Department of Horticulture, The Pennsylvania State University, 103 Tyson Bldg, University Park, PA 16802, USA.
Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park PA, USA.
New Phytol. 2012 Sep;195(4):823-831. doi: 10.1111/j.1469-8137.2012.04198.x. Epub 2012 Jun 11.
Although linkages of leaf and whole-plant traits to leaf lifespan have been rigorously investigated, there is a limited understanding of similar linkages of whole-plant and fine root traits to root lifespan. In comparisons across species, do suites of traits found in leaves also exist for roots, and can these traits be used to predict root lifespan? We observed the fine root lifespan of 12 temperate tree species using minirhizotrons in a common garden and compared their median lifespans with fine-root and whole-plant traits. We then determined which set of combined traits would be most useful in predicting patterns of root lifespan. Median root lifespan ranged widely among species (95-336 d). Root diameter, calcium content, and tree wood density were positively related to root lifespan, whereas specific root length, nitrogen (N) : carbon (C) ratio, and plant growth rate were negatively related to root lifespan. Root diameter and plant growth rate, together (R² = 0.62) or in combination with root N : C ratio (R² = 0.76), were useful predictors of root lifespan across the 12 species. Our results highlight linkages between fine root lifespan in temperate trees and plant functional traits that may reduce uncertainty in predictions of root lifespan or turnover across species at broader spatial scales.
尽管已经严格研究了叶片和整株植物特性与叶片寿命之间的联系，但对于整株植物和细根特性与根寿命之间的类似联系，人们的了解有限。在跨物种比较中，叶片中存在的特征组合是否也存在于根中，并且这些特征可以用于预测根寿命？我们使用小型根管在一个共同花园中观察了 12 种温带树种的细根寿命，并将它们的中值寿命与细根和整株植物特性进行了比较。然后，我们确定了哪一组综合特征最有助于预测根寿命模式。中值根寿命在物种间差异很大（95-336 d）。根直径、钙含量和树木密度与根寿命呈正相关，而比根长、氮（N）：碳（C）比和植物生长率与根寿命呈负相关。根直径和植物生长率（R²=0.62）或与根 N：C 比（R²=0.76）相结合，是 12 个物种中根寿命的有用预测因子。我们的研究结果强调了温带树木细根寿命与植物功能特征之间的联系，这可能会减少在更广泛的空间尺度上预测物种间根寿命或周转率的不确定性。
