Dan Razvan Popoviciu | Universitatea Ovidius Constanta (original) (raw)

Papers by Dan Razvan Popoviciu

Academy of Romanian Scientists Annals - Series on Biological Sciences, 2022

In the biomedical sciences field of recent years, phytotherapeutic products usage has intensifie... more In the biomedical sciences field of recent years, phytotherapeutic products usage has intensified because they are a safe and sustainable alternative, with less environmentally aggressive molecules that are able to meet therapeutic needs. Mature vegetal product Taraxacum sp., also known as dandelion, has been used for hundreds of years as a traditional remedy for liver, kidney, lung, gastric diseases and even some cancers, due to its antiinflammatory and antioxidant effects. The aim of this paper was to assess the contents of some bioactive principles and overall antioxidant potential of Taraxacum sp. hydroalcoholic extracts obtained from both plant organs, herba and radix. The vegetal product was collected in the period September-October 2021, from spontaneous flora of South Dobrudja area, Romania. Fresh plant was dried at room temperature on metal sieves, grind to a fine powder and extracted 10% concentration in ethanol 50% and 70% concentrations, using cold maceration and Soxhlet extraction, standard methods, followed by filtration at normal pressure. Obtained hydroalcoholic extracts were analysed by UV-Vis spectrophotometry for determining total carotenoids, flavonoids and total polyphenols content. The total antioxidant capacity was quantified through photochemiluminescence method by comparison with the standard substance used for calibration, Trolox® as tocopherol analogue by ACL (Antioxidant Capacity of Lipid Soluble Substances) procedure using Photochem apparatus, Analytik Jena AG, Germany. Total carotenoids and flavonoids concentration, respectively polyphenols contents, were highest in 70% ethanol extracts, for the two applied extraction methods. Total antioxidant capacity (TEAC) was variable, with increased values in 70% ethanol extracts of both vegetal products, herba and radix. The preliminary valuable obtained results, offer us the support for continuation of the studies regarding the therapeutic activity of Taraxacum sp. from Dobrudja spontaneous flora.

Academy of Romanian Scientists Annals Series on Biological Sciences, 2023

Carotenoids are pigments that occur naturally in bacteria, algae, fungi and plants and give them ... more Carotenoids are pigments that occur naturally in bacteria, algae, fungi and plants and give them their orange or red colour. The most important carotenoids that have beneficial effects on human health are beta-carotene, lutein, astaxanthin, lycopene and zeaxanthin. The main advantage of carotenoids lies in their antioxidant potential, the role of protecting the body's cells from damage by unstable oxygen molecules. The present paper presents the comparative content of carotenoid-type bioactive compounds present in the hydroalcoholic extracts obtained from different plant organs (roots, leaves and flowers) of the species
Taraxacum officinale (L.), dandelion. The plant product was collected from the spontaneous flora, the southern area of Dobrogea, Constanța county and from the eastern area of Transylvania, Harghita county, in May 2022. The obtained hydroalcoholic extracts of 10% concentration in 50% ethanol and respectively 70% ethanol, using the cold maceration method, in the dark, for 14 days, were analysed by UV-Vis spectrophotometry to determine the total content of carotenoids, beta-carotene and lutein. Total carotenoids content was higher in ethanolic extracts of roots and flowers of plants collected from the southern area of Dobrogea, and for the leaves the content of total carotenoids was higher in the ethanolic extracts of the
plants collected from the eastern area of Transylvania. The differential distribution observed in terms of the carotenoids content present in the various plant organs of the species Taraxacum officinale (L.), may be due to the influence of the climate and the type of soil characteristic of the two studied areas. Enriching the database regarding the concentration of analysed carotenoid-type bioactive principles can contribute to the evelopment and testing of hypotheses about the therapeutic potential of this valuable component of the Romanian spontaneous flora.

Pakistan Journal of Botany, 2024

Odontarrhena borzaeana (Nyár.) D. A. German (= Alyssum borzaeanum Nyár.) is an endemic and endang... more Odontarrhena borzaeana (Nyár.) D. A. German (= Alyssum borzaeanum Nyár.) is an endemic and endangered halophyte of the family Brassicaceae species grows on the sandy shores of the Black Sea. The aim of this research was to assess some anatomical features of vegetative organs of this species. Roots had a secondary structure with less developed suber and secondary cortex and bundle-like arrangement of the primary xylem towards the centre of the root (alternating with pith tissue). Stem had a primary structure, with differentiated cortex (the innermost 2-3 cell layers having a flattened shape). Flattened blocks of phloem were followed by xylem. Well-developed sclerenchyma layers were found both within and between vascular bundles, forming a continuous ring around the stem. Pith was parenchymatous and abundant. Leaf blades were amphistomatic and equifacial, with few layers of spongy parenchyma in the middle and well-developed palisade parenchyma towards both sides. Typical collateral bundles were each surrounded by a sheath of parenchymatous cells. Both stem and leaves were covered with massive stellate trichomes (larger on leaves), similarly to the ones reported in several related species.

Applied Sciences, 2024

Four plum cultivars commonly grown in Romania, ‘Angeleno’, ‘Anna Späth’, ‘Silvia’ and ‘Stanley’, ... more Four plum cultivars commonly grown in Romania, ‘Angeleno’, ‘Anna Späth’, ‘Silvia’ and ‘Stanley’, were analyzed with regard to several parameters, including water content, juice pH, phenolic compounds (total and some major classes), carotenoids, ascorbic acid and soluble sugars. Among the four studied cultivars, ‘Silvia’ ranked the highest in terms of total phenolic content (82,345 mg/kg DW), flavonoids (43,171 mg/kg) and anthocyanins (1991 mg/kg). Hydroxybenzoic acids were found to be an important phenolic component; up to 33,971 mg/kg was found in ‘Angeleno’. The hydroxycinnamic acid content was highest in ‘Stanley’, and stilbenes were most prevalent in ‘Anna Späth’. Tannins were found in significant amounts only in fruit peel and were only present in some of the cultivars. Carotenoids were mostly present in the epicarp, with the maximum amount identified in ‘Anna Späth’ (313 mg/kg). The main compounds were β-carotene (of which the highest amount was identified in ‘Silvia’), lutein (with the highest amount found in ‘Silvia’) and lycopene (with the highest amount detected in ‘Stanley’). ‘Silvia’ also contained the highest amounts of ascorbic acid (7895 mg/kg in pulp and 12,229 mg/kg in peel). The highest soluble sugar content was found in the pulp of ‘Stanley’ (142,120 mg/kg), while ‘Anna Späth’ contained the lowest amount of soluble sugar. ‘Stanley’ also had less acidic pulp juice. Among the four cultivars, ‘Silvia’ ranked the highest in most classes of bioactive compounds, including total phenolic compounds, flavonoids, anthocyanins, tannins (peel only), β-carotene, lutein and ascorbic acid.

Annals of the University of Craiova – Series: Horticulture, Biology, Food Products Processing, Environmental Engineering, 2024

Four maize cultivars grown locally, in Constanța county, were anlayized for their bioactive compo... more Four maize cultivars grown locally, in Constanța county, were anlayized for their bioactive compounds contents. They were found to contain variable amounts of carotenoids, 10-45 mg/kg, with notable amounts of lutein and lycopene. Phenolic inventory varied between 7,651-10,622 mg/kg, of which hydroxybenzoic acids were dominant (45-63%), followed by flavonoids (mostly flavanols, 21-29%). Ascorbic acid concentration was 165-219 mg/kg.

Annals of the University of Craiova – Series: Horticulture, Biology, Food Products Processing, Environmental Engineering, 2024

Bitter gourd (Brâncuși cultivar) stems, tendrils and leaves from plants locally grown at the "Ovi... more Bitter gourd (Brâncuși cultivar) stems, tendrils and leaves from plants locally grown at the "Ovidius" University, Constanța, were extracted in 70% ethanol solution and analyzed for antioxidant activity. The highest antioxidant activity was found in tendrils (53.08%), flowers (51.53%) and fruit pulp (49.64%). Lowest values of IC50 were found in flower (34.46 mg/L) and fruit pulp (39.47 mg/L) extracts. These values are high when compared to other known Cucurbitaceae, especially in regard to vegetative organs. Considering the known contents of bioactive compounds in M. Charantia organs, the antioxidant activity cannot be directly correlated to total phenolic concentrations, those of flavonoids or ascorbic acid.

Annals of the University of Craiova – Series: Horticulture, Biology, Food Products Processing, Environmental Engineering, 2024

Safflower cultivar CW 4440 was grown on two different water regimes: non-irrigated, and fulldose ... more Safflower cultivar CW 4440 was grown on two different water regimes: non-irrigated, and fulldose irrigated. Achenes were harvested and taken for biochemical analyses. They were found to contain low amounts of carotenoids, 2.38-4.38 mg/kg, with notable amounts of lutein and minor concentrations of xanthins. All carotenoids, except for cryptoxanthin, reached their highest values in irrigated plants, while β-carotene was found in detectable amounts only in irrigated plants. Phenolic inventory, on the other hands, was high compared to known data in literature

Annals of the University of Craiova – Series: Horticulture, Biology, Food Products Processing, Environmental Engineering, 2024

Locally-grown kiwano fruits, Tempus cultivar, were evaluated for their content in some main class... more Locally-grown kiwano fruits, Tempus cultivar, were evaluated for their content in some main classes of nutritional organic compounds. With 448/98 mg/kg DW (pulp/peel) total carotenoid content was average when compared to other Cucurbitaceae. Among identifiable carotenoids, lycopene was the only one in notable amounts, in peel (12% of total carotenoids). With 51,751/37,624 mg/kg, total phenolic inventory was extremely rich. Flavonoids were clearly dominant (78/49%). Hydroxycinnamic acids were found in significant proportions (11/27%). Fruit pulp also showed some amounts of tannins (5.9%) and stilbenes (2%), while coumarins were found in low amounts. Ascorbic acid was abundant, 20,140 mg/kg in pulp and 7,689 mg/kg in peel. Soluble sugars were 15,915 /6,634 mg/kg while lipids were 5,556 /2,721 mg/kg.

Annals of the University of Craiova – Series: Horticulture, Biology, Food Products Processing, Environmental Engineering, 2024

Flax from cultivar Alexin was grown on three different water regimes: non-irrigated, half-dose an... more Flax from cultivar Alexin was grown on three different water regimes: non-irrigated, half-dose and full-dose irrigated. Seeds were harvested and taken for biochemical analyses. They were found to contain low amounts of carotenoids, 7.57-12.79 mg/kg, with notable amounts of lycopene, lutein and zeaxanthin, but no detectable β-carotene. Phenolic inventory was also low, but consistent with values usually found in ungerminated linseed: 3,106-7,211 mg/kg, dominated by flavonoids (37-51%; of which minor amounts of flavanols and anthocyanins) and hydroxycinnamic acids (23-37%). Coumarins and stilbenes had low concentrations. Oil content ranged from 21.3% in non-irrigated plants to over 29% in fully irrigated ones. Ascorbic acid content showed little variation, with 985-1,187 mg/kg, while soluble sugars were 2,482-4,073 mg/kg. The concentrations of all these compounds, except for cryptoxanthin, were positively correlated to water dosage. The most affected by irrigation regime were phenolic compounds and sugars. The least influenced was ascorbic acid.

Annals of the University of Craiova – Series: Horticulture, Biology, Food Products Processing, Environmental Engineering, 2024

Stachys maritima Gouan is a perennial herbaceous plant from the Lamiaceae family. It only grows o... more Stachys maritima Gouan is a perennial herbaceous plant from the Lamiaceae family. It only grows on sand dunes, especially littoral ones. In Romania it is considered an endangered species, only found in few coastal areas of Tulcea and Constanța counties. Its vegetative organs (rhizome, aerial stem, leaf petiole and leaf blade) were harvested for anatomic analysis. The rhizome showed a secondary structure, with thin suber, compact and thin phloem and compact xylem annual growth rings, while pith was mostly replaced by xylem elements. Aerial stems had the four-ridged shape common in many Lamiaceae, with caps of angular collenchyma protecting four major, semicircular, collateral vascular bundles. Multiple secondary bundles were also found, joined together by sclerified external pith layers. Leaf petiole was filled with undifferentiated parenchyma, made up of large polygonal cells, similar in shape to stem cortex and pith. Leaf blade had a weakly differentiated bifacial structure and was amphistomatic. Stems and leaves were covered by dense, massive, lignified tector hairs. Secretory hairs were small, exclusively peltate, mostly found on stems.

European Journal of Medicine and Natural Sciences

Willofleaf cotoneaster (Cotoneaster salicifolius Franch.) is a low, prostrate shrub, grown in Rom... more Willofleaf cotoneaster (Cotoneaster salicifolius Franch.) is a low, prostrate shrub, grown in Romania as an ornamental plant. Its fruits are small, ovoid pomes. Fruit tissues were analyzed for total carotenoid content (through acetone extraction and spectrophotometry), flavonoid content (methanol extraction and spectrophotometry) and total concentration of phenolic and polyphenolic compounds (methanol extraction and spectrophotometric Folin-Ciocâlteu method). C. salicifolius fruits analyzed contained an average of 311.50 mg/kg DW carotenoids (heat-dried fruits – only 100.25 mg/kg). Average flavonoid concentration was 9,777.62 mg/kg in fresh frozen fruits and 4,574 mg/kg in dried ones. 25,056.09 mg/kg GAE was the average concentration of total phenolics in fresh fruits, while dry fruit powder contained 5,271 mg/kg GAE. These concentrations of bioactive compounds are comparable, or even have a higher than in pomes belonging to related species, including domestic cultivars of rowanberr...

Academy of Romanian Scientists Annals Series on Biological Sciences, 2023

Carotenoids are pigments that occur naturally in bacteria, algae, fungi and plants and give them... more Carotenoids are pigments that occur naturally in bacteria, algae, fungi and plants
and give them their orange or red colour. The most important carotenoids that have beneficial
effects on human health are beta-carotene, lutein, astaxanthin, lycopene and zeaxanthin. The
main advantage of carotenoids lies in their antioxidant potential, the role of protecting the
body's cells from damage by unstable oxygen molecules. The present paper presents the
comparative content of carotenoid-type bioactive compounds present in the hydroalcoholic
extracts obtained from different plant organs (roots, leaves and flowers) of the species
Taraxacum officinale (L.), dandelion. The plant product was collected from the spontaneous
flora, the southern area of Dobrogea, Constanța county and from the eastern area of
Transylvania, Harghita county, in May 2022. The obtained hydroalcoholic extracts of 10%
concentration in 50% ethanol and respectively 70% ethanol, using the cold maceration
method, in the dark, for 14 days, were analysed by UV-Vis spectrophotometry to determine the
total content of carotenoids, beta-carotene and lutein. Total carotenoids content was higher in
ethanolic extracts of roots and flowers of plants collected from the southern area of Dobrogea,
and for the leaves the content of total carotenoids was higher in the ethanolic extracts of the
plants collected from the eastern area of Transylvania. The differential distribution observed
in terms of the carotenoids content present in the various plant organs of the species
Taraxacum officinale (L.), may be due to the influence of the climate and the type of soil
characteristic of the two studied areas. Enriching the database regarding the concentration of
analysed carotenoid-type bioactive principles can contribute to the development and testing of hypotheses about the therapeutic potential of this valuable component of the Romanian
spontaneous flora

Revista de Chimie

The chromium bioaccumulation potential in Sinapis alba L. was studied in experimental hydroponic ... more The chromium bioaccumulation potential in Sinapis alba L. was studied in experimental hydroponic conditions. Mustard seedlings were grown in nutrient solution containing 50, 100, 250 and 500 ppm Cr. After 10 days, seedlings were analyzed for shoot length, biomass, leaf pigment (chlorophylls and carotenoids) and tissular Cr concentration. The Biological Accumulation Coefficients (BAC) were also determined. Cr content in S. alba dry mass reached 415-2,064 ppm, depending on ambient Cr concentration. BAC ranged between 8.30 to 4.13, with a peak at 100 ppm and lowest values at higher concentrations. Shoot length, biomass and pigment concentration values showed an average decrease at high Cr concentrations (mostly, at 500 ppm), without a definite statistical significance. Results indicate that S. alba is tolerant to high Cr levels and has hyperaccumulative abilities.

Revista de Chimie

Copper, manganese and zinc bioaccumulation potential was screened for three common Poaceae specie... more Copper, manganese and zinc bioaccumulation potential was screened for three common Poaceae species, Hordeum murinum ssp. murinum L., Leymus racemosus ssp. sabulosus (M. Bieb.) Tzvelev and Lollium perenne L., abundantly growing along the Romanian Black Sea Coastal area, Constanta County. The concentration of the selected heavy metals was analyzed though atomic absorption spectrometry in samples of aboveground plant organs and soils. To assess the potential for phytoaccumulation, the Biological Accumulation Coefficients (BAC) were calculated. Considering the minimal thresholds widely accepted in literature for Cu, Mn and Zn hyperaccumulators, none of the selected species can fit in this category. The highest average copper concentration was found in Hordeum murinum ssp. murinum L. (5.45 mg/kg). For manganese, the highest value was found in Lollium perenne L. (104.08 mg/kg), while for zinc, the maximum was reached in Leymus racemosus ssp. sabulosus (M. Bieb.) Tzvelev, tissue (62.95 mg/...

15th International Multidisciplinary Scientific GeoConference SGEM2015, WATER RESOURCES. FOREST, MARINE AND OCEAN ECOSYSTEMS, 2011

Seedlings of Sinapis alba L. species (white/yellow mustard) were grown in nutrient solution conta... more Seedlings of Sinapis alba L. species (white/yellow mustard) were grown in nutrient solution containing different concentrations 50, 100, 250 and 500 mg/kg Cu for 10 days. Seedlings were measured and weighed at the end of the experiment. Leaf pigment concentration (chlorophylls a and b and carotenoids), tissular copper concentration and Biological Accumulation Coefficients (BAC) were determined. Copper content in Sinapis alba L. tissues reached 74.54 171.20 mg/kg dry mass, with highest values at high ambient concentration. BAC reached 1.49 at 50 mg/kg and was subunitary at higher concentrations, between 0.75 0.34. Shoot length and biomass emphasize a significant decrease at high ambient copper levels, while photosynthetic pigment concentrations did not decrease. These results indicate a limited tolerance of white mustard to high copper concentrations and a limited bioaccumulation potential of this metal.

Bangladesh Journal of Botany, 2024

Five black tea types, Assam, Darjeeling, Earl Grey, English Breakfast and Oolong were tested for ... more Five black tea types, Assam, Darjeeling, Earl Grey, English Breakfast and Oolong were tested for their chlorophyll, carotenoid, flavonoid, total phenolic content and essential oil content. English Breakfast had the highest chlorophyll content (834 mg/kg) and Earl Grey had the highest carotenoid content (360 mg/kg). Total phenolic content was the highest in Darjeeling (an average of 40,874 mg/kg), while flavonoids, specifically, reached the highest concentrations in Oolong (498 mg/kg). Total essential oils were maximum in Assam tea blend (4,600 mg/kg). Tea pH values ranged between 6.13-6.66.

Bangladesh Journal of Botany, 2024

Lupinus polyphyllus Lindl. (garden lupin, large-leaved lupin) is a perennial herbaceous legume, u... more Lupinus polyphyllus Lindl. (garden lupin, large-leaved lupin) is a perennial herbaceous legume, used for ornamental purposes, for improving soil quality, as forage or in human food products. However, little is known about anatomical features of this species. Lupin vegetative organs (roots, petioles, leaf blades) were collected, cross sectioned and analyzed by bright-field microscopy. Lupin roots showed primary and incipient secondary structures, with a cortex featuring large-sized cells with rich cellular content and granular solid inclusions. Leaf petioles had rare peltate hairs and large sub-stomatal lacunes, a large medullary lacune and rich parenchyma. Leaf blades had typical bifacial structure, with three-layered palisade tissue and less proeminent midrib, with a collateral bundle, protected by small caps of collenchyma.

Analele Universităţii din Craiova, Dec 18, 2023

Bitter gourd fruits (Brâncuși cultivar) from local production were studied for their content in s... more Bitter gourd fruits (Brâncuși cultivar) from local production were studied for their content in some classes of nutritive compounds. Carotenoids (total, β-carotene, lycopene and lutein), phenolic compounds (total, flavonoids, anthocyanins, tannins), ascorbic acid, soluble sugars and lipids were determined. With 231/251 mg/kg DW (peel/pulp) total carotenoid content in M. charantia fruits was lower than in other known Cucurbitaceae. β-carotene was dominant in the peel while lycopene constituted a large fraction in the pulp. Lutein was found in low amounts (<1 mg/kg) only in the peel. On the contrary, with 13,527/18,598 mg/kg, the total phenolic inventory is richer than in many other related species. Flavonoids (8,763/14,545 mg/kg) were dominant in both peel and pulp. Of these, only a small fraction (267/212 mg/kg) were anthocyanins. Tannins constituted over 9.5% of the phenolic inventory. Ascorbic acid concentration was high, 14,689 mg/kg in peel and 12,847 mg/kg in pulp.

Academy of Romanian Scientists Annals - Series on Biological Sciences, 2022

Academy of Romanian Scientists Annals Series on Biological Sciences, 2023

Pakistan Journal of Botany, 2024

Applied Sciences, 2024

Annals of the University of Craiova – Series: Horticulture, Biology, Food Products Processing, Environmental Engineering, 2024

European Journal of Medicine and Natural Sciences

Academy of Romanian Scientists Annals Series on Biological Sciences, 2023

Carotenoids are pigments that occur naturally in bacteria, algae, fungi and plants and give them... more Carotenoids are pigments that occur naturally in bacteria, algae, fungi and plants
and give them their orange or red colour. The most important carotenoids that have beneficial
effects on human health are beta-carotene, lutein, astaxanthin, lycopene and zeaxanthin. The
main advantage of carotenoids lies in their antioxidant potential, the role of protecting the
body's cells from damage by unstable oxygen molecules. The present paper presents the
comparative content of carotenoid-type bioactive compounds present in the hydroalcoholic
extracts obtained from different plant organs (roots, leaves and flowers) of the species
Taraxacum officinale (L.), dandelion. The plant product was collected from the spontaneous
flora, the southern area of Dobrogea, Constanța county and from the eastern area of
Transylvania, Harghita county, in May 2022. The obtained hydroalcoholic extracts of 10%
concentration in 50% ethanol and respectively 70% ethanol, using the cold maceration
method, in the dark, for 14 days, were analysed by UV-Vis spectrophotometry to determine the
total content of carotenoids, beta-carotene and lutein. Total carotenoids content was higher in
ethanolic extracts of roots and flowers of plants collected from the southern area of Dobrogea,
and for the leaves the content of total carotenoids was higher in the ethanolic extracts of the
plants collected from the eastern area of Transylvania. The differential distribution observed
in terms of the carotenoids content present in the various plant organs of the species
Taraxacum officinale (L.), may be due to the influence of the climate and the type of soil
characteristic of the two studied areas. Enriching the database regarding the concentration of
analysed carotenoid-type bioactive principles can contribute to the development and testing of hypotheses about the therapeutic potential of this valuable component of the Romanian
spontaneous flora

Revista de Chimie

15th International Multidisciplinary Scientific GeoConference SGEM2015, WATER RESOURCES. FOREST, MARINE AND OCEAN ECOSYSTEMS, 2011

Bangladesh Journal of Botany, 2024

Analele Universităţii din Craiova, Dec 18, 2023

Atlhough few people acknowledge it, soil is one of the environments hosting the highest biodivers... more Atlhough few people acknowledge it, soil is one of the environments hosting the highest
biodiversity on this planet. A multitude of micro-and macroorganisms, bacteria, fungi,
protists, plants and animals populate the various types of soil.
Yet, a really remarkable thing about soil is not just its enormous biodiversity, but also the
variety and complexity of interactions among present organisms. At this level, we can find
complex symbioses, competition, predation and parasitism. These interactions are essential to
the continuous recycling of bioelements, in decomposing organic matter and making available
again its various components.
Thus, soil has a crucial contribution to the very existence of Earth’s biosphere. It provides
nutritional support to all land-based ecological communities and, is also the basis of any
agricultural production, thus, of our everyday food.
This is why knowledge of all these aspects of soil biology and ecology is important to
naturalists. This book is conceived as a guide to students, specialists and all people interested
in natural sciences.

puțină lume conștientizează, solul reprezintă unul dintre mediile cu cea mai mare biodiversitate ... more puțină lume conștientizează, solul reprezintă unul dintre mediile cu cea mai mare biodiversitate de pe această planetă. O multitudine de micro- și macroorganisme, bacterii, fungi, protiste, plante și animale populează diversele tipuri de sol.
Însă ceea ce este cu adevărat remarcabil la sol nu este numai enorma sa biodiversitate ci și varietatea și complexitatea interacțiunilor dintre organismele prezente. Găsim la acest nivel simbioze complexe, competiții, prădătorism și parazitism. Aceste interacțiuni sunt esențiale în recircularea permanentă a bioelementelor, în descompunerea materiei organice și repunerea în circulație a variilor sale componente.
Astfel, solul își aduce o contribuție esențială la existența biosferei terestre. El asigură suportul nutritiv al tuturor comunităților ecologice de pe uscat și, firește, constituie și baza oricărei producții agricole, așadar a hranei noastre zilnice.
De aceea, cunoașterea tuturor acestor elemente este indispensabilă naturalistului. Ea face obiectul disciplinei numite ȘTIINȚA SOLULUI (BIOLOGIA ȘI ECOLOGIA SOLULUI), studiată în ultimul an de facultate, de către studenții specializării Ecologie și Protecția Mediului.
Acest curs le este dedicat, dar nu se limitează la studenții acestei specializări. Am conceput această carte pentru toți cei preocupați de acest vast domeniu, fie ei specialiști sau nu.