Dendrochronological archives in the tropics of the Americas have been under-studied for a long time. Some of the challenges include the Identification of tree-ring boundaries in certain tree species, absence of winter dormancy associated to low temperatures in most of the cases, and logistic difficulties of fieldwork in remote sites. However, part of the slow progress is also related to the fact that historically much less resources have been inv...

The most biodiverse region in the world can be found in the tropical Andes (~5º-24ºS) between Venezuela and the Bolivian Altiplano, yet it is highly under-sampled in dendrochronology in part due to the prevalence of trees without rings (continuous growth) and the overall hyperdiversity of the ecosystems. The Madidi National Park (MNP) in northern Bolivia. (~14 ºS, -68°W) is a biodiversity hotspot with lowland rainforests and high montane environments that provide unique opportunities for t...

Maritime forests are extremely important for coastal protection as they buffer storm surge and wind, conserve nutrients, and store groundwater. They grow several 100 meters behind primary beach dunes or along intertidal marsh-forest ecotones and within range of salt spray, near shoreline estuaries, where they support large amounts of biodiversity and migratory birds. Trees in these forests typically handle small concentrations of salt spray, strong winds, and slight flooding, but prolonged...

Evidence of volcanic cooling and its human impacts has been described for various regions of the globe over the past several centuries to millennia, derived from paleoclimatic and historical data. Due to its remote location, detailed accounts of such impacts over Northwestern North America (NWNA) are still quite limited. Here we use a newly expanded tree-ring density network (derived from blue intensity as well as maximum latewood density parameters) to assess the climatic and human impact...

Ultra high resolution imaging is becoming standard across the sciences and must be a priority for dendrochronology. Large format scanners fail to resolve micro rings and the anatomical structures of increasing scientific interest. Meanwhile, current software limitations include cost, user experience, data management flexibility, and capacity for handling large file sizes. We argue for a new paradigm and present a technology framework that integrates gigapixel macro photography, a cloud-hos...

Tree-ring research has given generations of scientists a long memory of what is acceptable for a tree to be included for data analysis. The established criteria, however, were set through purposeful goals to maximize the response for climatic reconstructions. Ecology is different. Tree-rings are increasingly being used to study a wide swath of ecology, including the carbon cycle or the response of ecosystems to global changes. A fundamental aspect of ecology is to understand the range of r...

Dendroclimatic reconstructions play a key role in contextualizing recent climate change by improving our understanding of past climate variability. The climatically-sensitive blue intensity (BI) parameter is gaining prominence as a more accessible alternative to X-ray densitometry. Yet accurately representing low-frequency trends and high-frequency extremes using scanner-based BI remains a challenge due to color biases and resolution limitations. As part of the REPLICATE project, methodolo...

Half of the tributaries of the Amazon River originate in the tropical Andes; however, it is difficult to assess hydroclimatic conditions due to the scarcity of long, high-quality instrumental records. Data from the Global Precipitation Climatology Project (GPCP) provides a complete record since 1979 and offers a good representation of rainfall over the tropical Andes. Longer records are needed to improve our understanding of rainfall variability and summer monsoon behavior at various scale...

"Little is known about the impact of volcanoes on trees from the Southern Hemisphere. In this study, we investigated whether volcanic signals could be identified in ring widths from eight dendrochronological species from New Zealand, using superposed epoch analysis. We found that most species are good recorders of volcanic dimming and that the magnitude and persistence of the post-event response can be broadly linked to plant life history traits - whether the species responds as a 'stress ...

Dendrochronology is considered one the most precise of all the scientific dating techniques. However, it requires long sequences of tree rings and a master record for both the species and region in question. At the University of Groningen, we have been pioneering a new approach to dating that combines the precision of dendrochronology with the versatility of radiocarbon dating. It relies on the detection of spikes in the annual radiocarbon record, thought to b...

Humans have relied on wooden timber material for the construction of buildings, trade, ships, artifacts, and works of art for many millennia. Using dendrochronological methods, it is often possible to develop to build internally cross-dated but undated ‘floating’ tree-ring chronologies using this historic wooden material. However, the dynamic nature of human mobility and long-distance transport of timber can often make it difficult to accurately date and provenance wooden material. Accurat...

Coastal maritime forests in northeastern USA are mostly fragmented and currently threatened by climate change. This study focuses on American holly (Ilex opaca) trees located in the coastal maritime forests of Sandy Hook, N.J. and Fire Island, N.Y. to better understand how vulnerable and resilient these forests are to future climate scenarios. There are few published studies that use tree-ring methods in the maritime forests of N.J. and dendrochronological research on holly species has jus...

Ring-width (RW) and Blue Intensity (BI) parameters (earlywood - EWB, inverted latewood – LWBinv, and delta - DB) were measured from samples of Araucaria araucana from six sites in northern Patagonia, Argentina. The distance between the most southerly and northerly sites is ca. 130 kms. Despite a much weaker between-tree signal for the BI parameters than RW, principal component analysis identifies a much stronger regional between-site signal for the BI parameters. Split period correlation r...

The impacts of inland flooding caused by tropical cyclones (TCs), including loss of life, infrastructure disruption, and alteration of natural landscapes, have increased over recent decades. While these impacts are well documented, changes in TC precipitation extremes—the proximate cause of such inland flooding—have been more difficult to detect. Here, we present a latewood tree-ring–based record of seasonal (June 1 through October 15) TC precipitation sums (ΣTCP) from the region in North ...

(by bus, max 92 people)Designed for visitors and newcomers, the tour is based on the pleasure...