Vertical Distribution and Controlling Factors of Soil Inorganic Carbon in Poplar Plantations of Coastal Eastern China

Afforestation is a strategy to protect croplands and to sequestrate carbon in coastal areas. In addition, inorganic carbon is a considerable constitute of the coastal soil carbon pool. However, the vertical distribution and controlling factors of soil inorganic carbon (SIC) in plantations of coastal areas have been rarely studied. We analyzed the SIC content as well as physiochemical properties along soil profiles (0–100 cm) in young (YP) and mature (MP) poplar plantations in coastal eastern China. The soil profile was divided into six layers (0–10, 11–20, 21–40, 41–60, 61–80 and 81–100 cm) and a total of 36 soil samples were formed. The SIC content first increased from 0–10 cm (0.74%) to 11–20 cm (0.92%) and then fluctuated in the YP. In contrast, the SIC content increased with increasing soil depth until 40 cm and then leveled off, and the minimum and maximum appeared at 0–10 cm (0.54%) and 81–100 cm (0.98%) respectively in the MP. The soil inorganic carbon density was 12.05 and 12.93 kg m−2 within 0–100 cm in the YP and MP, respectively. Contrary to SIC, soil organic carbon (SOC) first decreased then levelled off within the soil profiles. Compared with the YP, the SIC content decreased 27.8% at 0–10 cm but increased 13.2% at 21–40 cm, meanwhile the SOC content in MP decreased 70.6% and 46.7% at 21–40 cm and 61–80 cm, respectively. The water-soluble Ca2+ and Mg2+ gradually decreased and increased, respectively within the soil profiles. The soil water-soluble Ca2+ increased 18.3% within 41–100 cm; however, the soil water-soluble Mg2+ decreased 32.7% within 21–100 cm in the MP when compared to the YP. Correlation analysis showed that SIC was negatively correlated with SOC, but positively correlated with soil pH and water-soluble Mg2+. Furthermore, structural equation modeling (SEM) indicated that SOC was the most important factor influencing the SIC content in the studied poplar plantations, indicating SOC sequestration promoted the dissolution of SIC. Therefore, our study highlights the trade-off between SIC and SOC in poplar plantations of coastal Eastern China.

Epiphytic lichens of woodland habitats in the lower Ticino river valley and in the “Bosco Siro Negri” Integral Nature State Reserve (NW Italy)

Epiphytic lichens were surveyed in the “Bosco Siro Negri” Integral Nature State Reserve (province of Pavia, Lombardy, NW Italy), which hosts a well-preserved fragment of oak-elm floodplain forest (Natura 2000 Habitat 91F0). The core woodland fragment hosted only four species on the tree boles, i.e. Lepraria finkii plus the forest specialists Coenogonium pineti, Diarthonis spadicea, and Opegrapha vermicellifera. An additional eight nitro- and photophytic species were recorded on the highest twigs of the canopy. The whole Reserve, including the neighbouring degraded woodlands and poplar plantations, hosted 27 epiphytic lichen taxa. The lower Ticino River valley between Vigevano and Pavia, in which the Reserve is located, was surveyed for epiphytic lichens in an additional 45 sites, including 15 wellpreserved oak-elm/hornbeam woodlands (Habitat 91F0), 15 degraded broadleaved woodlands with high occurrence of black locust and 15 poplar plantations. Overall, 32 species were recorded. Well-preserved woodlands had a lower species richness, but they hosted forest specialists not occurring in the other two habitats. Graphis pulverulenta and Lecania cyrtellina are new to Lombardy. Anisomeridium polypori, Diarthonis spadicea, Lecanora expallens and Pseudoschismatomma rufescens are reported from Lombardy for the second time.

Study of the work of a self-propelled mulcher in the preparation of forest soils for planting poplar in the conditions of Bulgaria

The article describes the use of mulcher technology in forestry for the care of forest crops, removal of overgrowth under power lines, in the right-of-way of gas and oil pipelines, railways and highways. With the help of mulchers, they create fire strips in the forest, make clearings. Mulchers clean fallen trees after fires, floods and hurricanes. They are involved in landscaping and agricultural work. The article examines the work of the PT-400 self-propelled tillage mulcher for the surface crushing of logging waste on the utilized poplar plantations of the Oryakhovsky state forestry in Bulgaria. The work of the Rotor Ferri S stump grinder was studied when crushing poplar stumps with a diameter of up to 50 cm. The hourly productivity of these machines at various operations was determined, and also the process of crushing stumps and felling residues by fractional composition was studied. The work of the mulcher was compared with the bulldozer technology and the mounted tractor stump grinder Rotor Ferri S. It was concluded that the mounted stump grinder Rotor Ferri S is the most suitable machine for grinding poplar stumps of any diameter, since its productivity significantly exceeds that of the PT-400 mulcher/tiller. The load on the tractor is minimal, which saves energy. At the same time, mulching technology is very effective and in demand.

CONDITION AND WATER DEFICIENCY OF BALSAMIC POPLAR LEAVES IN THE CONDITIONS OF POLYMETALLIC CONTAMINATION OF THE STERLITAMAK INDUSTRIAL CENTER

The paper presents materials on the water deficiency of leaves in the balsamic poplar in the conditions of polymetallic contamination of the Sterlitamak industrial center. The object of the research was poplar plantations located at different distances from the industrial enterprises of Sterlitamak. As a result, it was revealed that in the conditions of polymetallic contamination of the Sterlitamak industrial center at noon, with an increase in temperature and a decrease in relative humidity, the moisture consumption increases in the balsamic poplar. The maximum water deficit in the daytime is from 13 to 15 hours. In trees in conditions of polymetallic contamination of the SPC, the water consumption during the night hours is not covered by its intake, so the next day the morning hours began with some water shortage. As a result of the conducted studies, it was found that in the conditions of polymetallic pollution of the Sterlitamak industrial center, with the deterioration of the living condition and with a decrease in the proportion of absorbing roots of the balsamic poplar, significant changes in water deficit indicators are noted.

Mediterranean Pine Vole, Microtus duodecimcostatus: A Paradigm of an Opportunistic Breeder

Most mammalian species of the temperate zones of the Earth reproduce seasonally, existing a non-breeding period in which the gonads of both sexes undergo functional regression. It is widely accepted that photoperiod is the principal environmental cue controlling these seasonal changes, although several exceptions have been described in other mammalian species in which breeding depends on cues such as food or water availability. We studied the circannual reproductive cycle in males of the Mediterranean pine vole, Microtus duodecimcostatus, in the Southeastern Iberian Peninsula. Morphological, hormonal, functional, molecular and transcriptomic analyses were performed. As reported for populations of other species from the same geographic area, male voles captured in wastelands underwent seasonal testis regression in summer whereas, surprisingly, those living either in close poplar plantations or in our animal house reproduced throughout the year, showing that it is the microenvironment of a particular vole subpopulation what determines its reproductive status and that these animals are pure opportunistic, photoperiod-independent breeders. In addition, we show that several molecular pathways, including MAPK, are deregulated and that the testicular “immune privilege” is lost in the inactive testes, providing novel mechanisms linking seasonal testosterone reduction and testis regression.