Variation in stem xylem traits is related to differentiation of upper limits of tree species along an elevational gradient
Variation in stem xylem traits is related to differentiation of upper limits of tree species along an elevational gradient
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茎木质部性状的变化与树种沿海拔梯度上限的分化有关
DOI：
10.3390/f11030349
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发表时间：
2020
期刊：
影响因子：
2.9
通讯作者：
Guang-You Hao
中科院分区：
文献类型：
--
作者：
Da Yang;Ai-Ying Wang;Jiao-Lin Zhang;Corey J. A. Bradshaw;Guang-You Hao
许多植物的分布范围取决于环境条件和物种的功能特征。虽然许多研究评估了环境条件如何驱动植物分布，但调查木质部导管特性与海拔高度以及这些性状是否与树木的海拔分布相关的研究并不多。在这里，我们调查了中国东北长白山北坡三个温带山地森林群落沿大海拔梯度分布的十种落叶阔叶树种的分布上限。我们测量了与物种运输水和抵抗冰冻引起的空化能力相关的茎木质部特征，这些特征理论上代表了对沿海拔梯度的气候条件变化的重要适应。水力加权血管直径（D h ）与十个研究树种的上限呈负相关；然而，这种相关性似乎是由环孔树种组和散孔树种组之间的巨大差异驱动的。环孔树种（如水曲柳、山槐和黄柏）的导管比散孔树种宽得多，并且都局限于低海拔群落。 10个研究物种中D h.的变异系数(CV)为0.53，而种内分析表明10个物种中CV.最高仅为0.22。我们没有发现任何证据表明 D h 与七个散孔物种的上限之间存在关系。与海拔相比，与水力相关的木质部性状没有随降水量变化的明显模式，表明研究区域的水力功能在很大程度上与降水的影响脱钩。这一发现表明，木质部特征与物种分布的海拔限制相关，这主要通过木质部解剖学中环孔物种和散孔物种之间及其海拔分布的对比来证明。
The distribution limits of many plants are dictated by environmental conditions and.species’ functional traits. While many studies have evaluated how plant distribution is driven by.environmental conditions, there are not many studies investigating xylem vessel properties with.altitude, and whether these traits correlate with altitudinal distribution of tree. Here, we investigated.the upper limits of distribution for ten deciduous broadleaf tree species from three temperate montane.forest communities along a large elevational gradient on the north-facing slope of Changbai Mountain.in Northeast China. We measured stem xylem traits associated with a species’ ability to transport.water and resist freezing-induced cavitation that theoretically represent important adaptations to.changes in climatic conditions along the elevational gradient. Hydraulically weighted vessel diameter.(D h ) was negatively correlated with with the upper limit across the ten studied tree species; however,.the correlation seems to be driven by the large differences between ring- and diffuse-porous tree.species groups. The ring-porous tree species (e.g., Fraxinus mandshurica Rupr., Maackia amurensis Rupr..et Maxim., and Phellodendron amurense Rupr.) had considerably wider vessels than the diffuse-porous.species and were all limited to low-elevation communities. The coefficient of variation (CV) for D h.was 0.53 among the 10 studied species, while the intraspecific analysis showed that the highest CV.was only 0.22 among the 10 species. We found no evidence of a relationship between D h and the upper.limits across the seven diffuse-porous species. In contrast to elevation, hydraulic-related xylem traits.had no clear patterns of change with precipitation, indicating that hydraulic functionality was largely.decoupledfromtheinfluencesofprecipitationinthestudyarea. Thisfindingsuggeststhatxylemtraits.areassociatedwithaltitudinallimitsofspeciesdistribution, whichismostlyevidencedbythecontrasts.between ring- and diffuse-porous species in xylem anatomy and their altitudinal distributions.