Filipe Campelo

• PhD
• Researcher at University of Coimbra

Significance Forest trees can live for hundreds to thousands of years, and they play a critical role in mitigating global warming by fixing approximately 15% of anthropogenic CO 2 emissions annually by wood formation. However, the environmental factors triggering wood formation onset in springtime and the cellular mechanisms underlying this onset r...

Seasonality in tree cambial activity and xylem formation encompass large variation in environmental conditions. Abiotic stressors such as warming or drought also modulate plant behavior at species and individual level. Despite xylem formation susceptibility to carbon (C) and water availability, it is still unknown which are the key physiological va...

In their Letter, Elmendorf and Ettinger (1) question the dominant role of photoperiod in driving secondary growth resumption (hereafter referred to as xylem formation onset) of the Northern Hemisphere conifers, recently reported by Huang et al. (2). Their opinions are grounded on the following three aspects, including 1) the seasonality of the phot...

Mediterranean tree species have evolved to face seasonal water shortages, but may fail to cope with future increases in drought frequency and intensity. We investigated stem radial increment dynamics in two typical Mediterranean tree species, Aleppo pine (Pinus halepensis), a drought-avoiding species, and holm oak (Quercus ilex), a drought-tolerant...

Tree species inhabiting riparian forests under Mediterranean climate have evolved to face summer water shortage but may fail to cope with future increases in drought severity. Thus, understanding tree growth phenological variations in response to environmental conditions is necessary to assess the impact of seasonal drought in riparian forests. In...

Key message Resin production and growth in Pinus pinaster and Pinus pinea show a trade-off under varying environmental conditions, impacting future resin yields under climate change. Abstract Resin production in pines constitutes an important defense mechanism against biotic and abiotic factors, and it is also an important forestry product. In Por...

As major terrestrial carbon sinks, forests play an important role in mitigating climate change. The relationship between the seasonal uptake of carbon and its allocation to woody biomass remains poorly understood, leaving a significant gap in our capacity to predict carbon sequestration by forests. Here, we compare the intra-annual dynamics of carb...

Wood growth is key to understanding the feedback of forest ecosystems to the ongoing climate warming. An increase in spatial synchrony (i.e., coincident changes in distant populations) of spring phenology is one of the most prominent climate responses of forest trees. However, whether temperature variability contributes to an increase in the spatia...

Intra-Annual Density Fluctuations (IADFs) are an important wood functional trait that determine trees’ ability to adapt to climatic changes. Here, we use a large tree-ring database of 11 species from 89 sites across eight European countries, covering a climatic gradient from the Mediterranean to northern Europe, to analyze how climate variations dr...

Resin is a renewable forest resource that can increase the economic value of some forests in rural areas. Resin production is associated with climatic conditions. However, its impact on trees’ growth remains unclear. Here, we studied radial growth in six Portuguese Pinus pinaster forests that had been resin tapped for 5–7 years along a latitudinal...

Climate warming is expected to lengthen the growing season of tree species and enhance radial growth rates. Alternatively, a longer growing season could not lead to improved radial growth if wood production depends more on growth rate than on growing season length. We test these ideas by comparing leaf phenology data and the estimated start and end...

Wood formation during the growing season is shaped by the intra-annual variability of climatic conditions. In the Mediterranean, the cambial activity is seasonally constrained by winter low temperature and summer drought, resulting in bimodal growth patterns. Although bimodal growth is an ecologically important adaptation of woody species to season...

Despite growing interest in predicting plant phenological shifts, advanced spring phenology by global climate change remains debated. Evidence documenting either small or large advancement of spring phenology to rising temperature over the spatio‐temporal scales implies a potential existence of a thermal threshold in the responses of forests to glo...

Key message Pinus halepensis trees at the southern limit of the species distribution show less growth, low relative resilience, and more missing rings in response to increased temperatures and droughts. Abstract Climate change is increasing the frequency and intensity of extreme droughts in the northern hemisphere, leading to forest decline and tr...

Resin is a natural defensive substance produced by trees in response to injury and infection and is a sustainable and valuable non-timber forest product. Resin tapping is a traditional activity that besides increasing the economic profit of forest plantations, it provides ecosystem services and promotes the development of rural areas. However, the...

Tree growth takes place at different time scales ranging from hours to days. To understand growth responses to climate, continuous high-resolution measurements of tree diameter variations are needed, which are usually obtained with automatic dendrometers. Here, we monitored stem diameter increment of Quercus faginea Lambert growing in central Portu...

Key message Primary growth is less sensitive than secondary growth to water and phloem blockage in maritime pine saplings, with variations in radial growth resulting from tracheid production without altering their size. Abstract In plants, primary and secondary growth is regulated by internal and external factors. However, apical and cambial meris...

Resin harvesting is a traditional forestry activity that provides economic revenue along with crucial ecosystem services (i.e., fire protection and employment) thus contributing to the socioeconomic development of rural areas. In the Iberian Peninsula, Pinus pinaster Aiton has traditionally been exploited for resin to complement the profitability o...

Riparian ash forests subjected to seasonal drought are among the most endangered ecosystems in Europe. They are threatened by climate warming causing aridification and by land-use changes modifying river flow. To assess the impacts of these two stress factors on riparian forests, we studied radial growth and xylem anatomical traits in five narrow-l...

Mediterranean riparian forests are among the most threatened ecosystems in Europe. These ecosystems are exposed to land-use changes threatening their reduced habitat and by global warming, which is already triggering aridification processes. To assess the impact of these major threats, we studied the radial-growth responses to climate and drought i...

Tree rings are valuable proxies of past climate that allow inferring past growth responses to climate variability and extreme events, which is only possible considering that the relationship between tree growth and environmental conditions is linear and stable over time. However, in the last decades, divergent growth patterns have been observed in...

Poster presented at the online conference "XIX Encontro Nacional de Ecologia - Desafios para a nova década" organized by SPECO (Sociedade Portuguesa de Ecologia) between 9-12 Decemeber 2020. Title: "Climatic records from tree growth rates on tapped Pinus pinaster."

Although wood anatomical features can provide yearly resolved climatic information at sub-seasonal resolution, the occurrence of intra-annual density fluctuations (IADFs) might be triggered by several abiotic factors under different ecological settings. Here, we use information on cambial age and tree-ring width to standardize the frequency of IADF...

Key message Intra-annual wood density fluctuations are valuable indicators of the role of the local climate and provenance origins on tree growth. These intra-ring wood features were the most informative about local adaptation and phenotypic plasticity of Pinus halepensis Mill. in a provenance trial. This highlights the importance of taking provena...

Tree growth is one of the most studied aspects of tree biology, particularly secondary growth. In the Mediterranean region, cambial activity is mostly determined by water availability. Climatic projections for the Mediterranean region predict more frequent and intense droughts, and longer periods without precipitation. To investigate tree growth un...

Seasonality in trees' cambial activity and xylem formation encompass large variation in environmental conditions. Abiotic stressors such as warming or drought also modulate plants' behavior at species and individual level. Despite xylem formation susceptibility to carbon and water availability, it is still unknown which are the key physiological va...

Key message Reducing irrigation by up to 75% in spring decreased primary and secondary growth in Pinus pinaster Aiton saplings, whereas an extra irrigation in September prompted secondary growth, confirming the high plasticity of xylogenesis in this species. Context Water availability is the main limiting factor for plant growth and forest product...

Consequences of climate change will severely affect forest ecosystems in the near future, yet our understanding of how and why trees are responding to their abiotic environment is still limited. Intra-specific variation (ITV) in the growth response of trees to warming and drought has been widely neglected so far, but could play a key role for adapt...

The gradual increase in temperature over the last few decades is one of the major consequences of global change. It is also projected that drought frequency and intensity in the Mediterranean region will increase, promoting changes in plant responses to environmental conditions and ultimately species distribution. Studying past growth trends can he...

Trees change throughout their life stages, and although age-dependent changes are reported in the literature, the early life stages of trees are often excluded from these studies. The sapling/pole life stage corresponds to the establishment phase of a tree in the forest. To understand how wood formation changes in the early growing stages we compar...

In Mediterranean climates, bimodal growth patterns, corresponding to two peaks in radial increment during favorable seasons, have been described in several tree species. However, we lack a better mechanistic understanding of bimodality and its potential responses to the predicted warming and aridification trends. Filling this research gap is import...

The Azores Archipelago, located in the North Atlantic Ridge, experiences heavy rainfall and mild temperatures with weak seasonal differences due to oceanic influence. To our knowledge, there have been no dendrochronological studies in the Azores. The aim of this study is to explore the dendrochronological potential of Pinus pinaster Ait. growing in...

Temperature rising trend since the 1970’s has been pointed out as one major consequence of climate change affecting plant growth response to environmental conditions. The unprecedented temperature records in recent history makes vegetation response difficult to predict challenging management actions in the near future.

Intra-annual density fluctuations (IADFs) in tree rings are generally considered structural anomalies caused by deviations from the “normal course” of xylogenesis during the growing season. This definition is based on the bias that, under “normal conditions”, cambial activity stops once a year. Each tree ring can thus be dated to one calendar year,...

Tree rings are natural archives of climate and environmental information with a yearly resolution. Indeed, wood anatomical, chemical, and other properties of tree rings are a synthesis of several intrinsic and external factors, and their interaction during tree growth. In particular, Intra-Annual Density Fluctuations (IADFs) can be considered as tr...

Tree rings provide information about the climatic conditions during the growing season by recording them in different anatomical features, such as intra-annual density fluctuations (IADFs). IADFs are intra-annual changes of wood density appearing as latewood-like cells within earlywood, or earlywood-like cells within latewood. The occurrence of IAD...

Many anatomical features in trees result from their reaction to fluctuating environmental conditions, and some can be measured and dated. Recently, quantitative wood anatomy has been used to build time series, and consequently to study the responses of trees through time. This involves the application of dendrochronological techniques, although som...

Wood is the main terrestrial biotic reservoir for long-term carbon sequestration, and its formation in trees consumes around 15% of anthropogenic carbon dioxide emissions each year. However, the seasonal dynamics of woody biomass production cannot be quantified from eddy covariance or satellite observations. As such, our understanding of this key c...

Key message A new method is pro posed to standardize chronologies of intra-annual density fluctuations to improve their intra-annual climatic signal. Abstract In the Mediterranean area, intra-annual density fluctuations (IADFs) are triggered by short-term climatic variations during the growing season. It is known that the formation of these anatomi...

The formation of wood results from cambial activity and its anatomical properties reflect the variability of environmental conditions during the growing season. Recently, it was found that wood density variations in conifers growing under cold-limited environment result from the adjustment of cell wall thickness (CWT) to temperature. Additionally,...

The present work reports a first attempt to assemble long tree-ring chronologies from Portugal potentially useful for climate reconstructions. Three oak species (Quercus pyrenaica, Quercus faginea, and Quercus ilex) were sampled at three sites in southern Portugal to obtain tree-ring chronologies. The longest tree ring series covers 173 years exten...

Intra-annual density fluctuations (IADFs) are anatomical features formed in response to changes in the environmental conditions within the growing season. These anatomical features are commonly observed in Mediterranean pines, being more frequent in younger and wider tree rings. However, the process behind IADF formation is still unknown. Weekly mo...

July-to-October temperature variations are reconstructed for the last 800 years based on tree-ring widths from the Cazorla Range. Annual tree-ring width at this site has been found to be negatively correlated with temperature of the previous summer. This relationship is genuine, metabolically plausible, and cannot be explained as an indirect correl...

Tree-ring width integrates the prevailing environmental conditions during the whole growing season (annual resolution). Other wood anatomical traits, like intra-annual density fluctuations (IADFs), imprint environmental conditions within the growing season (sub-annual resolution). IADFs are anatomically characterized by latewood-like cells within e...

Mediterranean plants cope with cold wet winters and dry hot summers, with a drought gradient from northwest to southeast. Limiting climatic conditions have become more pronounced in the last decades due to the warming trend and rainfall decrease. Juniperus thurifera L., a long-lived conifer tree endemic to the western Mediterranean region, has a di...

Functional responses of riparian species can be used as surrogates for their vulnerability to climate-driven changes. In particular, black alder (Alnus glutinosa [L.] Gaertn.) might be highly susceptible to changes in habitat at the southern limit of its biogeographical distribution in the Mediterranean Basin. In this study, the long-term environme...

Context The knowledge on cambial activity in water-limited environments, such as the Mediterranean, is still fragmentary. Dendrochronological studies have determined that spring precipitation plays an important part in determining tree-ring width and the properties of tracheids. However, the complex relation between cambial phenology and climate is...

Neighboring trees growing under identical environmental conditions can exhibit different dynamics and periods of growth. Despite the recent advances in cambial biology, the exogenous and endogenous factors generating asynchronous xylem growths still remain undetermined. This study investigated timings and duration of xylem formation in maritime pin...

Dendroclimatology generally assumes that climate–growth relationships are age and size independent. However, there is evidence that climate response can be unstable across different age/size classes. In addition, the occurrence of some anatomical features, such as intra-annual density fluctuations (IADFs), is age dependent. The present study invest...

Juniperus thurifera L. is a long-lived conifer tree endemic to western Mediterranean region. It is well adapted to continental Mediterranean weather conditions such as negative winter temperatures or summer drought and is capable to maintain the photosynthetic activity all year round, making it a suitable species to study tree-ring sensitivity to c...

Dendrochronologia j o u r n a l h o m e p a g e : w w w . e l s e v i e r . d e / d e n d r o Technical note detrendeR – A Graphical User Interface to process and visualize tree-ring data using R a b s t r a c t In this paper, we present the package detrendeR, a Graphical User Interface to facilitate the visualization and analysis of dendrochronolo...

Aging in trees implies a progressive reduction in the growth rate, related to a shortening of the growing period and changes in the photosynthetic capability and efficiency. These changes may continue during the old-growth life stages following the juvenile phase and are reflected in tree-ring properties such as growth increment, density or stable...

The project MEDIATIC “Climate change over the Western Mediterranean and Atlantic Islands: a dendroclimatic and genetic survey of the genus Juniperus”, was financed by the Portuguese Ministry of Science, and started in May 2010. Within the climatic and biogeographic connection between the Western Mediterranean and the Atlantic Islands of Made...

Long-term data on radial increment dynamics in Mediterranean species may identify which climatic variables are the main constraints for radial growth and at which temporal scales they act. To this end, we examined stem radial fluctuations in Quercus ilex L., the dominant evergreen oak species in the Western Mediterranean Basin, over a period of 11y...

Climate projections for the Mediterranean area estimate a decline in total precipitation, warmer temperatures, and a higher frequency of extreme drought events. It is important to understand how trees respond to these climatic changes and which wood anatomical structures best document the trees response to those changes. The present work investigat...

We investigated whether vessel time series of Holm oak (Quercus ilex L.), a diffuse to semi-ring-porous species, can record a climatic signal which differs from the signal encoded in tree-ring width (TRW). The study was conducted in ten Q. ilex trees from a coppice stand in northeast Spain. Chronologies of TRW, mean vessel area (MVA) and maximum ve...

In forested wetlands, hydrology exerts complex and sometimes compensatory influences on tree growth. This is particularly true in semi-arid ecosystems, where water can be both a limiting resource and a stressor. To better understand these relationships, we studied hydrologic and edaphic controls on the density, growth, tree architecture and overall...

Time series of tree-ring anatomical features are important to understand the functional role of xylem plasticity over the life span of trees, and thus to reconstruct past ecological and climatic conditions. Holm oak (Quercus ilex L.) is a drought-tolerant tree widely distributed in the Mediterranean Basin. Chronologies of tree-ring width (TRW), ves...

Holm oak (Quercus ilex L.) is a long-lived species widely distributed across the Mediterranean Basin, with potential value for dendrochronology and dendroclimatology. However, tree-ring dating in Q.ilex is a complex task that has limited the number of dendrochronological studies using this evergreen species. In the present work, it was investigated...

Dendrochronology generally assumes that climate–growth relationships are age independent once the biological growth trend has been removed. However, tree physiology, namely, photosynthetic capacity and hydraulic conductivity changes with age. We tested whether the radial-growth response to climate and the intra-annual density fluctuations (IADFs) o...

The influence of climatic factors on tree-ring width and the formation of double rings was studied in Quercus ilex L. growing in a coppice stand left unmanaged for 22years. Ten trees were felled and discs were taken every 30cm from bole and dominant branches. Dendrometer bands were installed on 10 nearby trees and the data recorded were used to con...