The response of fast- and slow-growing Acacia species to elevated atmospheric CO2:: an analysis of the underlying components of relative growth rate
The response of fast- and slow-growing Acacia species to elevated atmospheric CO2:: an analysis of the underlying components of relative growth rate
复制标题
DOI：
10.1007/s004420050889
复制
发表时间：
1999-09-01
期刊：
影响因子：
2.7
通讯作者：
Evans, JR
中科院分区：
文献类型：
--
作者：
Atkin, OK;Schortemeyer, M;Evans, JR
在这项研究中，我们评估了二氧化碳浓度升高与无限的水和完整的营养对10种不同的相对增长率（RGR）的木本相思树的生长和氮经济的影响。具体来说我们询问快速生长和缓慢生长的物种对二氧化碳浓度升高的反应是否存在系统性差异。本文报道了4种生长缓慢的半干旱植物（Acacia aneura，A. colei，A. coriacea和A. tagonophylla）和6种中温环境速生树种银荆Acacia dealbata，A. implexa、黑腹拟步行虫A. mearnsii、黑腹拟步行虫A. melanoxylon、黑木A.和A.柳属植物）在具有环境（类似于350 ppm）或升高的（类似于700 ppm）大气CO2的温室中生长。所有物种都达到了更大的最终植物质量，除了A。aneura，和RGR，平均在所有物种，增加了10%，超过12周的时间内，当植物暴露于CO2浓度升高。RGR的刺激在整个12周的生长期内是明显的。CO2浓度升高导致每单位叶片干质量的叶面积减少，这主要是由于叶片厚度增加，每单位鲜质量的干物质含量增加的贡献较小。净同化率（NAR，增加植物质量每单位叶面积和时间）的植物生长在升高的CO2是在所有物种（平均30%以上，比植物在环境CO2），并负责增加RGR。较高的NAR与叶氮生产力的大幅增加，在所有10种相思树。植物氮浓度不变的增长，在CO2浓度升高的生长缓慢的相思树种，但下降了10%的快速增长的物种。氮的吸收率每单位根质量是较高的，在7个物种生长时，CO2浓度升高，每单位根质量的叶面积减少，CO2浓度升高的7个物种。在RGR的绝对增加，由于CO2浓度升高下的增长速度快，比生长缓慢的相思树种。
In this study we assessed the impact of elevated CO2 with unlimited water and complete nutrient on the growth and nitrogen economy of ten woody Acacia species that differ in relative growth rate (RGR). Specifically. we asked whether fast- and slow-growing species systematically differ in their response to elevated CO2. Four slow-growing species from semi-arid environments (Acacia aneura, A. colei, A. coriacea and A. tetragonophylla) and six fast-growing species from mesic environments (Acacia dealbata, A. implexa, A. mearnsii, A. melanoxylon, A. irrorata and A. saligna) were grown in glasshouses with either ambient (similar to 350 ppm) or elevated (similar to 700 ppm) atmospheric CO2. All species reached greater final plant mass with the exception of A. aneura, and RGR, averaged across all species, increased by 10% over a 12-week period when plants were exposed to elevated CO2. The stimulation of RGR was evident throughout the 12-week growth period. Elevated CO2 resulted in less foliage area per unit foliage dry mass, which was mainly the result of an increase in foliage thickness with a smaller contribution from greater dry matter content per unit fresh mass. The net assimilation rate (NAR, increase in plant mass per unit foliage area and time) of the plants grown at elevated CO2 was higher in all species (on average 30% higher than plants in ambient CO2) and was responsible for the increase in RGR. The higher NAR was associated with a substantial increase in foliar nitrogen productivity in all ten Acacia species. Plant nitrogen concentration was unaltered by growth at elevated CO2 for the slow-growing Acacia species, but declined by 10% for faster-growing species. The rate of nitrogen uptake per unit root mass was higher in seven of the species when grown under elevated CO2, and leaf area per unit root mass was reduced by elevated CO2 in seven of the species. The absolute increase in RGR due to growth under elevated CO2 was greater for fast- than for slow-growing Acacia species.