Valentí Rull's research while affiliated with Institut Botànic de Barcelona and other places

Publications (297)

Preprint
The concept of taxon cycle involves successive range expansions and contractions over time through which a species can maintain indefinitely its core distribution. Otherwise, it becomes extinct. A typical taxon cycle can be subdivided into four stages: (I) expansion, (II) population differentiation, (III) local extinction and incipient speciation (...
Preprint
In a recent paper, the author demonstrated that, in contrast with the prevailing view of eventual gradual regional differentiation from a hypothetical Cretaceous pantropical mangrove belt around the Tethys Sea, the Caribbean mangroves originated de novo in the Eocene after the evolutionary appearance of the first mangrove-forming tree species known...
Preprint
The concept of taxon cycle involves successive range expansions and contractions over time through which a species can maintain indefinitely its core distribution. Otherwise, it becomes extinct. A typical taxon cycle can be subdivided into four stages: (I) expansion, (II) population differentiation, (III) local extinction and incipient speciation (...
Preprint
Documenting prehistoric and historical hemp retting for fiber extraction is important in the study of human uses of this iconic plant and its cultural implications. In paleoecology, hemp retting is usually inferred from indirect proxies, notably anomalously high percentages of Cannabis pollen in lake sediments, but some recent studies have also use...
Preprint
Documenting prehistoric and historical hemp retting for fiber extraction is important in the study of human uses of this iconic plant and its cultural implications. In paleoecology, hemp retting is usually inferred from indirect proxies, notably anomalously high percentages of Cannabis pollen in lake sediments, but some recent studies have also use...
Preprint
Documenting prehistoric and historical hemp retting for fiber extraction is important in the study of human uses of this iconic plant and its cultural implications. In paleoecology, hemp retting is usually inferred from indirect proxies, notably anomalously high percentages of Cannabis pollen in lake sediments, but some recent studies have also use...
Preprint
The varved sediments of the Pyrenean Lake Montcortès (Pallars Sobirà, Lleida) embody a unique continuous high-resolution (annual) paleoarchive of the last 3000 years for the circum-Mediterranean region. A variety of paleoclimatic and paleoecological records have been retrieved from these uncommon sediments that have turned the lake into a regional...
Chapter
Paleoecological knowledge has largely been neglected in the study of Easter Island’s prehistory, defined as the time interval between Polynesian settlement (800–1200 CE, common era) and European contact (1722 CE). The initial works of Flenley and coworkers, carried out approximately four decades ago (Flenley and King 1984; Flenley et al. 1991), wer...
Article
Full-text available
Reliable predictions of long-term ecological and evolutionary processes require more information than the periodicity of the astronomical forces that drive them.
Article
The mangrove communities of the Caribbean region are considered descendants of former pantropical Late-Cretaceous mangroves that underwent regional differentiation after the tectonic closure of the Tethys Sea. The southern Caribbean area has been considered the cradle of Neotropical mangroves. These inferences were based mainly on qualitative evide...
Article
Full-text available
Anticipating future successional forest trends in the face of ongoing global change is an essential conservation target. Mountain forests are especially sensitive to environmental shifts, and their past responses to climatic and anthropogenic (external) drivers may provide a basis for improving predictions of future developments. This paper uses in...
Preprint
The varved sediments of the Pyrenean Lake Montcortès (Pallars Sobirà, Lleida) embody a unique continuous high-resolution (annual) paleoarchive of the last 3000 years for the circum-Mediterranean region. A variety of paleoclimatic and paleoecological records have been retrieved from these uncommon sediments that have turned the lake into a regional...
Article
Cannabis is among the oldest human domesticates and has been subjected to intensive artificial (human-mediated) selection throughout history to create a wide array of varieties and biotypes for diverse uses, including fiber, food, biofuel, medicine and drugs. This paper briefly reviews the available literature on the taxonomy, evolutionary origin a...
Preprint
Anticipating future successional forest trends in the face of ongoing global change is an essential conservation target. Mountain forests are especially sensitive to environmental shifts, and their past responses to climatic and anthropogenic (external) drivers may provide a basis for improving predictions of future developments. This paper uses in...
Article
Full-text available
Biology has so far had difficulties formulating general laws akin to physics and chemistry. Evolution and its propensity to reduce entropy could become a start for such laws in biology.
Article
Full-text available
The Mediterranean region is expected to be highly impacted by global warming, although the uncertainty of future scenarios, particularly about precipitation patterns remains quite large. To better predict shifts in its current climate system and to test models, more regional climate records are needed spanning longer than the instrumental period. H...
Article
Human actions have caused an increasing number of species to go extinct. Do the available data support concerns about a new mass extinction event?
Article
Palynological analysis of the last ca. 4300 cal year BP using a sediment core taken from high mountain (ca. 1900 m elevation) Lake Sant Maurici sediments (southern-central Pyrenees) showed remarkable vegetation constancy during the Bronze Age and the Middle Ages. Records of the Iron Age and the Roman period were missing due to a major sedimentary g...
Article
Full-text available
This study compares the Medieval (ca. 400–1500 CE; Common Era) dynamics of forests from low-mountain (Montcortès; ca. 1000 m a.s.l.) and high-mountain (Sant Maurici; 1900 m a.s.l.) areas of the Iberian Pyrenees, both of which experienced similar climatic forcing but different anthropogenic pressures. The main aim is to identify forest changes over...
Preprint
Cannabis is among the oldest human domesticates and has been subjected to intensive artificial (human-mediated) selection throughout history to create a wide array of varieties and biotypes for diverse uses, including fibre, food, biofuel, medicine and drugs. This paper briefly reviews the available literature on the taxonomy, evolutionary origin a...
Preprint
Cannabis is among the oldest human domesticates and has been subjected to intensive artificial (human-mediated) selection through history, to create a wide array of varieties and biotypes for a diversity or uses, including fiber, food, biofuel, medicine and drugs, among others. This paper briefly reviews the available literature on the taxonomy, th...
Preprint
Full-text available
The Mediterranean is one of the regions of the world where human-induced climate warming is expected to have large impacts on water and environmental resources. To predict shifts in the current climate system, more regional climate records, including seasonal-to-century scale variability spanning longer than the instrumental periods, are needed. To...
Preprint
This paper compares the Medieval (ca. 400–1500 CE) dynamics of forests from low-mountain (Montcortès; ca. 1000 m a.s.l.) and high-mountain (Sant Maurici; 1900 m a.s.l.) areas of the Iberian Pyrenees, both of which experienced similar climatic forcing but different anthropogenic pressures. The main aim is to identify forest changes over time and ass...
Preprint
This paper compares the Medieval (ca. 400–1500 CE) dynamics of forests from low-mountain (Montcortès; ca. 1000 m a.s.l.) and high-mountain (Sant Maurici; 1900 m a.s.l.) areas of the Iberian Pyrenees, both of which experienced similar climatic forcing but different anthropogenic pressures. The main aim is to identify forest changes over time and ass...
Article
Full-text available
The Pyrenean Lake Montcortès sediments hold the longest continuous and absolutely varve-dated record of the Mediterranean region, encompassing the last three millennia, from the Late Bronze Age to the present. The reconstruction of vegetation and landscape dynamics during this time period has advanced gradually, following the progress of absolute d...
Preprint
The Pyrenean Lake Montcortès sediments hold the longest continuous and absolutely varve-dated record of the Mediterranean region, encompassing the last three millennia, from the Late Bronze Age to the present. The reconstruction of vegetation and landscape dynamics during this time period has advanced gradually, following the progress of absolute d...
Preprint
Palynological analysis of the last ca. 4300 cal yr BP using a sediment core taken from high mountain (ca. 1900 m elevation) Lake Sant Maurici sediments (southern-central Pyrenees) showed remarkable vegetation constancy during the Bronze Age and the Middle Ages. Records of the Iron Age and the Roman period were missing due to a major sedimentary gap...
Article
A preliminary analysis of the timing of landscape anthropization in the southern-central Pyrenees shows the occurrence of an elevational gradient from the Bronze Age (basal belts) to the Middle Ages (alpine belts). This relationship is statistically significant and suggests an average anthropization rate of 40 m in elevation per century. The elevat...
Article
The varved sediments of Lake Montcortès (central pre-Pyrenees) have provided a continuous high-resolution record of the last ca. 3000 years. Previous chronological and sedimentological studies of this record have furnished detailed paleoenvironmental reconstructions. However, palynological studies are only available for the last millennium, when th...
Preprint
A preliminary analysis of the timing of landscape anthropization in the southern-central Pyrenees shows the occurrence of an elevational gradient from the Bronze Age (basal belts) to the Middle Ages (alpine belts). This relationship is statistically significant and suggests an average anthropization rate of 40 m in elevation per century. The elevat...
Preprint
The varved sediments of Lake Montcortès (central Pre-Pyrenees) have provided a continuous high-resolution record of the last ca. 3000 years. Previous chronological and sedimentological studies of this record have furnished detailed paleoenvironmental reconstructions. However, palynological studies are only available for the last millennium, when th...
Article
Easter Island (Rapa Nui) is well known for the enigmas surrounding its unique megalithic statues, the moai, and the prehistoric (i.e., pre-European contact) Rapanui society that built them. These enigmas include, among others, the time of the island’s settlement, the geographical origin of the first settlers, the technology associated with moai tra...
Preprint
Full-text available
The varved sediments of Lake Montcortès (central Pre-Pyrenees) have provided a continuous high-resolution record of the last ca. 3000 years. Previous chronological and sedimentological studies of this record have furnished detailed paleoenvironmental reconstructions. However, palynological studies are only available for the last millennium, when th...
Article
This paper explains in some detail the poorly known proposal of Stoppani (1873) regarding the Anthropozoic era, whose beginning was defined by the first traces of human presence on Earth. This author set the stratigraphical bases for the definition of the ‘human era’, but the proposal had two main weaknesses: the dismissal of biological evolution a...
Article
This paper presents three extreme examples of the potential consequences of human settlement on the vegetation of oceanic and continental islands. The Neotropical Pantepui continental archipelago of sky islands is an example of pristinity, due to the almost nonexistent human impact that results from the remoteness and inaccessibility of these islan...
Article
To appraise the application of isoprenoid glycerol dialkyl glycerol tetraethers (isoGDGTs) as paleoclimate proxies in small lakes we investigated the effect of seasonal variability in temperature and dissolved oxygen concentration (DO) on the GDGT contents and its proxy in the water column of an oligotrophic karst lake in the Catalan pre-Pyrenees (...
Chapter
Pantepui is an archipelago of sky islands formed by the flat summits of the Neotropical Guiana table mountains (tepuis) situated between the Orinoco and Amazon basins. Pantepui is a virtually pristine land and a natural laboratory to study the origin and evolution of Neotropical biodiversity. This review aims to synthesize the existing biological k...
Data
In order to provide an integrated overview of the basic functioning of Lake Montcortès related to our modern analogue studies, a synthesis of the main processes and their spatial and temporal course is presented (Figure 10). This figure is intended to serve as a guide for high resolution paleoecological and paleoenvironmental reconstructions and de...
Article
After decades of human-deterministic explanations for the collapse of the ancient Rapanui culture that inhabited Easter Island (Rapa Nui) before European contact (1722 CE), paleoecological studies developed over the last decade have provided sound evidence of climate changes and their potential socioecological impacts. Especially significant is the...
Chapter
This chapter analyzes biotic responses to the different types of climate change, depending on the tolerance of organisms and their ability to adapt, migrate or modify their geographical range. This analysis is conducted at the population and species levels (autecology), with an emphasis on the biogeographical reorganizations that these species have...
Chapter
This chapter discusses how the information presented in previous chapters can be used to attain informed predictions of future scenarios in the context of current and near-future climate changes. The thread of this discussion is the dilemma of whether humans will influence natural variability, thus changing the Earth System irreversibly and leading...
Chapter
This chapter introduces the climatic variability of the Quaternary period and its global and regional impact on the Earth System. The main objective is to provide a framework of natural environmental change suitable for understanding the biotic changes that are documented in the rest of the book. The chapter begins by introducing some basic notions...
Chapter
This chapter deals with the inception of our species and its consequences for the biosphere with an emphasis on the last glacial cycle, during which humans experienced maximum growth and expanded over the whole planet, thus significantly modifying its biotic and abiotic characteristics. The chapter begins with a brief summary of the origin and evol...
Chapter
The key topic of this chapter is evolution, and the main aim is to give a documented account of the processes that took place during the Quaternary and that gave rise to the current biodiversity and its geographical distribution. An underlying question of this subject is whether the Quaternary has been an epoch of biological diversification or of i...
Chapter
This chapter summarizes the most relevant paleoecological knowledge obtained during the three phases mentioned and its relevance for a better understanding of Easter Island’s prehistory, especially in aspects such as settlement, climate change, deforestation, and cultural change.
Chapter
This chapter is about synecology, or community ecology, and analyzes the dynamics of biological communities as a consequence of natural environmental changes, especially the climate changes described in Chapter 1. The main objective is to analyze how ecological communities have changed as a result of Quaternary climate variability and the resulting...
Chapter
This chapter is an introduction to the study of Easter Island’s paleoecology that provides the elements necessary to understand the inception of this discipline in the study of the island’s prehistory and considers all paleoecological archives available and all studies carried out in them to date. This chapter subdivides the paleoecological study o...
Chapter
This chapter is a succinct summary of the present-day Easter Island's conditions, whose aim is not to provide a thorough characterization but to situate the reader in context and to introduce the locations, terms, and concepts that are discussed throughout the book. The main subjects addressed are geography, geology, climate, hydrology, soils, land...
Chapter
This chapter presents a conceptual system called EHLFS (Environmental-Human-Landscape Feedbacks and Synergies) able to analyze Easter Island’s prehistory under a holistic perspective. The EHLFS system is first explained in some detail and is then applied to Easter Island using the paleoecological evidence summarized in Chapter 7.
Chapter
This chapter begins with an intense coring effort, between 2005 and 2009, with the participation of several research teams, followed by a substantial publication increase several years later (2012–19). All previous coring sites were revisited in a more systematic manner and novel relevant information was obtained on deforestation and land use patte...
Article
Full-text available
In Quaternary paleosciences, the rationale behind analogical inference presupposes that 19 former processes can be explained by causes operating now, although their intensity and rates can 20 vary through time. In this paper we synthetize the results of different modern analogue studies 21 performed in a varved lake. We discuss their potential valu...
Article
Easter Island deforestation has traditionally been viewed as an abrupt island‐wide event caused by the prehistoric Rapanui civilization, which precipitated its own cultural collapse. This view emerges from early palaeoecological analyses of lake sediments, which showed a sudden and total replacement of palm pollen by grass pollen shortly after Poly...
Article
Abstract Coastal wetlands have been proposed as highly threatened by the ongoing and future climatic change, including projected sea-level changes as an additional forcing factor compared to more inland locations. The limited knowledge generated to date in this topic has been primarily focused on those areas attaining a high population density, an...
Article
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...
Article
Full-text available
Easter Island (Rapa Nui) deforestation has traditionally been viewed as a single event, synchronous in time and space across the island and caused by Polynesian settlers. However, recent studies have challenged this idea, introducing the concept of spatiotemporal heterogeneity and suggesting a role for climate change. This paper presents a continuo...
Preprint
Full-text available
This paper presents three extreme examples of the potential consequences of human settlement on oceanic and continental islands. The Neotropical Pantepui continental archipelago of sky islands is an example of pristinity, which is due to the almost inexistent human impact because of the remoteness and inaccessibility of these islands as well as the...
Preprint
In the Quaternary paleosciences, the rationale behind analogical inference presupposes that former natural changes can be explained by causes operating now, although their intensity and rates can vary through time. In this paper we synthesise synthetize the results of different modern analog studies and discuss their value to obtain the best infere...
Preprint
Easter Island (Rapa Nui) deforestation has traditionally been viewed as a single event, synchronous in time and space across the island and caused by Polynesian settlers. However, recent studies have challenged this idea introducing the concept of spatio-temporal heterogeneity and suggesting a role for climate change. This paper presents a continuo...
Preprint
Full-text available
Easter Island deforestation has traditionally been viewed as an abrupt island-wide event caused by the prehistoric Rapanui civilization, which precipitated its own cultural collapse. This view emerges from earlier paleoecological analyses of lake sediments showing a sudden and total replacement of palm by grass pollen shortly after Polynesian settl...
Preprint
Full-text available
After decades of human-deterministic explanations for the collapse of the ancient Rapanui civilization that inhabited Easter Island (Rapa Nui) before European contact (1722 CE), paleoecological studies developed during the last decade have provided sound evidence for climate changes and their potential socio-ecological impact. Especially significan...
Preprint
Full-text available
The remote and isolated Easter Island (Rapa Nui) has been the arena for classic debates on the potential consequences of human overexploitation of natural resources as a microcosmic model for the whole planet. Human-deterministic hypotheses have traditionally been preferred to proposals involving climate changes as drivers of socioecological shifts...
Article
Full-text available
The discovery and settlement of the tiny and remote Easter Island (Rapa Nui) has been a classical controversy for decades. Present-day aboriginal people and their culture are undoubtedly of Polynesian origin, but it has been debated whether Native Americans discovered the island before the Polynesian settlement. Until recently, the paradigm was tha...
Article
Full-text available
Editorial summaries of selected papers relevant to Quaternary science published in high-impact multidisciplinary journals between December 2018 and February 2019 [...]
Chapter
This chapter reviews the available paleoecological information on Pantepui since the Last Glacial Maximum (LGM) in order to reconstruct the ecological dynamics that have led to the present configuration of plant communities and to unravel the potential environmental drivers involved, with emphasis on regional climate changes and fire. To date, no L...
Book
PREFACE EXTENDED ABSTRACT PART I. GENERAL ASPECTS Chapter 1. Definition and characterization of the Pantepui biogeographical province O. Huber, V. Rull, T. Vegas-Vilarrúbia, C. Señaris Chapter 2. History of scientific exploration of Pantepui O. Huber, C. Señaris, P. Berry Chapter 3. Climatic and ecological history of Pantepui and surrounding a...
Chapter
Studying the causes of biological diversification and the main environmental drivers involved is useful not only for the progress of fundamental science but also to inform conservation practices. Unraveling the origin and maintenance of the comparatively high Neotropical biodiversity is important to understand the global latitudinal biodiversity gr...
Chapter
Conservation-related concerns about Pantepui usually pertain to direct human impacts (biopiracy, invader species, fire, contamination, etc.), and little attention has been paid to indirect threats, such as global warming (GW). This chapter summarizes the studies carried out to date aimed at estimating the potential impact of the projected GW by the...
Article
Full-text available
Editorial summaries of selected papers relevant to Quaternary science published in high-impact multidisciplinary journals between 12 September and 10 December 2018. [...]
Preprint
This chapter reviews the available paleoecological information on Pantepui since the Last Glacial Maximum (LGM), in order to reconstruct the ecological dynamics that have led to the present configuration of plant communities and to unravel the potential environmental drivers involved, with emphasis on regional climate changes and fire. To date, no...
Preprint
Full-text available
Studying the causes of biological diversification and the main environmental drivers involved is useful not only for the progress of fundamental science but also to inform conservation practices. Unraveling the origin and maintenance of the comparatively high Neotropical biodiversity is important to understand the global latitudinal biodiversity gr...
Article
Full-text available
In the coming years, the Anthropocene Working Group (AWG) will submit its proposal on the ‘Anthropocene’ to the Subcommission of Quaternary Stratigraphy (SQS) and the International Commission on Stratigraphy (ICS) for approval. If approved, the proposal will be sent to the Executive Committee of the International Union of Geological Sciences (IUGS)...
Preprint
In the coming years, the Anthropocene Working Group (AWG) will submit its proposal on the ‘Anthropocene’ as a new geological epoch to the International Commission on Stratigraphy (ICS) for approval. If approved, the proposal will be send to the International Union of Geological Sciences (IUGS) for ratification. If the proposal is approved and ratif...
Preprint
In the coming years, the Anthropocene Working Group (AWG) will submit its proposal on the ‘Anthropocene’ as a new geological epoch to the International Commission on Stratigraphy (ICS) for approval. If approved, the proposal will be send to the International Union of Geological Sciences (IUGS) for ratification. If the proposal is approved and ratif...
Preprint
In the coming years, the Anthropocene Working Group (AWG) will submit its proposal on the ‘Anthropocene’ as a new geological epoch to the International Commission on Stratigraphy (ICS) for approval. If approved, the proposal will be send to the International Union of Geological Sciences (IUGS) for ratification. If the proposal is approved and ratif...
Article
Full-text available
Pacific islands are spread over thousands of kilometres of the Pacific Basin and are characterised by similar ecological features but very diverse geologic origins, from steep volcanoes to flat coral atolls. Several climatic phases have been shared across the region within the last 1,000 years. Numerous and abrupt societal and cultural changes duri...
Article
Full-text available
Although the interpretation of Quaternary records of interrelated environmental–ecological–human processes is necessarily complex, it is often addressed using too-simple deterministic approaches. This paper suggests a holistic framework called EHLFS (Environmental–Human–Landscape Feedbacks and Synergies) to tackle Quaternary complexity. The EHLFS s...
Article
Full-text available
This paper reviews the existing hypotheses concerning the cultural shift from the Ancient Cult (AC) to the Birdman Cult (BC) that occurred on Easter Island (Rapa Nui) during the last millennium and introduces a holistic new hypothesis called CLAFS (Climate-Landscape-Anthropogenic Feedbacks and Synergies), which considers a variety of potential driv...
Article
Quaternary (http://www.mdpi.com/journal/quaternary) has genuine interest in ‘palaeoinsights’ or essay papers addressing author’s personal views on different Quaternary topics in relation to either the discipline itself, its potential interest for society, or both. Insights on palaeosciences, in general, are also welcome provided they have impact on...
Chapter
The neotropical Guayana Highlands (GH) are one of the few remaining pristine environments on Earth, and they host amazing biodiversity with a high degree endemism, especially among vascular plants. Despite the lack of direct human disturbance, GH plants and their communities are threatened with extinction from habitat loss due to global warming (GW...
Article
Varved sediments provide unique opportunities to carry out high-resolution paleoclimatic and paleoenvironmental reconstructions with accurate time control. To better interpret the sediment record it is necessary to understand the physical, chemical and biological factors that influence varve formation and preservation. We explored the link between...
Article
Recent expansion of anoxia has become a global issue and there is potential for worsening under global warming. At the same time, obtaining proper long-term instrumental oxygen records is difficult, thus reducing the possibility of recording long-term changes in oxygen shifts that can be related with climate or human influence. Varved lake sediment...
Book
A compilation of papers on Science & Society issues published between 2009 and 2017 in EMBO Reports and other journals. Contents: 1) Beyond us; 2) The candid approach; 3) Who needs a greener revolution?; 4) Food security: green revolution drawbacks; 5) The myth of sustainable development; 6) Sustainability, capitalism and evolution; 7) Research eff...
Article
We live in a Quaternary world, that is, a world shaped by the interplay of the different compartments of the earth system—lithosphere, hydrosphere, atmosphere, biosphere, cryosphere—during the last ~2.6 million years. It is not possible to understand the current world—and, hence, to anticipate its possible future developments—without knowing the Qu...
Article
Late Pleistocene and Holocene paleoecological reconstructions from the neotropical Gran Sabana (GS) provide objective criteria to assess realistic and feasible restoration targets and to appraise the potential effects of global warming on the GS landscapes and ecosystems.
Article
This paper discusses the concept of potential natural vegetation (PNV) in light of the pollen records available to date for the Macaronesian biogeographical region, with emphasis on the Azores Islands. The classical debate on the convenience or not of the PNV concept has been recently revived in the Canary Islands, where pollen records of pre-anthr...
Article
The “Anthropocene”, defined as a new geological epoch characterized by the global human footprint on Earth System, has become a term frequently used in a varied range of fields. However, some fundamental misconceptions remain on the origin and the scientific validity of this term. A common misconception is that the “Anthropocene” term and concept o...
Article
The ‘Anthropocene’ is an old concept whose proposal of formalization as a new geological epoch does not yet exist and will likely need millennia to gather the necessary evidence.