Juan P. González-Varo

Juan P. González-Varo
Universidad de Cádiz | UCA · Department of Biology

Dr.

About

60
Publications
25,438
Reads
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2,204
Citations
Introduction
I am broadly interested in the effects of anthropogenic landscape changes on biodiversity. Specifically, I attempt to understand: (1) how habitat fragmentation affects the demographic and genetic processes of plant populations (2) how landscape composition shapes the outcome of plant-animal interactions such as pollination, frugivory and seed dispersal
Additional affiliations
March 2019 - January 2020
University of Oviedo
Position
  • Researcher
March 2018 - September 2018
Mediterranean Institute for Advanced Studies (IMEDEA)
Position
  • PostDoc Position
December 2015 - December 2017
University of Cambridge
Position
  • Fellow

Publications

Publications (60)
Article
Full-text available
1. Assessing dispersal events in plants faces important challenges and limitations. A methodological issue that limits advances in our understanding of seed dissemination by frugivorous animals is identifying ‘which species dispersed the seeds’. This is essential for assessing how multiple frugivore species contribute distinctly to critical dispers...
Article
Forbidden links are defined as pairwise interactions that are prevented by the biological traits of the species. We focus here on the neglected importance of intraspecific trait variation in the forbidden link concept. We show how intraspecific trait variability at different spatiotemporal scales, and through ontogeny, reduces the expected prevalen...
Article
Full-text available
Plants are shifting their ranges towards higher elevations in response to global warming, yet such shifts are occurring at a rate slower than is needed to keep pace with a rapidly changing climate. There is, however, an almost complete lack of knowledge on seed dispersal across altitude, a key process to understand what constrains climate-driven ra...
Article
Full-text available
Seed dispersal constitutes a pivotal process in an increasingly fragmented world, promoting population connectivity, colonization and range shifts in plants. Unveiling how multiple frugivore species disperse seeds through fragmented landscapes, operating as mobile links, has remained elusive owing to methodological constraints for monitoring seed d...
Article
Full-text available
Climate change is forcing the redistribution of life on Earth at an unprecedented velocity1,2. Migratory birds are thought to help plants to track climate change through long-distance seed dispersal3,4. However, seeds may be consistently dispersed towards cooler or warmer latitudes depending on whether the fruiting period of a plant species coincid...
Article
Avian seed dispersers are mostly identified by direct observations of fruit consumption or by analysis of seeds ejected by mist-netted birds. However, these methods typically require many fieldwork days to provide initial insight into which bird species disperse the seeds of a plant species or community of interest. Here, we highlight the advantage...
Article
Research on seed-dispersal mutualisms has been highly unbalanced towards the plants, largely overlooking the fitness effects of fruit resources on frugivorous animals. Moreover, despite morphological mismatches like gape limitation may reduce the abundance of fruits that are actually accessible to a frugivore species, there is very little evidence...
Article
Full-text available
Background and aims – Agricultural intensification and loss of farmland heterogeneity have contributed to population declines of wild bees and other pollinators, which may have caused subsequent declines in insect-pollinated wild plants. Material and methods – Using data from 37 studies on 22 pollinator-dependent wild plant species across Europe, w...
Article
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Agri‐Environmental Schemes (AES) have been proposed to mitigate the impact of agriculture on both taxonomic and functional biodiversity. However, a better knowledge of the mechanisms involved in the loss of agrobiodiversity is needed to implement efficient AES. An unbalanced effort on research towards arable lands compared to permanent crops, and o...
Article
Juvenile animals generally disperse from their birthplace to their future breeding territories. In fragmented landscapes, habitat-specialist species must disperse through the anthropogenic matrix where remnant habitats are embedded. Here, we test the hypothesis that dispersing juvenile frugivores leave a footprint in the form of seed deposition thr...
Article
Full-text available
Indirect interactions among plant species mediated by frugivorous animals can be central to population and community dynamics, since the successful seed dispersal of species may depend on facilitative or competitive interactions with heterospecific plants. Yet, empirical evidence on these interactions is very scarce and mostly available at small sp...
Article
In recent decades, there has been a remarkable expansion of pollinator-dependent crops. An increase in the use of commercial pollinator colonies associated with these crops may promote the spillover of managed pollinators into nearby natural habitats. There, these managed pollinators can exploit floral resources similar to those of wild pollinators...
Article
Full-text available
The seed dispersal effectiveness framework allows assessing mutualistic services from frugivorous animals in terms of quantity and quality. Quantity accounts for the number of seeds dispersed and quality for the probability of recruitment of dispersed seeds. Research on this topic has largely focused on the spatial patterns of seed deposition becau...
Article
Full-text available
Conservation policy decisions can suffer from a lack of evidence, hindering effective decision‐making. In nature conservation, studies investigating why policy is often not evidence‐informed have tended to focus on Western democracies, with relatively small samples. To understand global variation and challenges better, we established a global surve...
Article
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1.There is growing interest in understanding the functional outcomes of species interactions in ecological networks. For many mutualistic networks, including pollination and seed dispersal networks, interactions are generally sampled by recording animal foraging visits to plants. However, these visits may not reflect actual pollination or seed disp...
Article
Full-text available
1. There is growing interest in understanding the functional outcomes of species interactions in ecological networks. For many mutualistic networks, including pollination and seed dispersal networks, interactions are generally sampled by recording animal foraging visits to plants. However, these visits may not reflect actual pollination or seed dis...
Data
FIGURE S1 Flow diagram illustrating the survey methodology FIGURE S2 Ranking of barriers by role according to Human Development Index FIGURE S3 Proportion of different roles (Red: Policy position, Yellow: practitioners, Blue: Policy position) experiencing the barriers FIGURE S4 Proportion of male and female respondents to the online survey by ro...
Article
During the past decades, managed honeybee stocks have increased globally. Managed honeybees are particularly used within mass-flowering crops and often spill over to adjacent natural habitats after crop blooming. Here, we uniquely show the simultaneous impact that honeybee spillover has on wild plant and animal communities in flower-rich woodlands...
Article
Mass-flowering crops (MFCs) and beekeeping are increasing across agroecosystems globally. Managed honeybees could spillover after the blooming of MFCs into nearby natural habitats, especially if hive numbers are associated with the cover of MFCs at the landscape scale. Nevertheless, this phenomenon has been largely overlooked despite the potential...
Article
Mass-flowering crops lead to spatial redistributions of pollinators and to transient shortages within nearby semi-natural grasslands, but the impacts on plant-pollinator interactions remain largely unexplored. Here, we characterised which pollinator species are attracted by oilseed rape and how this affected the structure of plant-pollinator networ...
Article
Full-text available
While it is recognized that language can pose a barrier to the transfer of scientific knowledge, the convergence on English as the global language of science may suggest that this problem has been resolved. However, our survey searching Google Scholar in 16 languages revealed that 35.6% of 75,513 scientific documents on biodiversity conservation pu...
Article
Mass-flowering crops (MFCs) are increasingly cultivated and might influence pollinator communities in MFC fields and nearby semi-natural habitats (SNHs). Across six European regions and 2 years, we assessed how landscape-scale cover of MFCs affected pollinator densities in 408 MFC fields and adjacent SNHs. In MFC fields, densities of bumblebees, so...
Article
Full-text available
Extreme specialization is a common phenomenon in antagonistic biotic interactions but it is quite rare in mutualistic ones. Indeed, bee specialization on a single flower species (monolecty) is a questioned fact. Here, we provide multiple lines of evidence on true monolecty in a solitary bee (Flavipanurgus venustus, Andrenidae), which is consistent...
Article
Forbidden links are defined as pairwise interactions that are prevented by the biological traits of the species. We focus here on the neglected importance of intraspecific trait variation in the forbidden link concept. We show how intraspecific trait variability at different spatiotemporal scales, and through ontogeny, reduces the expected prevalen...
Article
Full-text available
Muchas especies de mamíferos carnívoros (Orden Carnivora) consumen frutos carnosos, transportan semillas en sus tractos digestivos y las defecansin dañarlas en condiciones apropiadas para la germinación. En este artículo, revisamos el conocimiento adquirido sobre este mutualismo en lasúltimas tres décadas, desde que tres trabajos pioneros revelaron...
Article
Little is currently known about the dynamics of mutualistic interactions in relation to land abandonment. Using data from two studies on frugivory and seed dispersal by carnivorous mammals carried out at the same site, and spanning three decades, we show how plant-frugivore interactions change in the long-term after a process of land abandonment in...
Article
Full-text available
1. Environmental stochasticity and low demographic rates may cause delayed extinctions of habitat-specialist species that were initially retained within remnant patches after habitat loss and fragmentation. Detecting such extinction debts opens opportunities to counteract future biodiversity loss, yet knowing the underlying causes of population dec...
Book
Full-text available
Natural Capital, and the ecosystem services derived from it, are essential to human well-be- ing and economic prosperity. Indeed, nature inspires and provides many solutions that can help us tackle some of the most pressing challenges of our time. For example, pollinators matter because a majority of European crops depend or benet from insect po...
Article
Full-text available
Pollination is an essential process in the sexual reproduction of seed plants and a key ecosystem service to human welfare. Animal pollinators decline as a consequence of five major global change pressures: climate change, landscape alteration, agricultural intensification, non-native species, and spread of pathogens. These pressures, which differ...
Article
Full-text available
Knowledge of the spatial scale of the dispersal service provided by important seed dispersers (i.e. common and/or keystone species) is essential to our understanding of their role on plant ecology, ecosystem functioning and, ultimately, biodiversity conservation. Carnivores are the main mammalian frugivores and seed dispersers in temperate climate...
Article
Full-text available
The loss or decline of vertebrate frugivores can limit the regeneration of plants that depend on them. However, empirical evidence is showing that this is still very scarce, as functionally equivalent species may contribute to maintain the mutualistic interaction. Here, we investigated the long-term consequences of the extinction of frugivorous liz...
Article
Full-text available
The mechanisms underlying heterozygosity-fitness correlations (HFCs) are subject of intense debates, especially about how important population features such as size or degree of isolation influence HFCs. Here, we report variation in HFCs between Large and Small populations of a self-compatible shrub (Myrtus communis) occurring within an extremely f...
Article
Full-text available
Habitat fragmentation may lead to declines in plant populations and ultimately to extinction through a disruption of demographic processes, which may result in bottlenecks or even a collapse in regeneration. Nevertheless, very few studies have assessed the net effects of habitat fragmentation on plant recruitment integrating its multiple demographi...
Article
Full-text available
Knowledge about how frugivory and seed deposition are spatially distributed is valuable to understand the role of dispersers on the structure and dynamics of plant populations. This may be particularly important within anthropogenic areas, where either the patchy distribution of wild plants or the presence of cultivated fleshy-fruits may influence...
Article
Full-text available
1. The long-term persistence of fragmented plant populations is predicted to be threatened by a loss of genetic variability and increasing inbreeding, which might lower offspring fitness through inbreeding depression. Assessing plant progeny performance together with measurements of genetic diversity and mating patterns is therefore essential in th...
Article
Full-text available
Variation in inbreeding depression (δ) among individual plants is considered to play a central role in mating system evolution and population genetics. Moreover, such variation could be linked to individual susceptibility to pollen limitation (PL) because those individuals strongly affected by δ for seed production will require more outcross pollen...
Article
Full-text available
The development of microsatellite markers was conducted in the Mediterranean common shrub Myrtus communis (myrtle) to assess levels of genetic diversity and patterns of gene flow across fragmented landscapes in southern Spain. Fourteen primer pairs were isolated showing clear and consistent patterns of amplification, three of which were apparently...
Article
Full-text available
Human-induced fragmentation and disturbance of natural habitats can shift abundance and composition of frugivore assemblages, which may alter patterns of frugivory and seed dispersal. However, despite their relevance to the functioning of ecosystems, plant-frugivore interactions in fragmented areas have been to date poorly studied. I investigated s...
Article
Ancient managed landscapes provide ideal opportunities to assess the consequences of habitat fragmentation on the patterns of genetic diversity and gene flow in long-lived plant species. Using amplified fragment length polymorphism (AFLP) and allozyme markers, we quantified seed-mediated gene flow and population genetic diversity and structure in 1...
Article
Full-text available
Pollinator assemblages may shift as a consequence of the destruction and fragmentation of natural hab-itats. The scarcity of mates and pollinators can lead plant populations to suffer from pollen limitation and a decrease in reproductive performance within fragmented areas. We studied the shift in pollinator assemblages along with pollen limitation...
Article
Full-text available
Throughout most of the north-west Iberian Peninsula, chestnut (Castanea sativa) woods are the principal deciduous woodland, reflecting historical and ongoing exploitation of indigenous forests. These are traditionally managed woodlands with a patchy distribution. Eurasian nuthatches (Sitta europaea) inhabit mature deciduous woods, show high site fi...
Article
Full-text available
Mate abundance is one of the most important sources of variation in plant mating systems. We examined within-population heterogeneity in the pollen pool at two spatial scales (sites and plants), and investigated the mating pattern variation in Myrtuscommunis under diverse situations of conspecific neighbourhood, using allozyme electrophoresis of na...
Article
Full-text available
Here we document long-term changes (1977-2004) occurred in the bird assemblages of two woodland patches in relation to the pattern of change in land use and bird populations at the landscape level. The patches selected are representative of the main forest ecosystems in the area: mixed deciduous and chestnut woodland. The study was conducted in Cau...

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Projects

Projects (2)
Project
This project aims at filling the knowledge gap on the fitness consequences of plant-frugivore mutualisms for the animal partners (resource provisioning). We will test whether local fruit abundance affects the body condition of frugivore populations, focusing on a resident passerine as study species (the Sardinian Warbler Sylvia melanocephala). We are working in Mediterranean forest patches of the Guadalquivir Valley, where the abundance of fleshy fruits in the understorey vary hugely among patches due to differences in local management and successional stage.
Project
Our central objective is to understand how plants move, and to assess the mechanisms and consequences of animal-mediated plant dispersal under global change scenarios. By using juniper woodland stands in Doñana National Park, we address three main themes within this framework: We first characterize the diversified patterns of interactions with animal frugivores to assess key functional roles of animal vectors, i.e., long- distance dispersal (LDD) and heterogeneous contributions to the seed shadows. Our second step will be to analyze how such interactions translate into actual dispersal of plant seeds in complex landscapes, i.e., how landscape attributes such as fragmentation affect the functional role of vectors and thus influence dispersal events and their outcomes in terms of genetic structuring of the seed shadow and recruitment. Finally, we examine how the interactions with animal vectors and then the movement of vectors in heterogeneous landscapes may ultimately determine how plants move and relate to other conspecifics through spacing patterns of recruitment (aggregation, genetic neighborhood) that ultimately convey range shifts.