Demography of the giant monocarpic herb Rheum nobile in the Himalayas and the effect of disturbances by grazing
Demography of the giant monocarpic herb Rheum nobile in the Himalayas and the effect of disturbances by grazing
复制标题
喜马拉雅山巨型单果草本植物大黄的种群统计及放牧干扰的影响
DOI：
10.1093/aob/mcz178
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发表时间：
2019
期刊：
影响因子：
4.2
通讯作者：
Stöcklin Jürg
中科院分区：
文献类型：
--
作者：
Song Bo;Stoll Peter;Peng Deli;Sun Hang;Stöcklin Jürg
背景在植物中，巨大的莲座状物种的多年生结合着一次大爆炸的繁殖，随后遗传个体的死亡是相对罕见的。这种长寿的单果植物通常生长缓慢，可以在沙漠、沼泽或热带或亚热带的高山地区找到。由于寿命较长，单果多年生植物有可能在繁殖前失去一切，这使得它们特别容易受到干扰。由于评估长寿种群是增长还是下降存在固有的困难，通常既不知道它们的人口学特征，也不知道放牧压力增加的后果。方法我们使用积分投影模型(IPM)来测量大黄的生长速度和开花时间。大黄是一种单果多年生植物，是喜马拉雅高海拔地区最引人注目的高山植物之一。在两个系列的分析中，由于牦牛的干扰或放牧而不再发现的玫瑰被视为失踪或死亡，从而模拟了在有和没有放牧牛影响的情况下的人口统计学。数据是从4500英里外的植物上收集的。在云南省香格里拉县西南部的中国。在连续四年(2011-2014)和两个种群中，分别测量了372只和369只个体，并估计了与大小相关的生长、存活和繁殖力参数。结果表明，种子的成活率、开花率和繁殖力均具有强烈的大小依赖性。达到开花大小的时间为33.5年[95%可信区间(CI)21.9-43.3，根据混合过渡和种群随机估计]。大黄随机种群增长率(λS)为1.013(95%CI为1.010-1.017)。当模型中考虑放牧牛(牦牛)的干扰时，λ降至<；1(0.940，95%CI 0.938-0.943)。结论我们得出结论，该物种的自然种群是可行的，但应采取保护措施，尽量减少放牧干扰，并保护这种生长缓慢的旗舰植物免受高喜马拉雅山脉的影响。
BackgroundPerennity of giant rosette species in combination with a single ‘big bang’ reproduction followed by death of the genetic individual is relatively rare among plants. Such long-lived monocarpic plants are usually slow growing and can be found in deserts, bogs or in alpine regions of the tropics or sub-tropics. Due to their longevity, monocarpic perennials risk losing everything before reproduction, which make them particularly susceptible to disturbances. Because of the inherent difficulties in assessing whether long-lived populations are growing or declining, usually neither their demography nor the consequences of increasing grazing pressure are known.MethodsWe used integral projection modelling (IPM) to measure the growth rate and passage time to flowering ofRheum nobile, a monocarpic perennial, and one of the most striking alpine plants from the high Himalayas. Rosettes which were no longer found due to disturbances or grazing by yaks were either treated as missing or as dead in two series of analysis, thereby simulating demography with and without the impact of grazing cattle. Data were collected from plants at 4500 m a.s.l. in Shangri-la County, Yunnan Province, south-west China. In four consecutive years (2011–2014) and in two populations, 372 and 369 individuals were measured, respectively, and size-dependent growth, survival and fecundity parameters were estimated. In addition, germination percentage, seedling survival and establishment probability were assessed.Key resultsThe probability of survival, flowering and fecundity were strongly size dependent. Time to reach flowering size was 33.5 years [95 % confidence interval (CI) 21.9–43.3, stochastic estimate from pooled transitions and populations]. The stochastic population growth rate (λs) ofRheum nobilewas 1.013 (95 % CI 1.010–1.017). When disturbance by grazing cattle (yaks) was accounted for in the model,λsdropped to values <1 (0.940, 95 % CI 0.938–0.943).ConclusionWe conclude that natural populations of this unique species are viable, but that conservation efforts should be made to minimize disturbances by grazing and to protect this slow-growing flagship plant from the high Himalayas.