The first principal component (PC1) contributed to 47.6 % of the variance and consisted in the meaningful contribution of two parameters: cellulose and other minor components with high square cosines, 0.8 and 0.73, respectively (subsection b in Fig. 1). Whereas the second principal component (PC2) explained 30.6 % of the total variance and was conformed by the meaningful contribution of hemicellulose and lignin (subsection b, in Fig. 1). After applying the ANOVA tests to PC1 and PC2 (using the coordinates of the observations for each one), statistical difference was obtained for the second component ( F = 4.558, p = 0.003), observing an increase of PC2 toward the extremes of the altitudinal gradient under study and a decrease at the center (Fig. 1d), where the altitude of 3100 masl was the lowest. There was no significant statistical difference for the first component (Fig. 1c). ATR-FTIR characterization The participation of local citizens and local authorities in renewable energy projects through renewable energy communities has resulted in substantial added value in terms of local acceptance of renewable energy and access to additional private capital which results in local investment, more choice for consumers and greater participation by citizens in the energy transition. Such local involvement is all the more crucial in a context of increasing renewable energy capacity. Measures to allow renewable energy communities to compete on an equal footing with other producers also aim to increase the participation of local citizens in renewable energy projects and therefore increase acceptance of renewable energy. The 36 wood samples were subjected to a spectroscopic analysis ATR-FTIR. A Frontier spectrophotometer (PerkinElmer) equipped with an external module for ATR was used, as per the following procedure: 32 scanning operations per each sample; spectral resolution of 4 cm −1, and wavenumber rank of 4000–400 cm −1. For instrumental control and data processing, Spectrum and Spekwin32 softwares were used. Measurements were carried out on all previously homogenized wood samples of A. religiosa, taking 0.03 g of dry base of similar particle size (less 60 mesh, 0.274 mm) from each of them. Samples were spread over the entire area of the diamond lens of the ATR, and a similar pressure was used on each measurement (80 %). For quantitative comparison of the absorbance intensity of each band, the spectrum magnitude was normalized with respect to the value of the band with the most intensity (1027 cm −1) [ 36]. Six spectra were obtained from each altitudinal level. However, to save time and resources, only one sample measurement was used for each tree, as the variation of the same tree sample was found to be negligible in comparison to that between different trees.

Emmanuel V, Odile B, Céline R (2015) FTIR spectroscopy of woods: a new approach to study the weathering of the carving face of a sculpture. Spectrochim Acta Part A Mol Biomol Spectrosc 136:1255–1259We discuss the application of various methods for the bioconversion of lignocellulosic biomass to end products i.e. biofuels. The lignocellulosic biomass must be pretreated to disintegrate lignocellulosic complexes and to expose its chemical components for downstream processes. After pretreatment, the lignocellulosic biomass is then subjected to saccharification either via acidic or enzymatic hydrolysis. Thereafter, the monomeric sugars resulted from hydrolysis step are further processed into biofuel i.e. bioethanol, biodiesel or butanol etc. through the fermentation process. The fermented impure product is then purified through the distillation process to obtain pure biofuel. Bioéthanol: le procédé (6)Bilans • Bilan masse dépendant de la matière première (1 t MS) • Exemple : teneur en cellulose = 40 % (m/m) • (hémicellulose : 25 % -20% xylanes, lignine : 20% ) • Rdts : • prétraitement 93% • hydrolyse 85 % • fermentation 46 % • Ethanol final : 160 kg (rdt = 70% / théorique) • + potentiellement 200 kg xylanes + 200 kg lignine • + potentiellement 86 kg éthanol ex C5 Séminaire Agrocarburants et développement durable – Grenoble, 28-29/01/2008 Passive energy systems use building design to harness energy. This is considered to be saved energy. To avoid double counting, energy harnessed in this way should not be taken into account for the purposes of this Directive. Pineda-López MR, Sanchez-Velásquez LR, Vazquez-Domínguez G, Rojo-Alboreca A (2013) The effects of land use change on carbon content in the aerial biomass of an Abies religiosa (Kunth Schltdl. et Cham.) forest in central Veracruz, Mexico. For Syst 22:82–93

Chen C, Luo J, Qin W, Tong Z (2014) Elemental analysis, chemical composition, cellulose crystallinity, and FT-IR spectra of Toona sinensis wood. Monatsh Chem 145:175–185Whittaker RH (1978) Direct gradient analysis: techniques. In: Whittaker RH (ed) Handbook of vegetation science 5. Ordination and classification of communities. Dr Junk W. Springer, The Hague, pp 9–51 Maréchal Y, Chanzy H (2000) The hydrogen bond network in I (β) cellulose as observed by infrared spectrometry. J Mol Struct 523:183–196

Güleç, Fatih; Parthiban, Anburajan; Umenweke, Great C.; Musa, Umaru; Williams, Orla; Mortezaei, Yasna; Suk‐Oh, Hyun; Lester, Edward; Ogbaga, Chukwuma C.; Gunes, Burcu; Okolie, Jude A. (12 October 2023). "Progress in lignocellulosic biomass valorization for biofuels and value‐added chemical production in the EU: A focus on thermochemical conversion processes". Biofuels, Bioproducts and Biorefining. doi: 10.1002/bbb.2544. La biomasse lignocellulosique donc la lignocellulose, se compose de lignine, une biomolécule qui est un des principaux composants du bois avec l’hémicellulose et la cellulose (un glucide).Gall H, Philippe F, Domon JM, Gillet F, Pelloux J, Rayon C (2015) Cell wall metabolism in response to abiotic stress. Plants 4:112–166 Hoch G, Körner C (2012) Global patterns of mobile carbon stores in trees at the high-elevation tree line. Glob Ecol Biogeogr 21:861–871 In addition to establishing a Union framework for the promotion of energy from renewable sources, this Directive also contributes to the potential positive impact which the Union and the Member States can have in boosting the development of the renewable energy sector in third countries. The Union and the Member States should promote research, development and investment in the production of renewable energy in developing and other partner countries while fully respecting international law, thereby strengthening their environmental and economic sustainability and their export capacity of renewable energy. To prepare for the transition towards advanced biofuels and minimise the overall direct and indirect land-use change impacts, it is appropriate to limit the amount of biofuels and bioliquids produced from cereal and other starch-rich crops, sugars and oil crops that can be counted towards the targets laid down in this Directive, without restricting the overall possibility of using such biofuels and bioliquids. The establishment of a limit at Union level should not prevent Member States from providing for lower limits to the amount of biofuels and bioliquids produced from cereal and other starch-rich crops, sugars and oil crops that can be counted at national level towards the targets laid down in this Directive, without restricting the overall possibility of using such biofuels and bioliquids.