Ruben Heleno

University of Coimbra | UC · Centre for Functional Ecology - Science for People & the Planet

Owing to food scarcity and to the high densities that vertebrates often reach on islands, typical insect- and seed-eaters widen their feeding niche and interact with a greater fraction of species than their mainland counterparts. This phenomenon, coined here ‘interaction release’, has been previously reported for single species but never for an ent...

Aim Four long‐distance dispersal ( LDD ) modes have generally been considered to play central roles in the colonization of islands by plants: anemochory (dispersal by wind), thalassochory (dispersal by oceanic currents), endozoochory (internal dispersal by animals) and epizoochory (external dispersal by animals). However, seeds can also be transpor...

In recent years, the analysis of interaction networks has grown popular as a framework to explore ecological processes and the relationships between community structure and its functioning. The field has rapidly grown from its infancy to a vibrant youth, as reflected in the variety and quality of the discussions held at the first international symp...

Alien plants are a growing threat to the Galápagos unique biota. We evaluated the impact of alien plants on eight seed dispersal networks from two islands of the archipelago. Nearly 10 000 intact seeds from 58 species were recovered from the droppings of 18 bird and reptile dispersers. The most dispersed invaders were Lantana camara, Rubus niveus a...

Climate change is forcing species to shift their distribution ranges. Animal seed dispersers might be particularly important in assisting plants tracking suitable climates to higher elevations. However, this role is still poorly understood due to a lack of comprehensive multi‐guild datasets along elevational gradients. We compiled seed dispersal ne...

Understanding how biotic interactions shape ecosystems and impact their functioning, resilience and biodiversity has been a sustained research priority in ecology. Yet, traditional assessments of ecological complexity typically focus on species-species interactions that mediate a particular function (e.g., pollination), overlooking both the synergi...

Seed dispersal is crucial for ecosystem persistence, especially in fragmented landscapes, such as those common in Europe. Ongoing defaunation might compromise effective seed dispersal, but the conservation status of pairwise interactions remains unknown. With a literature review, we reconstructed the first European-wide seed dispersal network and e...

Coastal grasslands host diverse arthropod communities and provide important ecosystem services. Islands, being isolated environments, are expected to have simpler ecosystems than continental areas, with the few successful colonizing species often attaining high densities; however, these patterns are still poorly documented for coastal grassland art...

When non‐native species invade ecosystems, coevolved plant–animal interactions and associated ecological functions are altered, often to the detriment of local biodiversity. While mutualistic interactions can benefit from—and assist with—ecological restoration through the removal of non‐native species, community‐level changes in antagonistic intera...

Animals can adjust their diet to maximize energy or nutritional intake. For example, birds often target fruits that match their beak size because those fruits can be consumed more efficiently. We hypothesized that pressure to optimize diet—measured as matching between fruit and beak size—increases under stressful environments, such as those that de...

Natural native forests are rapidly being replaced by anthropogenic forests often with a strong presence of invasive alien plant species. Eucalypt species are widely planted worldwide, with Eucalyptus globulus plantations being particularly expressive in Portugal. Poor forestry practices often lead to the associated expansion of invasive species, su...

Species phenology - the timing of key life events - is being altered by ongoing climate changes with yet underappreciated consequences for ecosystem stability. While flowering is generally occurring earlier, we know much less about other key processes such as the time of fruit ripening, largely due to the lack of comprehensive long-term datasets. H...

Agriculture is vital for supporting human populations, but its intensification often leads to landscape homogenization and a decline in non-provisioning ecosystem services. Ecological intensification and multifunctional landscapes are suggested as nature-based alternatives to intensive agriculture, using ecological processes like natural pest regul...

We provide an overview of the current state of knowledge of island frugivory and seed dispersal and identify knowledge gaps that are important for fundamental research on—and applied conservation of—island ecosystems. We conducted a systematic literature search of frugivory and seed dispersal on islands, omitting large, continental islands. This re...

Estimation of the number of colonization events between islands of the same archipelago for a species. It uses rarefaction curves to control for both field and genetic sample sizes as it was described in Coello et al. (2022).

World forests face many threats, including wildfires, with tremendous ecological, social, and economic implications. Mediterranean ecosystems have evolved in the presence of fire, but changes to fire regimes associated with other global changes pose new challenges to postfire community regeneration. Forest regeneration largely depends on plant adap...

Uncovering the temporal and spatial dynamics of biological communities in response to biotic and abiotic drivers is essential to predict the effects of environmental change on biodiversity. Similarly, estimating species vulnerability in the face of such dynamics is crucial for implementing effective conservation actions. We explored how bat diversi...

Seed dispersal is a critical process in plant colonisation and demography. Fruits and seeds can be transported by several vectors (typically animals, wind and water), which may have exerted strong selective pressures on plant’s morphological traits. The set of traits that favour dispersal by a specific vector have been historically considered as se...

Understanding how biotic interactions affect ecosystem functioning has been a research priority in natural sciences due to their critical role in bolstering ecological resilience. Yet, traditional assessment of ecological complexity typically focus on species-species effective interactions that mediate a particular function (e.g. pollination or see...

Public health and environmental concerns are increasing the pressure to reduce chemical pesticide usage, thereby requiring management alternatives to control pest damage to crops. Retaining semi-natural habitats within agricultural landscapes is often assumed to be one such alternative, by contributing to boost natural enemy populations and reduce...

Ants are amongst the most successful invaders worldwide and can markedly modify invaded communities through biotic interactions. Invasive ants, for example, can compete with native pollinators for resources, act as legitimate pollinators, or disrupt plant-pollinator mutualistic interactions, thereby affecting native plant reproduction. Ecological r...

Social Impact Statement In the face of the unprecedented rate of climate change, understanding whether plant species can track favourable climatic conditions is an urgent challenge. Recent independent studies suggest that the timing of fruiting (fruiting phenology) can strongly affect future vegetation dynamics and composition via direct seed dispe...

Background and aims: The Canary Islands have strong floristic affinities with the Mediterranean Basin. One of the most characteristic and diverse vegetation belt of the archipelago is the thermophilous woodland (between 200 and 900 m.a.s.l.). This thermophilous plant community consists of many non-endemic species shared with the Mediterranean Flor...

Species interactions can propagate disturbances across space via direct and indirect effects, potentially connecting species at a global scale. However, ecological and biogeographic boundaries may mitigate this spread by demarcating the limits of ecological networks. We tested whether large-scale ecological boundaries (ecoregions and biomes) and hu...

The cover image is based on the paper "Seed dispersal by frugivores from forest remnants promotes the regeneration of adjacent invaded forests in an oceanic island" Costa et al. 2022 (https://doi.org/10.1111/rec.13654). Picture description: Seychelles Blue Pigeon (Alectroenas pulcherrima), one of the main endemic frugivorous birds on the island of...

Keystone species are disproportionately important for ecosystem functioning. While all species engage in multiple interaction types with other species, keystone species importance is often defined based on a single dimension of their Eltonian niche, that is, one type of interaction (e.g. keystone predator). It remains unclear whether the importance...

Bees are a diverse group with more than 1000 species known from the Iberian Peninsula. They have increasingly received special attention due to their important role as pollinators and providers of ecosystem services. In addition, various rapid human-induced environmental changes are leading to the decline of some of its populations. However, we kno...

Arthropod declines have been linked to agricultural intensification. However, information about the impacts of intensification is still limited for many crops, as is our understanding of the responses of different arthropod taxa and trophic groups, thus hindering the development of effective mitigation measures. We investigated the impacts of olive...

Understanding what drives non‐native species naturalization (the establishment of a self‐sustainable population outside its native range) is a central question in invasion science. Plant capacity for long‐distance dispersal (LDD) is likely to influence the spread and naturalization of non‐native species differently according to their introduction p...

Invasive non‐native species can alter animal‐mediated seed dispersal interactions and ultimately affect the stability of recipient communities. The degree of such disturbances, however, is highly variable and depends on several factors, two of which have received little attention: the relative timing of native and non‐native fruiting phenologies, a...

Agricultural policies in the European Union (EU) are increasingly promoting organic management and integrated pest management (IPM) as environmentally friendly alternatives to high-input conventional management. While there is consensus that organic management is largely beneficial for biodiversity, including the natural enemies of crop pests, IPM...

Aim Colonization is a central topic in ecology and one of the cornerstones of island biogeography. Although the evolutionary history of island species is widely studied, the quantification of colonization is particularly challenging because the same area may be colonized multiple times by the same species, whereas initially successful colonization...

Biological invasions are a major threat to global biodiversity with particularly deleteri-ous consequences on oceanic islands. The introduction of large terrestrial animals-generally absent on islands-can disrupt important ecosystem functions, such as the dispersal of native seeds. However, while the consequences of plant invasions received much at...

Forest remnants often act as refuges for native plant species within a degraded and highly fragmented forest matrix. Understanding whether these native patches can function as feeding grounds for frugivores and seed sources for native plant dispersal into the surrounding forest can provide critical information on ecosystem functions on a landscape...

Species interactions can propagate disturbances across space, though ecological and biogeographic boundaries may limit this spread. We tested whether large-scale ecological boundaries (ecoregions and biomes) and human disturbance gradients increase dissimilarity among ecological networks, while accounting for background spatial and elevational effe...

Classical biocontrol is key for the successful management of invasive alien plants; yet, it is still relatively new in Europe. Although post-release monitoring is essential to evaluate the effectiveness of a biocontrol agent, it is often neglected. This study reports the detailed post-release monitoring of the first biocontrol agent intentionally i...

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...

Significance Invasive alien species pose major threats to biodiversity and ecosystems. However, identifying drivers of invasion success has been challenging, in part because species can achieve invasiveness in different ways, each corresponding to different aspects of demographics and distribution. Employing a multidimensional perspective of invasi...

Aim Seed dispersal by oceanic currents (thalassochory) is considered one of the main long‐distance dispersal (LDD) mechanisms for the colonization of oceanic islands by plants. Diaspores of littoral species are often hypothesized to be physiologically adapted to seawater dispersal, favouring interisland colonization. In this study, we experimentall...

Las semillas pueden ser pequeñas e ignoradas por un observador casual, pero ejercen fuerzas poderosas. Regeneran ecosistemas enteros y soportan redes alimenticias complejas. Han sido refinados por la selección natural para incrementar la supervivencia de las plantas y la persistencia de sus genes en el espacio y en el tiempo (Cain et al., 2000). La...

Seeds may be small and overlooked by a casual observer, but they exert powerful forces. They regenerate whole ecosystems and support complex food webs. They have been refined by natural selection to increase the persistence of plants and their genes over time and space (Cain et al., 2000). Seeds do not act alone, but rather enlist abiotic forces or...

The importance of keystone species is often defined based on a single type of interaction (e.g., keystone predator). However, it remains unclear whether this functional importance extends across interaction types. We conducted a global meta-analysis of interaction networks to examine whether species functional importance in one niche dimension is m...

This book contains 23 chapters divided into seven parts. Part I reviews the key hypotheses in invasion ecology that invoke biotic interactions to explain aspects of plant invasion dynamics; and reviews models, theories and hypotheses on how invasion performance and impact of introduced species in recipient ecosystems can be conjectured according to...

Many vertebrate species act as both plant pollinators and seed-dispersers, thus interconnecting these processes, particularly on islands. Ecological multilayer networks are a powerful tool to explore interdependencies between processes; however, quantifying the links between species engaging in different types of interactions (i.e. inter-layer edge...

Biological communities are intrinsically dynamic, with species and interactions changing over time. However, the temporal dynamics of species interaction networks is usually assessed using independent ‘snapshot’ networks, which may provide an incomplete representation of ecological processes. The use of temporal multilayer networks, where networks...

All organisms are ultimately dependent on a large diversity of consumptive and non-consumptive interactions established with other organisms, forming an intricate web of interdependencies. In 1992, when 1700 concerned scientists issued the first “World Scientists' Warning to Humanity”, our understanding of such interaction networks was still in its...

This book contains 23 chapters divided into seven parts. Part I reviews the key hypotheses in invasion ecology that invoke biotic interactions to explain aspects of plant invasion dynamics; and reviews models, theories and hypotheses on how invasion performance and impact of introduced species in recipient ecosystems can be conjectured according to...

Plant galls sustain diverse and complex communities of gallers, parasitoids and inquilines that provide exceptional systems to explore evolutionary, ecological and conservation questions. However, the structure and phenology of such communities are still largely unknown. In order to fill these gaps, we sampled plant galls along the Portuguese coast...

Biodiversity sustained by natural ecosystems, particularly forests, provides ecosystem services essential to human well-being. However, many forests have been severely transformed, notably via monospecific plantations and the spread of invasive species. Given the extension of these novel anthropogenic forests (plantations and invasive copses), it i...

Globalisation persistently fuels the establishment of non‐native species outside their natural ranges. While alien plants have been intensively studied, little is known about alien flower visitors, and especially, how they integrate into natural communities. Here, we focus on mutualistic networks from five Galápagos islands to quantify whether alie...

Mutualistic interactions like those established between plants and mycorrhizal fungi or seed dispersers are key drivers of plant population dynamics and ecosystem functioning; however, these interactions have rarely been explored together. We assembled a tripartite fungi–plant–disperser network in the Gorongosa National Park—Mozambique, to test (1)...

The structure of pollination networks, particularly its nestedness, contain important information on network assemblages. However, there is still limited understanding of the mechanisms underlying nested pollination network structures. Here, we investigate the role of Adaptive Interaction Switching (AIS), island area, isolation, age and sampling ef...

Fern sporangia may provide an important source of energy for bird species, which in turn can act as potential dispersers of viable spores. This study reports the first case of fern spore dispersal by land birds. We document the consumption of fern sporangia and evaluate the potential spore dispersal by Galápagos Finches on Santa Cruz Island. Overal...

Lizards have been reported as important pollinators on several oceanic islands. Here we evaluate the potential role of Galápagos lava lizards (Microlophus spp.) as pollinators across their radiation. During three years, we sampled pollen transport by nine lava lizard species on the 10 islands where they are present, including seven single‐island en...

PREMISE OF THE STUDY: The characteristic scarcity of insects on remote oceanic islands has driven non-flower specialized vertebrates to broaden their trophic niches and explore floral resources. From our previous studies in the Galápagos, we know that native insectivorous and frugivorous birds visit a wide range of entomophilous flowers and can als...

Seed dispersal allows plants to colonise new sites and escape from pathogens and intraspecific competition, maintaining plant genetic diversity and regulating plant distribution. Conversely, most plant species form mutualistic associations with arbuscular mycorrhizal (AM) fungi in a symbiosis established immediately after seed germination. Because...

Aim Biogeographical comparisons of interaction networks help to elucidate differences in ecological communities and ecosystem functioning at large scales. Neotropical ecosystems have higher diversity and a different composition of frugivores and fleshy‐fruited plants compared with Afrotropical systems, but a lack of intercontinental comparisons lim...