Effects of inoculation with stress-adapted arbuscular mycorrhizal fungus Glomus deserticola on growth of Solanum melogena L. and Sorghum sudanese Staph. seedlings under salinity and heavy metal stress conditions

The beneficial effects of a Glomus deserticola strain isolated from the rhizosphere of grasses (belonging to Poaceae family) growing along the industrial waste from a distillery were investigated under stress conditions. The study was conducted to assess the efficacy of the arbuscular mycorrhizal (AM) fungal ecotype in salinity and heavy metal (HM) tolerance of eggplant (Solanum melongena L.) in soils amended with various stress levels of NaCl, zinc and cadmium. Mycorrhizal (M) seedlings produced a significantly (p < 0.05) greater growth response and were more tolerant to salt and HM stresses than nonmycorrhizal (NM) seedlings in all treatments. The HM contents in the plant tissues were significantly higher in M than NM eggplants. Furthermore, when the efficacy was compared with other AM isolates in HM-polluted soils with Sudan grass (Sorghum sudanese Staph.) as a test plant, the AM ecotype responded best to these soils, as evident from the significantly greater growth response and its aggressiveness in colonizing roots in all soil types tested. These results suggest that this G. deserticola ecotype can be used as an effective tool to alleviate the adverse effects of excessive salinity and HM toxicity on plant growth. Finally, the isolate may have potential in the bioremediation of polluted soils.     

以应用为本的微生物学实验课程教学改革

针对微生物学实验课程特点和生物技术专业应用能力的需要,从优化教学内容、改革实验教学手段、利用网络学堂和本科生科学研究计划等方面,突出培养学生与微生物相关的应用能力,从而实现分层教学,提高学生综合实践能力.     

Soundscape effects on visiting experience in city park: A case study in Fuzhou,China

The main objective of this study was to reveal the relationships between sound/soundscape perception and public visiting experience in city parks, based on a questionnaire survey of 146 park users in West Lake park in Fuzhou, China. The results indicated that, the three visiting experience indicators, i.e., soundscape tranquil degree (STD), landscape aesthetic degree (LAD) and visiting satisfaction degree (VSD) were positively related with each other, and LAD (correlation coefficients = 0.728, p < 0.01) was more associated with VSD than STD (correlation coefficients = 0.565, p < 0.01). Perception of certain individual sounds was found in close relationships with the three indicators. Specifically, STD showed the most significant relationships with harmonious degree of individual sounds, where perception of traffic sounds showed the most negative effects, while perception of music related sounds and water sound showed positive effects. LAD was more associated with perceived occurrences of individual sounds, where traffic sounds and music related sounds showed the most significant effects again. Both perceived occurrences and dominant degree of individual sounds showed the most and equal relationships with VSD. Specifically, mechanical sounds showed the most negative effects, and dog barking showed significant negative effects too, while music related sounds could be the only kind of sound positively contributed to VSD. Social/demographical/behavioral factors and visit motivations all showed significant relationships with individual sound perception and visiting experience. Considering the effects of all associated factors, key factors were detected for each of the visiting experience indicators. All the three visiting experience indicators showed negative relationships with certain traffic sounds, while tree rustling sound was the only sound showing positive relationship with STD. Age was the most important social/demographical/behavioral factor showing positive relationships with LAD and VSD. The research results provided theoretical references for management and design of soundscapes to contribute to more satisfied experiences in city parks.     

Venomous Snake Restraint and Handling

Venomous snakes may be maintained as captive animals and are commonly exhibited in both zoos and private zoological collections. Veterinarians who treat reptile species may be asked to provide medical care to venomous snakes. The addition of venomous snakes to the practice can be exciting and rewarding. Training and experience handling venomous snakes are required before treating these animals in a veterinary practice. Both training and experience with handling venomous snakes are important not only to protect hospital personnel but the owner and patient as well. Veterinarians who wish to provide care for venomous snakes need to be familiar with the many tools used to make restraint and handling venomous animals as safe as possible.     

Bacterial community structure in fumigated soil

Soil microbial biomass has been determined since the mid 1970's by the chloroform fumigation incubation technique as proposed by Jenkinson and Powlson (1976). The microbial biomass C can be determined by subtracting the CO₂ emitted from an unfumigated soil (mineralization of soil organic matter) from that emitted from a chloroform fumigated inoculated soil (mineralization of soil organic matter and killed soil microorganisms) and dividing the difference by a proportionality factor (k_C = 0.45). The question remained which microorganisms recolonized a fumigated soil. An arable soil was fumigated for one day with ethanol-free chloroform or left unfumigated and incubated aerobically after removal of the chloroform for 10 days. The bacterial population structures were determined in the fumigated and unfumigated soil after 0, 1, 5 and 10 days by means of 454 pyrosequencing of the 16S rRNA gene. Fumigating the arable soil reduced significantly the relative abundance of phylotypes belonging to different groups, but increased the relative abundance of only four genera belonging to two phyla (Actinobacteria and Firmicutes) and two orders (Actinomycetales and Bacillales). The relative abundance of phylotypes belonging to the Micromonospora (Micromonosporaceae) increased significantly from 0.2% in the unfumigated soil to 6.7% in the fumigated soil and that of Bacillus (Bacillaceae) from 3.6% to 40.8%, Cohnella (Paenibacillaceae) from undetectable amounts to 0.6% and Paenibacillus (Paenibacillaceae) from 0.3% to 4.2%. The relative percentage of phylotypes belonging to the Acidobacteria, Bacteroidetes, Chloroflexi, Gemmatimonadetes and Proteobacteria (α- β-, δ- and γ-Proteobacteria) were significantly lower in the fumigated than in the unfumigated soil and in most of them the relative abundance of different bacterial orders (i.e. Gp3, Gp4, Gp6, Sphingobacteriales, Gemmatimonadales, Rhodospirillales, Burkholderiales, Xanthomonadales) was reduced strongly (P < 0.001). It was found that the relative abundance of a wide range of bacteria was reduced shortly after fumigating an arable soil, but only a limited group of bacteria increased in a fumigated arable soil indicating a capacity to metabolize the killed soil microorganisms or recolonize a fumigated soil.     

Clustering-based typology and analysis of private small-scale forest owners in Slovenia

Small-scale private forest owners (SPFO) have been recognized as a relatively heterogeneous social group; therefore typology and classification have become key to describe their characteristics and differences. Most of Slovenian forest is owned by SPFOs. To understand why these forest estates are relatively poorly managed, the owners' values and objectives were analysed. We conducted a questionnaire-based survey (n=387) and based our typology on three values and four management variables. The typology was constructed automatically, using the k-medoids clustering algorithm. Clustering resulted in two clusters, which were our basis for two types of owners: “engaged” and “detached”. We analysed these two types through socio-economic and broader geo-spatial perspectives. We found that multi-objective orientation and high valuation of production function are positively related to active forest management and to the likelihood that the forest will be managed in the future. Conversely, higher value to environmental and social function corresponds to lower management levels. Spatial patterns of owners residencies and forest estates influence managing decisions. Results confirm the importance of spatial factors and owner values and objectives for understanding forest management.     

Effect of planting date,fungicide timing and cultivar susceptibility on severity of narrow brown leaf spot and yield of rice

Narrow brown leaf spot (NBLS) of rice (Oryza sativa L.) is caused by Cercospora janseana (Racib). O. Const. (Synonyms: Cercospora oryzae Miyake, Passalora janseana Racib. U.). Experimental studies were conducted at Rice Research Station, Louisiana State University, and Agricultural Center, Crowley, to manage NBLS by fungicide application of propiconazole at different growth stages of rice cultivars having different susceptibility levels to NBLS in different planting dates. Results of these studies revealed that April (early) had less NBLS severity as compared to May (late) planting. Very susceptible cultivars, CL131 and Cheniere, had the highest and resistant cultivars, Della and Presidio, had the lowest NBLS severity at both the planting dates. Propiconazole application significantly reduced the NBLS severity in comparison to untreated. Fungicide application at panicle initiation was the most effective time to manage NBLS on the very susceptible and susceptible cultivars at both planting dates. NBLS on moderately susceptible cultivars was best managed by applying fungicide either at panicle initiation or early boot stage in early planting but panicle initiation was the best time to apply fungicide in late planting. Resistant cultivars did not need fungicide in April planting but did need in May planting. Rice yield was determined to be higher in April than May planting. Fungicide application at early boot stage protected the yield by 9.4% in April planting and 34.2% when applied at panicle initiation in May. Susceptible cultivar, Cheniere, exhibited the greatest yield and resistant cultivars had lowest yield in both the planting dates regardless of its susceptibility level to NBLS. Yield of very susceptible to susceptible cultivars was reduced in late planting but no effect was observed on yield of moderately susceptible and resistant cultivars.     

Urban parks can maintain minimal resilience for Neotropical bird communities

Birds may use urban parks as shelter and refuge, contributing with numerous ecosystem services upon which humans and other organisms depend on. To safeguard these services, it is important that bird communities of urban environments hold some degree of resilience, which refers to the capacity of a system to absorb disturbances and changes, while maintaining its functions and structures. Here we assessed the resilience of the bird community inhabiting an urban park in the Southeast region of Brazil. We classified birds in feeding guilds and identified discontinuities and aggregations of body masses (i.e., scales) using hierarchical cluster analysis. We then calculated five resilience indices for our urban park and for a preserved continuous forest (reference area): the average richness of functions, diversity of functions, evenness of functions, and redundancy of functions within- and cross-scale. The urban park had less species, lower feeding guild richness, and lower within-scale redundancy than the reference area. However, they had similar proportion of species in each function, diversity of functions, evenness of functions, and cross-scale redundancy. The lower species richness and, consequently, the lack of some species performing some ecological functions may be responsible for the overall lower resilience in the urban park. Our results suggest that the bird community of the urban park is in part resilient, as it maintained many biological functions, indicating some environmental quality despite the high anthropogenic impacts of this area. We believe that urban forest remnants with more complex and diverse vegetation are possibly more likely to maintain higher resilience in the landscape than open field parks or parks with suppressed or altered vegetation. We propose that raising resilience in the urban park would possibly involve increasing vegetation complexity and heterogeneity, which could increase biodiversity in a large scale.     

Secondary succession of nematodes in power plant ash dumps reclaimed by covering with turf

An analysis of successive changes in nematode assemblages in reclaimed waste area offers information about the sensitivity of species or groups of nematodes to specific conditions and ability to colonise new habitats. The study was carried in ash dumps being a by-product of the combustion of hard coal and reclaimed by covering with mineral turf (light loam warp soil) or organic turf (alder peat). In the first 3 years of reclamation diversity of nematodes was low, especially in the dump covered with mineral turf—Shannon diversity index below 3. Later on the value of Shannon index increased and did not differ from those recorded for meadows in Poland. In the ash dump reclaimed for a longer time period (8–11 years) the contribution of K strategist species was higher than in the dumps reclaimed for a shorter time period (2–5 years). At the earlier stages of succession bacterivores Acrobeloides, and two fungivores Aphelenchoides and Aphelenchus, predominated. In the ash dump reclaimed longer the dominance of these three genera decreased and some plant feeders achieved high contribution (> 30%). The composition of nematode communities depended significantly on the period of reclamation, but did not depend either on the soil moisture and pH or on season.     

Species richness and phylogenetic diversity comparisons of soil microbial communities affected by nickel-mining and revegetation efforts in New Caledonia

In order to understand the impact of human activities on soil microbial diversity, we investigated bacterial communities in samples recovered from four New Caledonia environments that have been disturbed by varying degrees of nickel mining associated activities: an undisturbed area with natural soil (characterized by pristine vegetation), a mine spoil (devoid of vegetation), two revegetated mine spoils by endemic plants. For each sample, total DNA was extracted and 16S rDNA clone library were constructed. 442 clones were sequenced and analyzed. Using these clones, diversity was estimated not only in terms of species richness (non-parametric estimators) and evenness (Reciprocal of Simpson's index), but also in terms of phylogenetic diversity (LIBSHUFF program). Statistically significant differences were detected in phylogenetic composition between mine spoils and natural soil (p = 0.001), between revegetated soils and natural soil (p = 0.001), and between revegetated soils and mine spoils (p = 0.001). On the other hand, no significant differences in species richness were observed between the different environmental samples.These findings provide insights into the response of bacterial community following environmental perturbations caused by nickel-mining activities and revegetation efforts.