Acacia Dealbata Research Articles

Gypsum Mortars with Acacia dealbata Biomass Waste Additions: Effect of Different Fractions and Contents

In recent decades, interest in the eco-efficiency of building materials has led to numerous research projects focused on the replacement of raw materials with mineral and biomass wastes, and on the production of mortars with low-energy-consuming binders, such as gypsum. In this context, five different fractions (bark, wood, branchlets, leaves, and flowers) of Acacia dealbata—an invasive species—were evaluated as fillers for premixed gypsum mortars, at 5% and 10% (vol.) addition levels and fixed water content. Although these biomass fractions had different bulk densities (>50% of variation), all the mortars were workable, although presenting different consistencies. As expected, dry density decreased with biomass addition, but, while mortars with addition at 5% presented a slight shrinkage, a slight expansion occurred with those with 10% addition. Generally, the mechanical properties decreased with the biomass additions even if this was not always proportional to the added content. The wood fraction showed the most positive mechanical results but flexural and compressive strengths of all the tested mortars were found to be higher than the lower standard limit, justifying further studies.

Change in fire frequency drives a shift in species composition in native Eucalyptus regnans forests: Implications for overstorey forest structure and transpiration

AbstractThe world's most iconic forests are under threat from climate change. Climate‐fire‐vegetation feedback mechanisms are altering the usual successional trajectories of forests. Many obligate seeder forests across the globe are experiencing regeneration failures and subsequent alterations to their recovery trajectories. For example, the persistence of Eucalyptus regnans F. Muell. forests in southeast Australia is highly vulnerable to the effects of climate‐driven increases in wildfire frequency. Shortening of the wildfire return interval from >100 years to < 20 years would inhibit or entirely stop regeneration of E. regnans, leading to replacement with understorey species such as Acacia dealbata Link. In this study, it is hypothesised that following such replacement, forest overstorey structure and transpiration will diverge. An experiment was designed to test this hypothesis by measuring and comparing overstorey transpiration and structural properties, including sapwood area and leaf area, between E. regnans and A. dealbata over a chronosequence (10‐, 20‐, 35‐ and 75‐/80‐year‐old forests). We found that overstorey structure significantly diverged between the two forest types throughout the life cycle of A. dealbata after age 20. The study revealed strikingly different temporal patterns of water use, indicating a highly significant eco‐hydrologic change as a result of this species replacement. Overall, the results provide a strong indication that after age 20, overstorey transpiration in Acacia‐dominated forests is substantially lower than in the E. regnans forests they replace. This difference may lead to divergence in water yield from forested catchments where this species replacement is widespread.

Origin makes a difference: Alternative responses of an AM-dependent plant to mycorrhizal inoculum from invaded and native soils under abiotic stress.

The presence of invasive alien plants (IAPs) alters the composition of soil arbuscular mycorrhizal (AM) fungal communities. Although fundamental for plant development, plant responses to AM from invaded soils have not been widely explored, especially under environmental stress.We compared plant growth, P accumulation, root colonization and the photosynthetic responses of the native AM‐dependent Plantago lanceolata growing in contact with AM fungi from communities invaded by Acacia dealbata Link (AMinv) or non‐invaded communities (AMnat) exposed to water and light restriction (shade).Under optimal growing conditions, plants in contact with AMnat produced higher leaf biomass and accumulated more P. However, plant responses to different AM inocula varied as the level of stress increased. Inoculation with AMinv promoted plant growth and root length under light restriction. When plants grew in contact with AMnat under drought, leaf P increased under severe water restriction, and leaf and root P increased under intermediate water irrigation. Growing in contact with the AMnat inoculum promoted root P content in both full light and light restriction. Colonization rates of P. lanceolata roots were comparable between treatments, and plants maintained photosynthetic activity within similar ranges, regardless of the level of stress applied.Our results suggest that origin of the inoculum (native soils versus invaded soils) did not affect the ability of AM species therein to establish effective mutualistic associations with P. lanceolata roots but did influence plant responses depending on the type and level of the abiotic stress.

Design and Testing of a Novel Unoccupied Aircraft System for the Collection of Forest Canopy Samples

Unoccupied Aircraft Systems (UAS) are beginning to replace conventional forest plot mensuration through their use as low-cost and powerful remote sensing tools for monitoring growth, estimating biomass, evaluating carbon stocks and detecting weeds; however, physical samples remain mostly collected through time-consuming, expensive and potentially dangerous conventional techniques. Such conventional techniques include the use of arborists to climb the trees to retrieve samples, shooting branches with firearms from the ground, canopy cranes or the use of pole-mounted saws to access lower branches. UAS hold much potential to improve the safety, efficiency, and reduce the cost of acquiring canopy samples. In this work, we describe and demonstrate four iterations of 3D printed canopy sampling UAS. This work includes detailed explanations of designs and how each iteration informed the design decisions in the subsequent iteration. The fourth iteration of the aircraft was tested for the collection of 30 canopy samples from three tree species: eucalyptus pulchella, eucalyptus globulus and acacia dealbata trees. The collection times ranged from 1 min and 23 s, up to 3 min and 41 s for more distant and challenging to capture samples. A vision for the next iteration of this design is also provided. Future work may explore the integration of advanced remote sensing techniques with UAS-based canopy sampling to progress towards a fully-automated and holistic forest information capture system.

Special Bioactivities of Phenolics from Acacia dealbata L. with Potential for Dementia, Diabetes and Antimicrobial Treatments

Some diseases still need better therapeutic approaches, including the prevention of development. Natural resources are investigated with this purpose; among them, we decided to use an invasive plant as a main strategy. This will help in two ways: screening new compounds in flowers prevents the plant from causing widespread damage by controlling the dissemination and also obtains crude material for further applications. In the present study, flower extracts from Acacia dealbata Link harvested in Portugal were studied during three stages of flowering. Phenolic compounds were evaluated using HPLC/DAD and the total phenolics as the total flavonoids content was determined. The bioactivities screened were antioxidant potential, inhibitory activities of some enzymes (acetylcholinesterase, lipase and α-glucosidase) and, to complete the screening, the inhibition of microbial growth was determined against Gram-negative and Gram-positive bacteria, as well as for yeasts. The data obtained suggested that the hydroethanolic extracts gave good results for all these biological activities and varied according to the maturation status of the flowers, with the early stage being the most active, which can be related to the chalcones content. This new approach will lead to the possible control of the invasive plant and also future perspective research for therapeutic purposes.

Acacia dealbata Link. Aboveground Biomass Assessment: Sustainability of Control and Eradication Actions to Reduce Rural Fires Risk

Invasive species are an environmental problem affecting worldwide ecosystems. In the case of Acacia dealbata Link., the negative impacts affect the productivity of the forests due to the competition established with native species while contributing to a significant increment in the available fuel load, increasing the risk of fire. In Portugal, chemical and mechanical methods are mostly used in the control of these species. However, the costs are often unsustainable in the medium term, being abandoned before completing the tasks, allowing the recovery of the invasive species. The establishment of value chains for the biomass resulting from these actions was pointed out by several authors as a solution for the sustainability of the control process, as it contributes to reducing costs. However, the problems in quantifying the biomass availability make it challenging to organize and optimize these actions. This work, which started from a dendrometrical analysis carried out in stands of A. dealbata, created a model to assess woody biomass availability. The model proved to be statistically significant for stands with trees younger than 20 years old. However, the amount of data collected and the configuration of the settlements analyzed do not allow extrapolation of the model presented to older settlements.

Assessment of Acacia dealbata as green manure and weed control for maize crop

AbstractAcacia dealbata Link is one of the main invasive species in southwestern Europe and a resource with potential value for agriculture. Our objective was to assess the value of A. dealbata vegetative aerial biomass used as green manure and as a tool for weed control in maize crops through three sequential experiments. In 2017, an experiment was carried out with acacia green manure vs inorganic fertilization of pots sown with a field corn and a sweet corn hybrid with strong and weak nutrient demand, respectively. Nutrients were not released from acacia green manure at an appropriate timing, and maize suffered nutrient deficit. In 2018, a pot experiment was made outdoors incorporating acacia green manure at different times before maize sowing, and we found that a 4-month period was required for maximum nutrient release from acacia green manure. In 2019, an early and a late-field experiments were performed by incorporating acacia green manure 4 months before maize sowing. Physiological and agronomic data were recorded in maize, along with soil data, for all years, and weed data the last year. Altogether, most effects and interactions between genotype or environment and fertilization treatment were not significant, and some deficiencies caused by acacia green manure fertilization depend on genotype and environment. Incorporation of acacia green manure 4 months before maize sowing partially controlled weeds and replaced inorganic fertilization. However, deficiencies should be corrected with additional weed control practices and fertilization treatments, according to the nutrient demand of the crop and the soil environment.

Comparative avifaunal richness and diversity in invasive Acacia dealbata patches and adjacent montane grasslands

Invasive alien species are regarded as the second greatest threat to biodiversity globally. Yet, at a local scale their effects may vary, underlying the requirement for more local-scale studies across taxa and settings. Here we consider the effects of an alien invasive tree (Acacia dealbata, 5–8 m tall) on avifaunal numbers, richness and diversity in A. dealbata patches of three sizes relative to adjacent montane grasslands. Analysis of historical aerial photographs showed that A. dealbata first occurred in the area in the late 1930s/early 1940s and has continued to spread, despite some efforts by the landowner to keep it in check. It now covers approximately 11% of the site. This has provided habitat for a number of bird species more characteristic of wooded vegetation types. The number, richness and diversity of birds were greater in A. dealbata patches than the adjacent grasslands of equivalent size. These measures increased with increasing patch size, but more rapidly for A. dealbata patches than grassland ones. Only six of the 48 species of birds recorded were common between the two vegetation types. The most common feeding guild in the A. dealbata patches was insectivores, whereas in the grasslands it was omnivores. Although the invasion of A. dealbata has added to the habitat diversity of the area, thereby facilitating increased avifaunal diversity, if it continues to spread, then the populations and perhaps richness of grassland birds are likely to be negatively affected.

Pharmacognostical studies on whole plant of Mimosa pudica L

Background: Mimosa pudica is a creeping, diffuse, prickly undershrub of genus mimosa, native to tropical America which is also scattered along tropical and subtropical parts of India. It is well known as a sensitive plant, shame plant, touch-me-not, humble plant, shyness princess, and sleeping plant by virtue of rapid leaf movements in response to touch. Aim: The intention of this research was to investigate the morphological, micro anatomical, powder microscopy, proximate, and phytochemical analysis in whole plant of M. pudica. Materials and Methods: The investigation on macroscopy, microscopy, and physiochemical and phytochemical analyses were implemented using standard methods. Results: This study divulged unique macroscopical and anatomical characters present in the whole plant of M. pudica. The powder microscopy revealed the presence of trichomes, paracytic stomata, starch grains, prismatic crystals, mucilage, and brownish content. The quantitative microscopy performed in epidermal peelings of leaf quantified the epidermal number, stomatal number, stomatal index, and palisade ratio which determine its quality and purity. The proximate analysis performed was within the specific limits. The phytochemical analysis identifies different phytoconstituents in n-hexane and ethyl acetate extract. Further quantitative estimation disclosed that the total quercetin equivalent in 1 g of ethyl acetate extract of M. pudica was to be 13.39 mg and 27.5 mg of total β-sitosterol equivalent in n-hexane extract of M. pudica. Conclusion: This research concludes the assessment in whole plant of M. pudica by pharmacognostical, physiochemical, and phytochemical estimation for its identification and confirmation of species epithet from adulterated, substituted, or similar distant group species such as Albizia julibrissin, Acacia dealbata, Neptunia gracilis, and Mimosa tenuiflora.

Bacterial Succession during Vermicomposting of Silver Wattle (Acacia dealbata Link).

Vermicomposting is the process of organic waste degradation through interactions between earthworms and microbes. A variety of organic wastes can be vermicomposted, producing a nutrient-rich final product that can be used as a soil biofertilizer. Giving the prolific invasive nature of the Australian silver wattle Acacia dealbata Link in Europe, it is important to find alternatives for its sustainable use. However, optimization of vermicomposting needs further comprehension of the fundamental microbial processes. Here, we characterized bacterial succession during the vermicomposting of silver wattle during 56 days using the earthworm species Eisenia andrei. We observed significant differences in α- and β-diversity between fresh silver wattle (day 0) and days 14 and 28, while the bacterial community seemed more stable between days 28 and 56. Accordingly, during the first 28 days, a higher number of taxa experienced significant changes in relative abundance. A microbiome core composed of 10 amplicon sequence variants was identified during the vermicomposting of silver wattle (days 14 to 56). Finally, predicted functional profiles of genes involved in cellulose metabolism, nitrification, and salicylic acid also changed significantly during vermicomposting. This study, hence, provides detailed insights of the bacterial succession occurring during vermicomposting of the silver wattle and the characteristics of its final product as a sustainable plant biofertilizer.

Canopy damage during a natural drought depends on species identity, physiology and stand composition.

Vulnerability to xylem cavitation is a strong predictor of drought-induced damage in forest communities. However, biotic features of the community itself can influence water availability at the individual tree-level, thereby modifying patterns of drought damage. Using an experimental forest in Tasmania, Australia, we determined the vulnerability to cavitation (leaf P50 ) of four tree species and assessed the drought-induced canopy damage of 2944 6-yr-old trees after an extreme natural drought episode. We examined how individual damage was related to their size and the density and species identity of neighbouring trees. The two co-occurring dominant tree species, Eucalyptus delegatensis and Eucalyptus regnans, were the most vulnerable to drought-induced xylem cavitation and both species suffered significantly greater damage than neighbouring, subdominant species Pomaderris apetala and Acacia dealbata. While the two eucalypts had similar leaf P50 values, E. delegatensis suffered significantly greater damage, which was strongly related to the density of neighbouring P. apetala. Damage in E. regnans was less impacted by neighbouring plants and smaller trees of both eucalypts sustained significantly more damage than larger trees. Our findings demonstrate that natural drought damage is influenced by individual plant physiology as well as the composition, physiology and density of the surrounding stand.

Nutraceutical and preservative potential of Acacia mearnsii and Acacia dealbata leaves for ruminant production and product quality enhancement

AbstractSeasonality and species are key aspects of the abiotic and biotic environment, respectively, that influence nutrient, phytochemical and antioxidant profiles of invasive alien plants leaf-meals. The current study investigated the effects of season on nutrient, amino acid, fatty acid, mineral, bioactive polyphenolic composition and antioxidant activity of Acacia mearnsii and A. dealbata leaf-meals. Overall, A. mearnsii leaf-meal harvested in the hot-dry-season had greater crude protein, ether extract, neutral detergent soluble fibre, 24 and 48 h in vitro neutral detergent fibre digestibility, macro-mineral contents, individual polyphenols, C18:1n9 and C18:2n6 compared to other leaf-meals. Regardless of the season, A. mearnsii leaf-meals had greater amino acid concentrations than A. dealbata leaf-meals. Hot-dry-season leaf-meals had a greater concentration of total flavonoids than the leaf-meals in the cool-wet-season irrespective of species. Antioxidant potency composite of the Acacia leaf-meals was in the order of A. dealbata × hot-dry-season > A. mearnsii × hot-dry-season > A. mearnsii × cool-wet-season > A. dealbata × cool-wet-season. The findings suggested that A. mearnsii leaf-meal harvested in the hot-dry-season has superior nutritional and polyphenolic profiles, which could support its use as a nutraceutical and preservative for the enhancement of ruminant production and product quality compared to other leaf meals.

Seed Germination Ecophysiology of Acacia dealbata Link and Acacia mearnsii De Wild.: Two Invasive Species in the Mediterranean Basin

Acacia dealbata and A. mearnsii are two invasive species found in coastal, mountain, and riparian Mediterranean habitats. Seed biology and germination traits are important drivers of the competitive performance of plants and may significantly contribute to biological invasions. The seeds of Acacia s.l. have physical dormancy due to an impermeable epidermal layer. The aim of this study was to assess the germination capacity of scarified and non-scarified seeds of A. dealbata and A. mearnsii from different areas of the Mediterranean Basin. To test the seed imbibition capacity, the increase in mass was evaluated. Non-scarified seeds were tested at 15, 20, and 25 °C in light conditions. Scarified seeds were tested at 5, 10, 15, 20, and 25 °C and 25/10 °C in light and dark conditions. Scarified seeds increased in mass more than non-scarified seeds. Both species showed a higher germination capacity at 25 °C in non-scarified seeds; A. dealbata reached a germination maximum of 55%, while A. mearnsii reached 40%, showing a difference among these populations. Scarified seeds of both species reached germination percentages >95% at all temperatures except at 5 °C in dark conditions. Scarification was necessary to break dormancy and promote germination. The present study provides new knowledge about the seed ecology and germinative behaviour of the two Acacia species under different pre-treatment, temperature, and photoperiod regimes, contributing to the understanding of their invasive behaviour.

Integral valorization of Acacia dealbata wood in organic medium catalyzed by an acidic ionic liquid

In this work, a novel delignification process was proposed for the fractionation of invasive species such as Acacia dealbata wood. Organosolv process catalyzed with an acidic ionic liquid, 1-butyl-3-methylimidazolium hydrosulfate was evaluated to obtain cellulose-enriched solids and liquid fractions rich in hemicelluloses derived compounds and lignin. Under selected operating conditions (190 °C, 60% ethanol, 60 min of reaction time and 0.6 g 1-butyl-3-methylimidazolium hydrosulfate/g wood), high solubilization of lignin and hemicelluloses and cellulose recovery (87.5%, 88.7% and 88.3%, respectively), with a pulp yield of 43.1% were achieved. Moreover, 62.6 % of lignin was recovered by precipitation from the black liquor (composed mainly by 4.43 g xylose/L, 7.66 g furfural/L and 3.59 g acetic acid/L). In addition, enzymatic digestibility of delignified wood was also assayed. Overall, this work presents an alternative biorefinery scheme based in the use of environmentally friendly solvent and catalyst for selective fractionation of A. dealbata wood.

Germinative behaviour of Acacia dealbata Link, Ailanthus altissima (Mill.) Swingle and Robinia pseudoacacia L. in relation to fire and exploration of the regenerative niche of native species for the control of invaders

Invasion of forest ecosystems by invader plants and forest fires are two of the most serious environmental problems in the world. Climate change is believed to strongly influence these processes, and the invasibility of invasive alien plants (IAPs) is likely to enhance landscape degradation. Therefore, it is urgent to study the germinative behaviour of invasive alien plants in relation to fire and detect possible barrier species of IAPs among native species. Tree species are usually the most damaging group of invasive alien plants. Acacia dealbata Link, Ailanthus altissima (Mill.) Swingle and Robinia pseudoacacia L. are 3 very damaging exotic invader trees in Europe and many other parts of the world. Therefore, the germination behaviour (germination percentage, viability pregermination, viability postgermination and germination rate) of these three species was experimentally studied against different products associated with fire (heat, smoke, ash and charcoal). The germination of A. dealbata and R. pseudoacacia was strongly stimulated by heat, while smoke, ash and charcoal barely changed the control values. None of these factors stimulated germination in A. altissima. Very high temperatures inhibited seed germination of the three species. The germination of R. pseudoacacia seeds was faster than that of A. dealbata and A. altissima seeds. Of the three species studied, A. dealbata and R. pseudoacacia have greater invasibility than A. altissima. A key role in invasive plant control research is to provide information to guide the decisions of forest managers involved in restoration. A possible solution is to use the biotic resistance of native vegetation to control biological invasions. For this purpose and based on extensive bibliographic revision, the regenerative niches of the three invasive species (germination, seedling growth and adult height) were compared with those of native European species to identify candidates for barrier species of IAPs between native species. Among the native species of Europe with characteristics in their regenerative niche suitable to successfully compete against these IAPs are tall shrub species such as Adenocarpus lainzii (Castrov.) Castrov., Cytisus multiflorus (L'Her.) or Cytisus striatus (Hill) Rothm. and tree species such as Corylus colurna L., Pinus sylvestris L. and Quercus ilex L. Therefore, the sowing of a good combination of shrub and tree species, selected according to their geographical distribution, could be an effective ecological measure to control the invasion of IAPs in burned areas. This information can be very valuable for implementing restoration measures in burned areas and should be verified with field experiments.

Production of nanocellulose gels and films from invasive tree species

Wood from invasive tree species Acacia dealbata and Ailanthus altissima was used to produce high value-added nanocellulose. Firstly, bleached pulps were produced from the wood of these tree species after kraft cooking. Afterwards, the resultant pulps were pre-treated by TEMPO-mediated oxidation (Acacia dealbata) or enzymatic hydrolysis (Ailanthus altissima) followed by high-pressure homogenization. Hydrogels were obtained and characterized for their main physical and chemical properties, including rheology measurements. After freeze-drying, the surface properties of the materials were evaluated by inverse gas chromatography. Results showed that nano/micro fibrils could be obtained from the wood of these invasive species. Rheometry studies showed that Acacia-TEMPO cellulose nanofibrils form strong gels with high yield stress point and viscosities (reaching ca. 100,000 Pa·s). Additionally, the surfaces of the obtained nanocelluloses showed a dispersive component of the surface energy near 40 mJ/m2 and a prevalence of the Lewis acidic character over the basic one, as typical for cellulose-based materials. Finally, films with good mechanical and optical properties could be obtained from the cellulose hydrogels. Acacia-TEMPO film (produced by filtration/hot pressing) showed a tensile strength of 79 MPa, Young's modulus of 7.9 GPa, and a transparency of 88%. The water vapor barrier, however, was modest (permeability of 4.9 × 10−6 g/(Pa·day·m)).

Prunus lusitanica L.: An Endangered Plant Species Relict in the Central Region of Mainland Portugal

Prunus lusitanica L. is a paleotropical relic species with an Ibero-Maghrebian distribution, which is presently considered as an endangered species, recognized by the Natura 2000 Network (92/43/EEC) as a priority habitat for conservation in Europe. The mountains in the Portuguese mainland central region offer the best location for this species to occur. The main objective of this study is to measure the current conservation status of the communities of P. lusitanica, through the collection of field data, such as the number of existing individuals of each population and their location, which will then be comparatively analyzed based on the previous literature, published at least 15 years ago. Soil characterization analysis was carried out and the main threats to conservation were identified. As a result, a decline of approximately 40% was observed in the number of individuals and in the quality of their habitat. The main threats to their conservation were found to be the seasonal occurrence of rural fires and the expansion of invasive species, such as Acacia dealbata Link and Ailanthus altissima (Mill.) Swingle. Finally, we present the main management methodologies that should be considered for the valorization of this important vegetational relic in the central region of mainland Portugal.

Leaf Thermal and Chemical Properties as Natural Drivers of Plant Flammability of Native and Exotic Tree Species of the Valparaíso Region, Chile.

Forest fires are one of the main environmental threats in Chile. Fires in this Mediterranean climate region frequently affect native forests and exotic plantations, including in several cases urban and rural settlements. Considering the scarcity of information regarding the fire response dynamics of tree species that are frequently affected by fires, this study aims to establish a flammability classification according to the evolution of the fire initiation risk presented by the most affected forest species in the Valparaíso region. Three exotic species, Eucalyptus globulus, Pinus radiata, and Acacia dealbata, and two native species, Cryptocarya alba and Quillaja saponaria, were studied. Flammability assays indicate that E. globulus, A. dealbata, and C. alba are extremely flammable, whereas P. radiata and Q. saponaria are flammable. Furthermore, E. globulus and A. dealbata have the highest heating values while Q. saponaria has the lowest values. The extreme flammability of E. globulus, A. dealbata, and C. alba indicates a high susceptibility to ignite. Furthermore, the high heat of combustion of E. globulus and A. dealbata can be associated with a high energy release, increasing the risk of fires spreading. In contrast, Q. saponaria has the lowest predisposition to ignite and capacity to release heat. Accordingly, this work shows that all studied tree species contain organic metabolites that are potentially flammable (sesquiterpenes, aliphatic hydrocarbons, alcohol esters, ketones, diterpenes, and triterpenes) and can be considered as drivers of flammability in vegetation. Finally, these preliminary results will aid in the construction of more resilient landscapes in the near future.

Lupane-type triterpenoids from Acacia dealbata bark extracted by different methods

The management of invasive species generates large amounts of biomass which end up in low value applications. However, these residues can potentially contain compounds with important bioactive properties. In this study the bark of Acacia dealbata Link (Fabaceae) was extracted by different methods targeting triterpenoids content and bulk product. Batch solid-liquid extraction (SLE-batch), Soxhlet extraction (n-hexane, dichloromethane, ethyl acetate and ethanol) and supercritical fluid extraction (SFE) (CO2 with/without ethanol or ethyl acetate) were performed under different pressure and/or temperature conditions in order to assess total extraction yield (ηTotal), extract concentrations and yields of lupenyl acetate and lupenone. The extracts composition was analysed by gas chromatography coupled to mass spectroscopy. Summarily: (i) the highest values of ηTotal were achieved with ethanol by both Soxhlet and SLE-batch, and by SFE at 300 bar, 80 ⁰C with 5 wt.% ethanol; (ii) the highest concentrations of triterpenoids were obtained with n-hexane by Soxhlet and SLE-batch and, and by SFE at 200 bar, 40 °C with 5 wt.% ethyl acetate; (iii) the maximum individual yields were achieved with ethanol by both Soxhlet and SLE-batch, and by SFE at 200 bar, 40 °C with 5 wt.% ethyl acetate. The solubilities of lupenyl acetate, lupenone, tetracosanoic acid and hexacosan-1-ol in the various solvents were theoretically estimated, providing important insights for the interpretation of the experimental results.

Carbon Sequestration Potential of Forest Invasive Species: A Case Study with Acacia dealbata Link

Biological invasions are of complex solution, consuming resources for their control and eradication. However, in many of the documented processes that are available, this is an attempt with no solution in sight. The possibility of increasing the pressure over these species while creating value chains has been presented as a method for ensuring the sustainability of their control and eradication processes. In the case of invasive forest species in Portugal, such as Acacia dealbata Link, this control is becoming increasingly important. In addition to the negative impacts on biodiversity, the proliferation of this species has economic implications due to its competition with forest production species such as Pinus pinaster Aiton and Eucalyptus globulus Labill. Another critical aspect to be considered is the increase of the risk of rural fires, which is enhanced by the accumulation of low-value biomass around production forests. In this work, the possibility of using this species as a vehicle for the capture and sequestration of carbon in the medium and long-term was evaluated from a perspective of providing ecosystem services as a measure to mitigate climate change. However, due to its highly heliophilous character, it was found that the growth capacity of this species is rapidly conditioned by the position of each tree within a stand, not being able to maintain that capacity in the medium and long term.