Department of Horticulture, Cornell University Ithaca, NY, USA.
Department of Biology, Syracuse University Syracuse, NY, USA.
Front Plant Sci. 2013 Nov 28;4:486. doi: 10.3389/fpls.2013.00486. eCollection 2013.
We examined the hydraulic properties of 82 native and non-native woody species common to forests of Eastern North America, including several congeneric groups, representing a range of anatomical wood types. We observed smaller conduit diameters with greater frequency in non-native species, corresponding to lower calculated potential vulnerability to cavitation index. Non-native species exhibited higher vessel-grouping in metaxylem compared with native species, however, solitary vessels were more prevalent in secondary xylem. Higher frequency of solitary vessels in secondary xylem was related to a lower potential vulnerability index. We found no relationship between anatomical characteristics of xylem, origin of species and hydraulic conductivity, indicating that non-native species did not exhibit advantageous hydraulic efficiency over native species. Our results confer anatomical advantages for non-native species under the potential for cavitation due to freezing, perhaps permitting extended growing seasons.
我们研究了 82 种常见于北美东部森林的本地和非本地木本植物的水力特性，包括几个同属群，代表了一系列不同的解剖木型。我们观察到非本地物种的导管直径更小，出现的频率更高，这与较低的计算潜在易损性指数相对应。然而，与本地物种相比，非本地物种的木质部中导管群集程度更高，而次生木质部中单独的导管更为普遍。次生木质部中单独导管的出现频率较高与较低的潜在易损性指数有关。我们没有发现木质部解剖特征、物种起源和水力传导率之间存在关系，这表明非本地物种在水力效率方面并不比本地物种具有优势。我们的研究结果表明，在由于冻结导致的潜在空化条件下，非本地物种具有解剖学上的优势，这可能允许它们延长生长季节。
