Are phenolics leaching from the lichen Cladina stellaris sources of energy rather than allelopathic agents for soil microorganisms?

Lichen phenolics that are known to leach out from lichen thalli during rainfall episodes are considered to be allelopathic or antimicrobial agents. On the other hand, small organic molecules originating from aboveground vegetation generally constitute an important C source for the soil microbial community. We studied the effects of leaching lichen acids on soil microbial processes by chemically removing usnic (UA) and perlatolic acid (PA) from the extracellular space of mat-forming lichen, Cladina stellaris, a dominant component of the ground vegetation in boreal oligotrophic forests. Removal of UA and PA did not affect the intracellular contents of the lichen. We hypothesized that if lichen acids have an adverse effect on soil biota, microbial respiration would increase underneath chemically manipulated lichen mats. In turn, if these substances provide energy source for the microorganisms, microbial respiration would decline under lichens from which PA and UA has been removed. Microbial metabolic activity, qCO₂ was significantly lower under the lichens from which UA and PA had been removed, thus supporting the latter hypothesis. Removing UA and PA did not affect the amount of microbial C, N and P, or soil nutrient concentrations. Our results suggest that the microbial community in the soil under a lichen carpet is adapted to the presence of these lichen secondary metabolites and can utilize them as a C source. The approach of removing lichen substances from the system could be used as an effective research tool as it can overcome several problems that are often common in the studies on allelopathic interactions.     

The Role of Education in Self–Employment Success in Finland

This paper analyzes the effect of self–employed persons’ education on the success of their firms during the economic downturn and upturn of the 1990's. It is found that the business cycle affects the relative closure rates of firms run by self–employed with any level of education. Exit probability is lower for the highly educated during bust, but higher in boom. This is accounted for by two facts. First, running a small firm is argued to be a less attractive choice to wage work, particularly for the highly educated, due to lower earning prospects, less stable stream of earnings, and the cultural tradition of working in large corporations. Second, the highly educated faced a higher outside demand for their labor than did the less educated during economic upturn. Finally, it was found that regardless of the state of aggregate economy, firms run by the highly educated have higher growth probabilities than those run by less educated persons.     

Genome-wide identification and characterization of novel long non-coding RNA in Ruminal tissue affected with sub-acute Ruminal acidosis from Holstein cattle

Veterinary Research Communications - Sub-acute ruminal acidosis is a type of metabolic disorder in which affected cattle show a considerable depression of rumen pH. This leads to a dramatic decline...     

Screening mycorrhiza species for plant growth,P and Zn uptake in pepper seedling grown under greenhouse conditions

We screened the mycorrhizal species for an inoculum protocol would green pepper seedling production and compensate for nutrient deficiency. Three greenhouse studies (on three successive years) were conducted under nursery conditions using five arbuscular mycorrhizal (AM) fungi and their mixture. The AM fungi, Glomus mosseae, G. clarum, G. caledonium, G. intraradices and G. etunicatum propagated on maize roots were used. The AM fungi were inoculated to seed stages and half of the seed stages inoculated plants were re-inoculated at the seedling stages. In Experiment I, plants were harvested once and in Experiments II and III, plants were harvested twice at different developmental stages.     

Previous exposure advances the degradation of an anthropogenic s-triazine regardless of soil origin

Purpose

Previous investigations—field samplings and laboratory experiments—support the hypothesis that the degradation of s-triazines is enhanced in previously exposed as compared to pristine soils in terrestrial environments. Despite this, bottlenecks of soil sampling and various soil modification practices in microcosm studies have made it difficult to guarantee that previous contamination history enhances contaminant degradation regardless of soil origin in terrestrial ecosystems. We test the hypothesis that the degradation of simazine (2-chloro-4,6-bis(ethylamino)-s-triazine) is enhanced in previously exposed soils as compared to pristine soils in 10 l buckets at the mesocosm scale.

Materials and methods

We collected soil at three separate sites consisting of a previously exposed and a pristine field. At every field, soil was collected at three separate plots and simazine degradation (days 0 and 65) and the response to atzB degrader gene primers (days 0 and 110) were followed. We analyzed the results using analysis of covariance (ANCOVA). Previous exposure and field site were assessed as fixed factors and initial simazine concentration and abiotic soil conditions as covariates.

Results and discussion

After the 65-day exposure, remaining simazine concentrations depended on previous exposure but not on collection site. The response to atzB gene primers was positive in all mesocosms where simazine degradation had been rapid. Soil moisture, pH, and organic matter content were insignificant. If soil moisture was not included in the ANCOVA model, previous exposure did not appear as a significant factor.

Conclusions

The results support the hypothesis that simazine is degraded more rapidly in previously exposed soils as compared to pristine environments, provided that degradation genes are available. Previously exposed soil might be used to enhance the degradation of simazine in recently contaminated terrestrial soils, supposing that the central requirements for microbial growth are adequate.     

Eco-geographic distribution of <Emphasis Type="Italic">Cicer isauricum</Emphasis> P.H. Davis and threats to the species

Wild Cicer species are considered as useful genetic resources for resistance to biotic and abiotic stresses due to limited resistance in cultivated chickpeas. As a wild perennial species in the genus Cicer L., Cicer isauricum P.H. Davis is an endemic species to Turkey and endangered status according to the International Union for Conservation of Nature criteria. Here we report on its eco-geographic distribution and environmental stresses that affect the species, and advocate for its in situ and ex situ conservation. A new population of the species was discovered in Geyikbay?r?, Güllük Mountains in Antalya, Turkey. Cicer isauricum not only suffers from significant biotic stresses such as ascochyta blight [Ascochyta rabiei (Pass.) Labr.], pod borer (Helicoverpa armigera Hübner) and broomrape (Orobanche sp.), but is also subjected to drought and heat stress in its habitat. Infection with ascochyta blight in natural habitats was diagnosed by molecular techniques, and pod borer and broomrape were observed only phenotypically. PCR amplification of the internal transcribed spacer region of genomic DNA from cultured fungal isolates, yielded sequences with 100% nucleotide identity with the corresponding sequence in GeneBank for Didymella rabiei Kovachevski (anamorph: A. rabiei). The pathogen may have co-evolved with C. isauricum in the newly discovered site. Because C. isauricum is exposed to drought and accompanying heat stress in its natural habitat, it appears able to tolerate heat stress up to 45 °C during podding stage and terminal drought in late summer from its woody, deep rooting. C. isauricum bears multiple flowers per axil, a potentially useful trait in cultivated chickpea. In conclusion, C. isauricum is a potential genetic source for resistance to biotic and abiotic stresses, in need of greater protection due to its endangered status.     

Recognizing the Interest of Forest Owners to Combine Nature-Oriented and Economic Uses of Forests

Protecting biodiversity within separate set-aside conservation areas has not been effective enough to halt its loss. Thus, new approaches to conserve biodiversity alongside production are needed. The non-market values of a forest may play an essential role when the forest owner decides the use of their land. However, so far the service offerings other than related to timber production, have been scant. The mismatch between decision support services offered and the service interests of forest owners may result in the objectives of forest owners remaining unfulfilled. The aims of this study were to explore the links between family forest owners’ forest management preferences and their objectives for the forest and secondly their preferences for decision support services. Data were collected in a postal survey in the Northern Karelia region, Finland in spring 2014. Data consist of 298 survey answers that were analysed using multi-variate analyses. Two typologies were combined: clustering of forest ownership objectives and the preferred forest management style. We found that the forest owner’s objectives were demonstrated by their preferred way of managing the forest. Opinions about different decision aid services varied between cluster groups. The groups emphasizing nature values considered biodiversity related information about their forest more necessary than other groups. They were also less satisfied with the usability of the forest management plan. Forest advisory services should better acknowledge the prevalence of multiple objectives also among forest owners who are interested in timber selling. Developing services for forest owners with diverse socio-economic backgrounds, information needs and objectives is important.