Exploring the potential of wild perennial grasses as a biomass source in semi-arid Mediterranean environments

Abstract

In Mediterranean environments, few perennial grass species are available for cultivation in rainfed systems and marginal lands, where plants with excellent adaptation are required. The aim of the present work was to determine the potentiality of five native Mediterranean perennial grasses for lignocellulosic biomass production. Wild accessions of three hemicryptophytes (Ampelodesmos mauritanicus, Hyparrhenia hirta, and Piptatherum miliaceum) and two geophytes (Saccharum spontaneum ssp. aegyptiacum and Sorghum halepense) were collected at three Mediterranean sites (Sicily, Sardinia and Majorca), and their morphological, physiological, productivity and quality traits were evaluated in the field. The species differed in height, with S. spontaneum and A. mauritanicus being the tallest. The leaf mass ratio ranged from 0.23 to 1.0 g g–1 among species. Maximum net photosynthesis was measured in the C4 species S. spontaneum and S. halepense (26.6 and 23.8 mmol CO2 m–2 s–1, respectively). A. mauritanicus showed the lowest transpiration rate and the highest instantaneous water use efficiency (2.7 mmol H2O m–2 s–1 and 6.9 mmol CO2 mmol H2O–1, respectively). S. spontaneum was the most productive species, yielding more than 18 Mg DM ha–1 as a three-year average. The highest content of acid detergent lignin was found in P. miliaceum, while A. mauritanicus was the species richest in hemicellulose and cellulose and poorest in ash. S. spontaneum showed the highest moisture content at harvest. Overall, the studied species showed interesting morphological, physiological, productive and qualitative traits. Nevertheless, additional research is necessary to investigate their long-term performance under different management strategies.

The Impact of Soil Water Content on Yield, Composition, Energy, and Water Indicators of the Bioenergy Grass Saccharum spontaneum ssp. aegyptiacum under Three-Growing Seasons

“…A similar downward trend was previously observed in the study by Cosentino et al [22], where rainfed Saccharum crops showed higher hemicellulose, cellulose, and lignin than mid and full irrigated crops. Biomass composition in Saccharum was comparable with levels found for many other perennial grasses, such as Miscanthus × giganteus, Miscanthus sinensis, Arundo donax, Cymbopogon hyrthus, Sorghum halepense, Oryzopsis milianea, and Panicum virgatum [21,25,26,56,57].…”

Context‐dependent concordance between physiological divergence and phenotypic selection in sister taxa with contrasting phenology and mating systems

“…In the current study, however, the large sample sizes obtained per taxon, the replication of each taxon within and among 2–4 populations, and the statistical control of variation in other plant attributes that are correlated with instantaneous gas exchange rates (e.g., leaf position on the stem, leaf temperature at the time of measurement, and the life cycle stage at which plants are measured) helped to account for the variance in physiological performance that can obscure differences between taxa. Numerous other recent studies have compared taxa, experimental treatments, or life history stages based on instantaneous gas exchange measurements (Mazer et al, 2010; Franks, 2011; Dudley et al, 2012, 2015; Gorai et al, 2015; Cheng et al, 2017; Gulias et al, 2018; Velikova et al, 2018; Wang et al, 2019; Scalon et al, 2021).…”

Drought Impact on the Morpho-Physiological Parameters of Perennial Rhizomatous Grasses in the Mediterranean Environment

“…The most recent Intergovernmental Panel on Climate Change report [20] forecasts that climate change will expose plants to increasing occurrences of combined abiotic stresses, including drought, higher temperatures, and increased atmospheric CO 2 concentrations in the coming decades. This would be especially intense in the Mediterranean basin, which is characterized by 2-6 months of drought periods in summer and shorter drought winter periods from autumn to spring [21]. Thus, the crops grown in the semi-arid Mediterranean area could be subjected to multiple stresses that are directly related to climate change.…”