Interspecific consistency and intraspecific variability of specific leaf area with respect to irradiance and nutrient availability
Interspecific consistency and intraspecific variability of specific leaf area with respect to irradiance and nutrient availability
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DOI：
10.1080/11956860.2003.11682753
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发表时间：
2003-01
期刊：
影响因子：
--
通讯作者：
B. Shipley;J. Almeida-Cortez
中科院分区：
文献类型：
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作者：
B. Shipley;J. Almeida-Cortez
摘要 比叶面积 (SLA) 是比较植物生态学中的一个常见变量，通常在田间种植的植物上进行测量，但 SLA 被认为是一种可塑性状。因此，本研究的动机是确定环境诱导的 SLA 可塑性在多大程度上可能掩盖种间趋势。具体来说，我们测试了以下假设：SLA 在低辐照度下比在高辐照度下对营养胁迫更敏感。为了检验这一假设，我们在 500、250 和 125 µmol m-2 s-1 辐照度以及全浓度 (1/1)、1/5 和 1/10 稀释的改良 Hoagland 水培溶液的阶乘组合中种植了六种草本菊科植物。全浓度溶液含有 8 mM 氮。在发芽后第21、28、35和42天收获植物。 SLA 在物种、收获日期和实验处理之间存在显着差异。一般来说，SLA 随着年龄的增长而降低，但在低辐照度下更为严重。 SLA 随着辐照度的降低而增加。 SLA 也随着养分浓度的增加而增加，但这种效应在较老的植物中在较高的辐照度下消失。这些趋势并非在每个物种中都可见。我们的假设得到了支持：SLA 在低辐照度下比在高辐照度下对营养胁迫的反应更敏感，但确切的反应是因物种而异的。尽管在种内水平上环境引起了 SLA 的变化，但跨环境仍保持了种间差异，证明使用 SLA 作为比较植物生态学中的有用性状是合理的。
Abstract Specific leaf area (SLA) is a common variable in comparative plant ecology that is often measured on field-grown plants, yet SLA is known to be a plastic trait. The motivation for this study was therefore to determine the degree to which environmentally induced plasticity in SLA might obscure interspecific trends. Specifically, we tested the hypothesis that SLA is more responsive to nutrient stress at low irradiance than at high irradiance. To test this hypothesis we grew plants of six species of herbaceous Asteraceae in factorial combinations of 500, 250, and 125 µmol m-2 s-1 irradiance and a full strength (1/1), a 1/5, and a 1/10 dilution of a modified Hoagland hydroponic solution. The full strength solution had 8 mM of nitrogen. Plants were harvested at 21, 28, 35, and 42 days from germination. SLA varied significantly between species, harvest dates, and experimental treatments. In general, SLA decreased with age, but more severely at low irradiance. SLA increased with decreasing irradiance. SLA also increased with increasing nutrient concentration, but this effect disappeared in the older plants at the higher irradiance. These trends were not seen in every species. Our hypothesis was supported: SLA is more responsive to nutrient stress at low irradiance than at high irradiance, but the exact response is species-specific. Despite these environmentally induced changes in SLA at the intraspecific level, the interspecific differences were maintained across environments, justifying the use of SLA as a useful trait in comparative plant ecology.