylem production. The results showed that if tree growth was constrained by environmental limitations, the ratio between xylem to phloem cells decreased and, in the most severely affected trees, more cells were formed preferentially in the phloem compared to xylem. We also briefly report the way in which to solve technical problems with tissue preparation due to extreme hardness and to the peculiar structure of Q. ilex wood and outer bark.

Impact of climatic conditions on the parameters of failure flow of military vehicles

2021 ◽  
pp. 095440702110202
Author(s):  
Nikolaj Dobrzinskij ◽  
Algimantas Fedaravicius ◽  
Kestutis Pilkauskas ◽  
Egidijus Slizys
Keyword(s):  
Climatic Factors ◽  
Armed Forces ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Technical Equipment ◽  
Factors Affecting ◽  
Military Vehicles ◽  
Equipment Reliability ◽  
Number Of Factors ◽  
The Impact

Relevance of the article is based on participation of armed forces in various operations and exercises, where reliability of machinery is one of the most important factors. Transportation of soldiers as well as completion of variety of tasks is ensured by properly functioning technical equipment. Reliability of military vehicles – armoured SISU E13TP Finnish built and HMMWV M1025 USA built were selected as the object of the article. Impact of climatic conditions on reliability of the vehicles exploited in southwestern part of the Atlantic continental forest area is researched by a case study of the vehicles exploitation under conditions of the climate of Lithuania. Reliability of military vehicles depends on a number of factors such as properties of the vehicles and external conditions of their operation. Their systems and mechanisms are influenced by a number of factors that cause different failures. Climatic conditions represent one of the factors of operating load which is directly dependent on the climate zone. Therefore, assessment of the reliability is started with the analysis of climatic factors affecting operating conditions of the vehicles. Relationship between the impact of climatic factors and failure flow of the vehicles is presented and discussed.

scholarly journals Improved Rice Technology Adoption: The Role of Spatially-Dependent Risk Preference

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 691
Author(s):  
Omotuyole Isiaka Ambali ◽  
Francisco Jose Areal ◽  
Nikolaos Georgantzis
Keyword(s):  
Field Experiments ◽  
Climatic Factors ◽  
Risk Preferences ◽  
Risk Preference ◽  
Probit Model ◽  
Climatic Conditions ◽  
High Yield ◽  
Risk Attitudes ◽  
Policy Action ◽  
Rice Varieties

This study analyses farmers’ adoption of improved rice technology, taking into account farmers’ risk preferences; the unobserved spatial heterogeneity associated with farmers’ risk preferences; farmers’ household and farm characteristics; farm locations, farmers’ access to information, and their perceptions on the rice improved varieties (i.e., high yield varieties, HYV). The study used data obtained from field experiments and a survey conducted in 2016 in Nigeria. An instrumental-variable probit model was estimated to account for potential endogenous farmers’ risk preference in the adoption decision model. Results show that risk averse (risk avoidant) farmers are less likely to adopt HYV, with the spatial lags of farmers’ risk attitudes found to be a good instrument for spatially unobserved variables (e.g., environmental and climatic factors). We conclude that studies supporting policy action aiming at the diffusion of improved rice varieties need to collect information, if possible, on farmers’ risk attitudes, local environmental and climatic conditions (e.g., climatic, topographic, soil quality, pest incidence) in order to ease the design and evaluation of policy actions on the adoption of improved agricultural technology.

Influence of Natural and Climatic Factors on Water Horizons Protection Degree in Site Evaluation for Radioactive Waste Disposal

2021 ◽  
Vol 24 (3) ◽  
pp. 301-310
Author(s):  
N. V. Harbachova ◽  
N. D. Kuzmina ◽  
N. V. Kulich ◽  
S. N. Yatsko ◽  
J. A. Korchova
Keyword(s):  
Radioactive Waste ◽  
Climatic Factors ◽  
Probabilistic Approach ◽  
Groundwater Vulnerability ◽  
Climatic Conditions ◽  
Radioactive Waste Disposal ◽  
Climatic Impact ◽  
Influence Zone ◽  
Site Evaluation ◽  
Numerical And Analytical Methods

In this paper, natural (geological and hydrological) and climatic impact conditions on the influence zone for two different sites of radioactive waste disposals have been studied. Probabilistic approach to assessment of the groundwater vulnerability from radionuclide contamination during disposal of radioactive waste is developed. As to climatic conditions, an effective numerical and analytical methods for annual precipitation rates assessment of rare recurrence have been proposed which allow to take into account uncertainties of rare events as well.

ASSESSMENT OF THE INFLUENCE OF THE MAIN CLIMATIC FACTORS ON THE YIELD OF WINTER CEREAL CROPS ON THE TERRITORY OF BELARUS FOR FORECASTING PURPOSES

2021 ◽  
pp. 41-48
Author(s):  
Halina A. Kamyshenka
Keyword(s):  
Computational Models ◽  
Climatic Factors ◽  
Climatic Conditions ◽  
Yield Variability ◽  
Cereal Crops ◽  
Winter Rye ◽  
Statistical Assessment ◽  
Winter Cereal ◽  
Temperature And Precipitation

The results of a statistical assessment of the influence of changing weather and climatic conditions of the territory of Belarus on the productivity of the main winter cereal crops are presented in order to build computational models of productivity. The calculations were made with respect to the climatic component as a predictor, taking into account the deviations of air temperature and precipitation from the long-term climatic norm of months that have the most significant effect on the yield of the studied crops. For winter rye and wheat, adequate models of yield variability have been built. The research results are relevant for solving forecasting problems.

scholarly journals Tree-Ring Growth of Larch (Larix decidua Mill.) in the Polish Sudetes—The Influence of Altitude and Site-Related Factors on the Climate–Growth Relationship

Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 663 ◽  
Author(s):  
Małgorzata Danek ◽  
Monika Chuchro ◽  
Adam Walanus
Keyword(s):  
Tree Ring ◽  
Climatic Factors ◽  
Negative Relationship ◽  
Thermal Conditions ◽  
Cambial Activity ◽  
Negative Influence ◽  
Larix Decidua ◽  
Related Factors ◽  
Local Conditions ◽  
Negative Effect

In this paper, the first study of a regional character on the influence of climatic factors on the tree-ring growth of European larch (Larix decidua Mill.) growing in the Polish Sudetes is presented. The obtained results indicate the relatively high diversity of the climatic signal observed in the tree rings of larches growing in the Sudetes. The most significant differentiating factor is altitude. The results suggest that the possible influence of local conditions (e.g., summit proximity, soil and bedrock characteristics, and exposure to strong winds) could also be of importance. A positive relationship between tree-ring growth and May temperatures was noted throughout the area; this indicates the principal importance of thermal conditions during the initial stage of cambial activity and tree-ring formation in larches from the Sudetes. The negative effect of the temperatures in the previous summer upon the tree-ring growth of larch in the subsequent year was also observed. The studies also indicate the negative influence of the water stress in summer (particularly in July of the previous year) upon the growth of trees. The negative relationship between tree-ring growth and the previous November temperature could be explained by the need for a late-autumn cooling, which affects the development of assimilation apparatus in spring of the subsequent year, which indirectly affects the tree-ring growth in the same year.

scholarly journals Effect of Climatic Factors on Stem Biomass and Carbon Stock of Larix gmelinii and Betula platyphylla in Daxing’anling Mountain of Inner Mongolia, China

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Dilawar Khan ◽  
Muhammad Atif Muneer ◽  
Zaib-Un- Nisa ◽  
Sher Shah ◽  
Muhammad Amir ◽  
...  
Keyword(s):  
Inner Mongolia ◽  
Negative Impact ◽  
Climatic Factors ◽  
High Temperature Stress ◽  
Climatic Conditions ◽  
Larix Gmelinii ◽  
Maximum Temperature ◽  
Betula Platyphylla ◽  
Stem Biomass ◽  
Annual Minimum Temperature

Climate change has become a global concern for scientists as it is affecting almost every ecosystem. Larix gmelinii and Betula platyphylla are native and dominant forest species in the Daxing’anling Mountains of Inner Mongolia, playing a major role in carbon sequestration of this region. This study was carried out to assess the effect of climate variables including precipitation and temperature on the biomass of Larix gmelinii and Betula platyphylla forests. For this purpose, we used the climate-sensitive stem biomass allometric model for both species separately to find out accurate stem biomass along with climatic factors from 1950 to 2016. A total of 66 random plots were taken to attain the data from this study area. Larix gmelinii and Betula platyphylla stem biomass have a strong correlation with annual precipitation (R2 = 0.86, R2 = 0.71, R2 = 0.79, and R2 = 0.59) and maximum temperature (R2 = 0.76, R2 = 0.64, R2 = 0.67, and R2 = 0.52). However, annual minimum temperature (R2 = 0.58, R2 = 0.43, R2 = 0.55, and R2 = 0.46) and annual mean temperature (R2 = 0.40, R2 = 0.22, R2 = 0.36, and R2 = 0.19) have a relatively negative impact on tree biomass. Therefore, we suggest that both species have a very strong adaptive nature with climatic variation and hence can survive under drought and high-temperature stress climatic conditions.

scholarly journals Living mulch strategy for organic cauliflower (Brassica oleracea L.) production in central and southern Italy

2015 ◽  
Vol 10 (2) ◽  
pp. 90 ◽  
Author(s):  
Stefano Canali ◽  
Gabriele Campanelli ◽  
Corrado Ciaccia ◽  
Mariangela Diacono ◽  
Fabrizio Leteo ◽  
...  
Keyword(s):  
Brassica Oleracea ◽  
Field Experiments ◽  
Southern Italy ◽  
Central Italy ◽  
Climatic Conditions ◽  
F1 Hybrid ◽  
Agronomic Practices ◽  
Burr Medic ◽  
The Mean ◽  
Sustainable Agricultural Systems

In sustainable agricultural systems, intercropping using living mulches (LM) provides many beneficial ecosystem services. The objective of these two-year field experiments was to study the suitability of different LM options of burr medic (<em>Medicago polymorpha</em> L. var. <em>anglona</em>) for organic cauliflower (<em>Brassica oleracea</em> L.) cultivation in two sites under Mediterranean conditions. In central Italy (Experiment 1) contemporary and delayed (to crop) sowings of LM were compared with a no-cover crop treatment, contrasting two local cauliflower cultivars and a F1 Hybrid. In southern Italy (Experiment 2) the sustainability of systems combining LM (anticipated and contemporary sowing compared with no-cover) and organic fertilisation strategies was assessed. The aboveground biomasses dry weights of cauliflower crop (heads and residues), burr medic and weeds were separately determined. Results suggested that in Experiment 1 the LM was not able to smother weeds establishment and growth, as a consequence of early sowing, while cauliflower yield was reduced. Moreover, the genotypes behaviour was greatly influenced by the LM sowing times. In Experiment 2, irrespective of the agronomic practices applied, climatic conditions notably influenced cauliflower cultivation and also reduced the mean yield. Therefore, the recorded differences between the two experimental sites highlighted the need to tailor the LM strategies to the different environmental conditions.

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