Foliar pH as a new plant trait:: can it explain variation in foliar chemistry and carbon cycling processes among subarctic plant species and types?
Foliar pH as a new plant trait:: can it explain variation in foliar chemistry and carbon cycling processes among subarctic plant species and types?
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DOI：
10.1007/s00442-005-0269-z
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发表时间：
2006-03-01
期刊：
影响因子：
2.7
通讯作者：
Aerts, R
中科院分区：
文献类型：
--
作者：
Cornelissen, JHC;Quested, HM;Aerts, R
植物性状作为重要生态系统特性和过程的种间变异的预测因子已变得流行。在这里，我们将叶面 pH 值作为一种可能的新植物性状引入，并测试了 (1) 绿叶 pH 值或落叶 pH 值是否与与生物地球化学循环相关的生化和结构叶面性状相关； (2) 根据养分吸收模式和更高的分类学定义，不同植物类型的绿叶 pH 值或凋落物 pH 值存在一致的变化； (3) 绿叶 pH 值可以预测植物种类和类型之间叶子消化率变化的显着比例； (4) 叶凋落物 pH 值可以预测植物种类和类型之间叶凋落物分解能力的很大比例的变化。我们发现了一些证据支持亚北极植物区系中多种物种的所有四种假设，尽管隐花植物（蕨类植物和苔藓）在给定 pH 下表现出相对较差的叶子消化率或凋落物分解性，从而往往会削弱这些模式。在种子植物物种中，绿叶 pH 值本身只能解释叶消化率种间变异的三分之一，而凋落物可分解性的种间变异则最多解释四分之一。然而，当作为第二个变量添加到回归模型中时，叶面 pH 值大大提高了叶面木质素和/或纤维素浓度作为这些过程的预测因子的能力。当物种被聚合成由更高的分类学和养分吸收模式定义的植物类型时，绿色特定叶面积比任何生化性状（包括 pH 值）更能预测可消化性或可分解性。叶面 pH 值作为一种新的预测性状的有用性，无论是否与其他性状结合，仍有待在更多植物物种、类型和生物群落中进行测试，以及与其他植物或生态系统性状和过程的关系。
Plant traits have become popular as predictors of interspecific variation in important ecosystem properties and processes. Here we introduce foliar pH as a possible new plant trait, and tested whether (1) green leaf pH or leaf litter pH correlates with biochemical and structural foliar traits that are linked to biogeochemical cycling; (2) there is consistent variation in green leaf pH or leaf litter pH among plant types as defined by nutrient uptake mode and higher taxonomy; (3) green leaf pH can predict a significant proportion of variation in leaf digestibility among plant species and types; (4) leaf litter pH can predict a significant proportion of variation in leaf litter decomposability among plant species and types. We found some evidence in support of all four hypotheses for a wide range of species in a subarctic flora, although cryptogams (fern allies and a moss) tended to weaken the patterns by showing relatively poor leaf digestibility or litter decomposability at a given pH. Among seed plant species, green leaf pH itself explained only up to a third of the interspecific variation in leaf digestibility and leaf litter up to a quarter of the interspecific variation in leaf litter decomposability. However, foliar pH substantially improved the power of foliar lignin and/or cellulose concentrations as predictors of these processes when added to regression models as a second variable. When species were aggregated into plant types as defined by higher taxonomy and nutrient uptake mode, green-specific leaf area was a more powerful predictor of digestibility or decomposability than any of the biochemical traits including pH. The usefulness of foliar pH as a new predictive trait, whether or not in combination with other traits, remains to be tested across more plant species, types and biomes, and also in relation to other plant or ecosystem traits and processes.