Data - Climate change impacts on Lactuca sativa.xlsx

Plant species are adapted to survive under specific ranges of temperature, water availability, and atmospheric CO₂ concentration. Climate change-induced shifts in these environmental conditions have the potential to significantly affect nearly all terrestrial plants. A number of studies have explored the impacts of changing one or two of the conditions listed above, but few have examined the combined effects of all three. To study the cumulative influences of the three environmental conditions, 350 Mānoa lettuce (<i>Lactuca sativa</i>) plants were grown in indoor growth chambers. Within the chambers, plants were grown under varying degrees of CO₂ concentration, water availability, and temperature for 21 days. At the end of this period, the leaf mass (biomass) of each plant was cut, dried, and weighed. Percent mortality and nitrogen content were also measured. Across all combinations of temperature and water availability, elevated CO₂ concentrations were associated with increased biomass production and survival rates. Survival and biomass decreased under high temperatures and both high and low water availability. The combination of environmental conditions that produced the largest amount of biomass was 750 ppm CO₂, 80% of soil water capacity, and 24 °C while the treatment that produced the least amount was ambient CO₂, 60% of soil water capacity, and 36 °C. Nitrogen content increased under high temperatures and water availability. These results suggest that although increased atmospheric CO₂ levels have the potential to promote lettuce growth, lettuce yield is still likely to decrease in many regions due to the negative effects of high temperatures, drought, and flooding.<br>

植物物种均适应于特定的温度、水分可利用性及大气CO₂浓度范围。气候变化引发的上述环境条件变动，可能对几乎所有陆生植物造成显著影响。目前已有多项研究探讨了上述1至2种环境条件变化的影响，但鲜有研究同时考察三者的综合效应。为探究这三种环境条件的累积影响，研究人员在室内生长箱中种植了350株马诺阿生菜（*Lactuca sativa*）。在生长箱内，植株被置于不同梯度的CO₂浓度、水分可利用性及温度条件下培养21天。试验周期结束后，采集每株植株的叶片质量（生物量），经切割、烘干后称重；同时还测定了植株的死亡率百分比与氮含量。在所有温度与水分可利用性的组合条件下，升高的CO₂浓度均与生物量积累及存活率提升呈正相关。在高温以及水分可利用性过高或过低的条件下，植株存活率与生物量均会下降。能够产生最大生物量的环境组合为750 ppm CO₂、土壤持水量的80%与24 ℃，而产生最低生物量的处理组为大气背景CO₂浓度、土壤持水量的60%与36 ℃。在高温以及水分可利用性过高或过低的条件下，植株氮含量会升高。本研究结果表明，尽管大气CO₂浓度升高有可能促进生菜生长，但在许多区域，受高温、干旱与涝渍的负面影响，生菜产量仍有可能下降。