Key message

The difference in gas exchange between C. formosensis and C. obtusa var. formosana reflects their ecological niches. Elevated growth temperature limited photosynthesis and acclimation of both species to a similar degree.

Elevated temperature caused by global warming influences the growth and physiology of trees. Seedlings of Chamaecyparis formosensis and C. obtusa var. formosana were used in this study to understand the influence of high temperature on mountain cloud forest trees. Because seedlings of these two species are dominant in the different ecological niches, C. formosensis dominant in gap while C. obtusa var. formosana under canopy, they might have different gas exchange parameters and different sensitivity to high temperatures. In this study, gas exchange of seedlings of these two species grown in five temperature regimes, 15/13 °C, 20/15 °C, 25/20 °C, 30/25 °C, and 35/30 °C (11/13 h) was compared. In comparison between the two species, C. formosensis had higher CO₂ assimilation rate (A) and transpiration rate (E) than C. obtusa var. formosana. In both species, A and stomatal conductance (g_s) were reduced by high growth temperature. The CO₂ compensation point and relative stomatal limitation of A increased at high temperature but the carboxylation efficiency was not influenced by growth temperature. Therefore, the response of A to growth temperature was influenced more by stomatal conductance than by biochemistry. The optimum temperature for A (T_opt) of both cypresses increased with growth temperature but no difference was found between two species. At high leaf temperature, seedlings grown at high temperatures did not have higher A than those grown at low temperatures. Accordingly, the difference in gas exchange between C. formosensis and C. obtusa var. formosana reflects their ecological niches. Elevated temperature limited photosynthesis and acclimation of both species to a similar degree.

中文翻译：

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生长温度对中华绒螯蟹和钝角梭菌气体交换的影响。福寿树幼苗占据不同的生态位

关键信息

C. formosensis和C. obtusa var之间气体交换的差异。福尔摩萨纳（Formosana）反映了他们的生态位。升高的生长温度将两个物种的光合作用和驯化限制在相似的程度。

由全球变暖引起的温度升高会影响树木的生长和生理。Chamaecyparis formosensis和C. obtusa var。的幼苗 在本研究中使用了formosana来了解高温对山云林木的影响。因为这两个物种的幼苗在不同的生态位中占优势，所以C. formosensis在缺口中占优势，而C. obtusa var。在土壤中占优势。福尔摩萨纳在冠层下，它们可能具有不同的气体交换参数和对高温的不同敏感性。在本研究中，这两种物种的幼苗在15/13°C，20/15°C，25/20°C，30/25°C和35/30°C的五个温度范围内进行的气体交换（11 / 13 h）进行了比较。比较这两个物种，C。formosensis的CO ₂同化率（A）和蒸腾速率（E）比C. obtusa var高。福尔摩萨纳。在两个物种中，高生长温度都会降低A和气孔导度（g _s）。CO _2的补偿点和相对气孔限制甲增加在高温但羧化效率不是由生长温度的影响。因此，A对生长温度的反应受气孔导度的影响大于受生化作用的影响。两种柏树的A（T _opt）的最佳温度均随生长温度的升高而增加，但两种树种之间没有发现差异。在高温下，高温下生长的幼苗比低温下生长的幼苗具有更高的A。因此，C。formosensis和C. obtusa var之间气体交换的差异。福尔摩萨纳反映了他们的生态位。升高的温度限制了两个物种的光合作用和适应程度。