Relationship between root growth potential and field performance in Aleppo pine

Commercial stocks of Aleppo pine in Spain vary in quality, but there is no accepted standard for evaluating quality. A RGP test was applied to six commercial seedling stocklots at two dates (November, February) and under two test conditions (growth-chamber, greenhouse). The RGP’s predictive ability was evaluated on two contrasting sites. There was a considerable variation in the RGP depending on application date, test conditions and stock factors. The RGP results for November were correlated with each other but they did not explain outplanting performance. The February results in the growth-chamber correlated well with survival at both sites. Regression models explained survival both in the lower (R ² = 97%) and in the higher (R ² = 92%) quality sites. RGP has a valid predictive ability for this species although it is sensitive to the test conditions. In this sense, a shorter and more intensive test performed right before planting may be more reliable.     

Use of a complexation of tebuconazole with beta-cyclodextrin for controlling foot and crown rot of durum wheat incited by Fusarium culmorum

The methodology for the inclusion of tebuconazole (TBC) in beta-cyclodextrin (betaCD), spectroscopic characterization of the inclusion complex, and its activity for the control of a major soilborne disease of wheat caused by Fusarium culmorum are reported. Controlled release measured by chemical shift of the diagnostic protons H(3) and H(5) of betaCD confirmed stability of the complex at the solid state and in aqueous solution. Greenhouse and field experiments were conducted on durum wheat (Triticum durum cv. Prometeo) sown in substrate or in soil artificially infested with a virulent strain of F. culmorum. The inclusion complex betaCD-TBC, applied as seed dressing in combination or not with carboxymethylcellulose, reduced the disease incidence caused by F. culmorum and improved grain yield, showing effects that were generally comparable to those observed upon application of a commercial formulation of TBC. In the field experiment, only seed treatment with the inclusion complex betaCD-TBC allowed yield that was not different from that obtained from the uninoculated control. These results prove that by the use of the betaCD-TBC complex it is possible to obtain release of TBC and bioavailabilty of the fungicide without compromising its effectiveness.     

Fiber yield and quality of fiber nettle (Urtica dioica L.) cultivated in Italy

To evaluate the production potential of fiber nettle crops in Tuscany (Italy), a German clone of fiber nettle was cultivated during 2006–2007.Although a longer experimentation is essential, the two first years of trials showed that the German clone used also seems to give good results in term of growth and fiber yield in an environment like central Italy, with higher temperatures and generally lower rainfall. Indeed the stalk mean dry matter obtained was about 15.4 Mg ha^?1 with a mean fiber content of about 11% of stalk dry matter, and the resulting fiber yield was 1696 kg ha^?1, comparable to or higher than those reported in the literature.The differences in chemical, physical and mechanical characteristics of fibers extracted from different portions of stalks seemed to indicate an intrinsic heterogeneity of the fibers along the stem. Fiber mean diameter values ranged from 47 to 19 μm and fiber length from 43 to 58 mm moving from stalk bottom to top. Tensile strength of the bottom part of the stalk was much lower than that of the other parts, with mean values of about 24 and 60 cN tex^?1, respectively. More constant mean values along the stalk were found for the elongation parameter (2.3–2.6%). Lignin content decreased moving toward the stalk top from about 4.4% to 3.5%.These physical–mechanical characteristics confirmed the potential of the fibers of nettle cultivated in Tuscany to be used for textile purposes. Indeed they were similar to hemp fibers in diameter, lignin content and elongation, and similar to flax or cotton in tensile strength.     

Assessing freshwater fish sensitivity to different sources of perturbation in a Mediterranean basin

Abstract –  The accuracy of bioassessment programmes is highly limited by the precision of the systems used to derive sensitivity–tolerance values for the organisms used as indicators. We provide quantitative support to the objective evaluation of freshwater fish species sensitivity to different sources of disturbance, accounting for co-variation issues not only between perturbations and natural gradients (especially river size), but also between different perturbations. With this aim, we performed two different principal component analyses: (i) on a general environmental matrix to obtain a perturbation gradient independent of river size effects and (ii) on human impairment-related variables to extract independent synthetic perturbation gradients. Then, we checked each species responses to those gradients to assess their sensitivity–tolerance through an available-used chi-squared analysis in the first approach and through a t -test/ ancova analysis in the second one. In this way, we obtained sensitivity–tolerance which could be included in future bioassessment tools, enabling effective evaluations.     

Promoting connectivity between priority freshwater sites for conservation in intermittent hydrological systems

1. Systematic conservation planning in freshwater ecosystems faces multiple challenges because of the dynamic nature of rivers and their multiple dimensions of connectivity. In intermittent hydrological systems connectivity is functional when water is available, allowing the exchange of aquatic individuals between isolated freshwater ecosystems. Integrating these isolated systems in their hydrological context is essential when identifying priority areas for conservation, in order to try to minimize the propagation of threats into target water bodies (management units) from the surrounding landscape.
2. Here, the use of a systematic planning approach is demonstrated to identify a set of priority management units to preserve freshwater biodiversity in an arid system of fragmented water bodies immersed in a landscape subject to a range of impacts.
3. Twenty-six water-dependent taxa from 59 mountain rock pools (gueltas) of three southern Mauritanian mountains were used as a case study. A conservation planning tool (marxan ) was used to find priority conservation areas to integrate intermittent hydrological systems in their hydrological context, promote connectivity, and minimize the downstream propagation of threats. Three types of connectivity were analysed: (i) no connectivity, (ii) connectivity between gueltas, and (iii) connectivity between gueltas and sub-catchments.
4. Considering different types of longitudinal connectivity affects the number and spatial allocation of the priority gueltas selected, and the conservation status of the gueltas and their upstream areas. Incorporating connections between gueltas and upstream locations in the modelling resulted in the selection of gueltas in areas with a low human footprint and in the increased connectivity of the solutions.
5. The results obtained revealed important locations for local biodiversity conservation, and the method presented can be used when assessing the propagation of potential waterborne threats into isolated management units. The framework developed allows connectivity to be addressed in conservation planning. It can be replicated in regions with similar isolated habitats that connect through intermittent hydrological systems and can also be applied to lateral and vertical hydrological connectivity.

     

Engaging recreational scuba divers in marine citizen science: Differences according to popularity of the diving area

1. Characterizing the composition of divers visiting different diving areas could help to design marine citizen science (MCS) projects that support biodiversity monitoring and marine conservation.
2. Recreational scuba divers mostly prefer warm and clear waters with coral reefs, and based on the Duffus and Dearden’s wildlife tourism framework we hypothesized that a more popular diving area is visited mostly by generalist divers, whereas in a less popular diving area a higher proportion of specialist divers would be found.
3. Recreational scuba divers were surveyed in diving centres at two diving areas, Rapa Nui (more popular, with warm and clear coral-reef waters) and the Chilean mainland (less popular, with productive and temperate–cold waters), to determine their diving profile, visiting profile, marine species knowledge, and interest and participation in MCS.
4. Support for our hypothesis (generalist divers on Rapa Nui and specialist divers on the mainland) was weak, but recreational divers on Rapa Nui were mostly foreign visitors who come for single visits, whereas divers from the mainland were predominantly Chileans who return repeatedly to the diving area. In both diving areas the divers expressed a strong interest to be trained and to participate in MCS, but divers from Rapa Nui were interested in brief pre-dive inductions, whereas divers from the Chilean mainland preferred intensive training courses.
5. Based on these findings we recommend specific MCS strategies for divers in both types of areas, e.g. simple protocols in more popular diving areas, with short pre-dive briefings for divers, and medium or long-term programmes in areas where most divers are local with high return rates. In these latter conditions more extensive training will be useful, which allows divers to gain more experience and assume higher responsibilities within an MCS project.

     

Spatial variability of switchgrass (Panicum virgatum L.) yield as related to soil parameters in a small field

The harvested biomass of switchgrass (Panicum virgatum L.) is generally much lower than its potential; this may be due to several factors including not recovering all the biomass at harvest, weed competition, pests, disease and spatial variation of soil features. The objective of this research was to quantify the yield spatial variation of switchgrass and relate it to soil parameters, in a field of about 5 ha, in 2004 and 2005. Several thematic maps of soil parameters and biomass yield were produced using GIS and geostatistical methods. Soil parameters changed consistently within very short distances and biomass yield varied from 3 to more than 20 Mg ha⁻¹. This remarkable variation indicates that the potential for increasing switchgrass productivity is a real prospect. Furthermore, spatial variation of yield showed similar patterns in the 2 years (r = 0.38^**), and therefore a major influence of site characteristics on switchgrass yield can be assumed to occur. Significant correlations were found between biomass yield and soil N, P, moisture and pH as well as between soil parameters. Some soil parameters such as sand content showed patchy spatial distribution. Conversely, a reliable spatial dependence could not be identified for other parameters such as P. Further research is needed.     

Effects of heat on the removal of polyphenols and in vitro protein digestibility of cowpea (Vigna unguiculata (L.) Walp.)

Simple wet heat treatments like simple boiling (atmospheric pressure, 100 °C) and pressurized boiling (higher than 100 °C) reduced the polyphenol content of mature dark red seeds of cowpea (Vigna unguiculata (L.) Walp.) cultivar UPL Cp 3 by 61 to 80% and improved in vitro protein digestibility (IVPD) by 6 to 26%. Pressurized steaming (higher than 100 °C) removed 48 to 83% of the polyphenols but increased IVPD by only 1.1 to 4.2%. Dry heat as exemplified by roasting and microwave treatment inactivated 58 to 71% of the tannins but increased IVPD by only 1%. All the heat treatments were effective in removing/inactivating polyphenols though different responses were observed with the resulting in vitro protein digestibilities.     

Effects of soaking in aqueous acidic and alkali solutions on removal of polyphenols and in vitro digestibility of cowpea

Mature dark red seeds of cowpea (Vigna unguiculata (L.) Walp.) UPL Cp 3, were subjected to several soaking treatments to remove their polyphenols. Soaking in water at room temperature for 8 and 24 h resulted in 17% and 21% loss of assayable polyphenols, respectively. Dilute solutions of alkali (Na₂CO₃, NaHCO₃, NH₄OH and KOH) and acid (CH₃ COOH, HCl and H₂ SO₄) were more effective in removing polyphenols up to 88% than higher concentrations of alkali and acid solutions.Vinegar (0.005–0.65 M CH₃ COOH) decreased polyphenols from 55 to 62% with a 6 to 14% improvement in in vitro protein digestibility (IVPD). Commercial lime (65% CaO) removed polyphenols from seeds soaked for 8 to 24 h by 70% with 2 to 10% increase in in vitro protein digestibility. Ash removed 40 to 60% of the polyphenols after 8 and 24 h of soaking with an increase in IVPD of 7 to 13%. Total polyphenols were significantly correlated (+0.92**) with protein precipitable polyphenols (condensed tannins).     

Seasonal and dietary effects on Vitamin D deficiencies detected in wild boar from mid‐western Spain

Vitamin D (VitD) is involved in important mammalian physiological mechanisms, such as Ca–P metabolism, bone development and immunological response. VitD deficiencies are frequently detected in domestic animals and related to various health problems (e.g., rickets, bone deformation). However, knowledge about the status of VitD in wildlife species, such as the wild boar, is scarce. The aims of this work were to explore VitD status in wild boar populations from mid‐western Spain and to elucidate the influence of daylight exposure and food supplementation in levels of VitD. Serum concentration of VitD (measured as 25‐hydroxivitaminD) was assessed in 276 wild boar from 27 game estates located in mid‐western Spain using a commercial ELISA kit. In 19 out of 27 estates, the staff supplied a specific VitD‐enriched food (2,000 UI/Kg) ad libitum throughout the year, while in the remaining estates (8), no food was supplied. Blood samples were extracted from hunted animals (198) between October and February of hunting seasons 2016/2017 and 2017/2018, and from live wild boar (78) that were captured, sampled and released (March–September of 2017). The percentage of animals with VitD deficiency (<20 ng/ml), VitD insufficiency (20–30 ng/ml) and VitD sufficiency (>30 ng/ml) was estimated, and the relationship of these levels to factors like sex, age and season was assessed using chi‐square tests. Furthermore, associations between daylight exposure and supplemental food with VitD levels were explored using linear models. Of the studied wild boar population, 82.2% showed a VitD deficiency or insufficiency. VitD deficiencies were more frequent in animals sampled in winter and spring. Furthermore, levels of VitD positively correlated with daylight exposure and supplemental food intake. Ad libitum supplementation with VitD‐enriched food was insufficient to prevent VitD deficiencies in wild boar from November to April, probably because food consumption is lower during this period.