Biomass Production and Quality of Twelve Fast-Growing Tree Taxa in Short Rotation under Mediterranean Climate

Abstract

Sustainable production of lignocellulosic biomass for energy use can contribute to climate change mitigation. This work aims to compare the biomass production of twelve fast-growing woody taxa belonging to the Eucalyptus, Casuarina, Populus and Paulownia genera, the quality of their biomass for energy use and its valorizing through transformation into pellets, as well as the effect of the crop on the soil. Over the course of two rotations, plant growth and biomass production were assessed. The yield of aboveground dry biomass ranged from 9 to 61 Mg ha−1 year−1 (equivalent to 137–867 GJ ha−1 year−1). The highest yields were obtained for Eucalyptus clones (51–61 Mg ha−1 year−1). The N-fixing species Casuarina equisetifolia and two Populus × euramericana clones (‘Adige’ and ‘AF2’) also achieved high yields (28–33 Mg ha−1 year−1), though significantly smaller than those of the eucalypts. Due to its low wood density, Paulownia fortunei was not very productive in terms of biomass (18 Mg ha−1 year−1), despite its good growth in diameter and height. However, some management practices, such as not removing nutrient-rich and poor-quality biomass fractions for energy use (leaves and thin branches) from the harvested crop, as well as the use of N-fixing species and by taking into account all nutrient inputs and outputs, can ensure the sustainability of the cultivation systems and improve degraded soils.

Forest Biomass in Bioenergy Production in the Changing Geopolitical Environment of the EU

“…The cost of producing fast-growing woody plants was estimated at about 75-87 USD per dry ton of wood mass in 2022, while the average European coal price was 350 USD per ton. In comparison with biomass produced from energy plantations and pruning cuts, the amount of forest fuel, logging residues, is less costly, especially when using an integrated wood harvesting system that allows cost-sharing between wood harvesting and residues as explained by Alaejos et al [78].…”

Coal Share Reduction Options for Power Generation during the Energy Transition: A Bulgarian Perspective

“…Paulownia wood has a low density of 0.208-0.282 kg/dm 3 [141][142][143], and its plantation in urban environments or industrial areas with heavy pollution leads up to an 80% reduction in air pollution [144]. A large number of reports confirm that Paulownia is very suitable for combined production, the so-called forestry and agro crops [144][145][146][147]. The deep root system of the Paulownia species allows the planting of agricultural crops with more superficially located roots in the inter-rows.…”

“…The process of cultivating Paulownia requires exceptional technological skills [145,147]. The present analysis does not involve a detailed soil analysis, which is generally needed to evaluate the soil characteristics of any territory selected as a Paulownia field.…”

Comparative Study of the Convertibility of Pretreated Miscanthus Straw Using Enzyme Preparations Produced by Different Recombinant Strains of Penicillium verruculosum

“…For instance, switchgrass has a dry biomass yield ranging from 14 to 27 t/ha [1], and the average yield of dry amaranth biomass is 19.1 t/ha [2]. Miscanthus sinensis hybrids can produce up 25-41 t/ha of dry matter, depending on their location and growing conditions [3][4][5], dry wheat straw and maize stalks production are up to 15 and 25 t/ha of dry matter, respectively, which are comparable with the annual biomass production of fast-growing trees [6]. High productivity is associated with C4photosynthesis often found in the species of Poaceae and Amaranthaceae grasses like food and feed crops such as sugar cane, maize, sorghum, bermudagrass, and amaranthus.…”