Growth response and acclimation of CO2 exchange characteristics to elevated temperatures in tropical tree seedlings

Abstract

Predictions of how tropical forests will respond to future climate change are constrained by the paucity of data on the performance of tropical species under elevated growth temperatures. In particular, little is known about the potential of tropical species to acclimate physiologically to future increases in temperature. Seedlings of 10 neo-tropical tree species from different functional groups were cultivated in controlled-environment chambers under four day/night temperature regimes between 30/22 °C and 39/31 °C. Under well-watered conditions, all species showed optimal growth at temperatures above those currently found in their native range. While non-pioneer species experienced catastrophic failure or a substantially reduced growth rate under the highest temperature regime employed (i.e. daily average of 35 °C), growth in three lowland pioneers showed only a marginal reduction. In a subsequent experiment, three species (Ficus insipida, Ormosia macrocalyx, and Ochroma pyramidale) were cultivated at two temperatures determined as sub- and superoptimal for growth, but which resulted in similar biomass accumulation despite a 6°C difference in growth temperature. Through reciprocal transfer and temperature adjustment, the role of thermal acclimation in photosynthesis and respiration was investigated. Acclimation potential varied among species, with two distinct patterns of respiration acclimation identified. The study highlights the role of both inherent temperature tolerance and thermal acclimation in determining the ability of tropical tree species to cope with enhanced temperatures.

Acclimation of Biochemical and Diffusive Components of Photosynthesis in Rice, Wheat, and Maize to Heat and Water Deficit: Implications for Modeling Photosynthesis

“…In many studies, short-term responses are taken as evidence to predict the future photosynthetic performance of a given species under a changing climate. However, there are at least two factors that can bias these responses: (i) interactions between stresses, and (ii) acclimation in the long-term (Centritto et al, 2002; Flexas et al, 2006a; Vile et al, 2012; Cheesman and Winter, 2013). Regarding interactions, these are evidenced by measuring at 38°C plants grown at CT and subjected to water deficit (CT-WD-38°C).…”

“…In nature plants face long-term exposure to water deficit and high temperature, and photosynthesis and mitochondrial respiration have been shown to acclimate to both water (Walters, 2005; Galmés et al, 2006; Flexas et al, 2009) and heat stress (Berry and Björkman, 1980; Yamori et al, 2005; Campbell et al, 2007; Sage and Kubien, 2007), although the capacity and mechanisms of plant acclimation may differ between species (Hikosaka et al, 2006; Kattge and Knorr, 2007; Dillaway and Kruger, 2011; Scafaro et al, 2011; Cheesman and Winter, 2013). In semi-arid climates like the Mediterranean, drought, and heat stress occur simultaneously and exert a combined effect on plant functioning (Mittler, 2006).…”

Will heterotrophic soil respiration be more sensitive to warming than autotrophic respiration in subtropical forests?

“…Temperatures in the tropics and subtropics have been reported as being close to the high‐temperature threshold for plant growth (Doughty & Goulden, ). Therefore, climate warming in these regions could reduce plant photosynthesis or even cause plant death (Cheesman & Winter, ; Doughty & Goulden, ). These studies indicated that the responses of R h and R a to climate warming in tropical and subtropical forests could be very different from those in temperate or boreal forests.…”

The Arctic oscillation, climatic variability, and biotic factors influenced seedling dynamics in a Caribbean moist forest

“…Although the temperature range for maximum growth of tropical trees species is 25–35°C (Larcher ), we documented a negative effect of elevated temperature on seedling and sapling RGRh. Additionally, seedlings of 10 neo‐tropical tree species from different functional groups that were grown in controlled environments under well‐watered conditions and various day and night time temperature regimes (30–39°C and 22–31°C, respectively) all showed optimal growth at temperatures above their native range (Cheesman and Winter ). Under the highest temperature regime (daily average of 35°C) however, the non‐pioneer species experienced catastrophic failure or had a significantly lower growth rate, while the growth rates of three lowland pioneers were marginally lower (Cheesman and Winter ).…”

“…). In addition, temperature in the tropics is expected to increase by 2–3°C by 2100 (Corlett ), and consequently, tropical lowland forests will experience temperature regimes that have not occurred since the mid Quaternary (Cheesman and Winter ). Humid tropical lowland ecosystems have a reasonably stable climatic envelope (Wright et al.…”