High-fidelity representation of climate variations by Amburana cearensis tree-ring chronologies across a tropical forest transition in South America

2022 ◽  
pp. 125932
Author(s):  
Lidio López ◽  
Ricardo Villalba ◽  
David Stahle
2018 ◽  
Vol 52 ◽  
pp. 113-122 ◽  
Author(s):  
Christine Lucas ◽  
Paulina Puchi ◽  
Ludmila Profumo ◽  
Alex Ferreira ◽  
Ariel Muñoz

2014 ◽  
Vol 11 (3) ◽  
pp. 4591-4636 ◽  
Author(s):  
E. M. Veenendaal ◽  
M. Torello-Raventos ◽  
T. R. Feldpausch ◽  
T. F. Domingues ◽  
F. Gerard ◽  
...  

Abstract. Through interpretations of remote sensing data and/or theoretical propositions, the idea that forest and savanna represent "alternative stable states" is gaining increasing acceptance. Filling an observational gap, we present detailed stratified floristic and structural analyses for forest and savanna stands mostly located within zones of transition (where both vegetation types occur in close proximity) in Africa, South America and Australia. Woody plant leaf area index variation was related in a similar way to tree canopy cover for both savanna and forest with substantial overlap between the two vegetation types. As total woody plant canopy cover increased, so did the contribution of middle and lower strata of woody vegetation to this total. Herbaceous layer cover also declined as woody cover increased. This pattern of understorey grasses and herbs being progressively replaced by shrubs as canopy closure occurs was found for both savanna and forests and on all continents. Thus, once subordinate woody canopy layers are taken into account, a less marked transition in woody plant cover across the savanna-forest species discontinuum is observed compared to that implied when trees of a basal diameter > 0.1m are considered in isolation. This is especially the case for shrub-dominated savannas and in taller savannas approaching canopy closure. An increased contribution of forest species to the total subordinate cover is also observed as savanna stand canopy closure occurs. Despite similarities in canopy cover characteristics, woody vegetation in Africa and Australia attained greater heights and stored a greater concentration of above ground biomass than in South America. Up to three times as much aboveground biomass is stored in forests compared to savannas under equivalent climatic conditions. Savanna/forest transition zones were also found to typically occur at higher precipitation regimes for South America than for Africa. Nevertheless, coexistence was found to be confined to a well-defined edaphic/climate envelope consistent across all three continents with both soil and climate playing a role as the key determinants of the relative location of forest and savanna. Taken together these observations do not lend support the notion of alternate stable states mediated through fire-feedbacks as the prime force shaping the distribution of the two dominant vegetation types of the tropical lands.


2020 ◽  
Vol 228 ◽  
pp. 106087 ◽  
Author(s):  
A. Lara ◽  
R. Villalba ◽  
R. Urrutia-Jalabert ◽  
A. González-Reyes ◽  
J.C. Aravena ◽  
...  

2011 ◽  
Vol 309 (3-4) ◽  
pp. 221-233 ◽  
Author(s):  
V. Daux ◽  
J.L. Edouard ◽  
V. Masson-Delmotte ◽  
M. Stievenard ◽  
G. Hoffmann ◽  
...  

Author(s):  
Ricardo Villalba ◽  
Hector R. Grau ◽  
Jose A. Boninsegna ◽  
Gordon C. Jacoby ◽  
Alberto Ripalta

2020 ◽  
Author(s):  
Milena Godoy-Veiga ◽  
Giuliano Locosselli ◽  
Lior Regev ◽  
Elisabetta Boaretto ◽  
Gregório Ceccantini

<p>Tree-ring chronologies are an excellent climate archive for their spatial and temporal resolution. While networks of chronologies have been built outside the tropics helping to understand past regional climate trends, tropical regions still lag behind in terms of spatial coverage. Dendrochronological studies, however, may succeed in seasonally dry tropical forests where the growing season is well defined. <em>Amburana cearensis</em>, found in both dry and wet forests in South America, is poorly explored for dendrochronological purposes, with no previous study in Brazil. Therefore, we sampled trees growing in a seasonally dry forest in a karstic area in Central-Eastern Brazil, under the South American Monsoon domain, in order to explore this species potential for dendroclimatological studies in the region. We build a tree-ring width chronology using 26 trees. We found a strong common growth signal among trees, with an r-bar of 0.51 and an average mean sensitivity of 0.50. The standard tree-ring width chronology showed a significant negative correlation with Vapor-Pressure Deficit during the entire wet season (0.54), negative correlation with temperature at the end of the wet season (0.45), and a positive correlation with the sum of precipitation during the wet season (0.46). Further stable isotopic analysis will provide additional records of climate variability in the region. Since Amburana cearensis occurs across most of the seasonally dry forests and savannas from South America, it has a great potential to be used to develop climate reconstructions and verify the effects of climate change currently affecting the region.</p>


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