The regrowth of a C3 forage Stylosanthes capitata in a rain-fed field provided the weekly data collection in the southeast of Brazil during a heat event in autumn. A system named Trop-T-FACE simulated the free-air carbon dioxide enrichment and the enhanced temperature in four climatic regimes: current atmospheric conditions (Control), CO2 enrichment (600 ppm, eC), warming (2 °C above ambient canopy temperature, eT), and a combination of eC + eT. The area and biomass of foliage per shoot decreased, and the number of flowers per shoot and flowered ramification increased under single eC treatment besides the increment in palisade parenchyma of leaves. Increased investment in flowering in eC occurred notably when the soil water content was higher than 0.30 m3 m–3. Single eT treatment also impaired the area or biomass of foliage production per shoot, raised the shoot mortality, and promoted the increment of the spongy leaf parenchyma. There was some mitigation of the adverse effects of foliage production of eT or eC in eC + eT, but under this combined treatment, the shoot mortality also increased. Changes in leaf tissues under eC or eT or some mitigation of adverse effects in eC + eT did not offset the constraints on leaf growth per shoot. The harmful impact on foliage production by eC, eT, or eC + eT under rain-fed conditions indicated no advantages for feeding the livestock with the C3 forage S. capitata in expected climate change under field conditions.

中文翻译：

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田间二氧化碳浓度升高并不能抵消气候变暖或干旱对 C3 牧草叶片生长的限制

C的再生3饲料柱花草在巴西东南部秋季高温事件期间，一个雨水灌溉的田地提供了每周的数据收集。一个名为 Trop-T-FACE 的系统模拟了四种气候条件下的自由空气二氧化碳富集和温度升高：当前大气条件（控制）、CO2富集（600 ppm，eC），升温（高于环境冠层温度 2 °C，eT），以及 eC + eT 的组合。单次eC处理除了增加叶片栅栏薄壁组织外，每枝叶面积和生物量减少，每枝花数和开花分枝增加。当土壤含水量高于 0.30 m 时，eC 的开花投资显着增加3米–3. 单一的 eT 处理还损害了每枝叶片产生的面积或生物量，提高了枝条死亡率，并促进了海绵状叶薄壁组织的增加。在eC+eT中，eT或eC对叶片产生的不利影响有所缓解，但在这种联合处理下，枝条死亡率也有所增加。eC 或 eT 下叶片组织的变化或 eC + eT 不利影响的某些缓解并不能抵消对每枝叶片生长的限制。eC、eT 或 eC + eT 在雨养条件下对叶子生产的有害影响表明用 C 喂养牲畜没有优势3饲料头孢菌在现场条件下的预期气候变化中。