Diurnal and seasonal carbon balance of four tropical tree species differing in successional status

This study addressed some questions about how a suitable leaf carbon balance can be attained for different functional groups of tropical tree species under contrasting forest light environments. The study was carried out in a fragment of semi-deciduous seasonal forest in Narandiba county, São Paulo Estate, Brazil. 10-month-old seedlings of four tropical tree species, Bauhinia forficata Link (Caesalpinioideae) and Guazuma ulmifolia Lam. (Sterculiaceae) as light-demanding pioneer species, and Hymenaea courbaril L. (Caesalpinioideae) and Esenbeckia leiocarpa Engl. (Rutaceae) as late successional species, were grown under gap and understorey conditions. Diurnal courses of net photosynthesis (Pn) and transpiration were recorded with an open system portable infrared gas analyzer in two different seasons. Dark respiration and photorespiration were also evaluated in the same leaves used for Pn measurements after dark adaptation. Our results showed that diurnal-integrated dark respiration (Rdi) of late successional species were similar to pioneer species. On the other hand, photorespiration rates were often higher in pioneer than in late successional species in the gap. However, the relative contribution of these parameters to leaf carbon balance was similar in all species in both environmental conditions. Considering diurnal-integrated values, gross photosynthesis (Pgi) was dramatically higher in gap than in understorey, regardless of species. In both evaluated months, there were no differences among species of different functional groups under shade conditions. The same was observed in May (dry season) under gap conditions. In such light environment, pioneers were distinguished from late successional species in November (wet season), showing that ecophysiological performance can have a straightforward relation to seasonality.

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Photosynthetic Characteristics, Dark Respiration, and Leaf Mass Per Unit Area in Seedlings of Four Tropical Tree Species Grown Under Three Irradiances

Photosynthetica ◽

10.1023/b:phot.0000046163.83729.e5 ◽

2004 ◽

Vol 42 (3) ◽

pp. 431-437 ◽

Cited By ~ 38

Author(s):

Y. L. Feng ◽

K. F. Cao ◽

J. L. Zhang

Keyword(s):

Tree Species ◽

Unit Area ◽

Dark Respiration ◽

Photosynthetic Characteristics ◽

Tropical Tree ◽

Tropical Tree Species ◽

Leaf Mass

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Temperature response of CO2 exchange in three tropical tree species

Functional Plant Biology ◽

10.1071/fp15320 ◽

2016 ◽

Vol 43 (5) ◽

pp. 468 ◽

Cited By ~ 37

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.

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Long-term tree ring chronologies from sympatric tropical dry-forest trees: individualistic responses to climatic variation

Journal of Tropical Ecology ◽

10.1017/s0266467401001031 ◽

2001 ◽

Vol 17 (1) ◽

pp. 41-60 ◽

Cited By ~ 75

Author(s):

BRIAN J. ENQUIST ◽

A. JOSHUA LEFFLER

Keyword(s):

Tree Species ◽

Southern Oscillation ◽

Dry Forest ◽

Tropical Tree ◽

Rooting Depth ◽

Forest Trees ◽

Growth Responses ◽

Wet Season ◽

Tropical Tree Species

The influence of local precipitation and temperature on long-term growth dynamics in two species of seasonally dry tropical forest trees were investigated. Growth records were extracted from tree rings in Guanacaste province, Costa Rica. These chronologies provide a long-term (c. 85-y) record of tree growth for two species with contrasting phenologies. Annual growth, in both species, was dependent on annual and/or monthly variation in local precipitation but less so on temperature. For each species, however, patterns of growth reflected unique degrees of sensitivity to monthly rainfall and rainfall during previous years. It is hypothesized that such differences were due to the rooting depth of these species. A review of the literature also indicated similar diverse cambial growth responses by tropical trees to variation in annual and monthly climate. Lastly, it was shown that variation in longer term fluctuations in the Pacific and Atlantic oceans, as measured by the El Niño Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO), significantly influenced local precipitation in Guanacaste only during the wettest portion of the wet season. Such temporal sensitivity may have differentially influenced the longer-term growth of some tropical tree species but not others. Together, these results support the hypothesis that tropical tree species respond individualistically to variation in local and regional climate and that some tropical assemblages may in fact be structured by species-specific differences in soil water-use.

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