11 documents found, page 1 of 2
Variations in Amazon forest productivity correlated with foliar nutrients and m...
Mercado, Lina; Patiño, Sandra; null, Tomas; Fyllas, Nikolaos M.; Weedon, Graham P.; Sitch, Stephen A.; Quesada, Carlos Alberto; Phillips, Oliver L.The rate of above-ground woody biomass production, WP, in some western Amazon forests exceeds those in the east by a factor of 2 or more. Underlying causes may include climate, soil nutrient limitations and species composition. In this modelling paper, we explore the implications of allowing key nutrients such as N and P to constrain the photosynthesis of Amazon forests, and also we examine the relationship bet...
Height-diameter allometry of tropical forest trees
Feldpausch, Ted R.; Banin, Lindsay F.; Phillips, Oliver L.; Baker, Timothy R.; Lewis, Simon L.; Quesada, Carlos Alberto; Affum-Baffoe, KofiTropical tree height-diameter (<i>H:D</i>) relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955 concurrent <i>H</i> and <i>D</i> measurements encompassing 283 sites in 22 tropical countries. Utilising this data...
Structural, physiognomic and above-ground biomass variation in savanna-forest t...
Veenendaal, Elmar M.; Torello-Raventos, Mireia; Feldpausch, Ted R.; null, Tomas; Gerard, France F.; Schrodt, Franziska; Saiz, GustavoThrough 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 located mostly within zones of transition (where both vegetation types occur in close proximity) in Afri...
Tree height integrated into pantropical forest biomass estimates
Feldpausch, Ted R.; Lloyd, Jon; Lewis, Simon L.; Brienen, Roel J.W.; Gloor, Manuel E.; Monteagudo-Mendoza, Abel; Lopez-Gonzalez, GabrielaAboveground tropical tree biomass and carbon storage estimates commonly ignore tree height (H). We estimate the effect of incorporating H on tropics-wide forest biomass estimates in 327 plots across four continents using 42 656 H and diameter measurements and harvested trees from 20 sites to answer the following questions: ; 1. What is the best H-model form and geographic unit to include in biomass models to mi...
Foliar trait contrasts between African forest and savanna trees: Genetic versus...
Schrodt, Franziska; null, Tomas; Feldpausch, Ted R.; Saiz, Gustavo; Quesada, Carlos Alberto; Schwarz, Michael; Ishida, Francoise Yoko; Compaoré, HalidouVariations in leaf mass per unit area (Ma) and foliar concentrations of N, P, C, K, Mg and Ca were determined for 365 trees growing in 23 plots along a West African precipitation gradient ranging from 0.29 to 1.62m a-1. Contrary to previous studies, no marked increase in Ma with declining precipitation was observed, but savanna tree foliar [N] tended to be higher at the drier sites (mass basis). Generally, Ma w...
Leaf-level photosynthetic capacity in lowland Amazonian and high-elevation Ande...
Bahar, Nur H.A.; Ishida, Francoise Yoko; Weerasinghe, Lasantha K.; Guerrieri, Rossella; O'Sullivan, Odhran S.; Bloomfield, Keith J.; Asner, Gregory P.We examined whether variations in photosynthetic capacity are linked to variations in the environment and/or associated leaf traits for tropical moist forests (TMFs) in the Andes/western Amazon regions of Peru. We compared photosynthetic capacity (maximal rate of carboxylation of Rubisco (Vcmax), and the maximum rate of electron transport (Jmax)), leaf mass, nitrogen (N) and phosphorus (P) per unit leaf area (M...
Analysing Amazonian forest productivity using a new individual and trait-based ...
Fyllas, Nikolaos M.; Gloor, Manuel E.; Mercado, Lina; Sitch, Stephen A.; Quesada, Carlos Alberto; null, Tomas; Galbraith, David R.; Torre-Lezama, A.Repeated long-term censuses have revealed large-scale spatial patterns in Amazon basin forest structure and dynamism, with some forests in the west of the basin having up to a twice as high rate of aboveground biomass production and tree recruitment as forests in the east. Possible causes for this variation could be the climatic and edaphic gradients across the basin and/or the spatial distribution of tree spec...
Edaphic, structural and physiological contrasts across Amazon Basin forest-sava...
Lloyd, Jon; null, Tomas; Schrodt, Franziska; Ishida, Francoise Yoko; Feldpausch, Ted R.; Saiz, Gustavo; Quesada, Carlos Alberto; Schwarz, MichaelSampling along a precipitation gradient in tropical South America extending from ca. 0.8 to 2.0 m ag-1, savanna soils had consistently lower exchangeable cation concentrations and higher C/N ratios than nearby forest plots. These soil differences were also reflected in canopy averaged leaf traits with savanna trees typically having higher leaf mass per unit area but lower mass-based nitrogen (Nm) and potassium ...
The influence of C3 and C4 vegetation on soil organic matter dynamics in contra...
Saiz, Gustavo; Bird, Michael I.; Wurster, Christopher M.; Quesada, Carlos Alberto; Ascough, Philippa L.; null, Tomas; Schrodt, FranziskaVariations in the carbon isotopic composition of soil organic matter (SOM) in bulk and fractionated samples were used to assess the influence of C3 and C4 vegetation on SOM dynamics in semi-natural tropical ecosystems sampled along a precipitation gradient in West Africa. Differential patterns in SOM dynamics in C3/C4 mixed ecosystems occurred at various spatial scales. Relative changes in C / N ratios between ...
Biome-specific effects of nitrogen and phosphorus on the photosynthetic charact...
null, Tomas; Ishida, Francoise Yoko; Feldpausch, Ted R.; Grace, John; Meir, Patrick W.; Saiz, Gustavo; Séné, Olivier; Schrodt, FranziskaPhotosynthesis/nutrient relationships of proximally growing forest and savanna trees were determined in an ecotonal region of Cameroon (Africa). Although area-based foliar N concentrations were typically lower for savanna trees, there was no difference in photosynthetic rates between the two vegetation formation types. Opposite to N, area-based P concentrations were—on average—slightly lower for forest trees; a...