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...

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...

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 semi-arid Chaco is one of the most extensive forest formations in South America and has been subjected to high deforestation rates since the 1970s. At present, the main ecological, social and production problem in the region is the variation in water availability, a complex situation that combines a negative water balance and flood events. In this work, we studied the spatial and temporal variability of precipitation patterns, using rainfall instrumental records and tree rings of Schin...

Africa is faced with a number of challenges including climate change and ecological disturbance due to various anthropogenic activities. These problems adversely affect the forests and also ecosystem services. My appreciation for the forests motivated me to pursure my undergraduate studies in Forestry. I first applied dendrochronology during my PhD research which focused on understanding the climate change vulnerability of the Zambezi teak forests in Zambia. However, lack of research facil...

Historical accounts in the Brazilian Digital Library provide independent support for most of the tree-ring reconstructed wet season rainfall extremes in the eastern Amazon during the late-18th and 19th centuries. Newspapers, government reports, and other documents describe crop failure, livestock mortality, water shortages, and ship groundings on the Amazon River during many of the tree-ring reconstructed drought extremes. Heavy rains and flooding are described during some of the wet extre...

Regional teleconnections permit cross-continental modeling of hydroclimate throughout the world. Tree-rings are a good hydroclimatic proxy used to reconstruct drought and streamflow in regions that respond to common global forcings. We used a multi-species dataset of 32 tree-ring width chronologies from Chile and Uruguay as a climate proxy to infer annual streamflow (Q) variability in the Negro River basin, a grassland-dominated watershed of lowland Southeastern South America. A positive l...

The ongoing North American megadrought has persisted since the year 2000, and has been characterized by anomalously low amounts of winter and summer precipitation. The climate systems providing these seasonal precipitation regimes are distinct in their origins but overlapping in their geographic ranges. However, our understanding is still incomplete in how alternation in water resources influences forest growth and physiology during extreme and persistent drought, including whether replete...

The current climate warming is unique in terms of its ubiquity and synchrony on a global scale. Over the last millennium, pre-industrial periods with warmer and colder temperatures occurred at different times in different locations around the globe (Neukom et al., 2019). Long-term temperature reconstructions in the Southern Hemisphere remain sparse and not always consistent among them (Lara et al., 2020). Therefore, to understand the temporal and spatial patterns of global-scale temperatur...

Information garnered from historical timbers and wooden artifacts (e.g. houses, barns, ships) can greatly enhance our understanding of human, ecological, and climate history, especially in regions where few old-growth forests and trees remain, tree longevity is relatively short (less than 300-400 years), and environmental conditions break down wood rather quickly, like in mesic to wet regions Over the last decade plus, the application of tree-ring techniques on woo...

Session reescheduled from June 28th to June 29th

The ongoing North American megadrought has persisted since the year 2000, and has been characterized by anomalously low amounts of winter and summer precipitation. The climate systems providing these seasonal precipitation regimes are distinct in their origins but overlapping in their geographic ranges. However, our understanding is still incomplete in how alternation in water resources influences forest growth and physiology during extreme and persistent drought, including whether replete...

How old are tropical trees? This fundamental question has long driven the curiosity of laymen and scientists. But only recently, a great number of studies conducted by many brave dendrochronologists resulted in a significant tree-ring-based knowledge that allows us to start accurately estimating tree ages across the globe. As science goes, not only knowing the longevity of tropical trees is essential to understanding forest dynamics and its role in biogeochemical cycles, but one must also ...

Under elevated CO2, photosynthetic carbon isotope discrimination is expected to increase in response to photosynthesis stimulation. While this response is widely documented in laboratory and field experiments, long-term proxies indicate that such response is not universally observed in response to the growth of atmospheric CO2. We investigated historical trends of  photosynthetic carbon isotope discrimination derived from carbon isotope measurements of tree rings (Δ13C) from 147 chron...