Leaf temperature changes with incident light intensity, but it is unclear how the concurrent changes influence leaf photosynthesis. We examined the time courses of CO₂ gas exchanges and chlorophyll fluorescence of seedling leaves in four tropical tree species in response to lightflecks under three different temperature conditions. The three conditions were two constant temperatures at 30°C (T₃₀) and 40°C (T₄₀), and a simulated gradually changing temperature from 30 to 40°C (T_dyn). The time required to reach 50% of the full photosynthetic induction under T₄₀ was similar to, or even larger than, that under T₃₀. However, the induction of assimilation rate (A) and electron transport rate of photosystem II (ETR II) and Rubisco activation process were generally accelerated under T_dyn compared to those at either T₃₀ or T₄₀. The acceleration in photosynthetic induction under T_dyn was significantly greater in the shade-tolerant species than in the shade-intolerant species. A modified photosynthetic limitation analysis indicated that the acceleration was likely to be mainly due to ETR II at the early stage of photosynthetic induction. The study suggests that concurrent increases in leaf temperature with light may increase leaf carbon gain under highly fluctuating light in tropical tree seedlings, particularly in shade-tolerant species.

叶片温度随入射光强度而变化，但尚不清楚同时发生的变化如何影响叶片的光合作用。我们研究了在三种不同温度条件下，四种热带树种对斑点的响应，CO ₂气体交换和幼苗叶片的叶绿素荧光的时程。这三个条件是在30°C（Ť₃₀）和40°C（Ť₄₀），以及从30到40°C（Ť_dyn）。达到50％的光合作用诱导所需的时间Ť₄₀倍于甚至大于Ť₃₀。但是，同化率的诱导（一种）和光系统II（ETR II）的电子传输速率和Rubisco活化过程通常在 Ť_dyn与任何_一家相比Ť₃₀或Ť₄₀。光合作用下的光合作用加速Ť_dyn在耐荫物种中明显大于耐荫物种。修改后的光合作用限制分析表明，加速可能主要归因于光合作用诱导初期的ETR II。研究表明，在高度波动的光照下，热带树木的幼苗，特别是在耐荫树种中，随着温度的升高叶片温度的同时升高可能会增加叶片碳的吸收。