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The contribution of energy from biomass sources is projected to increase in Britain to assist in meeting renewable energy targets and reducing anthropogenic CO2 emissions. With increasing concerns over the sustainability of food crop-based biofuels, purpose-grown lignocellulosic biomass crops such as Miscanthus and short rotation coppice (SRC) willow have been promoted as more sustainable feedstocks for the production of heat and electricity as well as for the future production of liquid biofuels. With the introduction of the Energy Crops Scheme, land-use change (LUC) for lignocellulosic biomass crop production has become increasingly common in Britain in recent decades. However, there is limited understanding of the impact this has on soil organic carbon (SOC) stocks and limited predictability concerning the overall trajectory, magnitude and rate of SOC changes under a range of different conditions. Using a chronosequence of 93 biomass crop plantations in England and Wales, mainly of 1 to 14 years age, empirical models were developed to determine the short term trajectory of SOC stocks following LUC from arable and grassland to SRC willow and Miscanthus production. SOC stocks were calculated for each site using a fixed sampling depth of 30 cm and estimated changes were inferred by comparing with typical pre-change SOC stocks. These results indicate that only LUC from arable crops to SRC willow demonstrated an overall increase in SOC stocks, by an estimated 15.3 ± 2.2 t C ha-1 (± 95% confidence intervals) after 14 years and 68.8 ± 49.4 t C ha-1 after 22 years. LUC from arable crops to Miscanthus and from both arable crops and grassland to SRC willow and Miscanthus demonstrated no overall net effect on SOC stocks. Soil texture and climate data were measured for each site and multivariable models were created to assess the influence of different environmental conditions on SOC trajectory. In most cases the addition of these explanatory variables improved the model fit, and the models provide some preliminary estimates of more region-specific changes in SOC following LUC. Since LUC to biomass crops often causes a loss of SOC, at least in the short term, the potential for pyrogenic carbon (PyC) to ameliorate this effect was investigated. Studies indicate that PyC can interact with and stabilise native SOC, a process termed negative priming, although the potential for PyC to reduce LUC-induced losses of SOC by negative priming has not yet been assessed. Although negative priming has been observed in many studies, most of these are long term incubation experiments which do not account for the impact of environmental weathering of PyC on interactions with native SOC. Here the aim was to assess the impact of environmentally weathered PyC on native SOC mineralisation at different points in LUC from arable crops to SRC willow. Soil was sampled to a 5 cm depth from multiple recently established SRC willow plantations approximately 2 years after amendment with PyC. Cumulative CO2 flux was measured weekly from incubated soil and soil-surface CO2 flux was also measured in the field. The results demonstrate a PyC-induced increase in CO2 flux for the surface 5 cm of soil. However, no net effect on soil-surface CO2 flux was observed in the field. Although the mechanisms for these contrasting effects remain unclear, they do not suggest that PyC can reduce LUC-induced SOC losses through negative priming.

Most energy sources are derived from the sun, directly or indirectly. Stopping the increase of heat-trapping carbon dioxide in the atmosphere will likely require more reliance on current rather than ancient terrestrial solar input. Yet which forms of renewable energy are most appropriately used is a significant question for the twenty-first century. This dissertation concerns the potential supply of biomass energy crops as a renewable energy source in Massachusetts. Biomass represents a low-efficiency solar collector, and supplying society with an important portion of its energy from biomass would require a great deal of land. The cellulosic biomass crop evaluated in this research is switchgrass, among the most studied of possible biomass crops. The study looks at biomass energy crop potential from three perspectives. First, a biomass crop supply function is developed for switchgrass by 1) using a GIS model to estimate land availability by current land use and soil type; 2) using a crop-growth simulation model to estimate potential switchgrass yields; 3) estimating marginal production cost by land parcel; and 4) calculating a supply function from marginal production costs. Total technical potential is estimated to be about 1.3 million dry metric tons of switchgrass per year, though financial constraints would likely limit production to some portion of the estimated 125,000 metric tons per year that could be produced on existing grasslands. Next, the study examines circumstances under which landowners might opt to make land available for biomass crop production. The social challenge of minimizing biomass energy cost is described. Potential biomass crop landowner decisions are characterized in a theoretical utility maximization model, with results suggesting that non-price attributes of crop production are likely important to landowners. Finally, an empirical study using a landowner survey assesses interest in growing biomass crops, and uses contingent valuation (CV) to estimate landowner willingness to accept (WTA) land rent for biomass crops. The median estimate is $321/ha/yr, with a much-higher mean estimate of $658/ha/yr (based on a parametric estimator). While the realistic potential for biomass crops is some fraction of technically feasible potential, there are other potentially important roles for biomass crops in Massachusetts, for example in preserving unused farmland that would otherwise revert to forest.

The objective of the thesis is to evaluate the possibility of the effective use of waste and phytomass specifically grown for energy purposes in the protected area of National Park Podyjí. The task was to characterize the source of phytomass in this environmentally sensitive area. The data were collected by studying documents, visits to enterprises and institutions, and personal consultations with business and other stakeholders. The result of this work is a brief assessment of the production potential and the factors influencing its development. Due to the nature of the territory, to suggest measures for efficient use of land for the production of energy phytomass with regard to the attitudes of farmers and the authority of nature and landscape.

The aim of the work was to study the communities of epigeic beetles in plantations of energetic plants (Dactylis glomerata, Arrhenatherum elatius, Phalaris arundinacea, Helianthus tuberosus) and in surrounding lawn biotope. The method of pitfall trapping was used for beetle sampling from 2008 to 2010 during the growing season. Carabid beetles (Carabidae) and rove beetles (Staphylinidae) were used as bioindicators. In total 69 species and 1789 individuals were captured and evaluated. Eurytopic species were more common than stenotopic in all habitats, also the value of the index of beetle communities was low in all plots. RDA analysis proved the influence of surrounding biotope on beetle communities. It was concluded that communities of epigeic beetles might be also affected by the climatic factors, long termed population fluctuations of individual species, edge effect and microclimate inside the vegetation.

L'obiettivo della ricerca è stato quello di identificare la coltura bioenergetica con il maggior potenziale di sequestro del carbonio (C); sono state considerate tre colture perenni arboree (pioppo, robinia e salice) e tre colture erbacee perenni (canna comune , miscanto e panico ) al sesto anno dal loro impianto e coltivate nello stesso ambiente. In primo luogo sono state misurate le variazioni dei tassi del C organico del suolo (COS) per il primo 1 m, mentre per i primi 30 cm di suolo è stato stimato il grado di stabilita del COS valutando sette frazioni di COS che presentano differenti gradi di stabilizzazione; in secondo luogo, sono stati caratterizzati gli apparati radicali delle sei specie per la stessa profondità di suolo, per valutare dove le specie accumulano la biomassa radicale lungo il profilo di suolo. I risultati confermano che l’impianto di colture bioenergetiche perenni su superfici precedentemente dedite a colture annuali gestite convenzionalmente rappresenta una opzione valida per sequestrare C nel soulo. Tuttavia, è stata osservata una diversa capacità di sequestro di C tra specie arboree ed erbacee: le specie arboree hanno dimostrato aumentre il contenuto di COS nel primo strato di suolo ( 0-10 cm di suolo), ma la loro capacità di allocare biomassa radicale negli strati profondi del suolo è limitata; mentre, la specie erbacee allocano un’alta quantità di biomassa radicale negli strati profondi del suolo, ma solo il panico ed il miscanto hanno aumentato il contenuto di C nel primo strato di suolo. / The objective of the present research was to identify the bioenergy crop with the greatest carbon sequestration potential among three perennial woody crops (poplar, black locust and willow) and three perennial herbaceous crops (giant reed, miscanthus and switchgrass) at the sixth year from plantation and in the same location. First of all the SOC stock variations for the first 1 m soil depth and the quantification of seven soil C fractions related to SOC stabilization level of the first 30 cm of soil were assessed; secondly, a characterization of the root system and the traits which affect the carbon allocation in soil were considered. The results confirm that the establishment of perennial bioenergy crops in previous arable fields can be a suitable option to sequester carbon (C) belowground. However, a different C sequestration capacity was observed between woody and herbaceous crops: woody species showed the greatest SOC sequestration potential in the first soil layer (0-10 cm of soil) but their ability to allocate root biomass in the deeper soil layers was limited; while, the herbaceous species allocated a high amount of root biomass in the deeper soil layers, but only switchgrass and miscanthus sequester C in the first soil layer.