TerrHum: an iPhone app for classifying forest humipedons.

The knowledge of a little number of specific terms is necessary to investigate and describe the forest topsoils: diagnostic components, diagnostic organic and organic-mineral horizons and the 17 series of humus horizons composing all the observed real forest not submerged topsoils. Diagnostic horizons are grouped in humus forms, which represent five humus systems. To become a good topsoil investigator is then only a question of field experience. No mean to do otherwise: you must go in the field with a blade and a good manual and put your hand in the soil. You have to make a hole and to observe on your knee a wall of the pit, from the top to the bottom, detecting all the characters that you find indicated in the manual. At the beginning you will be discouraged, things change from a site to another and never are exactly as in the manual. After few days of difficult survey, you will be able to know your soil even without doing a hole. Be patient and follow what it is indicated in the published first eight articles of Humusica (http://intra.tesaf.unipd.it/people/zanella/hmanual.html). On the poster, you find some examples of diagnostic properties of forest topsoils, and a dichotomy key of classification, you can copy paste and take with you in the field. An iPhone application (Terrhum) allows to bring in the field the necessary information for a fast classification of the topsoil

TerrHum: an iOS application for classifying terrestrial humipedons and some considerations about soil classification

International audienceThe name TerrHum is an abbreviation of the words “Terrestrial” (not hydromorphic, not submerged) and “Humipedon” (organic and organic-mineral humus horizons). With this application, it is possible to describe and classify terrestrial forest and grassland topsoils in a system published as a Special Issue entitled “Humusica 1– Terrestrial Natural Humipedons” in the journal Applied Soil Ecology. The iOS application TerrHum allows the storage of the main content of Humusica 1 on a cellular phone. Images, diagrams and simplified tables of classification may be recalled with a few touches on the screen. Humus forms, representing five humus systems, are classified based on the vertical arrangement of diagnostic horizons and their attributes. TerrHum allows accessing specific figures that are stored in a virtual cloud and can be downloaded the first time the user recalls them. Once all figures have been opened in the device, the application is ready to use, without any further internet connection. The application is in continuous evolution

Beyond microbial diversity for predicting soil functions: A mini review

Since the advent of sequencing technologies, the determination of microbial diversity to predict microbial functions, which are the major determinants of soil functions, has become a major topic of interest, as evidenced by the 900 publications dealing with soil metagenome published up to 2017. However, the detection of a gene in soil does not mean that the relative function is expressed, and the presence of a particular taxon does not mean that the relative functions determined in pure culture also occur in the studied soil. Another critical step is to link microbial community composition or function to the product analyzed to determine flux rates. Indeed, flux rates might not only be highly dynamic, but several metabolites can depend on different reactions, which makes the link to one process of interest difficult or even impossible. This review also discusses biases caused by sampling, storage of samples, DNA extraction and purification, sequencing (amplicon- vs. metagenome sequencing), and bioinformatic data analysis. Insights and the limits of predicting microbial interactions by network inference methods are critically discussed, and finally, future directions for a better understanding of soil functions by using measurements of microbial diversity are presented

Nannipieri, P., Ascher, J., Ceccherini, M.T., Landi, L., Pietramellara, G. & Renella, G. 2003. Microbial diversity and soil functions. European Journal of Soil Science, 54, 655\u2013670.: Reflections by P. Nannipieri, J. Ascher-Jenull, M. T. Ceccherini, L. Giagnoni, G. Pietramellara & G. Renella

Our review of 2003 discussed the meaning of both microbial diversity and microbial activity at the dawn of the \u2018soil omics\u2019 era. It focused on problems with the methods to determine them and on the main ways that soil functions depend on microbial processes. Between 2003 and 2016, the molecular techniques applied in the study of soil microbial diversity have improved markedly. Sequencing techniques today provide accurate estimates of microbial diversity in soil, whereas determining the expression of microbial genes as synthesized proteins is still problematic (Renella et al., 2014a). The assumption was and still is that with a fuller understanding of microbial diversity we might be able to control some soil functions. This is a fallacy because soil functions depend on microbial activity and not only on microbial diversity. A better understanding of the link between microbial diversity and microbial activity might be obtained by an integration of molecular and classical techniques. Sequencing techniques have confirmed the primary role of soil properties in shaping soil microbial diversity and the redundancy of species involved in soil processes such as the mineralization of organic C. Future research should improve techniques for the characterization of soil proteomics, promote the combination of classical and molecular approaches, promote hypothesis\u2010 more than technology\u2010driven research and propose molecular markers as indicators of soil quality, for example, the gene copy/gene expression or gene/enzyme activity ratios

Culturable fungi associated with wood decay of Picea abies in subalpine forest soils: a field-mesocosm case study

Fungi are the principal wood decomposers in forest ecosystems and their activity provides wood necromass to other living organisms. However, the wood decay mechanisms and the associated microbial community are largely unknown, especially in Alpine areas. In this study, the culturable fraction of fungal communities associated with the decomposition of Norway spruce (Picea abies [L.] Karst) deadwood in subalpine forest soils were determined using microbiological methods coupled with molecular identification. Fungal communities were evaluated using in-field mesocosms after one year of exposition of P. abies wood blocks along an altitudinal gradient ranging from 1200 up to 2000 m a.s.l. comprising eight subalpine sites, four of them located at north- and other four at south-facing slopes. Although many saprotrophic species were isolated from the wood blocks, several white-rot species as the pathogenic fungi Armillaria cepistipes and Heterobasidion annosum, along with soft-rot fungi such as Lecytophora sp. were identified. Our results further indicated that the wood-inhabiting fungal community was mainly influenced by topographic features and by the chemical properties of the wood blocks, providing first insights into the effect of different slope exposure on the deadwood mycobiome in the subalpine forest ecosystem

TerrHum: an iPhone app for classifying forest humipedons. Abstract and poster accepted and published.

The knowledge of a little number of specific terms is necessary to investigate and describe the forest topsoils: diagnostic components, diagnostic organic and organic-mineral horizons and the 17 series of humus horizons composing all the observed real forest not submerged topsoils. Diagnostic horizons are grouped in humus forms, which represent five humus systems. To become a good topsoil investigator is then only a question of field experience. No mean to do otherwise: you must go in the field with a blade and a good manual and put your hand in the soil. You have to make a hole and to observe on your knee a wall of the pit, from the top to the bottom, detecting all the characters that you find indicated in the manual. At the beginning you will be discouraged, things change from a site to another and never are exactly as in the manual. After few days of difficult survey, you will be able to know your soil even without doing a hole. Be patient and follow what it is indicated in the published first eight articles of Humusica (http://intra.tesaf.unipd.it/people/zanella/hmanual.html). On the poster, you find some examples of diagnostic properties of forest topsoils, and a dichotomy key of classification, you can copy paste and take with you in the field. An iPhone application (Terrhum) allows to bring in the field the necessary information for a fast classification of the topsoil