## 1 Introduction  
Invasive alien species and non-native species represent a serious risk to the biodiversity of an area. One of the most significant affectations of natural ecosystems is biological invasion, which represents a threat to biodiversity conservation [1]. Due to globalization and the expansion-annexation of territories, the presence of non-native species has become increasingly common [2]. The presence of non-native riparian species is a growing problem that modifies and disturbs native forests, causing major problems for both flora and fauna. These situations must be controlled by applying management programs, which often include burning that would also damage native species in the surrounding area and is not considered an environmentally friendly solution. Other management alternatives produce bio waste by cutting and cleaning fields, which are often neglected as a valuable resource [2]. For these reasons, knowing the potential application of vegetable waste, we oriented our research towards an opportunity for a sustainable alternative to by-products derived from non-native species processing. This study was focused on the Umia riparian vegetation in Galicia, an area in which the restoration and respect of its biodiversity is being promoted. Derived from the ecosystem management decisions of the council area, there are several unused residues generated from the extraction of three of the non-native species. This waste has been used for the extraction and analysis of bio-compounds of each species, which could be used in the arts as pigments or colorants, as well as in food or pharmaceutical industries, due to the high concentration of antioxidants present in the extractions [2; 3; 4] (Figure 1). The selected species for this study were _Eucalyptus globulus_, _Tradescantia funniensis_, and _Arundo donax_, some of which are considered to have the most fast-spreading capacities in Mediterranean and humid ecosystems such as the Galician river forest [1]. _Eucalyptus globulus_: The genus _Eucalyptus_, part of the Myrtaceae family, consists of more than 900 species and subspecies of trees and shrubs [5]. Due to its characteristics, the _Eucalyptus_ genus has high resistance to fire, drought, and soil acidity which, combined with its fast growing capacities, makes it an important source of resources. The main subspecies of _Eucalyptusytus_ are: _globulus_, _maidenii_, _bisocotta_, and _pseudo globulus_. They all originate from Tasmania and Australia. _Eucalyptus globulus_ expanded throughout the world, especially  
Figure 1: Extraction methods and selected species used in the present study. in Mediterranean, subtropical, and tropical climate areas where its development was thriving, between 1800 and 1850 [6], although the first Eucalyptus planted in Europe was in 1774 at Kew Botanic Gardens [7]. According to the catalog of the exotic flora of Galicia by [PERSON] [8], the species was first recorded in 1955 for cultivation and was recognized as invasive. Nowadays, this situation has changed; currently it is not catalogued as an invasive species in Spain, but as a non-native species. Despite the popular belief that _Eucalyptus globulus_ was introduced into Galicia by [PERSON], it is known that it was introduced around 1850 in a plantation in Santa Marta de Ortigueira, according to [PERSON] and [PERSON] (2016) [7]. In Australia, Eucalyptus occupies 95% of the wooded areas and in Spain between 1973 and 1995 the area occupied by this species increased from 390,277 to 460,000 ha. In 2019, according to the study 'Eucalyptus in Galicia: relevant environmental and socioeconomic aspects' published by COSE (Confederation of Forestry Organizations of Spain), it comprised 20% of the wooded population of Galicia and accounted for 60% of the wooded destined for forestry falling. Eucalyptus bark has a rich chemical composition, but it is usually discarded when the wood is used for timber, paper, or charcoal.