The production and turnover of extramatrical mycelium of ectomycorrhizal fungi in forest soils: role in carbon cycling

There is growing evidence of the importance of extramatrical mycelium (EMM) of mycorrhizal fungi in carbon (C) cycling in ecosystems. However, our understanding has until recently been mainly based on laboratory experiments, and knowledge of such basic parameters as variations in mycelial production, standing biomass and turnover as well as the regulatory mechanisms behind such variations in forest soils is limited. Presently, the production of EMM by ectomycorrhizal (EM) fungi has been estimated at ~140 different forest sites to be up to several hundreds of kg per ha per year, but the published data are biased towards Picea abies in Scandinavia. Little is known about the standing biomass and turnover of EMM in other systems, and its influence on the C stored or lost from soils. Here, focussing on ectomycorrhizas, we discuss the factors that regulate the production and turnover of EMM and its role in soil C dynamics, identifying important gaps in this knowledge. C availability seems to be the key factor determining EMM production and possibly its standing biomass in forests but direct effects of mineral nutrient availability on the EMM can be important. There is great uncertainty about the rate of turnover of EMM. There is increasing evidence that residues of EM fungi play a major role in the formation of stable N and C in SOM, which highlights the need to include mycorrhizal effects in models of global soil C stores

Diversity of the genus Tuber from the West Balkan areas using molecular characterisation

Peer Reviewe

Evolution-based approach needed for the conservation and silviculture of peripheral forest tree populations

The fate of peripheral forest tree populations is of particular interest in the context of climate change. These populations may concurrently be those where the most significant evolutionary changes will occur; those most facing increasing extinction risk; the source of migrants for the colonization of new areas at leading edges; or the source of genetic novelty for reinforcing standing genetic variation in various parts of the range. Deciding which strategy to implement for conserving and sustainably using the genetic resources of peripheral forest tree populations is a challenge. Here, we review the genetic and ecological processes acting on different types of peripheral populations and indicate why these processes may be of general interest for adapting forests and forest management to climate change. We particularly focus on peripheral populations at the rear edge of species distributions where environmental challenges are or will become most acute. We argue that peripheral forest tree populations are “natural laboratories” for resolving priority research questions such as how the complex interaction between demographic processes and natural selection shape local adaptation; and whether genetic adaptation will be sufficient to allow the long-term persistence of species within their current distribution. Peripheral populations are key assets for adaptive forestry which need specific measures for their preservation. The traditionally opposing views which may exist between conservation planning and sustainable forestry need to be reconciled and harmonized for managing peripheral populations. Based on existing knowledge, we suggest approaches and principles which may be used for the management and conservation of these distinctive and valuable populations, to maintain active genetic and ecological processes that have sustained them over time

Simulating ectomycorrhizal fungi and their role in carbon and nitrogen cyclingin forest ecosystems

Although ectomycorrhizal fungi play an important role in forest ecosystem functioning, they are usually not included in forest growth or ecosystem models. Simulation is hampered by two main issues: a lack of understanding of the ecological functioning of the ectomycorrhizal fungi and a lack of adequate basic data for parameterization and validation. Concerning these issues, much progress has been made during the past few years, but this information has not found its way into the forest and soil models. In this paper, state-of-the-art insight into ectomycorrhizal functioning and basic values are described in a manner transparent to nonspecialists and modelers, together with the existing models and model strategies. As such, this paper can be the starting point and the motivator to include ectomycorrhizal fungi into existing soil and forest ecosystem models

Review of measurement methods of small energy for the assesment of "energy-harvesting" circuits and micropower systems

W artykule omówiono trzy metody pomiaru małych energii dla oceny układów zasilania typu „energy-harvesting” i systemów mikromocowych. Opisano klasyczną metodę techniczną, jak i estymację energii zarówno poprzez pomiar ładunku oraz wykorzystanie równoważenia ładunku. Niezależnie od metody pomiaru, zwrócono uwagę na specyficzny, impulsowy i nieregularny charakter poboru energii przez systemy mikromocowe oraz podobny impulsowy charakter energii wytwarzanej przez przetworniki energy harwester (EH).The article is concern on the issues of measurement methods of small energy low-power devices which collecting the Energy avilable in the enviroment. The main difficulty in constructing such devices is an estimation of energy demand. The average power consumption the low-power system is typically calculated in microwatts. Accurate measurement of the energy consumed by a typical micropower system is problematic - measuring device must have a large dynamic range. It is assumed that the measured currents can be varied by at least two orders of magnitude. There must be a wide band width due to the fact that a large current is consumed in a very short time (pulse). Similar requirements determine the measurement of the Energy supplied from alternative sources. Electrical energy available at the output of converter usually appears irregularly in pulses of varying intensity of current and different voltages. For this reasons technical method and use of current-voltage converters are useless. The another method assumes sampling the signals of supply voltage and current and performing multiplication and integration numerically, but it have a number of drawbacks. Charge counting method gives more reliable results than the voltage and current measurement, even using high-speed A/D converters. Unfortunately, it is problematic to use the circuit in this form to measure the amount of energy generated by the EH source, because the measured current is flowing out of the system. The concept of measurement based on the principle of operation on the A/D converters to the load balancing is a bit more complicated in hardware implementation. The meter built according to the Figure 6 allows the measurement of the flow charge with an accuracy not worse than 2.5% on the highest resolution, and not worse than 1.2% for a resolution of 5 thousand plots. This type of device may measure the charge flowing in one direction, for example from the source to the battery