http://hdl.handle.net/10256/16375 Tue, 01 Jul 2025 19:51:43 GMT 2025-07-01T19:51:43Z http://hdl.handle.net/10256/26675 Caracterització poblacional de la tortuga de rierol al riu Orlina : perspectives de futur Vilaseca Iglesias, Jaum The Mediterranean pond turtle (Mauremys leprosa) is one of the two freshwater turtles of the Iberian Peninsula, also distributed in North Africa and southern France. In the past, its populations suffered a sharp decline due to human impact, including habitat fragmentation and loss, capture, and indiscriminate trade. Currently protected by law in Spain, it is considered a vulnerable species, although expanding in Catalonia. However, threats persist, and with climate change, its future remains uncertain. This study analyses the conservation status of M. leprosa in the Orlina River (Alt Empordà), characterizing the population based on size and sex structure, sex ratio, age classes proportions (juveniles/adults), biometrics, population size, and dynamics. Current data are compared with those from previous years: 2001, 2003, 2006, and 2008. The methodology used was Capture-Mark-Recapture (CMR) with custom-made traps. This allowed for the identification of sex, age class, and biometric measurements. Recapture data were entered into the MARK™ program along with data from previous years, enabling the estimation of population size and superpopulation for the period 2001-2024, as well as population dynamics through survival, capture probability, and recruitment parameters. The population structure was graphically compared across years and for the entire period using population pyramids by size and group (juveniles, males, and females). The sex ratio and juvenile-to-adult proportion were statistically tested using the chi-square test and Fisher’s exact test. Biometric data and population estimates were compared between years using ANOVA. The results show a well-structured but aging population, with larger adult individuals and fewer juveniles compared to other years. The sex ratio in 2024 is more skewed towards males tan the first decade of the 2000s. Population estimates indicate a slight decline over the study period, although not statistically significant. The conservation of aquatic ecosystems and connectivity between populations are key to the future survival of M. leprosa in Alt Empordà Sat, 01 Feb 2025 00:00:00 GMT http://hdl.handle.net/10256/26675 2025-02-01T00:00:00Z http://hdl.handle.net/10256/25898 Efectes de la intensitat de la llaurada sobre les propietats fisicoquímiques del sòl i el desenvolupament de diferents cultius Rossell Triado, Maria The most widespread models of conventional agriculture worldwide are based on achieving maximum production but have many deficiencies in terms of biodiversity conservation, soil health, etc. Moreover, these systems are fragile and unsustainable in the face of the current climate change situation. Agroecology is the science aimed at creating resilient and less polluting systems by understanding the functioning of natural systems. Soil health is often an overlooked parameter but is essential for achieving profitable crops. A soil with good health is characterized by good structure and a healthy microbial community, thus functioning as a living system capable of self-regulation. Tillage is a factor that can affect soil health. A study was conducted in Pallars Jussà comparing five crops that are not widely established in the region under three different tillage intensities (no tillage, medium intensity tillage, and high intensity tillage). The study includes two legume crops (Lens culinaris and Vicia faba), two cereal crops (Hordeum distichon L. and Triticum spelta), and one polyculture (Vicia sativa with Avena sativa), all managed ecologically. This study is particularly relevant in Pallars Jussà because this region has the potential to become self-sufficient and sustainable in response to climate change and population needs. The effects of tillage intensity on the soil's physicochemical properties in the short term and the response of the five crops to different tillage intensities were studied. The results show that tillage affects soil properties, making it more aerated and with greater water infiltration capacity. There is no clear trend regarding its effect on chemical properties, but it is observed that untilled soils have a more active microbial community in converting nutrients into forms usable by plants. Tillage also affects crop growth; plants in tilled soils grow more and experience less stress. However, there is no direct effect of tillage on the atmospheric nitrogen fixation of legumes. Nor does any plant species show increased productivity under a specific tillage regime Mon, 01 Jul 2024 00:00:00 GMT http://hdl.handle.net/10256/25898 2024-07-01T00:00:00Z http://hdl.handle.net/10256/25897 Implementació i pla de comunicació de la restauració d’un bosc de Gongolaria barbata a Port Lligat Puiggener Cases, Anna Mediterranean marine forests, dominated by species of the genera Cystoseira, Ericaria and Gongolaria, are crucial habitats, in terms of diversity, productivity and structural complexity, providing food and habitat for many species. These forests are suffering a generalized regression in recent years due to various threats related to anthropogenic activities, habitat destruction, overgrazing and environmental changes linked to climate change. In this context, the conservation of these habitats is essential for maintaining of ecosystem services. However, when conservation is not sufficient, non-invasive restorations play an important role in recovering the biodiversity and the functionality of these ecosystems. Active restoration actions require the participation of all societal actors, so making a long-term communication strategy is crucial for raising and gaining social support for these actions. In this work, the ex situ restoration of a Gongolaria barbata forest is carried out in the Cap de Creus Natural Park, specifically in Port Lligat. The initial success of the restoration is evaluated based on the period of restoration and the restored areas. An initial analysis of the social perception and the Marine Forests team’s stance towards scientific dissemination is also conducted, to create a communication plan for the project focused on conveying the importance of marine forests to a young audience. The results reveal that restoration is possible in the three areas of the zone, showing an important initial success, and that it is better to start these actions in winter, when the water temperature is lower. The need for long-term monitoring is emphasized to declare a successful restoration in the future, and to pay attention to growth progress during the summer. Finally, a realistic and coherent communication plan is proposed, aligning with the needs and capabilities of the Marine Forests team. The plan identifies the most direct actions and the formats most commonly used by the target audience are determined. It highlights the importance of using new dissemination channels, in addition to conventional ones, such as social media and, specifically, TikTok, an application with a high dissemination potential among young people Mon, 01 Jul 2024 00:00:00 GMT http://hdl.handle.net/10256/25897 2024-07-01T00:00:00Z http://hdl.handle.net/10256/25896 Avaluació dels efectes de la vespa asiàtica (Vespa velutina) en la biodiversitat Galvany Wirkus, Alek Biological invasions represent a significant contributor to global biodiversity loss. Their high dispersal capacity, competitiveness, and lack of predators have enabled them to displace and exterminate numerous native species. This study focuses on the yellow-legged hornet (Vespa velutina), an invasive species that has become established in Europe in recent decades. Among the effects described, the impact on honeybees stands out, as it hinders the survival of colonies in bee farms. Conversely, the effects on biodiversity are not as clear. In light of this, the present study aims to deepen our understanding of these effects by focusing on two lines of research. On the one hand, the behaviour of this species was studied in ivy (Hedera helix) populations, as flowering coincides with the peak activity of the yellow-legged hornet. This was achieved by several recounts of the individuals present in the populations and by recording the behaviour of the yellow-legged hornet in order to identify potential capture preferences and to provide a detailed account of the behaviour observed in these populations. On the other hand, the influx of the invasive species in different plant species was compared in order to identify potential preferences in resource searching. Finally, a bibliographical review of the impacts described to date, has compiled the current state of knowledge on the subject, thus facilitating its dissemination to local administrations. In relation to the results obtained on ivy populations, a positive relationship with the Calliphoridae family was demonstrated, which significantly describes the abundance of the invasive taxon. Furthermore, behavioural analysis showed that hunting is the main activity exerted by the hornet in ivy populations, although the recorded capture success is low. In terms of plant species selection, only Fatsia japonica and Eriobotrya japonica were visited by the yellow-legged hornet, indicating a clear preference over other species. Finally, the literature review revealed a more comprehensive understanding of the impacts on honey bees compared to the other impacts. While several studies have addressed the impact on biodiversity, the results remain inconclusive Mon, 01 Jul 2024 00:00:00 GMT http://hdl.handle.net/10256/25896 2024-07-01T00:00:00Z