A collaborative approach to investigate site fidelity, home range, and homing behavior of cabezon (Scorpaenichthys marmoratus)

Understanding the area use requirements of species targeted for protection by marine protected areas (MPAs) is critical to the future conservation efforts of economically important fish species. Knowledge of home range size and site fidelity is essential in determining whether species will benefit from the protection offered by a MPA, the size of the area needed to protect individuals, and the extent to which surrounding unprotected areas may be supplemented through post-recruitment movement or “spillover”. We utilized a traditional mark and recapture approach, along with GIS spatial analysis to investigate the site fidelity, home range, and homing behavior of the economically important fish species cabezon (Scorpaenichthys marmoratus) on the south central coast of California. In collaboration with members of the commercial live-fish fishery, a total of 1240 sub-adult and adult cabezon were tagged during 10 days of fishing from September to December of 2004 along ∼18 km of coastline. A public awareness and reward program resulted in 330 total recaptures from 290 different individuals (23% recapture rate) with recaptured individuals at liberty up to 1000 days after initial tagging. A majority of individuals displayed high site fidelity, with 81% of recapture events occurring within 100 m of their initial capture locations, and only 9 individuals (.03%) recaptured greater than 1 km. Most individuals (64%) displayed home ranges less than 1000 m². Ten individuals recaptured after experiencing translocation of up to 5.3 km displayed strong homing behavior, returning to within 14 m of their initial capture locations. Findings suggest that under circumstances where suitable habitat is available in nearby unprotected areas, that adult “spillover” will likely be limited to areas within 100 m from MPA boundaries. In addition, the size of the area needed to protect individual cabezon, should be at least 1000 m². Findings from this study demonstrate many of the potential benefits of scientists and fishers working together to investigate area use patterns of economically important fish species to facilitate future design and assessment of MPAs.     

Application of organic amendments followed by soil plastic mulching reduces the incidence of Phytophthora capsici in pepper crops under temperate climate

A greenhouse experiment was performed to study the effectiveness of the application of organic amendments followed by soil plastic mulching for control of Phytophthora capsici in temperate climate regions. The organic amendments were i) a non-composted mixture of sheep manure and chicken litter; ii) a semicomposted mixture of horse manure and chicken litter, and iii) Brassica carinata pellets + Sinapis alba as fresh green manure. In particular, we studied the effect of treatments on P. capsici oospore survival, disease incidence and soil properties. The treatment with B. carinata + S. alba resulted in a 93% reduction in disease incidence. The application of the semicomposted and non-composted mixture followed by soil plastic mulching caused 86 and 65% reduction, respectively, in disease incidence due, at least partially, to a decrease in oospore viability, the production of NH₃ and an increase in soil microbial activity. Significantly higher values of dehydrogenase, β-glucosidase, urease and acid and alkaline phosphatase activities were detected in treated soils, possibly resulting in pathogen suppression. The application of organic amendments followed by soil plastic mulching can be a good option for control of P. capsici in protected pepper crops under temperate climate.     

Habitat suitability,coverage by protected areas and population connectivity for the Siamese crocodile Crocodylus siamensis Schneider, 1801

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Fish anesthesia: effects of the essential oils of Hesperozygis ringens and Lippia alba on the biochemistry and physiology of silver catfish (Rhamdia quelen)

The anesthetic activities of the essential oils (EOs) of Hesperozygis ringens (EOHR) and Lippia alba (EOLA) and their effects in silver catfish (Rhamdia quelen) after anesthesia and recovery were investigated. Fish (32.19 ± 1.24 g) were submitted to one of the following treatments for each EO: basal group, control, or anesthesia (150, 300, or 450 μL L^?1 EO). After that the anesthesia was induced or simulated and the biometric measurements were completed, fish were transferred to anesthetic-free aquaria to allow for recovery. Fish were sampled at 0, 15, 30, 60, and 240 min after recovery. At time 0 of recovery, the ventilatory rate was lower in the groups anesthetized with either EO. In comparison with the basal group, control fish showed an increase in plasma glucose, aspartate aminotransferase (AST), and Na⁺ levels and a reduction in Na⁺/K⁺-ATPase activity at 0 min of recovery. Plasma levels of ammonia and Na⁺ were lower in the fish anesthetized with EOLA (450 μL L^?1) and EOHR (all concentrations), respectively, than in the control fish. Additionally, lactate, AST, alanine aminotransferase, K⁺ plasma levels, and gill Na⁺/K⁺-ATPase and H⁺-ATPase activities were higher in the fish anesthetized with either EOHR or EOLA than in the control fish. The EOs promoted slight changes in silver catfish that enabled both an adaptive response and the recovery of most of the measured parameters after 240 min regardless of concentration or EO that was used. These findings support the use of EOHR and EOLA as anesthetics for fish.     

A probabilistic model for tropical tree seed desiccation tolerance and storage classification

Knowledge of seed desiccation tolerance is fundamental for conservation and use of forest species. The protocol used for classification of seed desiccation tolerance and storage is time consuming and many times limited by the lack of information about optimum conditions for seed germination and treatments to overcome seed dormancy. This study evaluated 66 Brazilian tree species aiming to correlate seed characteristics with desiccation tolerance. For this purpose, a model was established to explain the relationship of tegument/seed mass ratio (SCR), seed mass, and water content of embryo + endosperm with desiccation tolerance. The principal component analysis showed the establishment of two groups, indicating the interaction between desiccation tolerance and seed characteristics. Recalcitrant seeds are more often associated with the water content of embryo + endosperm and water content of tegument + endocarp, while orthodox seeds are more associated with SCR and number of seeds per kilogram. The classification found using the model proposed was significantly correlated with desiccation tolerance and storage, with 92% confidence for the analyzed species. Seeds morphological characteristics can be used for prediction of desiccation tolerance and storage behavior; however, the use of a model that combines more variables increases the chance of accurate classification.     

Monitoring of eucalyptus sprouts control using digital images obtained by unmanned aerial vehicle

This study evaluated the effectiveness of chemical control for eradicating eucalyptus sprouts using images obtained with Unmanned Aerial Vehicle (UAV). The study was carried out in eucalyptus plantations in Itabela, BA, in replanting areas during pre-planting application of herbicide. Aerial images obtained by a UAV were used to evaluate the effectiveness of the herbicide application for sprouts control. After the images were acquired, they were processed to calculate the normalized difference vegetation index (NDVI) and submitted to a supervised classification to quantify the percentage reduction of sprout green matter. The percentage data were submitted to analysis of variance and the means were compared by Tukey test at 5%. The differences, both visual and average percentages were observed only during the evaluation period with no evident effect of the treatments on sprout control. The images provided by the UAV allowed to monitor and identify visually the plots where biomass reduced or increased and to evaluate the effectiveness of chemical control of eucalyptus sprouts, indicating areas where it was nonexistent, partial or total.     

Using Limestone to Improve Soil Fertility and Growth of Mango (Mangifera Indica L.)

Soil acidity is one of the most important factors limiting crop production. The objective of this work was to evaluate the effects of limestone application on the soil chemical properties, nutrition and yield of mango plants in an orchard under implementation. The design was randomized blocks, with five limestone doses (0; 2; 4; 6 and 8 t ha^?1) and four replications. Soil chemical analyses were performed (at 12, 24, 36 and 48 months after the experiment implementation) in the layers 0–20; 20–40 and 40–60 cm deep. Nutrition status and yield were assessed during the first and second crop seasons. The highest fruit yield was associated with the application of 3.9 and 3.8 t ha^?1 of limestone in the 2008/09 and 2009/10 seasons, respectively, that is, the dose recommended by the literature for raising base saturation to 80%, as a function of the fertility conditions of the soil initially obtained.     

Ammonia,Nitrous Oxide,Carbon Dioxide and Methane Emissions from Commercial Broiler Houses in Mediterranean Portugal

Limited data are available on ammonia (NH₃), nitrous oxide (N₂O), carbon dioxide (CO₂) and methane (CH₄) emissions from poultry housing in Mediterranean countries. The aim of the present study was to assess the NH₃, N₂O, CO₂ and CH₄ emission rates from commercial breeding hen and broiler houses under Mediterranean climate conditions. Research was conducted at one commercial breeding hen house and in two commercial broiler houses located in central Portugal. The environmental conditions, gas concentrations and ventilation rates were measured in the cold (8.0?±?2.1 °C) and hot (20.7?±?1.9 °C) season for the breeding hen house, whereas for the two broiler houses, measurements were made during one fattening cycle in the fall (17.3?±?1.7 °C) season. Results showed that the annual average emission rates for breeding hen and broiler houses were 0.52?±?0.27 and 0.06?±?0.01 for NH₃, 0.030?±?0.042 and 0.006?±?0.001 for N₂O, 169.6?±?56.2 and 58.0?±?15.1 for CO₂ and 0.092?±?0.131 and 0.0113?±?0.0002 g day^?1 bird^?1 for CH₄, respectively. The N₂O emission rates observed in breeding hen houses may have been overestimated, being higher than previously reported for Mediterranean countries.     

An inconvenient truth about xylem resistance to embolism in the model species for refilling <Emphasis Type="Italic">Laurus nobilis</Emphasis> L.

Key message

Direct, non-invasive X-ray microtomography and optical technique observations applied in stems and leaves of intact seedlings revealed that laurel is highly resistant to drought-induced xylem embolism. Contrary to what has been brought forward, daily cycles of embolism formation and refilling are unlikely to occur in this species and to explain how it copes with drought.

Context

There has been considerable controversy regarding xylem embolism resistance for long-vesselled angiosperm species and particularly for the model species for refilling (Laurus nobilis L.).

Aims

The purpose of this study was to resolve the hydraulic properties of this species by documenting vulnerability curves of different organs in intact plants.

Methods

Here, we applied a direct, non-invasive method to visualize xylem embolism in stems and leaves of intact laurel seedlings up to 2-m tall using X-ray microtomography (microCT) observations and the optical vulnerability technique. These approaches were coupled with complementary centrifugation measurements performed on 1-m long branches sampled from adult trees and compared with additional microCT analyses carried out on 80-cm cut branches.

Results

Direct observations of embolism spread during desiccation of intact laurels revealed that 50% loss of xylem conductivity (Ψ₅₀) was reached at ??7.9?±?0.5 and ??8.4?±?0.3 MPa in stems and leaves, respectively, while the minimum xylem water potentials measured in the field were ??4.2 MPa during a moderate drought season. Those findings reveal that embolism formation is not routine in Laurus nobilis contrary to what has been previously reported. These Ψ₅₀ values were close to those based on the flow-centrifuge technique (??9.2?±?0.2 MPa), but at odds with microCT observations of cut branches (??4.0?±?0.5 MPa).

Conclusion

In summary, independent methods converge toward the same conclusion that laurel is highly resistant to xylem embolism regardless its development stage. Under typical growth conditions without extreme drought events, this species maintains positive hydraulic safety margin, while daily cycles of embolism formation and refilling are unlikely to occur in this species.

     

Improvement of degraded physical attributes of a saline-sodic soil as influenced by phytoremediation and soil conditioners

This study aimed to evaluate the use of phytoremediation and soil conditioners in the recovery of physical attributes of a saline-sodic Fluvic Neossol in Brazil Northeast. The applied treatments were: Atriplex nummularia L., as phytoremediation plant, due to its ability to extract salts from the soil; organic conditioners, such as bovine and sheep manure; gypsum and polymer, as chemical conditioners. Samples with preserved structure were collected at the time of the experiment installation and 18 months after in the layers 0–10 cm and 10–30 cm. The analyzed attributes were: water dispersed clay, dispersion index, bulk density, penetration resistance, soil porosity, and saturated hydraulic conductivity. The use of sheep manure, gypsum and polymer promoted an increase in saturated hydraulic conductivity in the 0–10 cm layer from 4.51 to 16.37 cm day^?1, 11.26 to 23.95 cm day^?1 and 7.24 to 22.77 cm day^?1, respectively. Gypsum increased the macroporosity in the superficial layer by 42.6%. Atriplex and polymer were more efficient at reducing soil penetration resistance. The polymer was more efficient at improving the physical properties. However, it is necessary to consider phytoremediation with Atriplex as a more sustainable alternative that can still be used as complementary fodder in animal feed.