Biology subjects

Ottaviani, G.

Publications and source records attributed to Ottaviani, G..

5 recordsLinked to original sources

bioRxiv2026

ASSESSING POST-FIRE VEGETATION TRAJECTORIES USING MACHINE LEARNING AND REMOTE SENSING: EVIDENCE FROM A MEDITERRANEAN SITE

Fire has acted as a major eco-evolutionary force since the evolutionary appearance of plants, shaping plant-traits, diversity, vegetation assembly, and ecosystem functioning. Its ecological role depends on long-term fire regimes. Anthropogenic land-use change and climate warming are disrupting these regimes, particularly in densely populated regions such as the Mediterranean Basin. In the Italian peninsula (Mediterranean region) fire activity peaks during the dry summer months and is projected to intensify under climate change scenarios. Recent methodological developments - based on emerging satellite data, ground-based observations combined with Random Forest (RF) habitat classification, and spectral indices such as the NDVI provide a robust framework for monitoring post-fire land-cover dynamics over time. In this study, we applied RF modelling to classify vegetation cover using a 2017-2024 satellite imagery time series of the Monte Pisano area (central Italy) to assess pre- and post-fire vegetation trajectories. Evergreen shrubs and trees exhibited rapid post-fire regrowth, whereas coniferous stands showed slower recovery rates. NDVI trends revealed an expected sharp decline immediately after the fire, followed by gradual recovery of broadleaf forests and shrubland communities. Moreover, our results indicated a progressive increase in the cover of native deciduous and evergreen species of high conservation value (listed under the Habitat Directive). The framework delivers spatially explicit insights into post-fire recovery, supporting targeted management, restoration under European Nature Restoration Regulation, and long-term monitoring in Mediterranean ecosystems. Incorporating fine-scale environmental variables may further improve classification accuracy and enhance assessments of vegetation resilience and ecosystem recovery following fire events. HighlightsO_LIRecurring fires strongly affect ecosystem structure and function in Mediterranean landscapes. C_LIO_LIIntegrating remote sensing with Random Forest models enables effective monitoring of post-fire vegetation recovery over time. C_LIO_LINDVI time series provide reliable proxies for tracking vegetation vigor and land-cover change. C_LIO_LIPost-fire recovery trajectories are shaped by fire severity, vegetation physiognomy, plant functional types, and soil conditions. C_LIO_LITargeted restoration and management interventions informed by spatial-temporal vegetation patterns are urgently needed. C_LIO_LIThe proposed framework aligns with objectives of the EU Nature Restoration Regulation for ecosystem and habitat recovery. C_LI

ecology↗

bioRxiv2023

On the quest for novelty in ecology

The volume of scientific publications continues to grow, making it increasingly challenging for scholars to publish papers that capture readers attention. While making a truly significant discovery is one way to attract readership, another approach may involve tweaking the language to overemphasize the novelty of results. Using a dataset of 52,236 paper abstracts published between 1997 and 2017 in 17 ecological journals, we found that the relative frequency of novelty terms (e.g. groundbreaking, innovative) nearly doubled over time. All journals but one exhibited a positive trend in the use of novelty terms during the studied period. Conversely, we found no such trend for confirmatory terms (e.g. confirm, replicated). Importantly, only papers using novelty terms were associated with significantly higher citation counts and were more often published in journals with a higher impact factor. While increasing research opportunities are surely driving advances in ecology, the writing style of authors and the publishing habits of journals may better reflect the inherently confirmatory nature of ecological research. We call for an open discussion among researchers about the potential reasons and implications of this language-use and scientometrics issue.

ecology↗

bioRxiv2021

Sticking around: plant persistence strategies on edaphic islands

O_LISpecies extinction risk at local scales can be partially offset by strategies promoting in-situ persistence. We explored how persistence-related traits of clonal and non-clonal plants in temperate dry grasslands respond intra- and interspecifically to variation in environmental conditions (soil, climate) and insularity. C_LIO_LIWe focused on edaphic island specialist species, hypothesizing that plants experiencing harsh soil environments and strong insularity are distinguished by traits supporting enhanced persistence, such as small stature, long lifespan and resource-conservative strategies. We used linear mixed-effect models and bivariate ordinary least squares linear models to explore the response of species triats to environmental and biogeographic predictors. C_LIO_LIWe found general support for this hypothesis. Soil properties and insularity emerged as the most important drivers of trait patterns. However, clonal species showed more consistent responses to variation in environmental conditions and insularity than non-clonal plants, which were characterized by distinct species-specific responses. C_LIO_LISoil properties and insularity confirmed their major role in shaping the persistence strategies of edaphic island plant species. These drivers may exert their effect on specific functions (e.g. belowground resource conservation captured by BDMC). Additionally, we unambiguously identified that clonal species had different persistence strategies than non-clonal ones. C_LI

ecology↗

bioRxiv2021

Insularity forcing on plant persistence strategies in edaphic island systems

AimTrait-based approaches are increasingly implemented in island biogeography, providing key insights into the eco-evolutionary dynamics of insular systems. However, what determines persistence of plant species once they have arrived and established in an island remains largely unexplored. Here, we examined links between non-acquisitive persistence strategies and insularity across three terrestrial edaphic island systems, hypothesising that insularity promotes strategies for local persistence. LocationEurope: Western Carpathians, Moravia, and Cantabrian Range. Time periodPresent. Major taxa studiedVascular plants. MethodsFor each system, we used linear models at the island scale to test whether persistence-related plant trait patterns (average trait values and diversity) depend on three insularity metrics (island size, isolation and target effect). We focused on patterns of edaphic island specialists because, in contrast to matrix-derived species, their presence is confined to the edaphic islands. ResultsWe found that insularity metrics explained large proportions in the variation of the average and diversity of persistence-related traits of edaphic island specialists. Insularity was associated with a decline in the proportion of island specialists that have clonal abilities, yet it affected trait values of specialists towards enhanced abilities to persist locally (e.g. more extensive lateral spread) while reducing trait variability. Higher degrees of insularity within the systems were translated to stronger effects on functional trait patterns. Main conclusionsInsularity affects plant species diversity, distribution and forms in terrestrial island-like systems, similarly as it is assumed for true islands. Insularity - measured using a single (island size, isolation) or combined (target effect) predictors - may operate selecting for enhanced and less diverse persistence strategies. Ultimately, this process, which we call insularity forcing, operates as a selective process to promote species ability to avoid local extinction and to persist on terrestrial islands.

ecology↗

bioRxiv2021

Climate fluctuations drive the recruitment and growth of temperate grassland plants

Recent climate warming is associated with the increasing magnitude and frequency of extreme events, including heatwaves and drought periods worldwide. Such events can have major effects on the species composition of plant communities, hence on biodiversity and ecosystem functioning. Here we studied responses of Central European dry grassland plants to fluctuating temperature and precipitation over the last thirty years with monthly temporal resolution. We assessed the seasonal and annual dynamics of plant recruitment and growth based on the analysis of annual growth rings from the root collar. Although most studies so far applied such methods to trees and shrubs, we focused on typical grassland plants, two forbs and two chamaephytes. We related the recruitment and annual growth to monthly and annual precipitation, temperature and aridity between 1991 and 2019. We revealed species-specific responses, namely the (i) recruitment of deep-rooted, heavy-seeded species was positively affected by precipitation in both late winter-early spring and summer, whereas recruitment of shallow-rooted, light-seeded species was weakly influenced by climate fluctuations; (ii) growth of shallow-rooted species was more adversely affected by high summer temperature and drought than the growth of deep-rooted species. The population age structure of all the studied species was affected by the climate of the past decades. Most individuals established in the wet period of the 2000s, fewer in the precipitation-poorer 1990s, and the establishment was considerably reduced in the dry and warm period of the 2010s. Our findings indicate that the change towards warmer and drier climate has a profound effect even on drought-adapted ecosystems such as temperate dry grasslands. However, plant responses to various climatic extremes are species-specific, depending on their characteristics, such as life form or rooting depth. Consequently, the ongoing and anticipated climate warming will likely result in complex changes in species composition and other ecosystem properties of temperate grasslands

ecology↗