Comparison of temperate and tropical rainforest tree species: photosynthetic responses to growth temperature

Abstract

Little is known about the differences in physiology between temperate and tropical trees. Australian rainforests extend from tropical climates in the north to temperate climates in the south over a span of 33° latitude. Therefore, they provide an opportunity to investigate differences in the physiology of temperate and tropical trees within the same vegetation type. This study investigated how the response of net photosynthesis to growth temperature differed between Australian temperate and tropical rainforest trees and how this correlated with differences in their climates. The temperate species showed their maximum rate of net photosynthesis at lower growth temperatures than the tropical species. However, the temperate species showed at least 80% of maximum net photosynthesis over a 12-16°C span of growth temperature, compared with a span of 9-11°C shown by the tropical species. The tropical species showed both larger reductions in maximum net photosynthesis at low growth temperatures and larger reductions in the optimum instantaneous temperature for net photosynthesis with decreasing growth temperature than the temperate species. The ability of the temperate species to maintain maximum net photosynthesis over a greater span of growth temperatures than the tropical species is consistent with the greater seasonal and day-to-day variation in temperature of the temperate climate compared with the tropical climate.

Phenotypic Plasticity in Photosynthetic Temperature Acclimation among Crop Species with Different Cold Tolerances

“…Growth temperature-dependent changes in optimum photosynthetic temperature were greater in plants native to desert habitats than in plants native to coastal habitats (Bjö rkman et al, 1975;Pearcy, 1977;Mooney et al, 1978) and were greater in temperate evergreen species than in tropical evergreen species (Hill et al, 1988;Read, 1990;Cunningham and Read, 2002). They suggested that these differences in the phenotypic plasticity were attributed to the extent of the daily and seasonal temperature variations.…”

“…Plants native to low-temperature environments and those grown at low temperatures generally exhibit higher photosynthetic rates at low temperatures and lower optimum temperatures, compared with plants native to high-temperature environments and those grown at high temperatures (Mooney and Billings, 1961;Slatyer, 1977;Berry and Bjö rkman, 1980;Sage, 2002;Salvucci and Crafts-Brandner, 2004b). For example, the optimum temperature for photosynthesis differs between temperate evergreen species and tropical evergreen species (Hill et al, 1988;Read, 1990;Cunningham and Read, 2002). Such differences have been observed even among ecotypes of the same species (Bjö rkman et al, 1975;Pearcy, 1977;Slatyer, 1977).…”

“…The temperature dependence of leaf photosynthetic rate shows considerable variation between plant species and with growth temperature (Berry and Bjö rkman, 1980;Cunningham and Read, 2002;Hikosaka et al, 2006). Plants native to low-temperature environments and those grown at low temperatures generally exhibit higher photosynthetic rates at low temperatures and lower optimum temperatures, compared with plants native to high-temperature environments and those grown at high temperatures (Mooney and Billings, 1961;Slatyer, 1977;Berry and Bjö rkman, 1980;Sage, 2002;Salvucci and Crafts-Brandner, 2004b).…”

Local ecotypic and species range-related adaptation influence photosynthetic temperature optima in deciduous broadleaved trees

“…Taxa can be adapted to their different thermal origins and thus differ in T opt when they grow in a common environment (Berry and Björkman 1980;Cunningham and Read 2002;Gunderson et al 2010). However, it is not clear whether they would still show differences in T opt even when co-occurring, since strong ecotypic adaptation to the common environment might erase any species-scaled differences.…”

“…There is evidence that species or ecotypes growing in colder environment often but not always have lower photosynthetic temperature optima (T opt ) than those growing at higher temperatures (Björkman et al 1972;Fryer and Ledig 1972;Slatyer 1977;Berry and Björkman 1980;Cavieres et al 2000;Cunningham and Read 2002;Gunderson et al 2010). Taxa can be adapted to their different thermal origins and thus differ in T opt when they grow in a common environment (Berry and Björkman 1980;Cunningham and Read 2002;Gunderson et al 2010).…”