Photosynthesis–nitrogen relationships in tropical forest tree species as affected by soil phosphorus availability: a controlled environment study

2014 ◽  
Vol 41 (8) ◽  
pp. 820 ◽  
Author(s):  
Keith J. Bloomfield ◽  
Graham D. Farquhar ◽  
Jon Lloyd
Keyword(s):  
Tropical Forest ◽  
Tree Species ◽  
Tropical Trees ◽  
Leaf Nitrogen ◽  
Phosphorus Availability ◽  
Tropical Tree ◽  
P Availability ◽  
Soil P ◽  
Tropical Tree Species ◽  
Soil P Availability

Tropical soils are often characterised by low phosphorus availability and tropical forest trees typically exhibit lower area-based rates of photosynthesis (Aa) for a given area-based leaf nitrogen concentration ([N]a) compared with plants growing in higher-latitude, N-limited ecosystems. Nevertheless, to date, very few studies have assessed the effects of P deprivation per se on Aa ↔ [N]a relationships in tropical trees. Our study investigated the effect of reduced soil P availability on light-saturated Aa and related leaf traits of seven Australian tropical tree species. We addressed the following questions: (1) Do contrasting species exhibit inherent differences in nutrient partitioning and morphology? (2) Does P deprivation lead to a change in the nature of the Aa ↔ [N]a relationship? (3) Does P deprivation lead to an alteration in leaf nitrogen levels or N allocation within the leaf? Applying a mixed effects model, we found that for these Australian tropical tree species, removal of P from the nutrient solution decreased area-based photosynthetic capacity (Amax,a) by 18% and reduced the slope of the Amax,a ↔ [N]a relationship and differences among species accounted for around 30% of response variation. Despite greater N allocation to chlorophyll, photosynthetic N use efficiency was significantly reduced in low-P plants. Collectively, our results support the view that low soil P availability can alter photosynthesis–nitrogen relationships in tropical trees.

Physiological linkage in co-variation of foliar nitrogen and phosphorus in tropical tree species along a gradient of soil phosphorus availability

2015 ◽  
Vol 31 (3) ◽  
pp. 221-229 ◽  
Author(s):  
Amane Hidaka ◽  
Kanehiro Kitayama
Keyword(s):  
Tree Species ◽  
Tropical Tree ◽  
Scaling Exponent ◽  
P Availability ◽  
Nitrogen And Phosphorus ◽  
Foliar Nitrogen ◽  
Soil P ◽  
Tropical Tree Species ◽  
Foliar N ◽  
Senesced Leaves

Abstract:In order to understand the stoichiometric balance between foliar nitrogen (N) and phosphorus (P) on P-poor soils, we investigated how foliar N and P attributes (i.e. N and P concentrations in green and senesced leaves, N and P resorption efficiencies) of 30 tropical tree species co-vary along a gradient of soil P availability across three forests on Mount Kinabalu, Borneo. We found strong and positive correlations between foliar N and P in the concentrations and resorption efficiencies within each forest and across the three forests. Slopes of standardized major axis between foliar N and P concentrations for both green and senesced leaves were not different among the three forests, although the values of the scaling exponent in the relationships of foliar N to P across the three forests were significantly lower than 1. We suggest that down-regulation of N concentrations in green leaves on P-poor soils is one of several possible mechanisms explaining why N concentrations decrease with decreasing P concentrations in both green and senesced leaves toward a lower P availability in soils. On the other hand, the physiological and ecological reasons why N and P resorption efficiencies are positively correlated with each other across tree species remain unclear.

scholarly journals Classification of Tropical Forest Tree Species Using Meter-Scale Image Data

2019 ◽  
Vol 11 (12) ◽  
pp. 1411 ◽  
Author(s):  
Matthew Cross ◽  
Ted Scambos ◽  
Fabio Pacifici ◽  
Orlando Vargas-Ramirez ◽  
Rafael Moreno-Sanchez ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Tree Species ◽  
Near Infrared ◽  
Single Species ◽  
Forest Tree ◽  
Tropical Tree ◽  
Forest Composition ◽  
Species Classification ◽  
Tropical Tree Species

Accurate classification of tropical tree species is critical for understanding forest habitat, biodiversity, forest composition, biomass, and the role of trees in climate variability through carbon uptake. The aim of this study is to establish an accurate classification procedure for tropical tree species, specifically testing the feasibility of WorldView-3 (WV-3) multispectral imagery for this task. The specific study site is a defined arboretum within a well-known tropical forest research location in Costa Rica (La Selva Biological Station). An object-based classification is the basis for the analysis to classify six selected tree species. A combination of pre-processed WV-3 bands were inputs to the classification, and an edge segmentation process defined multi-pixel-scale tree canopies. WorldView-3 bands in the Green, Red, Red Edge, and Near-Infrared 2, particularly when incorporated in two specialized vegetation indices, provide high discrimination among the selected species. Classification results yield an accuracy of 85.37%, with minimal errors of commission (7.89%) and omission (14.63%). Shadowing in the satellite imagery had a significant effect on segmentation accuracy (identifying single-species canopy tops) and on classification. The methodology presented provides a path to better characterization of tropical forest species distribution and overall composition for improving biomass studies in a tropical environment.

scholarly journals Ruzigrass affecting soil-phosphorus availability

2013 ◽  
Vol 48 (12) ◽  
pp. 1583-1588 ◽  
Author(s):  
Alexandre Merlin ◽  
Zhenli Li He ◽  
Ciro Antonio Rosolem
Keyword(s):  
Cover Crops ◽  
Cropping System ◽  
Phosphorus Availability ◽  
Phosphorus Fertilization ◽  
P Availability ◽  
P Fertilization ◽  
Rock Phosphates ◽  
P Fractionation ◽  
Soil P ◽  
Soil P Availability

The objective of this work was to evaluate the effectiveness of ruzigrass (Urochloaruziziensis) in enhancing soil-P availability in areas fertilized with soluble or reactive rock phosphates. The area had been cropped for five years under no-till, in a system involving soybean, triticale/black-oat, and pearl millet. Previously to the five-year cultivation period, corrective phosphorus fertilization was applied once on soil surface, at 0.0 and 80 kg ha-1 P2O5, as triple superphosphate or Arad rock phosphate. After this five-year period, plots received the same corrective P fertilization as before and ruzigrass was introduced to the cropping system in the stead of the other cover crops. Soil samples were taken (0-10 cm) after ruzigrass cultivation and subjected to soil-P fractionation. Soybean was grown thereafter without P application to seed furrow. Phosphorus availability in plots with ruzigrass was compared to the ones with spontaneous vegetation for two years. Ruzigrass cultivation increased inorganic (resin-extracted) and organic (NaHCO3) soil P, as well as P concentration in soybean leaves, regardless of the P source. However, soybean yield did not increase significantly due to ruzigrass introduction to the cropping system. Soil-P availability did not differ between soluble and reactive P sources. Ruzigrass increases soil-P availability, especially where corrective P fertilization is performed.

Temperature response of CO2 exchange in three tropical tree species

2016 ◽  
Vol 43 (5) ◽  
pp. 468 ◽  
Author(s):  
Martijn Slot ◽  
Milton N. Garcia ◽  
Klaus Winter
Keyword(s):  
Tropical Forest ◽  
Tree Species ◽  
Temperature Response ◽  
Carbon Fluxes ◽  
Co2 Exchange ◽  
Tropical Tree ◽  
Membrane Properties ◽  
Complete Suppression ◽  
Tropical Tree Species ◽  
Successional Species

Tropical forests play a critical role in the global carbon cycle, but our limited understanding of the physiological sensitivity of tropical forest trees to environmental factors complicates predictions of tropical carbon fluxes in a changing climate. We determined the short-term temperature response of leaf photosynthesis and respiration of seedlings of three tropical tree species from Panama. For one of the species net CO2 exchange was also measured in situ. Dark respiration of all species increased linearly – not exponentially – over a ~30°C temperature range. The early-successional species Ficus insipida Willd. and Ochroma pyramidale (Cav. ex Lam.) Urb. had higher temperature optima for photosynthesis (Topt) and higher photosynthesis rates at Topt than the late-successional species Calophyllum longifolium Willd. The decrease in photosynthesis above Topt could be assigned, in part, to observed temperature-stimulated photorespiration and decreasing stomatal conductance (gS), with unmeasured processes such as respiration in the light, Rubisco deactivation, and changing membrane properties probably playing important additional roles, particularly at very high temperatures. As temperature increased above Topt, gS of laboratory-measured leaves first decreased, followed by an increase at temperatures >40−45°C. In contrast, gS of canopy leaves of F. insipida in the field continued to decrease with increasing temperature, causing complete suppression of photosynthesis at ~45°C, whereas photosynthesis in the laboratory did not reach zero until leaf temperature was ~50°C. Models parameterised with laboratory-derived data should be validated against field observations when they are used to predict tropical forest carbon fluxes.

Development and characterization of 15 microsatellite loci for Cariniana estrellensis and transferability to Cariniana legalis, two endangered tropical tree species

2008 ◽  
Vol 10 (4) ◽  
pp. 1001-1004 ◽  
Author(s):  
Marcela Corbo Guidugli ◽  
Tatiana de Campos ◽  
Adna Cristina Barbosa de Sousa ◽  
Juliana Massimino Feres ◽  
Alexandre Magno Sebbenn ◽  
...  
Keyword(s):  
Microsatellite Loci ◽  
Tree Species ◽  
Tropical Tree ◽  
Tropical Tree Species ◽  
Cariniana Legalis

scholarly journals Large differences in leaf cuticle conductance and its temperature response among 24 tropical tree species from across a rainfall gradient

2021 ◽  
Author(s):  
Martijn Slot ◽  
Tantawat Nardwattanawong ◽  
Georgia G. Hernández ◽  
Amauri Bueno ◽  
Markus Riederer ◽  
...  
Keyword(s):  
Tree Species ◽  
Temperature Response ◽  
Tropical Tree ◽  
Rainfall Gradient ◽  
Tropical Tree Species ◽  
Leaf Cuticle
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