Medicinal Plants in Semi-Natural Grasslands: Impact of Management

Semi-natural grasslands (SNG) are valuable for their high biodiversity, cultural and landscape values. Quantitative information about medicinal plants (MP) in SNG facilitates the evaluation of ecosystem services of these habitats. Different literature sources were used to assess the ratio and frequency of MP species in several Estonian SNG and to evaluate the impact of management on these values. Lists of MP species according to different MP definition scenarios are available. The ratio of MP species in the local plant species list was the largest in alvars, followed by floodplain and wooded meadows. The average number of MP species in wooded meadows and alvars was about twice of that found in naturally growing broadleaved forest (according to the most detailed MP species list, 7.2, 7.8 and 4.3 plot⁻¹, respectively). Fertilization of wooded meadows had no significant impact on MP species ratio, but decreased the percentage of MP biomass. Coastal meadows had few MP species and the impact of management quality depended on adopted MP scenarios. Comparison of Ellenberg indicator values revealed that MP species were more drought-tolerant, with higher commonness and more anthropophyte than the rest of studied grassland species.

PESFOR-W: Improving the design and environmental effectiveness of woodlands for water Payments for Ecosystem Services

The EU Water Framework Directive aims to ensure restoration of Europe’s water bodies to “good ecological status” by 2027. Many Member States will struggle to meet this target, with around half of EU river catchments currently reporting below standard water quality. Diffuse pollution from agriculture represents a major pressure, affecting over 90% of river basins. Accumulating evidence shows that recent improvements to agricultural practices are benefiting water quality but in many cases will be insufficient to achieve WFD objectives. There is growing support for land use change to help bridge the gap, with a particular focus on targeted tree planting to intercept and reduce the delivery of diffuse pollutants to water. This form of integrated catchment management offers multiple benefits to society but a significant cost to landowners and managers.

New economic instruments, in combination with spatial targeting, need to be developed to ensure cost effective solutions – including tree planting for water benefits - are realised. Payments for Ecosystem Services (PES) are flexible, incentive-based mechanisms that could play an important role in promoting land use change to deliver water quality targets. The PESFOR-W COST Action will consolidate learning from existing woodlands for water PES schemes in Europe and help standardize approaches to evaluating the environmental effectiveness and cost-effectiveness of woodland measures. It will also create a European network through which PES schemes can be facilitated, extended and improved, for example by incorporating other ecosystem services linking with aims of the wider forests-carbon policy nexus.

Chemical characteristics of biomass from nature conservation management for methane production

The aim of the current study was to assess the biochemical methane potential (BMP) of different functional groups harvested from different semi-natural grassland types that are valuable for nature conservation purposes. Ensiling of particular biomass did not significantly influence its methane yield, however, the ranking of functional groups by their methane yield varied during the experiment. During the first days of the experiment, methane was released most rapidly by legumes and other forbs with higher N and P contents. At the end of the BMP experiment the quantity of methane produced was higher in grasses and sedges/rushes with lower K, Mg and lignin content. Hence, measurement of feedstock chemical composition is an essential input to develop suitable technology for anaerobic digestion of late harvested biomass from semi-natural grasslands.

Energetic conversion of European semi-natural grassland silages through the integrated generation of solid fuel and biogas from biomass: energy yields and the fate of organic compounds

Twelve European habitat types were investigated to determine the influence of the IFBB technique (integrated generation of biogas and solid fuel from biomass) on the fate of organic compounds and energy yields of semi-natural grassland biomass. Concentration of organic compounds in silage and IFBB press cake (PC), mass flows within that system and methane yields of IFBB press fluids (PF) were determined. The gross energy yield of the IFBB technique was calculated in comparison to hay combustion (HC) and whole crop digestion (WCD). The IFBB treatment increased fibre and organic matter (OM) concentrations and lowered non-fibre carbohydrates and crude protein concentrations. The PF was highly digestible irrespective of habitat types, showing mean methane yields between 312.1 and 405.0 LN CH4 kg(-1) VS. Gross energy yields for the IFBB system (9.75-30.19MWh ha(-1)) were in the range of HC, outperformed WCD and were influenced by the habitat type.

Mineral concentrations in solid fuels from European semi-natural grasslands after hydrothermal conditioning and subsequent mechanical dehydration

The integrated generation of solid fuel and biogas from biomass (IFBB) is particularly designed for the conversion of semi-natural and high biodiversity grassland biomass into energy. This biomass is problematic in common energy conversion techniques, e.g. biogas conversion or combustion, because of its chemical composition. The IFFB process separates the material into a fibre rich solid fuel and a fluid, which is rich in minerals and highly digestible constituents and is used for anaerobic digestion. Biomasses from 18 European semi-natural grassland sites have been processed in an IFBB prototype. The impact of different chemical and botanical parameters on mass flow of mineral plant compounds and their concentrations in the fuel has been investigated. Fuel quality was significantly influenced by chemical and botanical parameters and the quality could be significantly improved during processing. Biomass with a high grass proportion and fibre content showed the best fuel qualities after IFBB treatment.

Life cycle assessment of the integrated generation of solid fuel and biogas from biomass (IFBB) in comparison to different energy recovery, animal-based and non-refining management systems

The study compares energy production from semi-natural grasslands by the integrated generation of solid fuel and biogas from biomass (IFBB) through mechanical separation of the biomass with the dry fermentation (DF) and hay combustion system (HC). In addition, traditional use for beef cattle production and non-refining systems of landscape conservation, i.e. mulching and composting, are considered. Highest conversion efficiency (45-54% of the gross yield), net savings of fossil fuels (44-54 GJ ha(-1)) and net savings of greenhouse gases (2.9-3.7 t CO(2-eq)ha(-1)) are obtained by HC and IFBB. Potentials of DF are limited due to low digestibility of the mature biomass.

Leaf rust induced volatile organic compounds signalling in willow during the infection

Plants are known to emit volatile organic compounds (VOC) in response to various biotic or abiotic stresses. Although the VOC emission in the case of insect attacks is well described, there is only little known about the impact of pathogens on plant emission. In the present study, we used a willow-leaf rust system to describe the effects of a biotrophic fungal infection on the VOC emission pattern of willow leaves. We detected that isoprene emissions from rust-infected leaves decreased threefold compared to control. The total monoterpene emissions did not change although a stress-signalling compound (Z)-beta-ocimene showed an increase in infected plants on several days. The infection also increased the emission of sesquiterpenes and lipoxygenase products (LOX) by factors of 175-fold and 10-fold, respectively. The volatile emission signals showed two clear peaks during the experiment. At 6, 7 and 12 days post-infection (dpi), the relative volatile emission signal increased to about sixfold compared to uninfected plants. These time points are directly connected to rust infection since at 6 dpi the first rust pustules appeared on the leaves and at 12 dpi necrosis had developed around several pustules. We present correlations between LOX and sesquiterpene emission signals, which suggest at least two different steps in eliciting the volatile emission.