Biology subjects

Chozas, S.

Publications and source records attributed to Chozas, S..

3 recordsLinked to original sources

bioRxiv2025

Fire shifts the structure and dynamics of woody plant communities in a mediterranean coastal dune ecosystem

Coastal dune ecosystems are dynamic and fragile environments shaped by complex interactions between vegetation and its characteristic abiotic factors. This study investigates the effects of the wildfire that affected the Donana Nacional Park (SW Spain) in 2017 on the composition and structure of woody plant communities in two adjacent Mediterranean coastal dune areas: one affected by fire (Cuesta Maneli) and one unburned (Laguna del Jaral). Using a combination of several analyses (such as non-metric multidimensional scaling (NMDS); Mantel tests; and co-occurrence analyses), we examined how fire influences species distribution, abundance, and their interactions along a coastal-inland gradient. Our results reveal that fire homogenizes woody plant community composition across the coastal-inland gradient, reducing spatial differentiation and increasing overall species abundance in the burned area. Soil characteristics influenced species composition significantly only in the unburned site, suggesting that fire disrupted abiotic filtering processes. Co-occurrence patterns indicate more neutral interactions in the burned area, consistent with reduced competition and increased resource availability post-disturbance. In contrast, the unburned site displayed structured communities with stronger negative co-occurrence at the smaller scales and spatial clustering of species. Spatial pattern analyses showed that positive co-occurrence was more prevalent in the burned area, particularly at smaller spatial scales, indicating potential facilitation effects during early post-fire recovery. These findings highlight how fire reshapes community structure and dynamics after succession. Understanding these processes is critical for effective conservation and management of Mediterranean coastal dune ecosystems facing increasing anthropogenic pressures and climate change-related disturbances.

ecology↗

bioRxiv2024

Aridity and coexistence with vascular plants determine the dynamics of coastal dune bryophyte communities

The bryophyte communities of Atlantic coastal dunes help stabilising these habitats by promoting nutrient fixation, contributing to soil consolidation and enhancing water retention. Because of climate change and sea level rise, negative impacts on this dune vegetation have already been recorded, including habitat loss, shifts in species distribution and the spread of invasive bryophyte species. Moreover, in this stressful environment, biotic interactions may play a key in shaping plant diversity at these scales. We characterised coastal dune vegetation in 32 sampling sites along a latitudinal aridity gradient across the western Iberian Atlantic. We aimed to assess the potential interactions among moss species and between mosses and vascular plants, and analyse their relationship with abiotic factors to explain the community dynamics of dune bryophytes, and forecast how these communities may respond to climate change. Our results showed that the moss community is mainly influenced by aridity and temperature, with biotic interactions playing a minor, yet significant, role. As aridity increases, moss cover in these dune environments will decrease, and interactions with other plants are unlikely to compensate for this decline, thus in a climate change scenario we expect a decrease in coastal bryophyte community as well as the ecosystem services they provide; simultaneously the spread of the alien moss species Campylopus introflexus, linked to lower aridity, may also slow down. Consequently, the changing climate will shift optimal conditions for moss species to higher latitudes, pushing competition further north

ecology↗

bioRxiv2024

Drivers of temporal bias in biodiversity recording by citizen scientists

O_LICitizen science data is increasingly important for ecological research, biodiversity conservation and monitoring. However, these data often suffer from biases due to uneven recording efforts by citizen scientists. Biases caused by intra-annual differences in recording activity can be particularly severe, hindering the use of citizen science data in research areas such as population dynamics and phenology. Therefore, understanding the factors driving recording activity is essential. C_LIO_LIIn this study, we provide a detailed assessment of how weather and calendar-related factors influence biodiversity recording activity by citizen scientists at a daily resolution. To perform this, we analyse the recording patterns for six tree species in the Iberian Peninsula, which maintain a fairly consistent appearance throughout the year. Observation data were collected from iNaturalist, a leading platform for citizen-science data. We used boosted regression trees (BRT) to compare observed recording activity patterns with those expected by chance. Our analysis included a comprehensive set of explanatory variables, such as day of the week, month, holidays, temperature, accumulated precipitation, wind intensity, and snow depth. C_LIO_LIThe BRT models effectively identified the drivers of recording activity, with the correlation between predicted and observed temporal patterns (left out of model training) ranging from 0.47 to 0.96, depending on the species. The day of the week, daily temperature, and month of the year consistently emerged as the main drivers. Recording activity was higher on weekends, to some extent on Fridays, and during the spring months. Extreme low and high temperatures generally correlated with lower recording activity, although there were exceptions. Wind speed and precipitation had a moderate influence, with higher wind intensity and accumulated precipitation leading to decreased activity. Holidays and accumulated snow had very minor relevance across species. C_LIO_LIOur findings show that citizen scientists record more frequently on weekends, during mild weather, and in spring. By addressing these biases, we can maximize the utility of citizen-collected data for research and applied purposes, ensuring robust and reliable conclusions that enhance ecological understanding and conservation efforts. C_LI

ecology↗