Pedro Miguel Raposeiro

Research Centre in Biodiversity and Genetic Resources - InBIO Associate Laboratory - Pólo Açores

The decomposition of leaf litter of terrestrial origin is a fundamental process in aquatic ecosystems in forest contexts. Little is known about what drives leaf litter decomposition in oceanic islands. We examined the relative importance of leaf litter identity (Acacia melanoxylon, Pittosporum undulatum, Morella faya) and environmental conditions o...

Freshwater systems on volcanic oceanic islands have very particular characteristics as a result of their geological origins, relatively small size, distances from source areas for colonizers, and distinct catchment morphology. These factors result in freshwater communities that are clearly distinct from continental systems. Chironomid spatial and t...

Oceanic islands freshwater systems are unique due to their volcanic origin, oceanic situation, catchment morphology and the presence of distinct freshwater communities when compared with continental systems. This study provides an update of Azorean chironomid fauna records, distribution data and includes biogeographical comments, based on collectio...

Subfossil biotic assemblages in lakes’ surface sediments have been used to infer ecological conditions across environmental gradients. Local variables are usually the major drivers of assemblage composition, but in remote oceanic islands biogeo- graphic filters may play a significant role. To assess the contribution of local and regional filters in...

Following environmental changes, communities disassemble and reassemble in seemingly unpredictable ways. Whether species respond to such changes individualistically or collectively (e.g. as functional groups) is still unclear. To address this question, we used an extensive new dataset for the lake communities in the Azores' archipelago to test whet...

Bacteriohopanepolyols (BHPs) are a diverse class of lipids produced by bacteria across a wide range of environments. In this study, we aim to further identify BHPs related to ecological niches and/or specific bacteria by characterizing the distribution of BHPs in suspended particulate matter (SPM) of the water column and in sediments in a range of...

Paleoclimatological information derived from the study of lacustrine sedimentary records is not only biased by taphonomical processes but also by potential differences in the expression of climate variability in the sediments due to site-specific factors. Using a multiproxy approach (the elemental and isotopic compositions of organic matter, diatom...

Understanding the environmental response to the last glacial termination in regions located in transitional climate zones such as the Atlantic Iberian mountains is crucial to estimate potential changes in regions affected by current glacial melting. We present an 8.5‐m‐long, solid last deglaciation and Holocene chronostratigraphic record including...

The species–area relationship (SAR) is one of the most distinctive biogeographic patterns, but global comparisons of the SARs between island and mainland are lacking for microbial taxa. Here, we explore whether the form of the SAR and the drivers of species richness, including area, environmental heterogeneity, climate and physico‐chemistry, differ...

Knowledge about cyanobacteria diversity in the Azores is spread over several publications, dating from 1874, with some of them not generally available to the scientific community due to their restricted access. The dispersion and sometimes inaccessibility of this information hinder a deeper analysis and a better understanding of the biodiversity of...

Human land use and climate change threaten ecosystems and natural resources, particularly on remote islands such as the Azores Archipelago in the North Atlantic. Since the official Portuguese settlement of the archipelago in the 15th and 16th centuries humans have extensively modified the Azorean landscape, with invasive plants dominating the prese...

Lake sedimentary archives from volcanic regions frequently contain a rich and continuous record of tephra layers, providing a critical source of information to reconstruct a most complete eruptive history of neighbouring volcanic centres. Lake sediments from volcanic islands are particularly useful as the typical small size of these islands and the...

A multiproxy approach was applied to a sediment core retrieved from the deep crater lake Funda, located in the middle of the North Atlantic Ocean on Flores Island, Azores archipelago (Portugal). The purpose of this study was to determine how this ecosystem responded to natural and anthropogenic forces over the last millennium. We distinguished thre...

Background The Madeira Island (Portugal; 32°24’–33°07’N, 16°16–17°16’W; 796 km2) is an oceanic island located in the North Atlantic, about 980 km south of Portugal and about 700 km west of the African coast. The presence of freshwater invertebrates in oceanic islands has always raised questions concerning dispersal, colonisation and evolution. Ther...

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and tot...

Significance We use a diverse set of lake and landscape proxy indicators to characterize initial human occupation and its impacts on the Azores Archipelago. The occupation of these islands began between 700 and 850 CE, 700 years earlier than suggested by documentary sources. These early occupations caused widespread ecological and landscape disturb...

Research in Macaronesia has led to substantial advances in ecology, evolution and conservation biology. We review the scientific developments achieved in this region, and outline promising research avenues enhancing conservation. Some of these discoveries indicate that the Macaronesian flora and fauna is composed of rather young lineages, not Terti...

Lacustrine sequences from active volcanic settings usually hold a rich and continuous record of tephra layers, providing a critical source of information to reconstruct a most complete eruptive history of a region. Lake sedimentary records on volcanic islands are particularly useful as the typical small size of these islands and their steep subaeri...

This dataset presents the distribution of freshwater macroinvertebrates in Madeira Island streams.

Freshwater systems on remote oceanic islands are particularly vulnerable to biological invasions. The case of freshwater ecosystems in the Azores Archipelago is especially relevant considering the islands’ youth and remoteness, and low natural connectivity. This study presents a review of the introduction and presence of non-indigenous freshwater s...

Background Testate amoebae are a polyphyletic group of protists living preferentially in soils, freshwaters and wetlands. These Protozoa have a worldwide distribution, but their presence and diversity in the Azores (a remote oceanic archipelago) is poorly known, with only twelve taxa recorded so far. The published information reflects occasional ol...

Freshwater diversity, and diatoms in particular, from Desertas Islands (Madeira Archipelago, Portugal) is poorly known, although the Islands are protected and became a Natural Reserve in 1995. During two field expeditions in 2013 and 2014 to Deserta Grande Island, several freshwater and terrestrial habitats were sampled. The analysis of these sampl...

Collections were undertaken, and occurrence data recorded during 2020 in São Miguel Island. The collectors were Martin Souto, Vitor Gonçalves and Pedro Miguel Raposeiro. Identification was done by Martin Souto and Xabier Pontevedra-Pombal. Production and analysis of scanning electron microscopy images was done by Xabier Pontevedra-Pombal. Study are...

Here, we present the data obtained from the samples collected in a field campaign during the spring of 2015 which aims for a better understanding of the diversity and distribution patterns of freshwater diatoms in Madeira Island. Following European and Portuguese standards and recommendations for routine diatom sampling and analysis, we collected s...

Diatom from Deserta Grande (Madeira Archipelago, Portugal) Study area Desertas subarchipelago is formed by three uninhabited small islets belonging to the Madeira Archipelago located 20 km southeast of Madeira Island. Deserta Grande is the largest of the three islets, with an area of approximately 10 km2 and a maximum altitude of 479 m. The Deserta...

Non-Pollen Palynomorphs (NPPs) are sub-fossil remains from a wide range of organisms that can be sensitive to various ecological and/or anthropogenic factors. Here we describe NPPs from the sedimentary record of Lake Caldeirão (Corvo Island, 400m a.s.l.), which spans the last two millennia. There are three successional NPP assemblages that track ch...

The discovery and colonization of remote oceanic islands drastically modified their ecosystems and the settlement of the Azores archipelago was no exception. One of the first impacts of human arrival is the change in vegetation due to land clearance practices (e.g. slash and burn), which is often associated with increase of macroscopic charcoal par...

The discovery and settlement of the Azores archipelago is generally attributed to the Portuguese during the XVth century, but recent insights have raised questions about whether the islands were discovered earlier. Paleolimnological data from São Miguel suggest that the island was settled 150 years before the official Portuguese arrival date. To pi...

Diatom distribution in Madeira Island streams (Portugal) Study area Madeira is a typical oceanic island with unique biodiversity under increasing pressure. Madeira island is located 600 km off the Atlantic coast of North Africa, has an area of 742 km2 and a maximum altitude of 1861 m (Pico Ruivo). Madeira island comprises approximately 126 catchmen...

The camoebians are ubiquitous microorganisms in aquatic ecosystems with a characteristic theca that is very resistant to physicochemical degradation; thus, they are incorporated into paleoecological records, providing valuable information. The Doniños freshwater lake (43° 29.50’’ N, 8° 18.70’’ W) (4 m a.s.l.) is a coastal back-barrier perched lake...

This study presents the first morphological description and illustration of the late instar larva of Limnephilus atlanticus Nybom 1948, an endemic caddisfly from the Azores. Taxonomic comparisons with a recently recorded limnephilid species, Limnephilus affinis (Limnephilidae), and notes of their ecology and distribution in the Azores are also prov...

Aquatic hyphomycetes are a phylogenetically heterogeneous group of fungi living preferentially in fast flowing, well-aerated forest streams. These fungi have worldwide distribution, but with the exception of Articulospora tetracladia , no aquatic hyphomycete taxon was previously recorded on Madeira Island. Aquatic hyphomycetes were sampled from 40...

The Azores are oceanic islands located in the Northern Atlantic Ocean and are particularly rich in aquatic systems, ranging from freshwater, brackish, marine and thermal habitats. Due to the increase in local anthropogenic pressures and global warming, several azorean lakes began to reveal signs of eutrophication that led to the implementation of m...

Shredders play a crucial role in litter decomposition in streams. However, in oceanic islands, many streams have low shredder density and richness, and microbes seem to be the main litter decomposers. Here, we evaluate the effects of shredders and aquatic hyphomycetes on litter decomposition in insular streams. Three leaf species differing in physi...

Study area Madeira is a typical oceanic island with unique biodiversity under increasing pressure. Madeira island is located 600 km off the Atlantic coast of North Africa, has an area of 742 km2 and a maximum altitude of 1861 m (Pico Ruivo). Madeira island comprises approximately 126 catchments and 200 streams ranging from 1st to 6th order. Funding...

Shredders play a crucial role in litter decomposition in streams. However, in oceanic islands, many streams have low shredder density and richness, and microbes seem to be the main litter decomposers. Here, we evaluate the effects of shredders and aquatic hyphomycetes on litter decomposition in insular streams. Three leaf species differing in physi...

Cyanobacteria from freshwater lakes in the Azores Archipelago, Portugal The data present here come from samples collected during several monitoring programs developed between 1996 and 2018 which aimed to characterize the biodiversity of inland aquatic ecosystems (lakes and streams) from the islands of Santa Maria, São Miguel, Terceira, Pico, São Jo...

The impacts of natural- and human-induced processes on lake ecosystems in remote oceanic islands remain to be fully elucidated. These lakes are excellent candidates to analyze the importance of anthropogenic vs. natural forces driving lacustrine long-term ecological evolution from previous pristine pre-colonized conditions. Disentangling the effect...

Global patterns of biodiversity have emerged for soil microorganisms, plants and animals, and the extraordinary significance of microbial functions in ecosystems is also well established. Virtually unknown, however, are large-scale patterns of microbial diversity in freshwaters, although these aquatic ecosystems are hotspots of biodiversity and bio...

As águas termo-minerais apresentam diferentes quantidades de sais minerais que dependem do tempo e da natureza das rochas com as quais a água esteve em contacto. Dentro destas, as águas termais são aquelas cuja temperatura é mais elevada que a temperatura ambiente, em pelo menos 5°C. Portugal é um dos países da Europa mais rico neste tipo de ocorrê...

Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent probl...

Leaf litter from riparian vegetation is the main energy for forest streams. Litter is decomposed mainly by microbial and detritivore macroinvertebrates, thus diversity and abundance of decomposers will be determinant of litter decomposition. Oceanic freshwater systems tend to be species poor but rich in endemism due to their physical isolation. The...

Until recently, the distribution in the surface of lake sediments of the diatom and chironomid assemblages and their attributes (species richness/diversity) in relation to water depth and sedimentary environments have been identified but not quantified. The influence of environmental variables on assemblage distribution and taxa richness in a high...

Environmental reconstructions based on lacustrine sedimentary records are important tools to assess long-term changes in lake conditions and correlate these changes with environmental drivers, such as climatic fluctuations, volcanic activity and anthropogenic disturbances. Here we present the main impacts of these drivers on Lake Caveiro (Pico isla...

During the second half of XX century, lake eutrophication has become a matter of concern all over the world. The increase in lake productivity has been mainly related to inputs of nutrients, particularly phosphorus (P) and nitrogen (N), originated by local human activities. However, evidence of lake eutrophication on remote areas with no significan...

Cladocera occupy an intermediate trophic level in aquatic food webs, responding to bottom-up and top-down control of the food web. Furthermore, Cladocera shells are resistant to degradation and their remains often accumulate in lake sediments. Therefore, Cladocera fossil remains from lake sediments can be used to assess past environmental condition...

Cladocera occupy an intermediate trophic level in aquatic food webs, responding to bottom-up and top-down control of the food web. Furthermore, Cladocera shells are resistant to degradation and their remains often accumulate in lake sediments. Therefore, Cladocera fossil remains from lake sediments can be used to assess past environmental condition...

Until recently, the distribution of diatom and chironomid assemblages and their attributes (species richness/diversity) in relation to water depth and sedimentary environments have been identified but not quantified. The influence of environmental variables on assemblage distribution and taxa richness in a deep, monomictic lake in São Miguel Island...

It has been widely reported that shredders play an important role in leaf decomposition, especially in continental temperate streams. However, the paucity of shredders in many oceanic island streams leads to a relatively greater contribution of microbes to litter decomposition in these streams. In the present study we investigated the importance of...

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to thei...

Insight into how environmental change determines the production and distribution ofcyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus onhepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g.,anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their p...

In comparison with other Macaronesian archipelagos, Azorean freshwater macroinvertebrates are characterized by a smaller list of species at the archipelago regional scale. Although knowledge of the freshwater fauna of the Azores has improved in recent years through the implementation of the "Water Framework Directive", we are still far from having...

The Azores archipelago has provided significant clues to the ecological, biogeographic and evolutionary knowledge of oceanic islands. Palaeoecological records are comparatively scarce, but they can provide relevant information on these subjects. We report the palynological reconstruction of the vegetation and environmental dynamics of the São Migue...

Oceanic freshwater communities tend to be species poor but rich in endemism due to their physical isolation. The ecology of endemic freshwater species is, however, poorly known. This study assessed allometric relationships, feeding preferences, growth and survival of larvae of the endemic stream insect Limnephilus atlanticus (Trichoptera, Limnephil...

CIBIO-Açores, a research unit based at the University of the Azores and integrated in the Research Network on Biodiversity and Evolutionary Biology (InBIO, Associated Laboratory), organizes the first edition of its Spring Seminar with the purpose of disseminating its research activities within the academic community, but also with the funding agenc...

The Azores archipelago has provided significant clues to the ecological, biogeographic and evolutionary knowledge of oceanic islands. Palaeoecological records are comparatively scarce, but they can provide relevant information on these subjects. We report the palynological reconstruction of the vegetation and landscape dynamics of the São Miguel Is...

Forest change occurs worldwide, especially on islands where space is a limiting factor for human activities. The replacement of diverse native forests by tree monocultures and subsequent changes in litter input characteristics can have strong effects on stream communities and processes. Aquatic decomposers and litter decomposition can be particular...

Little is known about the effect of top predator introduction in historically fishless communities, especially on remote islands. This issue is important because it might strongly affect climate reconstructions derived from biota assemblages such as chironomids. Head capsule larval remains of chironomids have been studied in a 660 years lacustrine...