Biology subjects

Colom, P.

Publications and source records attributed to Colom, P..

3 recordsLinked to original sources

bioRxiv2025

The interplay of climate change, urbanization, and species traits shapes European butterfly population trends

Species populations naturally fluctuate, yet long-term trend analysis can reveal patterns of success, decline, or stability under global change pressures. While responses to climate change are well-documented, its synergy with another major global driver, urbanization, remains understudied. Here, we analyzed long-term monitoring data from over 8,400 populations of 145 butterfly species across Europe, representing a high diversity of species traits, to assess population trends in response to climate change and urbanization. We examined how population responses vary between urban and rural contexts, providing insights into the influence of site-specific conditions. Climate warming was associated with population declines, which were more pronounced in urban areas. The effect of precipitation varied between environments: increases in precipitation generally benefited populations in rural areas but had detrimental effects in urban ones. Aridity consistently drove population declines across environments, with slightly stronger effects in urban areas. Species with colder climatic niches declined the most in response to warming, increased aridity, and reduced precipitation, while trophic specialists were particularly vulnerable to aridity and precipitation changes in urban environments. Although increasing urbanization did not explain overall population trends, its effects became evident when considering species traits, with certain traits being more vulnerable to urbanization. Specifically, species with narrow climatic niches declined the most in response to urbanization in rural areas, while those and larger body sizes decline the most in urban environments. Our findings highlight the complex interplay between environmental change, landscape context, and species traits in shaping biodiversity outcomes. Importantly, our results suggest that urbanization generally amplifies the impact of climate change on insect population trends.

ecology↗

bioRxiv2022

Spatial variation in relative abundances of two butterfly species sharing both host plant and natural enemies

The decline of insect populations is of great concern because they play an essential part in several services that are key for ecosystem functioning and human well-being. Therefore, full understanding of the processes and factors shaping spatial variation in insects is required for their effective conservation. Here, we study a system comprising two congeneric butterfly species (Brimstone Gonepteryx rhamni and Cleopatra G. cleopatra) that share both host plants and natural enemies and analyse whether biotic and/or abiotic factors explain their relative abundances. The two species coexist in continental Spain but not on a nearby archipelago, where only the Cleopatra occurs. The hypotheses tested were based on (H1) dispersal behaviour; (H2) apparent competition mediated via shared parasitoids; and (H3) environmental conditions (overwintering habitat availability, abundance of host plants and temperature). H1 explained differences in Brimstone abundance between climate regions on the mainland since in warmer summers populations increased in cooler areas but decreased in warmer areas. Cleopatra did not show the same pattern but was found to have twice the number of summer adults on one island than on the mainland. It is unlikely that H2 can explain this result because, although richer parasitoid communities were found on the mainland, larval mortality rates were similar. H3 was important in explaining variation in abundances between sites within each climate region even though similar environmental conditions were found on the mainland and on the islands. Our study demonstrates the complexity of any attempt to understand insect population dynamics in space due to the number of factors that are potentially involved. We argue thus that a more comprehensive approach taking into account landscape topography and resource connectivity on a broader scale is required to unravel the factors shaping the relative abundance of insects in island systems.

ecology↗

bioRxiv2020

Spatio-temporal responses of butterflies to global warming on a Mediterranean island over two decades

In recent decades, efforts have been made to understand how global warming affects biodiversity and in this regard butterflies have emerged as a model group. The most conspicuous sign that warming is affecting the ecology of butterflies are the phenological advances occurring in many species. Moreover, rising temperatures are having a notable impact - both negative and positive - on population abundances. To date, patterns have generally been analysed at species level without taking into account possible differences between populations, which, when they are noted, are mostly attributed to large-scale climate differences across a latitudinal gradient. In this work, we use a long-term database of butterflies from the island of Menorca (Balearic Islands, Spain) to investigate how phenology and population dynamics have been affected by climate warming during the past two decades. In addition, we assess how responses are modulated by habitat characteristics and by species biological cycles. Our results show that species respond differently to warming at a local scale depending on season and habitat, and that coastal habitats in the Mediterranean region are particularly sensitive to the effects of climate change. Furthermore, our findings suggest that the effects of temperature could be partially offset in more inland habitats such as forests and deep ravines. The positive effect of temperature on ravine populations during the summer suggests that butterflies disperse across habitats as a response to rising temperatures during the season. This type of dispersal behaviour as a response to warming could be especially important in island ecosystems where the possibilities of modifying altitudinal or latitudinal distributions are often severely limited.

ecology↗