Chu Celia C, Field Christopher B, Mooney Harold A
Department of Biological Sciences, Stanford University, 94305, Stanford, CA, USA.
Department of Plant Biology, Carnegie Institution of Washington, 94305, Stanford, CA, USA.
Oecologia. 1996 Sep;107(4):433-440. doi: 10.1007/BF00333932.
The effects of CO enrichment and soil nutrient status on tissue quality were investigated and related to the potential effect on growth and decomposition. Two California annuals, Avena fatua and Plantago erecta, were grown at ambient and ambient plus 35 Pa atmospheric CO in nutrient unamended and amended serpentine soil. Elevated CO led to significantly increased Avena shoot nitrogen concentrations in the nutrient amended treatment. It also led to decreased lignin concentrations in Avena roots in both nutrient treatments, and in Plantago shoots and roots with nutrient addition. Concentrations of total nonstructural carbohydrate (TNC) and carbon did not change with elevated CO in either species. As a consequence of increased biomass accumulation, increased CO led to larger total pools of TNC, lignin, total carbon, and total nitrogen in Avena with nutrient additions. Doubling CO had no significant effect on Plantago. Given the limited changes in the compounds related to decomposibility and plant growth, effects of increased atmospheric CO mediated through tissue composition on Avena and Plantago are likely to be minor and depend on site fertility. This study suggests that other factors such as litter moisture, whether or not litter is on the ground, and biomass allocation among roots and shoots, are likely to be more important in this California grassland ecosystem. CO could influence those directly as well as indirectly.
研究了二氧化碳浓度升高和土壤养分状况对组织质量的影响，并探讨了其对生长和分解的潜在影响。在未添加养分和添加养分的蛇纹石土壤中，种植了两种加利福尼亚一年生植物，即野燕麦和直立车前，分别置于环境二氧化碳浓度和环境二氧化碳浓度加35帕的条件下。在添加养分的处理中，二氧化碳浓度升高导致野燕麦地上部分氮浓度显著增加。在两种养分处理中，二氧化碳浓度升高还导致野燕麦根部木质素浓度降低，在添加养分的情况下，直立车前地上部分和根部的木质素浓度也降低。两种植物中，总非结构性碳水化合物（TNC）和碳的浓度均未随二氧化碳浓度升高而变化。由于生物量积累增加，在添加养分的情况下，二氧化碳浓度升高导致野燕麦中TNC、木质素、总碳和总氮的总量增加。二氧化碳浓度翻倍对直立车前没有显著影响。鉴于与分解性和植物生长相关的化合物变化有限，大气二氧化碳浓度升高通过组织组成对野燕麦和直立车前产生的影响可能较小，且取决于土壤肥力。本研究表明，在这个加利福尼亚草原生态系统中，其他因素，如凋落物湿度、凋落物是否在地面以及根和地上部分之间的生物量分配，可能更为重要。二氧化碳可能会直接或间接地影响这些因素。
