Lhasa National Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
Sci China Life Sci. 2010 Sep;53(9):1142-51. doi: 10.1007/s11427-010-4054-9. Epub 2010 Nov 23.
Plant traits and individual plant biomass allocation of 57 perennial herbaceous species, belonging to three common functional groups (forbs, grasses and sedges) at subalpine (3700 m ASL), alpine (4300 m ASL) and subnival (≥5000 m ASL) sites were examined to test the hypothesis that at high altitudes, plants reduce the proportion of aboveground parts and allocate more biomass to belowground parts, especially storage organs, as altitude increases, so as to geminate and resist environmental stress. However, results indicate that some divergence in biomass allocation exists among organs. With increasing altitude, the mean fractions of total biomass allocated to aboveground parts decreased. The mean fractions of total biomass allocation to storage organs at the subalpine site (7% ± 2% S.E.) were distinct from those at the alpine (23% ± 6%) and subnival (21% ± 6%) sites, while the proportions of green leaves at all altitudes remained almost constant. At 4300 m and 5000 m, the mean fractions of flower stems decreased by 45% and 41%, respectively, while fine roots increased by 86% and 102%, respectively. Specific leaf areas and leaf areas of forbs and grasses deceased with rising elevation, while sedges showed opposite trends. For all three functional groups, leaf area ratio and leaf area root mass ratio decreased, while fine root biomass increased at higher altitudes. Biomass allocation patterns of alpine plants were characterized by a reduction in aboveground reproductive organs and enlargement of fine roots, while the proportion of leaves remained stable. It was beneficial for high altitude plants to compensate carbon gain and nutrient uptake under low temperature and limited nutrients by stabilizing biomass investment to photosynthetic structures and increasing the absorption surface area of fine roots. In contrast to forbs and grasses that had high mycorrhizal infection, sedges had higher single leaf area and more root fraction, especially fine roots.
对 57 种多年生草本植物的植物特性和个体植物生物量分配进行了研究，这些植物属于三个常见的功能群（草本植物、禾本科植物和莎草科植物），分别位于亚高山（海拔 3700 米）、高山（海拔 4300 米）和亚高山带（≥5000 米），以检验这样一个假设，即在高海拔地区，植物会减少地上部分的比例，并将更多的生物量分配到地下部分，特别是贮藏器官，随着海拔的升高，以便发芽并抵抗环境压力。然而，研究结果表明，器官之间的生物量分配存在一些差异。随着海拔的升高，总生物量分配给地上部分的平均值减少。在亚高山地区（7%±2%S.E.），总生物量分配给贮藏器官的平均值明显不同于高山地区（23%±6%）和亚高山带（21%±6%），而所有海拔高度的绿叶比例几乎保持不变。在 4300 米和 5000 米处，花茎的平均值分别减少了 45%和 41%，而细根分别增加了 86%和 102%。禾本科植物和草本植物的比叶面积和叶面积随着海拔的升高而降低，而莎草科植物则呈现相反的趋势。对于所有三个功能群，叶面积比和叶面积根质量比随着海拔的升高而降低，而细根生物量则增加。高山植物的生物量分配模式的特点是减少地上生殖器官，扩大细根，而叶片的比例保持稳定。通过稳定对光合作用结构的生物量投资，增加细根的吸收表面积，高山植物可以在低温和有限养分的情况下补偿碳的获取和养分的吸收。与具有高菌根感染的草本植物和禾本科植物相比，莎草科植物具有更高的单叶面积和更多的根分数，特别是细根。
