Fine-root carbon and nitrogen concentration of European beech (Fagus sylvatica L.) in Italy Prealps: possible implications of coppice conversion to high forest

Fine-root systems represent a very sensitive plant compartment to environmental changes. Gaining further knowledge about their dynamics would improve soil carbon input understanding. This paper investigates C and N concentrations in fine roots in relation to different stand characteristics resulting from conversion of coppiced forests to high forests. In order to evaluate possible interferences due to different vegetative stages of vegetation, fine-root sampling was repeated six times in each stand during the same 2008 growing season. Fine-root sampling was conducted within three different soil depths (0-10; 10-20; and 20-30 cm). Fine-root traits were measured by means of WinRHIZO software which enable us to separate them into three different diameter classes (0-0.5, 0.5-1.0 and 1.0-2.0 mm). The data collected indicate that N concentration was higher in converted stands than in the coppiced stand whereas C concentration was higher in the coppiced stand than in converted stands. Consequently the fine-root C:N ratio was significantly higher in coppiced than in converted stands and showed an inverse relationship with fine-root turnover rate, confirming a significant change of fine-root status after the conversion of a coppice to high forest

Fine-root seasonal pattern, production and turnover rate of European beech (Fagus sylvatica L.) stands in Italy Prealps: Possible implications of coppice conversion to high forest

The aim of this study was to investigate the possible effects of coppice conversion to high forest on the beech fine-root systems. We compared the seasonal pattern of live and dead fine-root mass (d<2 mm), production and turnover in three beech stands that differed in management practices. Tree density was higher in the 40-year-old coppice stand than in the stands that were converted from coppice to high forest in 1994 and 2004, respectively. We found that a reduction in tree density reduced the total fine-root biomass (Coppice stand, 353.8 g m-2; Conversion 1994 stand, 203.6 g m-2; Conversion 2004 stand, 176.2 g m-2) which continued to be characterised by a bimodal pattern with two major peaks, one in spring and one in early fall. Conversion to high forest may also affect the fine-root soil depth distribution. Both fine-root production and turnover rate were sensitive to management practices. They were lower in the Coppice stand (production 131.5 g m-2 year-1; turnover rate 0.41 year-1) than in the converted stands (1994 Conversion stand: production 232 g m-2 year-1, turnover rate 1.06 year-1; 2004 Conversion stand: production 164.2 g m-2 year-1, turnover rate 0.79 year-1)

Effect of tree density on root distribution in Fagus sylvatica stands: a semi-automatic digitising device approach to trench wall method

5Knowledge of root profiles is essential for measuring and predicting ecosystem dynamics and function. In the present study, the effects of management practices on root (0.5 <= ø < 20 mm) spatial distribution were examined in a 40-year-old coppice stand (CpS 1968) and other two stands converted from coppice to thinned high forest in 1994 (CvS 1994) and 2004 (CvS 2004), respectively. The use of a semi-automatic digitising device approach was compared with a conventional root mapping method in order to estimate the time per person required from fieldwork to the final digital map. In July 2009, six trench walls per stand were established according to tree density, i.e. as equidistant as possible from all surrounding trees. Findings highlighted differences between the stands with CvS 1994 showing a lower number of small roots (2 <= ø < 5 mm), a higher mean cross-sectional area (CSA) of coarse roots (5 <= ø < 20 mm) and different root depth distribution as compared to CpS 1968 and CvS 2004 whose values were close to each other. The three diameter classes selected in this study showed significant relationships in terms of number of roots, scaling down from coarse- to small- and fine-roots. Forest management practices significantly affected only the number of small roots. The number of fine roots (0.5 <= ø < 2 mm) was isometrically related to their root length density (RLD, cm cm-3). No relationship occurred with RLD of very fine roots (ø < 0.5 mm). In conclusion, forest management practices in terms of conversion thinnings significantly affected belowground biomass distribution of beech forest in space and time. In particular, frequency of coarse roots was related to the stand tree density, frequency of small roots was related to the cutting age. Size of coarse roots was related to tree density but only several years after felling. The allometric relationship occurring between fineand small-roots highlighted how fine root number and RLD were only indirectly affected by forest management practices. These findings suggest that future investigations on the effect of forest thinning practices on fine-root traits like number, length and biomass several years after felling cannot ignore those on small roots.openDi Iorio, A.; Montagnoli, A.; Terzaghi, M.; Scippa, G.S.; Chiatante, D.DI IORIO, Antonino; Montagnoli, A.; Terzaghi, M.; Scippa, G. S.; Chiatante, Donat

Influence of soil temperature and water content on fine-root seasonal growth of European beech natural forest in Southern Alps, Italy

In tree species, fine-root growth is influenced by the interaction between environmental factors such as soil temperature (ST) and soil moisture. Evidences suggest that if soil moisture and nutrient availability are adequate, rates of root growth increase with increasing soil temperature up to an optimum and then decline at supraoptimal temperatures. These optimal conditions vary between different taxa, the native environment and the fine-root diameter sub-classes considered. We investigated the effects of seasonal changes of both ST and soil water content (SWC) on very fine (d < 0.5 mm) and fine-root (0.5 < d < 2 mm) mass (vFRM, FRM) and length (vFRL, FRL) in Italian Southern Alps beech forests (Fagus sylvatica L.). Root samples were collected by soil core method. Turnover rate was higher for the very fine (0.51) than for the fine (0.36) roots. vFRM, FRM, vFRL and FRL displayed a complex seasonal pattern peaking in summer when SWC was around 40 % and ST was around 14 \ub0C. Above this temperature, under almost constant SWC, all above mentioned root traits decreased. vFRM, FRM, vFRL and FRL showed significant second-order polynomial relationship (p < 0.05) with SWC for both diameter classes, with the only exception of SRL. ST showed the same kind of relationship significant only with vFRM and vFRL, the latter within the 12-16 \ub0C smaller range. Interpolation analysis between root mass and length for both diameter classes and investigated soil environmental characteristics (ST and SWC) showed a clear roundish delineation only for vFRM. In conclusion, these findings clarified the occurrence of a bimodal fine-root growth seasonal pattern for our beech forest. The optimal growth ST and SWC ranges were delineated only for very fine roots, giving further evidence on this root category as the more responsiveness to soil environmental changes. Furthermore, F. sylvatica seems to adopt an intensive strategy to cope with decreasing SWC. Finally, fine-root growth, mainly radial type, seems to be driven by SWC, whereas very fine-root growth, mainly longitudinal type, seems to be driven by ST

Redescription of Cardiosporidium cionae (Van Gaver and Stephan, 1907) (Apicomplexa: Piroplasmida), a plasmodial parassite of ascidian haemocytes

Cardiosporidium cionae (Apicomplexa), from the ascidian Ciona intestinalis L., is redescribed with novel ultrastructural, phylogenetic and prevalence data. Ultrastructural analysis of specimens of C. intestinalis collected from the Gulf of Naples showed sporonts and plasmodia of C. cionae within the host pericardial body. Several merogonic stages and free merozoites were found in the pericardial body, together with sexual stages. All stages showed typical apicomplexan cell organelles, i.e. apicoplasts, rhoptries and subpellicular microtubules. Merogonic stages of C. cionae were also produced inside haemocytes. A fragment of the rSSU gene of C. cionae was amplified by PCR using DNA extracted from the pericardial bodies. The amplified product showed closest affinity with other apicomplexan representatives and a 66 bp unique insertion, specific for C. cionae, at position 1644. Neighbour-joining phylogenetic analysis placed C. cionae in a clade with other piroplasm genera, including Cytauxzoon, Babesia and Theileria spp. The parasite was found in different populations of C. intestinalis with highest prevalence in October–November. Ultrastructural and DNA data showed that the organism, described in 1907 from the same host but not illustrated in detail, is a member of a novel marine apicomplexan radiation of tunicate parasites

Poplar woody root proteome during the transition dormancy-active growth

Woody plants living in temperate climates finely regulate their growth and development in relation to seasonal changes; their transition from vegetative to dormancy phase represents an adaptation to their environment. Events occurring in the shoot during onset/release from dormancy have been largely investigated, whereas in woody roots they remain completely unknown. In recent years, we have been interested in understanding the molecular and physiological events occurring in poplar woody root during release from dormancy. Here, we propose the results of a comparative analysis of the proteome of poplar woody root sampled at different time points: T0 (dormancy condition), T1 (release from dormancy), and T2 (full vegetative condition). This study identified proteins that may be involved in the long-term survival of a dormant root or landmarking a specific time point

Asymmetrical copper root pruning may improve root traits for reforesting steep and/or windy sites

Our research demonstrates that plant material can be produced in the nursery with asymmetrical root systems, which may have utility for reforestation of difficult planting sites characterized by steep slopes and/or windy conditions. Such a root system can be generated using chemical root pruning by applying cupric carbonate (Cu) that can arrest the development of, or cause mortality to, root apical meristems resulting in the formation of new lateral roots with an overall increase in the biomass, length, and volume of the root system. Our objective was to investigate the effect of chemical root pruning on the morphological and architectural traits of adventitious roots produced by poplar cuttings (Populus nigra L.) grown in containers coated with Cu in various symmetrical (Side, Bottom, Side + Bottom) and asymmetrical (half side + half bottom) patterns. After six weeks, roots of the cuttings were extracted from different container depths (Top, Middle, and Bottom) and portions (non-coated, Cu-coated), and analyzed. The root systems reacted to all coating patterns by increasing length, biomass, volume, and average diameters, but magnitude of increase was further affected by depth. In particular, root growth was unaffected at the Top of the container, and length was the highest at the Bottom depth. The Middle depth had a significant increment in both biomass and volume. Also, the root population increased in diameter as a possible response to Cu exposure. Interestingly, in the asymmetrically coated containers this depth response in the non-coated portions was of higher magnitude than in the Cu-coated portions

Biochar Enhances Plant Growth, Fruit Yield, and Antioxidant Content of Cherry Tomato (Solanum lycopersicum L.) in a Soilless Substrate

Biochar soil amendment can improve growing medium water and nutrient status and crop productivity. A pot experiment was conducted using Solanum lycopersicum var. cerasiforme plants to investigate the effects of biochar amendment (20% application rate) on a soilless substrate, as well as on plant growth, fruit yield, and quality. During the experiment, substrate characteristics, plant morphological traits, and root and leaf C/N content were analyzed at three sampling points defined as early stage (36 days after germination), vegetative stage (84 days a. g.), and fruit stage (140 days a. g.). Fruit morphological traits, titratable acidity, lycopene, and solid soluble content were measured at the end of the experiment. Biochar ameliorated substrate characteristics (Nav increase of 17% and Ctot increase of 13% at the beginning of the study), resulting in a promotion effect on plant root, shoot, and leaf morphology mainly at the vegetative and fruit stages. Indeed, at these two sampling points, the biochar-treated plants had a greater number of leaves (38 and 68 at the vegetative and fruit stages, respectively) than the untreated plants (32 and 49, respectively). The biochar also increased leaf area with a rise of 26% and 36% compared with the values measured in the untreated plants. Moreover, the amendment increased twofold root length, root surface area, and root, stem, and leaf biomasses in comparison with untreated plants. Regarding plant productivity, although fruit morphology remained unchanged, biochar increased flower and fruit numbers (six times and two times, respectively), acidity (75%), lycopene (28%), and solid soluble content (16%). By unveiling promoting changes in morphological traits, fruit number, and antioxidant content occurring in cherry tomato plants growing in a biochar-treated soilless substrate, it could be possible to highlight the importance of biochar for future applications in the field for enhancing plant production and fruit quality in a sustainable agriculture framework